Emulsification and antioxidation of biosurfactant extracts from Chinese medicinal herbs fermentation in vitro

• The emulsification and antioxidation of potential BECMHF were detected in vitro.
• BECMHF had good DPPH, superoxide scavenging and superoxide dismutase-like activity.
• BECMHF enhanced the antioxidative effect with amphoteric nature of biosurfactant.
• Potential biosurfactant with amphoteric structure proven was analyzed by TLC and NMR.
• The emulsification and antioxidation of BECMHF have food and cosmetic applications.

Much attention has been paid to biosurfactants produced using microorganisms, but little direct evidence for the development of natural biosurfactants combined with Chinese medicinal herbs are available. We investigated the emulsification and antioxidation of biosurfactant extracts from Chinese medicinal herb fermentation (BECMHF) in vitro and their application in water retention capacity and the skin prick and allergy test (SPAT) index for skin cells. The results showed that the water retention capacity of BECMHF was positively associated with the emulsification index. The SPAT index of 8 Chinese medicinal herbs was 0 at a 1% or 2% concentration, suggesting no sensitivity or adverse effects on the skin cells. Eight BECMHFs produced using Alcaligenes piechaudii CC-ESB2 exhibited antioxidant capabilities, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and superoxide scavenging activity, and superoxide dismutase (SOD)-like activity at a concentration of 10 mg/ml. The mechanism involved inhibitory effects on nitrite, inducible nitric oxide synthase (iNOS) expression, and reactive oxygen species (ROSs) generation. BECMHFs exhibit favorable antioxidative properties in health food and satisfactory emulsifying and moisturizing characteristics in cosmetic formulations, which have potential applications in the health food and cosmetic industries, respectively.