Abstract: | Plants which are used by traditional healers in Tanzania have been evaluated to obtain preliminary data of their toxicity using the brine shrimps test. The results indicate that 9 out of 44 plant species whose extracts were tested exhibited high toxicity with LC50 values below 20µg/ml. These include Aloe lateritia Engl. (Aloaceae) [19.1µg/ml], Cassia abbreviata Oliv. (Caesalpiniaceae) [12.7µg/ml], Croton scheffleri Pax (Euphorbiaceae) [13.7µg/ml], Hymenodactyon parvifolium Brig (Rubiaceae) [13.4µg/ml], Kigelia Africana L. (Bignoniaceae) [7.2µg/ml], and Ocimum suave Oliv. (Labiatae) [16.7µg/ml]. Twelve plants gave LC50 values between 21 and 50µg/ml, 11 plants gave LC50 values between 50 and 100 µg/ml, and 18 plants gave LC50 values greater than 100 µg/ml. |