The use of medicinal plants for treatment of humans and animals is entrenched in the Maasai culture and traditional knowledge related to it is passed on from one generation to the next. A handful of researchers have in the past decades documented this knowledge. No single study has documented medicinal plant uses of the Maasai community as a whole. This review provides a consolidated database of the diversity and uses of medicinal plants among the Maasai in Kenya. The study will help conserve traditional medicinal plant knowledge that is valuable for the development of modern medicine. Relevant information on medicinal plants used by the Maasai of Kenya was extracted from journals, books, M.Sc., and Ph.D. dissertations. We found evidence of 289 plant species used by the Maasai of Kenya in traditional medicine. Most species were used to treat health conditions in the categories gastrointestinal and respiratory system disorders. The most used families were Leguminosae, Asteraceae, Malvaceae, Euphorbiaceae, and Lamiaceae. Medicines were commonly prepared as a decoction and administered through oral ingestion, with roots reported to be the preferred plant part for medication. The Maasai preference for roots compared to other plant parts may be unsustainable and could threaten species availability in the future.

Knowledge and practice of medicinal plant use is embedded in the Maasai culture. However, it is not known how that knowledge and practices are acquired by children and transferred across generations. We assessed children’s knowledge of medicinal plants and their uses, methods of knowledge acquisition and transfer, and how that process is influenced by demographic attributes such as gender, level of education, and age. We interviewed 80 children who were 6–17 years old. Mann–Whitney U, Kruskal–Wallis tests and Spearman Rank order correlation were performed to determine the influence of gender, level of education, and age when they are in the process of acquiring ethnomedicinal plant knowledge. The Maasai children acquired knowledge of medicinal plants progressively with their age. Ethnomedicinal knowledge was not influenced by gender or level of education. The children were introduced to the knowledge of local medicinal plants and their use at an average age of seven years and the knowledge was transferred indiscriminately to both girls and boys. This study aids in the protection and conservation of medicinal plant knowledge by encouraging the sustainability of the local cultural heritage.

Dodonaea viscosa Jacq (Sapindaceae) is a medicinal plant with a worldwide distribution. The species has undergone enormous taxonomic changes which caused confusion amongst plant users. In Kenya, for example, two varieties are known to exist based on morphology, i.e., D. viscosa var. viscosa along the coast, and D. viscosa var. angustifolia in the Kenyan inland. These two taxa are recognized as distinct species in some reports. This prompted us to apply metabolomics to understand the relationship among naturally occurring populations of D. viscosa in Kenya, and to identify compounds that can assist in taxonomic delineation of the different varieties of D. viscosa from different parts of Kenya. The phytochemical variability of Kenyan D. viscosa var. angustifolia populations collected from four different geographical regions (Nanyuki, Machakos, Nairobi, and Narok) and one coastal D. viscosa var. viscosa (the Gazi) were analyzed by LC-MS using a metabolomics-driven approach. Four known compounds, two diterpenoids (dodonic acid (1), hautriwaic acid lactone (3), and two flavonoids (5,7,4′,5′-tetrahydroxy-3,6,2′-trimethoxyflavone (2) and catechin (4)) were isolated and purified from the Gazi coastal collection. The presence of these compounds and their relative abundance in other populations was determined by LC-MS analyses. Multivariate statistical analyses of LC-MS data was used for the visualization of the patterns of variation and identification of additional compounds. Eleven discriminant compounds responsible for separating chemometric clusters were tentatively identified. In an antimicrobial assay, hautriwaic acid lactone (3) and catechin (4) were the most active compounds followed by the extract from the coastal (Gazi) population. The clustering pattern of the five populations of D. viscosa suggested that the metabolite profiles were influenced by geo-environmental conditions and did not support the current classification of D. viscosa based on morphology. This study disputes the current classification of D. viscosa in Kenya and recommends revision using tools such as molecular phylogenetics.

Chalo DM, Lukhoba C, Fidahussein DS, Nguta JM. 2017. Antimicrobial activity, toxicity and phytochemical screening of selected medicinal plants of Losho, Narok County, Kenya. Biofarmasi (Rumphius J Nat Prod Biochem) 15: 29-43. In Kenya, microbial infections are a major cause of morbidity. The effectiveness of antibiotic is threatened by the increase of resistance of pathogenic microbes against most available drugs because new pathogens continue to emerge. Nowadays, herbal remedies offer hope since they are readily available and cheap. The aim of this research was to investigate the activity of antimicrobial, the lethality of brine shrimp and phytochemical composition of crude extracts of four selected plants namely Schrebera alata (Oleaceae), Ormocarpum kirkii (Papilionoideae), Helichrysum forskahlii (Asteraceae) and Cussonia holstii (Araliaceae) that are medicinally used by herbalists from Losho, Narok County Kenya for treatment of ear, nose and throat infections, gastrointestinal disorders and skin diseases. Qualitative antimicrobial susceptibility test against five microorganisms, methicillin-resistant Staphylococcus aureus, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans was investigated using agar diffusion methods to produce inhibition zones and the data accrued were analyzed using Analysis of variance. Minimum inhibitory concentrations were determined by broth microdilution method. Toxicity of the extracts was analyzed using brine shrimp lethality assay. The median fatal concentration of fifty was determined by data analysis using Finney‟s computer program. Phytochemical screening for flavonoids, sterols, alkaloids, tannins, quinones and terpenoids and saponins was determined using standard procedures. The observation showed that the organic crude extracts of H. forskahlii had the highest inhibition zone against methicillin-resistant S. aureus of 19.5 and 18.5 mm in agar well and agar disk diffusion respectively. In addition, organic extracts of H. forskahlii showed the highest antifungal inhibition zone of 8.5 mm in agar well diffusion. Minimum values of inhibitory concentrations varied from 15.625 to 250 mg/mL. Organic crude extracts of H. forskahlii and C. holstii were found to be highly toxic with lethal concentration of 0.009 mg/mL. All plant crude extracts contained flavonoids, sterols, alkaloids, tannins, quinones, and terpenoids. Saponins were present in all the plant extracts except in organic extracts of H. forskahlii. This study promoted the first record of antimicrobial activity, toxicity and phytochemical composition of S. alata and C. holstii. The study has shown that H. forskahlii and O. kirkii possess promising antimicrobial activity against microbes of health importance and could lead to the isolation of new, safe and efficacious antimicrobial compounds. Further research should be carried on O. kirkii and S. alata to isolate and characterize the compounds responsible for the observed activity.