Acute, subacute, and sub-chronic toxicity evaluation of Bletilla formosana tubers in rats

Abstract

Bletilla formosana (Hayata) Schltr. is an important economic medicinal and edible plant in China. Its tubers (BFTs) are traditionally consumed as a beverage and canned foods for promoting human health. In this paper, the nutrients, the contents of total phenol, flavonoids, and polysaccharides, and the safety and toxicity of BFT are determined. The chemical analysis reported that BFT is rich in proteins, polysaccharides, polyphenols, flavonoids, and trace elements. The acute (14 days), subacute (28 days), and sub-chronic (90 days) toxicities of BFT were evaluated for the first time in female and male rats. An acute toxicity study showed that the female rats by single oral administrations of BFT with 10,000 mg/kg body weight (BW) did not have behavioral changes and mortality, indicating that 50% lethal dose (LD50) of BFT was over 10,000 mg/kg BW. Similarly, BFT at 5000 mg/kg BW for consecutive 28 and 90 days in rats was also not toxic for rats after the analysis of physiological and biochemical parameters. Additionally, there are no significant differences on the histopathological changes of the heart, liver, spleen, lung, kidney, ovary, or testis between the control and BFT groups. Our findings revealed that BFT with concentration of less than 5000 mg/kg BW are safe for the female or male rats, indicating that BFT could be regarded as a safe food source.