Phytochemical and elemental analysis of Cyrtanthus obliquus and Lippia javanica.

Abstract

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.