Abstract:
The herbs used as phytomedicines for the treatment of diabetes, malaria and
pneumonia in Kisii region, Southwest Kenya are Carissa spinarum, Urtica dioica,
Warburgia ugandensis, Senna didymobotrya, Physalis Peruviana, Bidens pilosa,
Leonotis nepetifolia and Toddalia asiatica. The objective of this study was to
standardize the selected eight herbs. Leaf samples of these herbs were obtained from
Kisii region, washed, air-dried and milled. Standardization parameters namely:
phytochemical screening, heavy metal analysis, antimicrobial activity and
identification of functional groups were studied. The pH levels of the aqueous extract
were measured using a pH meter. Results showed that the pH values ranged from
5.27 to 7.50. Phytochemical studies indicated presence of saponins, tannins,
flavonoids, steroids and terpenoids in eight herbs while alkaloids in two, cardiac
glycoside in five and anthraquinones in one and all were confirmed by TLC. Heavy
metal analysis was done by atomic absorption spectrometry. The results showed the
heavy metal present as: Fe, Cr, Cu, Zn, Co, Mn, Ni, Pb, Cd and Hg. The biological
activity of these herbs by well diffusion method indicated that hexane,
dichloromethane, ethyl acetate and ethanol extracts against Staphylococcus aureus,
Escherichia coli and Candida albicans, showed antimicrobial and antifungal activity.
The FTIR spectra analysis indicated the functional groups present as: OH, CH2 and
CH3, C-N, C=N, C=C, C=O, C-O, C≡N and N≡C. Therefore extracts from these
herbs have a potential to control Staphylococcus aureus, Escherichia coli and
Candida albicans. These findings if incorporated with the existing knowledge and
experiences that the traditional healers have, could improve their utilization.
