Browsing by Author "Moodley, Roshila."

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A phytochemical and elemental analysis of senecio serratuloides DC, and its antidiabetic potential.
(2024) Gumede, Andile.; Koorbanally, Neil Anthony.; Moodley, Roshila.; Mshengu, Bongiwe Pridesworth.
Senecio serratuloides DC, from the Asteraceae, has been widely used in South African traditional medicine for the treatment of various conditions such as swollen gums, chest pains, sores, cuts, burns and ulcers. This study was conducted to determine a chemical profile of the plant, both in terms of the secondary metabolites and essential and toxic elements contained in the plant. The plant extracts were further tested for their antibacterial (minimal inhibitory concentrations) and antidiabetic potential (α-amylase and α-glucosidase inhibitory activity). The phytochemical analysis of the leaves and stems resulted in the isolation of the sterols, β- sitosterol (S1) from the stems, and stigmasterol (S2) and stigmasterol glucoside (S3) from the leaves. A further rare sterol, 18α-ursa-12,20(30)-dien-3β-ol (S4) was also isolated from the leaves. Three flavonoids, quercetin (S5), quercetin-3-O-glucoside (S6) and hesperidine (S7) were also isolated from the leaves, along with an aromatic acid, caffeic acid (S8). Extracts of the plant showed good in vitro antidiabetic activity, with the methanol extract from the leaves exhibiting the highest activity against α-glucosidase and α-amylase. However, the extracts did not exhibit any significant antibacterial activity in the assays carried out. The elemental analysis of the plant indicated a decreasing order of Ca > Mg > Zn > Fe > Co > Cu > Cr > Mn > Ni > As > Se. The leaves also showed good quantities of vitamin C, with an appreciable amount being extracted during the cooking phase. The results also show that moderate consumption of the leaves pose no probable threats of metal poisoning. The extracts obtained from S. serratuloides DC were found to have no antibacterial activity. This is surprising, since some of the isolated compounds were reported to have shown some antibacterial properties, however, these may have been too low to have any significant effect in the crude extracts.
Analytical and biochemical studies of selected seaweeds obtained from the eastern coast of South Africa`s Indian Ocean in KwaZulu-Natal.
(2015) Magura, Judie.; Jonnalagadda, Sreekantha Babu.; Moodley, Roshila.
Abstract available in PDF file.
Analytical and mycochemical studies on selected wild growing mushrooms of the Genus Boletus, Russula, Lactarius and Termitomyces distributed in KwaZulu-Natal, South Africa.
(2021) Rasalanavho, Muvhango.; Jonnalagadda, Sreekantha Babu.; Moodley, Roshila.
Abstract available in PDF.
Automotive trace metal concentrations on the South African national road (N3) and its impact on the environment.
(2018) Batwa-Ismail, Mohammed Zaheer.; Mutanga, Onisimo.; Moodley, Roshila.
The environment is currently experiencing the negative effects of globalisation and unsustainable development with environmentally harmful activities increasing at an alarming rate in South Africa and other developing countries. This is due to these countries circumventing the implementation of environmental policies against foreign investors, such as vehicle manufacturers and chemical industries, to allow for a reduction in fiscal austerity by increasing the gross domestic product. The effects of these activities have a greater impact on the environment and population of developing nations than developed ones. Heavy metal contamination is one of the major concerns related to vehicle manufacturers and toxic chemical industries in terms of environmental management. The aim of this research was to assess the impact of vehicle pollution along the South African National Road (N3) between Durban and Hilton as it is one of the major transportation routes from the harbour. The elemental concentrations in the leaves of Bidens pilosa, that are picked and cooked by communities that live along the roadside, were investigated. The concentrations of thirteen elements were selectively investigated to determine the impact of soil quality on elemental uptake by vegetation and to assess for potential metal toxicities. Soil was evaluated for metal pollution by calculation of geo-accumulation indices and enrichment factors. Common sources of contamination were identified by principal component analysis and spatial distribution of toxic elements; lead and cadmium was developed via geographic information system (GIS). The study showed Bidens pilosa to contain high concentrations of toxic metals especially that of lead, which were linked to high soil concentrations. Soil quality indicators showed soils to be moderately to heavily contaminated in some areas and moderately contaminated in others. Enrichment results showed moderate to significantly enriched soils. Statistical analyses indicated different sources for the toxic metals (cadmium and lead) and the Kriging interpolation study depicted and demonstrated the spatial diffusion of both cadmium and lead concentrations throughout the study area of the N3. The road transport sector is a key source for heavy metal contamination as it is the preferred method of transport by most industries in South Africa and other developing countries. This study therefore provides insight into the impacts of vehicle pollution in the surrounding environment.
Biosynthesis of silver and selenium nanoparticles using extracts of Commelina Africana and their biological activity.
(2019) Mhlongo, Silungile Pearl.; Moodley, Roshila.
Commelina africana is an indigenous medicinal plant that belongs to the Commelinacaea family. This plant is traditionally used for the treatment of venereal diseases and burns, and it is eaten as a vegetable. Despite the plants medicinal and nutritional significance, it has not been phytochemically investigated. Nanoparticles are currently being investigated for their medicinal value. Different synthesis techniques, especially those that are less toxic, inexpensive and more environmentally friendly are being explored. The use of plant material to synthesise nanoparticles is known to be a greener and safer method. These nanoparticles have potential for applications in the biomedical sciences. Currently, silver nanoparticles (AgNPs) are being used for the dressing of wounds and prevention of infections. Selenium nanoparticles (SeNPs) are being used biologically as antioxidants. This study aimed at extracting, isolating and characterising the secondary metabolites from C. africana. The crude aqueous and methanolic extracts from the plant were used to synthesise AgNPs and SeNPs at varying extract volumes. The crude extracts served as reducing agents and reduced Ag+ and Se4+ to their elemental states. The synthesised nanoparticles were tested for their antioxidant activities (using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays) and antibacterial activities relative to the extracts from which they were synthesised and known standards. Four phytosterols (stigmasterol, ergosterol peroxide, β-sitosterol and campestanol) were isolated and identified from the extracts of C. africana. AgNPs and SeNPs were synthesised using the plant material and characterised using spectroscopic and microscopic techniques. AgNPs consisted of spheres and SeNPs showed a mixture of spheres and rods. Both types of nanoparticles had a wide particle size range.For the antioxidant activity, ergosterol peroxide showed good radical scavenging activity by the DPPH test whilst SeNPs synthesised using the methanol extract showed good radical scavenging activity and reducing potential by the DPPH and FRAP tests, respectively. Crude extracts, phytocompounds and nanoparticles were tested against two Gram-positive bacteria (Enterococcus faecalis and Staphylococcus aureus) and four Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae and Chromobacterium violaceum) for their antibacterial activity. Plant synthesised AgNPs showed satisfactory inhibitory activity against the growth of all bacterial strains except E. faecalis. These nanoparticles also exhibited anti-quorum sensing abilities indicating their potential to block cell-to-cell signalling that is used to determine their physiological activities and for co-ordinated gene expression. This study adds to the base of knowledge on the medicinal plant species, C. Africana and highlights the synergistic effects between AgNPs and SeNPs with active plant biomolecules for biological systems. The findings of this study also indicate that medicinal plants can be used as a greener and more environmentally friendly technique for the synthesis of AgNPs and SeNPs.
The effect of isolated and nanoencapsulated flavonoids from Eriocephalus africanus on apoptotic factors and microRNA expression in cancer.
(2020) Magura, Judie.; Mackraj, Irene.; Moodley, Roshila.
Cancer continues to be a major health burden worldwide, with millions of new cases being diagnosed each year. Among women breast cancer remains a leading cause of cancer-related morbidity and mortality globally, despite the significant advances in detection and individualised treatments. The ideal non-surgical approach for the treatment of breast cancer would be anticancer therapeutics that are delivered directly to the tumour site for complete elimination of cancerous cells without being toxic to surrounding healthy cells. However, current chemotherapeutics encounter numerous challenges due to adverse side effects and progressive drug resistance albeit effective. In light of this, identifying new effective therapies with minimal toxic and chemosensitizing effects as well as target specificity is crucial in combating cancer. Emerging evidence has supported the use of plant-derived chemicals as novel alternative treatment options, owing to their minimal side effects and toxicity. Plant-derived polyphenols have gained considerable research interest due to their ability to inhibit proliferation, initiate apoptosis and arrest the cell cycle of cancerous cells by modulating related pathways. Furthermore, incorporation of active plant-derived polyphenols into novel technologies such as nanosystems, offers more optimal therapies through improved bioavailability and target specificity. In this regard, this study demonstrates, for the first time, the potential of phytochemicals isolated from the methanolic extract of the medicinal plant, Eriocephalus africanus, as an alternative therapeutic strategy in breast cancer treatment using ER-positive human adenocarcinoma (MCF-7) cell lines. Spectroscopic techniques including nuclear magnetic resonance spectroscopy (NMR), infrared spectroscopy (IR) and mass spectrometry (MS) were used to identify the isolated compounds as hesperidin (flavanone), luteolin (flavone) and apigenin (flavone). Preliminary anticancer screening using the 3-(4,5dimethylthiazolyl)-2,5-diphenyl-tetrazolium bromide (MTT) assay revealed hesperidin and luteolin to be potent against MCF-7. Dysregulated cellular apoptotic death is a hallmark of cancer and chemotherapy resistance; thus, the development of anticancer drugs targeting apoptosis is a widely used, effective anticancer treatment strategy. In this study, the efficacy of hesperidin and luteolin in targeting the apoptotic pathway was evaluated. Treatment of breast cancer cells with hesperidin and luteolin resulted in the downregulated expression of key anti-apoptotic Bcl-2; upregulated expression of pro-apoptotic Bax and caspases -8, -9 and -3. In addition, hesperidin and luteolin demonstrated the ability to effect epigenetic control through altering the expression of apoptotic microRNAs (-16, -21 and -34a). Moreover, treatment with hesperidin and luteolin resulted in significant accumulation of MCF-7 apoptotic cells into the G0/G1 and sub-G1 cell cycle phases, respectively. Encapsulation of hesperidin into nanoemulsions improved the cytotoxic and apoptotic effects in MCF-7 without being cytotoxic to non-cancerous human cell lines (HEK 293), halted the progression of the MCF-7 cells in the G2/M phase, and exhibited potential therapeutic activity through inhibiting the expression of oncomirs miR-21 and -155 overexpressed in breast cancer. Encapsulation of luteolin into solid nanoparticles generated from cleaved stearylamine exhibited non-selective cytotoxicity and decreased cell viability (< 10%) in both MCF-7 and HEK 293 cells, thus no further investigations were conducted using luteolin-loaded solid nanoparticles. Collectively, findings from this study provide new evidence on the effects of flavonoids isolated from E. africanus on apoptotic and epigenetic control in breast cancer, increasing our knowledge of the molecular basis of their anticancer activity.
Elemental and phytochemical studeis of two rhoicissus species (Rhoicissus Digitata AND Rhoicissus Tomentosa) found in KwaZulu-Natal, South Africa.
(2019) Uwumubyeyi, Valentine.; Moodley, Roshila.; Mshengu, Bongiwe Pridesworth.
Abstract available in PDF.
Elemental composition and nutritional value of the edible fruits of coastal red milkwood (Mimusops caffra) and Transvaal red milkwood (Mimusops zeyheri) and the impact of soil quality.
(2017) Mngadi, Sihle Vitalis.; Moodley, Roshila.; Jonnalagadda, Sreekantha Babu.
Mimusops caffra and Mimusops zeyheri, both of the plant family Sapotaceae are indigenous plant species that grow widely in most parts of South Africa and the edible fruits of these species are picked and eaten raw in rural communities across South Africa. This is done to help overcome the challenge of dietary diversity especially in these resource-limited communities where diets are based on starch staples that lack fruit and vegetables. Despite the dependence on these fruit for food and nutrition security, information on their nutritional value is lacking. The aim of this research was therefore to analytically investigate the elemental distribution of essential and toxic elements in the two edible fruits and corresponding growth soil using Inductively Coupled Plasma- Mass Spectrometry (ICP-MS). The nutritional value of the fruits was assessed to evaluate the plants potential as a source of nutrients and the impact of soil quality on elemental uptake was evaluated to determine the plants potential to accumulate toxic metals. The elemental analysis showed concentration of the elements in M. caffra fruit to be (in descending order): K > Na> Ca > Mg > Si > Al > Fe > Zn > Mn > Ni > Cr > Cu > Pb > Mo > Sb > As > Se > V > Cd > Co whilst for M. zeyheri fruit it was (in descending order): K > Na> Ca > Mg > Fe > Al > Zn > Mn > Cu > Cr > Sr > Pb > As > Li > Ni ≈ Co > Rb > U > Bi > Ga > Be > Tl > Mo > Ba > Ag > Cd. The concentration of most essential elements in both fruits was found to be within acceptable limits. M. caffra fruits were found to be rich in Fe, Si and Cr and M. zeyheri fruits were found to be rich in Cr and Mn. Analysis of soil and plant showed that M. caffra and M. zeyheri do not tend to accumulate toxic elements and would therefore be safe for human consumption. Statistical analyses showed that contamination in soil by the various heavy metals came from various sources however soil contamination did not affect the concentration of heavy metals in the fruits thereby indicating the plants ability to take up metals to meet metabolic needs and exclude metals, if at elevated levels, for survival.
Elemental distribution in selected edible nuts and the impact of soil quality on the chemical characteristics of macadamia (Macadamia integrifolia) nuts
(2007) Moodley, Roshila.
Environmental and nutritional imperatives make it necessary to carry out regular and reliable
Elemental distribution in selected edible trifolium species (clover) and the impact of soil quality on the chemical characteristics of trifolium dubium
(2017) Gounden, Thaveshan.; Moodley, Roshila.; Jonnalagadda, Sreekantha Babu.
Trifolium (clover) species are edible herbs that are rich in proteins, phytocompounds and essential macro and micro-nutrients. These herbaceous plants can therefore contribute significantly to the nutritional needs of people and can play a significant role in traditional medicine. With malnutrition becoming a growing problem amongst poverty-stricken communities in African countries where food is unaffordable, the use of Trifolium, a common perennial herb, can provide much needed nutrition and can ameliorate food insecurity. The bioactive phytocompounds in Trifolium species promote its use in traditional medicine as this is an affordable and, debatably, better form of treatment. South Africa has a rich diversity of Trifolium species, however there is little to no information regarding the nutritional value of these herbs and the uptake of toxic heavy metals which can cause adverse health effects if ingested. The main aim of this study was to evaluate the elemental distribution and nutritional value of five edible Trifolium species, namely Trifolium africanum, Trifolium burchellianum, Trifolium repens, Trifolium dubium and Trifolium pratense in KwaZulu-Natal, South Africa. The results obtained were used to assess the potential of these herbs to alleviate malnutrition in KwaZulu-Natal. The chemical composition of the five edible herbs was determined by analysing for proteins, lipids, dry ash and carbohydrates. T. dubium proved to accumulate the highest concentrations of toxic heavy metals (Cd and Pb), therefore the elemental distribution of essential and toxic metals in T. dubium were assessed for impact of soil quality on uptake by the plant by obtaining samples from ten different geographic locations in KwaZulu-Natal. Trifolium species investigated in this study were rich in essential nutrients with concentrations of elements varying significantly (p<0.05) and were found in decreasing order of Ca > Mg > Fe > Mn > Zn > Se > Cu > Cr > Pb > Ni > Co > Cd > As. The species had vi adequate levels of lipids (4.2 to 8.6%), proteins (35.1 to 45.4%) and carbohydrates (26.7 to 47.0%). The results obtained suggested that T. pratense was the most suitable species for human consumption due to it having undetectable levels of toxic metals (As, Cd and Pb) and being rich in macro and micro-nutrients, especially Fe (7.84 mg/10 g, dry mass) and Se (0.36 mg/10 g, dry mass). The elemental uptake in T. dubium varied significantly with geographic location (p<0.05) and were found to be in descending order of Ca > Mg > Fe > Zn > Mn > Se > Ni > Cr > Cu > Co > Pb > Cd > As, where the availability and accumulation of heavy metals from soil were controlled by the plant to meet physiological needs. Soil quality parameters such as pH ranged from 6.15 to 6.68, soil organic matter ranged from 0.9 to 2.6% and cation exchange capacity ranged from 4.25 to 9.05 meq/100g. In general, this study indicated that Trifolium species investigated contain adequate concentrations of essential elements and low to undetectable levels of toxic elements which make it a safe and valuable source of nutrition. Therefore, these plant species can contribute positively to the diet of poverty-stricken communities and can aid in improving food insecurity in KwaZulu-Natal.
Green synthesis of silver, selenium and zinc oxide nanoparticles using extracts and isolated secondary metabolites of chrysanthemoides monilifera and harpephyllum caffrum and their biological activity.
(2018) Vundla, Ntombizodwa.; Moodley, Roshila.; Pruessner, Karin.
The method of using plant extracts for the synthesis of metal-based nanoparticles is a recently developed technique which is not only cost effective but environmentally friendly. It has very low energy requirements, needs no specialised equipment and reactions are completed within minutes. The resultant materials can be applied to catalysts, medicine, electronics and optics. The biological activity of plant extracts and nanoparticles have each been studied and are well known. In addition to being green, nanoparticles produced by the plant-mediated synthesis route are being utilised in biomedical applications with the added advantage of increased activity arising from the synergistic effects of both the biologically active nanoparticles and plant extracts or phytocompounds. In this project, extracts and phytocompounds from the indigenous, South African, medicinal plant species Chrysanthemoides monilifera and Harpephyllum caffrum were obtained and used to synthesise and stabilise silver, zinc oxide and selenium nanoparticles. The plant extracts and phytocompounds were characterised using spectroscopic techniques. Quercetin was isolated from the extract of C. monilifera and catechin from the extract of H. caffrum. The growth of nanoparticles was investigated at various concentrations of phytocompounds. The synthesised nanoparticles were characterised using spectroscopic and microscopic techniques. Growth seemed to occur by agglomeration and subsequent re-orientation. Changes in concentration had an effect on the yield, shapes and sizes of the synthesised nanoparticles. To investigate the synergistic or antagonistic effect of the capping agents on the biological activity of synthesised nanoparticles, freestanding (uncapped) nanoparticles were synthesised, using sodium borohydride as a reducing agent, for comparison. Results showed biosynthesised nanoparticles to be capped with plant biomolecules. The biosynthesised nanoparticles had a wider size distribution than freestanding nanoparticles. The particles were tested for their antioxidant activity using three different assays (1,1-diphenyl-2-picrylhydrazyl radical (DPPH•) radical scavenging, ferric reducing antioxidant power (FRAP) and H2O2 radical scavenging. The results showed plant biomolecules to enhance the antioxidant activity of the biosynthesised nanoparticles. The anti-microbial activities of the nanoparticles were evaluated with the Kirby-Bauer disc diffusion susceptibility test. Capping of selenium and zinc oxide nanoparticles with plant biomolecules did not have any effect on antibacterial activity. H. caffrum was found to enhance the activity of the silver nanoparticles whilst quercetin promoted its anti-quorum sensing ability.
Phytochemical and analytical studies on two indigenous medicinal plants found in KwaZulu-Natal : Carissa macrocarpa and Harpephyllum caffrum.
(2012) Moodley, Roshila.; Jonnalagadda, Sreekantha Babu.; Koorbanally, Neil Anthony.
Vulnerable communities and rural households usually turn to natural resources for their nutritional and healthcare needs. However, very little is known about the nutritional and medicinal value of many plant species utilized by these communities despite widespread scientific research on medicinal plants. This is mainly due to the huge numbers of medicinal plants that are in use. This study aimed at investigating two plants species that are indigenous to KwaZulu-Natal and contain edible fruits namely Carissa macrocarpa and Harpephyllum caffrum, as a source of secondary metabolites and essential dietary elements, because of their claimed medicinal value and nutritional potential. The analytical results indicate that the fruits are a good source of essentiary dietary elements and can contribute to the recommended dietary allowances (RDAs) for most nutrients. Phytochemical analysis shows that the fruits of C. macrocarpa are rich in the pharmacologically active pentacyclic triterpenoids whose immune boosting properties are well-known. The fruits can therefore be consumed to boost the immune system in areas where immune boosting supplements are out of reach. The fruits of H. caffrum were found to be rich in the flavan- 3-ol antioxidant, (+)-catechin. The fruits can therefore be used as a substitute for antioxidant supplements taken in Western and European countries. This study lends scientific credence and validity to the ethnomedicinal use of these plants and reveals the nutritional and medicinal benefits of consuming the indigenous edible fruits. It also adds to the growing body of research on indigenous medicinal plants.
Phytochemical and elemental analysis of Cyrtanthus obliquus and Lippia javanica.
(2012) Mahlangeni, Nomfundo Thobeka.; Jonnalagadda, Sreekantha Babu.; Moodley, Roshila.
A growing number of South Africans are relying more and more on alternative medicine for their healthcare needs due to the high cost of commercially available medicines and lack of medical aid. To these people, traditional medicine has provided an alternative form of treatment with medicinal benefits that are claimed to be the same as conventional medicine but at a lower cost. Many herbal tonics and concoctions are used in traditional medicine, one of which is Imbiza, a herbal tonic comprising plant parts of different medicinal plants, which is deemed to be more effective than the use of a single medicinal plant. The safety and efficacy of these herbal preparations sold in the street markets as well as in rural areas have not yet been proven. The study investigates two of the plants that are used to make Imbiza, namely Cyrtanthus obliquus bulbs and Lippia javanica leaves. Phytochemical studies of the extracts of C. obliquus bulbs yielded two new chalcones, two new dihydrochalcones and a lanostane triterpenoid. Antioxidant activity of the chalcones and dihydrochalcones was moderate and lower than ascorbic acid. GC-MS profiling of the various extracts of L. javanica leaves showed the presence of monoterpenes, sesquiterpenes and amino compounds. Total and water extractable concentrations of selected elements were determined in C. obliquus bulbs collected from eight market sites around the KwaZulu-Natal province. The levels of the elements were found to be in decreasing order of Ca > Mg > Fe > Zn > Mn > Cu ≈ Se > Pb > Cr for total concentrations and Ca > Mg > Fe > Zn > Mn for water extractable forms. A high percentage of Zn (77.5-91.5 %) was shown to extract into water. Total and water extractable concentrations of selected elements were determined in L. javanica leaves and corresponding soil samples collected from ten different locations around the KwaZulu-Natal province. The levels of the elements were found to be in decreasing order of Ca > Mg > Fe > Zn > Mn > Cu > Se > Cr > Pb > Co > Cd for total concentrations and Ca > Mg > Fe > Zn > Cu > Cr > Pb for water extractable forms. A high percentage of Cr (71.8 - 93.9 %) was shown to extract into water. Imbiza has been recognized by traditional healers and herbalist for the treatment of minor and chronic illnesses, which range from chest infections to cancer. Previous studies have shown that the compounds identified in this research (chalcones, dihydrochalcones, monoterpenes and sesquiterpenes) have indeed anticancer activities. This study therefore adds to the growing body of research on indigenous medicinal plants.
Phytochemical and elemental analysis of nettles found in KwaZulu-Natal, South Africa.
(2016) Mahlangeni, Nomfundo Thobeka.; Moodley, Roshila.; Jonnalagadda, Sreekantha Babu.
There is a rich diversity of indigenous edible plants in South Africa. Rural communities have for years, been collecting indigenous edible medicinal plants for food and for their medicinal properties. However, a combination of a shortage of food and lack of diversity in the diet has resulted in many South Africans suffering from malnutrition. Malnutrition, food insecurity and nutrient deficiencies which help propogate non-communicable diseases are amongst the top concerns in South Africa. Knowledge on the elemental composition, nutritional and medicinal value of medicinal plants would allow for safe consumption of these plants and improve overall health. The aim of this study was to investigate the secondary metabolites in the Laportea and Obetia nettles found in KwaZulu-Natal (South Africa) and to conduct an elemental investigation into the nutritional composition of these nettles to determine their suitability for consumption and their contribution to recommended dietary allowances. The study showed that cooked and raw leaves of nettles (L. peduncularis, L. alatipes, and O. tenax) were rich sources of macronutrients and essential elements which are comparable to common vegetables. The nettles, L. alatipes and O.tenax, have higher macronutrient content than elemental content relative to the nettles, L.peduncularis and U. dioica, after cooking. Soil quality indicators (geo-accumulation indices and enrichment factors) showed moderate to no contamination of nettle growth soils around KwaZulu-Natal. Statistical analysis showed the association of these metals in the different sites. Phytochemical analysis of the nettles showed that the nettles were rich in β-carotene and sterols owing to their use as natural anti-diabetic agents. This study provides information on the nutritional value of nettles and shows that they can serve as an affordable alternative to commercially available herbs and it also lends scientific credence to the ethno-medicinal use of nettles.
Phytochemical and elemental studies of two indigenous medicinal plants of South Africa, Bridelia micrantha and Sideroxylon inerme.
(2014) Shelembe, Bongisiwe Gladys.; Jonnalagadda, Sreekantha Babu.; Moodley, Roshila.
Bridelia micrantha (Euphorbaceae) and Sideroxylon inerme (Sapoacaea) are two indigenous medicinal plants found in KwaZulu-Natal and are both known as ‘uMhlalamagwababa’ in isiZulu. These two plants species have similar physical properties, they both contain black, berry-like edible fruits and they both produce milk sap. This similarity has led to them being confused for one species so they are both used by traditional healers to treat a variety of the same illnesses. Different parts of B. micrantha and S. inerme are used traditionally to treat a variety of ailments; the bark is used to treat burns, wounds, venereal diseases, tapeworm and toothache. They are also used as anti-diarrhoeal and anti-bacterial agents. The main aim of this study was to isolate, characterise and identify the phytocompounds in the leaves, stem bark, roots and fruits of the two plant species, B. micrantha and S. inerme, to evaluate if they can be used interchangeably in traditional medicine. The isolated compounds were also assessed for their antioxidant activity to determine the plants potential as natural antioxidants. The impact of soil quality parameters on elemental uptake of the wild fruits of B. micrantha from eight different geographic locations in KZN as well as the nutritional value of the edible fruits was also determined to evaluate the plants potential as a nutraceutical. The phytochemical investigation of S. inerme revealed the presence of three pentacyclic triterpenes (friedelin, stigmasterol and a mixture of α and β –amyrin), one carotenoid (lutein) and one megastigmane (apocynol B). Two flavonoids (quercetin and quercetin-3-O-glucoside) and two triterpenes (oleanolic acid and acacic acid lactone) were isolated from B. micrantha. The free radical scavenging activity of the extracts and selected phytocompounds was determined by the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. The antioxidant activity for both plants was good but that of B. micrantha was better than that of S. inerme. The concentrations of elements in the fruits were found to be in decreasing order of Mg > Ca > Mn > Zn ≈ Fe > Cu > Co > Ni > Cr > Pb > As ≈ Cd. It was also found that 100 g of the fruit contained about 90.1% moisture, 3.2% ash, 4.1% proteins, 0.9% oil and 1.7% carbohydrates. This study shows that the fruits of B. micrantha are a good source of essential elements and have low levels of the toxic metals investigated. The classes of compounds isolated from B. micrantha and S. inerme validate the ethnomedicinal use of these plant species in traditional medicine however, since the isolated compounds from each species were different it can be concluded that they cannot be used interchangeably for their medicinal benefit. The results obtained from this study provide baseline information on the plants’ potential as a source of medicine and also revealed the nutritional benefits of consuming the edible wild fruits of B. micrantha.
Phytochemical investigation and biological studies of some South African plant species (Asteraceae and Hyacinthaceae)
(2021) Oyetunde-Joshua, Funsho Mary.; Moodley, Roshila.
Plants used in conventional medicine for the treatment of different ailments have been the bedrock for modern therapeutics. Scilla nervosa from the Hyacinthaceae family and Helichrysum panduratum and Helichrysum actutaum from the Asteraceae family are plants used in traditional medicine in South Africa. However, limited information exists on the biological potential and safety of these plants. This research aimed to phytochemically investigate these plants by isolating and characterizing their secondary metabolites and testing their biological activities. The phytochemical investigation of S. nervosa yielded eleven compounds, including two novel homoisoflavonoids, two novel lanostane-type triterpenes, five known homoisoflavonoids, one stilbene and one sterol glucoside. The cytotoxicity of the homoisoflavonoids was good against the Caco-2 tumor cell line but moderate against the HepG2 cell line and the methanol extract of the leaves showed promising activity against Caco-2 and HepG2 cell lines, giving IC50 values of 7.79 and 9.29 μg/mL, respectively. For homoisoflavonoids, polarity influenced activity, with the least polar compounds being more active. Likewise, saturation between the benzopyrone ring and ring C contributed to activity. The homoisoflavonoids with methoxy substituents displayed better antibacterial activity than those with hydroxy substituents but these were still lower than flavonoids. Molecular docking using MraY phospho-MurNAc-pentapeptide translocase was conducted on the bioactive homoisoflavonoids to rationalize their antibacterial activity. The results showed isolates to bind in the same active site of the substrate, with a slight difference due to the presence of the hydroxy group. The phytochemical investigation of H. panduratum led to the isolation of a sterol, a sterol glucoside, three triterpenes, a phenolic glucoside, and one homoisoflavonoid, which is the first report of this group of flavonoids from Helichrysum genus. The plant was shown to have moderate antibacterial activity. Screening of the quorum sensing-controlled phenotype of bioluminescence in Vibrio harveyi BB120 was conducted. The methanol extract of the leaves could inhibit Gram-negative N-acyl homoserine lactone-based and global crosstalk autoinducer-2-based quorum sensing. The cytotoxicity assay showed reduced activity towards Caco-2, HepG2 and the regular cell line Hek 293, making it safe for human use. H. acutatum yielded three compounds, a sterol, a sterol glucoside and a cinnamic acid derivative. The plant showed no antibacterial activity and no cytotoxicity towards the normal cell line, Hek 293, making it safe for human consumption. The ethyl acetate extract of the root demonstrated good antioxidant activity, which could be attributed to the cinnamic acid derivative. The leaves of H. panduratum are rich in arbutin, a natural hydroquinone form, making it valuable in cosmetology. The antibacterial potential of the isolated homoisoflavonoids could be enhanced by synthetic manipulations of the molecular framework. These modifications could also improve selectivity towards tumor cell lines. The findings from this study provide scientific evidence for the use of the plants in traditional medicine, especially H. acutatum, for which there are no reports on its use or biological activity.
Phytochemical investigation and tissue culture studies on the South African knob trees, Zanthoxylum Capense and Senegalia Nigrescens.
(2017) Sunday, Bodede Olusola.; Moodley, Roshila.; Shaik, Shakira.
Abstract available in PDF file.
Phytochemical, elemental and biological studies of three Ficus species (Moraceae) found in KwaZulu-Natal, South Africa.
(2017) Ogunlaja, Olumuyiwa Olufisayo.; Moodley, Roshila.; Jonnalagadda, Sreekantha Babu.
Ficus (Moraceae), with over 800 species, is one of the understudied genera in modern pharmacognosy. Rural households depend on their fruits for food while other plant parts such as leaves and bark are utilised for medicinal purposes. Phytochemical analyses and biological activities of different plant parts, as well as the nutritional value of the edible fruits of many of the species are yet to be investigated. This study aimed at investigating three Ficus species (Ficus burtt-davyi, Ficus sur Forssk and Ficus sycomorous Linn) that produce edible fruits and are indigenous to KwaZulu-Natal, South Africa, as a source of secondary metabolites and essential dietary elements, due to their claimed medicinal and nutritional value. Plant material was subjected to chromatographic analyses and isolated compounds were identified using spectroscopic techniques and by comparison with previously reported data. Fruit and soil samples that were collected from sites within KwaZulu-Natal, were digested and analysed for macro, micro and toxic elements by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). The phytochemical investigation of F. burtt-davyi revealed the bark to be rich in pentacyclic triterpenoids (lupeol and lupeol acetate) and the known antioxidant flavonoid ((+)-catechin) whilst the leaves were rich in sterols (β-sitosterol, campesterol, and stigmasterol). Both leaves and fruits also contained phaeophytin a, lutein and α-amyrin. This is the first phytochemical report on this species. The cytotoxic results indicated that lupeol and (+)-catechin, the most abundant bioactive compounds in the stem bark, were responsible for its synergistic cytotoxic effects against breast and colorectal adenocarcinoma cell lines. This study supports the use of this plant species as a substitute for antioxidant supplements and as an alternative medicine for oxidative stress related iv non-communicable chronic diseases in vulnerable communities. The phytochemical analysis of F. sur revealed two pharmacologically active triterpenoids (lupeol and sitosterol), one pheaophytin (pheaphytin a) and one flavonoid (epicatechin). The analytical results indicated that the fruits of F. burtt-davyi, F. sur and F. sycomorous are good sources of essential dietary elements and can contribute significantly (p < 0.05) to the recommended dietary allowances (RDAs) for most nutrients. The fruits of F. sur and F. burttdavyi are good dietary sources of Se and Mn, respectively. The concentrations of As, Cd, and Pb were below the instrument detection limits in all three figs indicating that the species do not tend to accumulate these toxic elements. Data from this study showed that metal interactions in soil influenced their availability, but uptake was to a greater extent controlled by the plant. Statistical analyses revealed synergistic relationships in the plants, thereby confirming that uptake of elements is controlled to meet metabolic needs. Overall, this study validates the ethnomedicinal use of these figs and reveals the nutritional and medicinal benefits of consuming the indigenous edible fruits. It also addressed the need for analytical information on the elemental concentrations in indigenous edible fruits consumed in South Africa.
Phytochemical, elemental and biotechnological study of cryptocarya latifolia, an indigenous medicinal plant of South Africa.
(2013) Hamza, Mohammed Falalu.; Moodley, Roshila.
Cryptocarya latifolia (Lauraceae) is an indigenous South African plant used in ethnomedicinal practices. Traditional healers in KwaZulu-Natal, South Africa are extensively using the bark of C. latifolia as a substitute for Ocotea bullata, resulting in the decline of existing populations and also causing its conservation status to come under scrutiny. If no conservation efforts are instigated, the depletion and extinction of this species in the natural habitat is highly probable. Therefore, in this study, a phytochemical investigation of the leaves and fruits of C. latifolia was performed to determine their suitability, as a replacement for the bark, for medicinal use. From the leaves, a new compound, 5-hexyltetrahydro-2H-pyran-2-one (4) was isolated together with known compounds, quercetin-3-O-rhamnoside (1), β-sitosterol (2), copaene (3) and nerolidol (5). In addition, some important monoterpenoids, diterpenoids, sesquiterpenoids and essential oils were isolated and identified using gas chromatography-mass spectrometry (GC-MS). Quercetin-3-O-rhamnoside (1) and β-sitosterol (2) were also isolated from the edible fruits. Anti-oxidant activity of the isolated compounds using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging assay indicated good anti-oxidant activity of all compounds, except β-sitosterol (2), compared to ascorbic acid. The results reveal that the leaves and fruits can be used, instead of the bark, as a source of antioxidants. The analytical study conducted on the fruits of C. latifolia indicated that they are a good source of important dietary elements and may contribute significantly to the diet. The elements were found to be in increasing order of Pb
Phytochemistry and anti-cancer potential of compounds isolated from Kenyan medicinal plants, Moringa oleifera and Prunus africana.
(2014) Chepkoech, Maiyo Fiona.; Singh, Moganavelli.; Moodley, Roshila.
Cancer is one of the leading causes of death worldwide and of all the cancer related deaths occurring worldwide, 70% are in low and middle income countries. In Africa, the disease kills more people than HIV, TB and malaria combined. In Kenya, cancer continues to claim millions of lives. The poor prognosis of cancer in Kenya is due to a lack of facilities for diagnosis and treatment which is further worsened by poor access to these facilities resulting in the majority of Kenyans turning to herbal medicine for treatment. Natural products have been an invaluable source of therapeutic drugs with 60% of cancer chemotherapy in the market today being plant-derived drugs. However, challenges such as drug toxicity and resistance facing chemotherapy it has become imperative to find alternate drugs with improved specificity and efficiency. The current study focuses on two plants, Moringa oleifera and Prunus africana which are widely used in Kenya for cancer treatment and are reputed to cure various malignancies. There is need to obtain insight into the phytochemistry of these plants and their supposed activity as well as bioprospecting for potential novel anticancer drugs. In this work, the phytochemistry, in-vitro cytotoxicity and apoptosis induction activity of isolated phytocompounds on mammalian colorectal adenocarcinoma (Caco-2), hepatocellular carcinoma (HepG2) and the non-cancer human embryonic kidney cell (HEK293) cell lines are reported. Phytochemical studies using different chromatographic and spectroscopic techniques led to the isolation of six compounds, namely quercetin-3-O-glucoside, 4-(β-d-glucopyranosyl-1→4-α-l-rhamnopyranosyloxy)-benzyl isothiocyanate, lutein, β-sitosterol, β-amyrin and sitosterol-3-O-glucoside. These were successfully purified and their structures were confirmed using spectroscopic techniques. GC-MS profiling of P. africana extract revealed 9 compounds of interest. Four of the purified compounds were tested for potential anticancer activity using in-vitro cytotoxic and immunofluorescent techniques. The MTT cell proliferation assay was used to test for cytotoxic activity and dual staining using acridine orange and ethidium bromide were used to study apoptosis. A concentration dependent cytotoxicity was observed across all cell lines with low activity on the non-cancer HEK293 cell line. 4-(β-d-glucopyranosyl-1→4-α-l-rhamnopyranosyloxy)-benzyl isothiocyanate was the most cytotoxic compound tested across all cell lines based on IC50 values with β-amyrin being the least cytotoxic. All compounds tested exhibited higher cytotoxic activity on the colorectal adenocarcinoma (Caco-2) cell line than the hepatocellular (HepG2) cancer cell line. Further investigation on possible mechanisms of action using immunofluorescent studies confirmed apoptosis as one of the modes of cell death which was also selective to cancer cells. Higher apoptotic indices were observed on the cancer cell lines than the non-cancer cell line. The findings in this study will contribute to the existing knowledge on natural products and their anticancer activity and will provide a basis for development of potential novel cancer drugs.