Turmeric (Curcuma longa) and its major constituent (curcumin) as nontoxic and safe substances: Review

Curcumin is the major constituent of turmeric (Curcuma longa). Turmeric has been widely used as a spice in foods and for therapeutic applications such as anti-inflammatory, antihyperlipidemic, and antimicrobial activities. Turmeric and curcumin are nonmutagenic and nongenotoxic. Oral use of turmeric and curcumin did not have reproductive toxicity in animals at certain doses. Studies on human did not show toxic effects, and curcumin was safe at the dose of 6 g/day orally for 4-7 weeks. However, some adverse effects such as gastrointestinal upsets may occur. Moreover, oral bioavailable formulations of curcumin were safe for human at the dose of 500 mg two times in a day for 30 days, but there are still few trials and more studies are needed specially on nanoformulations and it should be discussed in a separate article. In addition, curcumin is known as a generally recognized as safe substance. This review discusses the safety and toxicity of turmeric and curcumin in medicine. Turmeric and curcumin are nontoxic for human especially in oral administration. Turmeric and curcumin are also safe in animals. They are nonmutagenic and are safe in pregnancy in animals but more studies in human are needed.