Phytochemical Composition and Toxicological Profiling of Curcuma longa (Turmeric) Root Extract in Rats

Abstract

Background: Curcuma longa Linn (turmeric) is a common medicinal plant used in Africa for the treatment of diseases. In this study, its extract was evaluated to ascertain its phytochemical composition and toxicity in wistar rats. Methods: The prepared rhizome ethanol extract was first subjected to preliminary phytochemical evaluation and then lethal dose (LD50) test. In the sub-acute toxicity test, 20 adult wistar rats assigned to 4 groups of 5 rats each were administered oral graded doses of the extract. Group 1 served as control while groups 2, 3 and 4 received 250, 500 and 1000 mg/kg body weight of the extract over a period of 28 days, after which blood samples were collected for haematological and serum biochemical analyses. Results: Results obtained from the phytochemical analysis revealed the presence of saponins, tannins, phenolics, flavonoids, steroids, terpenoids, cardiac glycosides and alkaloids in extract, with alkaloids being most abundant (41.20+0.53 mg/100g)  and terpenoids, the least (3.98+0.03 mg/100g). Lethal dose value for the extract was found to be >5000mg/kg body weight. Results of sub-acute toxicity evaluation of the extract showed no deleterious effect on liver and kidney function parameters with these parameters being not significantly different from their control values (p<0.05). Treatment with the extract also caused significant hypolipidemia (p<0.05) but increased the values of high-density lipoprotein cholesterol. The activities of antioxidant enzymes and red blood cell counts were also significantly increased following treatment with the extract, especially at higher dose levels. Conclusion: Therefore, we conclude that C. longa extract may be safe for use in the treatment of diseases when administered via the oral route.