Biotransformation of ginsenoside Rb1 with wild Cordyceps sinensis and Ascomycota sp. and its antihyperlipidemic effects on the diet‐induced cholesterol of zebrafish

Biotransformation major ginsenoside into minor ginsenoside via microbial fermentation has been proposed as a viable option to produce minor ginsenoside, because of its biological activity superior to major ginsenoside. Cordyceps sinensis contains a complex enzymatic system and many ingredients with medicinal value that could be useful tools for biotransformation applications in the ginseng industry. Wild C. sinensis and Ascomycota sp. were collected from Changbai Mountain and identified. Analysis by UPLC-MS and HPLC indicates that the underlying pathway of major ginsenoside Rb1 during fermentation with strains was Rb1→Rd→F2→CK and Rb1→Rd→Rg3. C. sinensis and Ascomycota sp. can be applied to minor ginsenoside preparation in the food and medical industries. The antihyperlipidemic effects of Rb1 were further screened from fermentation in larvae zebrafish based on the fluorescence intensity. In the adult zebrafish model, treatment with high-dose ginsenoside Rb1 group exhibited a significant decrease in the plasma total cholesterol (TC) and triglyceride (TG) levels by 36.49% (p < .05) and 29.97% (p < .05), respectively, compared with high cholesterol group (HC). Furthermore, ginsenoside Rb1 treatment decreased the mRNA levels of LDLR and SREBP2 in the adult zebrafish liver. Ginsenoside Rb1 diet supplement significantly increased the mRNA expression of HMGCR and CYP7A1. These results suggest that ginsenoside Rb1 attenuates hypercholesterolemia via the downregulation of cholesterol synthesis and assembly or secretion of lipoproteins as well as the upregulation of cholesterol transport and efflux, providing a novel idea of ginsenoside keeping cholesterol levels down for the clinical application. PRACTICAL APPLICATIONS: Wild Cordyceps sinensis has the potential to be applied to the preparation for minor ginsenoside. Furthermore, the final fermentation product has more functional characteristics, including cordyceps acid, cordycepin, and adenosine. Wild Cordyceps sinensis and Ascomycota sp. could potentially be employed in the food and medical industries.