Ethnobotanical surveys were conducted in four different indigenous groups in Southern parts of Tamilnadu, India, using a questionnaire. The herbal practitioners in the study area were interviewed, and information on medicinal plants was collected from the traditional healers called "Vaidyars". This survey covers 72 medicinal plants belonging to 53 families that are used for the treatment of snakebite in a traditional way. Traditional approach was evaluated scientifically with some selected plant extracts (7.2 mg/kg bw) and partially purified fractions (2.4 mg/kg bw) were orally administered to mice experimentally envenomed with rattlesnake venom s.c. injection (2.5-15 microg/kg bw). Tested fractions (Aristolochia indica, Hemidesmus indicus, Gloriosa superba, Strychnos nux-vomica, Eclipta prostrata, and Andrographis paniculata) showed potent neutralizing effect against the venom. Compared to the extracts, administration of purified fractions was more effective in increasing the body weight. Control mice injected with the venom alone showed weight loss and severe toxicity at 15 microg/kg bw. The purified fractions (2.4 mg/kg bw) produced significant protection against venom induced changes in serum SOD and LPx levels. The isolated fractions effectively inhibited the toxic effect of snake venoms in vitro than in vivo. The above observations confirmed the protective activity of plants-Aristolochia indica, Hemidesmus indicus, Gloriosa superba, Strychnos nux-vomica, Eclipta prostrata, and Andrographis paniculata against the lethal action of snake venom and need further investigation.