Biological and pharmacological assays of the extracts of Gentiana oliveri and its pure alkaloid gentianine indicated to be highly efficacious. Toxicity in vertebrates was evaluated by chronic toxicity assay in rats. LD50 was found to be greater than 1000. Slightly elevated values of serum glutamate pyruvate transaminase and lactate dehydrogenase were observed at higher doses, but hypoglycemia did not occurred. At lower doses it was found to be non-toxic.