Screening of Plants Used as Traditional Anticancer Remedies in Mkuranga and Same Districts, Tanzania, Using Brine Shrimp Toxicity Bioassay

BACKGROUND: Inadequate specialized cancer hospitals and high costs are contributing factors that delay cancer patients from accessing health care services in Tanzania. Consequently, majority of patients are first seen by Traditional Health Practitioners (THPs) before they access specialized services. This study presents ethnomedical information and preliminary evaluation of 25 plant species claimed by THPs in Mkuranga and Same districts of Tanzania on use for treatment of cancer. Literature search and laboratory investigation results are presented to support evaluation. METHODS. THIS STUDY WAS A SINGLE DISEASE ETHNOMEDICAL ENQUIRY FOCUSING ON PLANTS BEING USED FOR CANCER TREATMENT: Face-to-face interviews and questionnaires were administered to eight (8) THPs in Mkuranga and Same districts on the claimed plants and their use for management of cancer. Plants were selected based on being frequently mentioned and emphasis given by THPs. Literature search and brine shrimp toxicity (BST) of methanol : dichloromethane (1:1) extracts was used as surrogates to evaluate strength of the claims. RESULTS: This study reports 25 plant species used by the THPs in two districts of Tanzania. Eight plants (32%) have been reported in the literature to have activity against cancer cells. BST results revealed, 14 (56%) plants exhibited high toxicity against brine shrimps. The most active plants included Croton pseudopulchellus Pax (LC(50) 4.2 μg/ml), Dalbergia melanoxylon Guill. & Perr. (LC(50) 6.8 μg/ml), Loranthus micranthus Linn (LC(50) 4.0 μg/ml), Ochna mossambicensis Klotzsch (LC(50) 3.3 μg/ml), and Spirostachys africana Sond. (LC(50) 4.4 μg/ml); their toxicity was comparable to that of Catharanthus roseus (L) G. Don. (LC(50) 6.7 μg/ml), an established source of anticancer compounds. Nine other plants had LC(50) values between (19.8 and 71.6) μg/ml, indicating also potential to yield anticancer. CONCLUSION: Literature search and BST results provide a strong support of the potential of the claimed plants to yield active anticancer compounds.