Research J. Pharmacognosy and Phytochemistry 2010; 2(5): 397-402 S. Parimalakrishnan et.al. 397 ISSN 0975- 2331 Research Journal of Pharmacognosy and Phytochemistry. 2(5): Sept.-Oct. 2010, 397-402 Research Article *Corresponding Author: Dr. S. Pairmalakrishnan, Assistant Professor, Annamalai University, Annamalai Nagar–608002, Tamil Nadu, India. Mobile: 09487210061, Phone: +914144239738. E-mail: parim75@hotmail.com Received on 19.07.2010 Accepted on 04.08.2010 © A&V Publication all right reserved Preliminary Toxicity Evaluation of Bidens pilosa Extracts Using Experimental Mice S. Parimalakrishnan 1 *, V.D. Sundar 2 , I. Ulaganathan 2 , S. Nandhakumar 2 and Akalanka Dey 1 1 Annamalai University, Annamalai Nagar-608002, TamilNadu, India 2 GIET School of Pharmacy, Rajahmundry, AP, India ABSTRACT: 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 LD 50 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. KEYWORDS: Acute, Sub-acute toxicity, hematological parameters INTRODUCTION: Safety pharmacology is a step ahead than toxicological evaluation because ethics plays an important role in animal studies and human clinical trials. Therefore safety pharmacology is implemented animal screening stages. Traditional or folk healing herbal medicines are used approximately by 60% of the world population both in the developing and developed countries. The herbal recipes are prepared most often from a combination of two or more plant products which may contain active constituents with multiple physiological and biochemical activities and could be used in the treatment of a various diseases 1 . They are administered in most disease conditions over a period of time without proper dosage monitoring and consideration of toxic effects that might result from such prolonged usage of drugs. Bidens pilosa (Family - Asteraceae) is found in waste lands throughout India. It was been already investigated because of its wide range of medicinal applications. Its leaves are used as treatment for rheumatism, sore eyes, abdominal troubles, ulcers swollen glands and toothaches 2 , cancer, cough 3 . It is commonly used for inflammatory, diuretic, jaundice, conjunctivitis, abscesses, mycosis and urinary infections and stimulates childbirth 4 . Emollient, astringent, fever, malaria, leucorrhea, diabetes, sore throat, tonsillitis and vaginal infections also treated. Apart from this plant is applied externally for fungal infections, ulcers, diaper rash, insect bites, and hemorrhoids 5 . The scope of the present study was to evaluate the safety profile of entire plant extract of Bidens pilosa by carrying out the acute and sub acute toxicity