Journal of Pharmaceutical Research International

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.