Safety evaluation of mutagenecity, acute and subacute toxicity study of <i>Chlorella vulgaris</i> CK-22 in rats

Abstract

The aim of this study was to evaluate the safety of Chlorella vulgaris CK-22 as a food supplement. We examined mutagenicity, acute toxicity and subacute toxicity using Wistar rats administered Chlorella powder (CP). In the mutagenesis test, CP exhibited no mutagenecity in the in vitro assay. In the acute toxicity test, CP was administered orally at 0 mg/kg, 1,000 mg/kg, 2,000 mg/kg and 5,000 mg/kg body weight to Wistar rats (five animals/sex/group). No significance changes were observed test article-related during the 14-day observation period. The LD 50 of CP was estimated to be more than 5,000 mg/kg body weight in rats. In the subacute toxicity test, CP was administered at 0%, 2.5%, 5% and 10% in pelleted rodent diet to Wistar rats (ten animals/sex/groups). No mortality or treatment-related clinical signs were observed in any of the groups during the 28-day observation period. In both sexes, renal histopathology was conducted in the control and 10% groups, because absolute and relative renal weights increased in the 10% groups compared to the control groups. Based on the histopathology of the kidneys, the no-observed-adverse-effect level (NOAEL) is greater 8.57 g/kg body weight/day for males and 8.62 g/kg body weight/day for females.

Toxicity study of Chlorella vulgaris water extract on female Sprague Dawley rats by using the Organization for Economic Cooperation and Development (OECD) Guideline 420

“…A previous study on C. vulgaris strain CK-22 has reported the LD 50 of this alga to be more than 5000 mg kg −1 BW (Himuro et al 2014). In another study, the intake of carotenogenic of C. vulgaris did not demonstrate any Fig.…”

“…No mortality and clinical signs of toxicity were observed in both single dose and 28-day oral toxicity test on Wistar rats. This algae also exhibited no mutagenicity in the in vitro assay suggesting that C. vulgaris is safe as a food supplement (Himuro et al 2014). However, with the immense ongoing and future research of the pharmacological effect of C. vulgaris, it is beneficial to thoroughly investigate the potential hepatotoxicity of this alga.…”

Orange peels and Chlorella vulgaris supplementation ameliorate gamma radiation‐induced oxidative stress by regulating TGF‐β and NOX2/NOX4 signaling pathways

“…Orange peels and/or C. vulgaris supplementation did not affect the basal expression levels of biochemical and immunological parameters, indicating that they are safe to use as a food supplement . 23 However when administered before and with irradiation they could attenuate radiation induced hazards.…”

“…Chlorella vulgaris is one of the most extensively utilized photosynthetic microalgae as a dietary supplement 22 . It exhibited no mutagenicity, reflecting the safety to use as a dietary supplement 23 . C. vulgaris is believed to be a good source of “proteins, essential amino acids, carbohydrates, dietary fibers, fatty acids, nucleic acids, vitamins, growth factors, minerals, and chlorophyll.” 24,25 Thangaraj et al 26 reported that C. vulgaris is a rich source of crude protein (47.08%), crude fat (5.68%), crude fiber level (2.87%), and gross energy (4,377 kcal/kg).…”