Preliminary Toxicity Evaluation of Bidens pilosa Extracts Using Experimental Mice

The present study was carried out to evaluate acute and sub-acute toxicity in mice (Swiss albino mice). In acute toxicity study, the test material of methanolic extract of B. pilosa (MEBP) (Asteraceae) was administered orally at dose levels 3, 3.5, 4, 4.5, 5 and 5.5 g/kg, b.wt are observed. The mortality signs behavior using Finley's probit analysis LD₅₀ dose was calculated as 4.5 g/kg b.wt. In the sub-acute toxicity study, methanolic and petroleum ether extracts of B. pilosa (MEBP and PEBP) were administered at dose levels of 200 and 400 mg/kg b.wt, p.o., once a day for 28 days. All the animals were sacrificed on 29^th day and blood was collected and various hematological parameters such as total count of RBC, WBC, DLC and Hb content were monitored and serum protein levels evaluated. Histopathological evidence of the viscera showed congestion and focal necrosis of the liver and renal tubules. It is apparent from the results that the MEBP is safe; however the depression in respiration mechanism that lead to the death of the mice needs to be investigated further.