Safety evaluation of Mucor rouxii CFR-G15 biomass containing ω-6 fatty acids in rats

Mucor rouxii CFR-G15 is an oleaginous zygomycetous fungus. The mycelia of the fungus accumulate 35.0 ± 0.8% total lipid of which, 18.55 ± 0.46% is gamma linolenic acid. Acute and subchronic studies were conducted by feeding rats with dry biomass of M. rouxii CFR-G15 to assess the safety of the oils in the fungal mycelium. For acute toxicity studies, adult male rats fed with diet at 0, 5000, 10,000, 25,000, 50,000 mg/kg bw for 1 day, and the animals were monitored for 14 days. Rats weighing 35 ± 2.5 g were fed for 13 weeks with a diet incorporating 2500, 5000, 10,000 and 20,000 mg/kg (w/w) dry biomass for subchronic toxicity studies. Control consists of the diet without the dry biomass. Dietary feeding of M. rouxii biomass at any level showed no significant changes (p > 0.05) in food intake, body weight, organs weight and serum enzymes. Macroscopic and microscopic observations revealed that the vital organs were unaffected by the feed containing the dry biomass. However, triglycerides and cholesterol levels in serum were decreased significantly (p < 0.05) in the test rats. The results of this study suggests that feeding fungal mycelia containing oil is safe when fed to rats and also shows positive effects on controlling triglycerides and cholesterol.

► GLA is an important intermediate in eicosanoid metabolism in human. ► Presence of GLA in Mucor rouxii CFR-G15 makes it a potential source of SCO. ► Acute and sub chronic studies were conducted with dry biomass of M. rouxii on rats. ► The dried biomass of M. rouxii was found to be safe in rats at all levels used. ► Significant reduction in triglycerides and cholesterol levels in serum lipids.