Acute and Subchronic Toxicity Studies of Aqueous, Methanolic and n-Hexane Root Extracts of Curcuma longa L. on Albino Rats

Introduction: The rapid increase in the use and consumption of herbal remedies worldwide has been stimulated by several factors, including the notion that most herbal products are safe and effective.

Aim: This work was designed to evaluate the acute and subchronic toxicity of oral administration of the aqueous, methanolic and n-Hexane root extracts in rats.

Methodology: The LD50 was conducted in two phases. In the first phase, oral doses of 10, 100 and 1000 mg/kg body weight of the extracts were administered and rats observed daily for two weeks. In the second phase, 1600, 2900 and 5000 mg/kg body weight of the extracts were administered respectively. Signs accompanying toxicity and possible death of animals were monitored for two weeks to ascertain the median lethal dose LD50 as well as effect on body weight. Subchronic toxicity were also determined using Lorke’s method to assess the effect of the aqueous, methanolic and n-hexane extracts on kidney and liver parameters after 28 days of oral administration of 10, 100 and 1000 mg/kg body weight.

Results: The LD50 was found to be > 5000 mg/kg body weight, no casualty recorded in two weeks. There was no significant weight decrease (P>0.05) among dose groups up to 1000 mg/kg body weight. In subchronic toxicity study there was significant decreases (P>0.05) in AST, ALT and albumin levels while ALP and total protein showed significant increases (P>0.05). Also, there was significant (P>0.05) decreases in Urea, Creatinine, K+ and HCO3- in treated groups III and IV while Na+ and Cl- shows no significant difference in all the treated groups.

Conclusion: The safety usage of extracts from curcuma longa L. at a dose of less than or equal to 5000 mg/kg body weight is considered to be safe.