Antioxidant, cytotoxic, and antidiabetic activities of Dendropanax morbifera extract for production of health-oriented food materials

Antioxidant, cytotoxic and anti-diabetic effects of fermented and non-fermented Dendropanax morbifera extracts were compared to assess the potential utility of this species in the development of health-oriented food. The non-fermented extract (NFDE) was obtained from leaves and branches of D. morbifera and the fermented extract (FDE) was prepared by inoculation with Lactobacillus plantarum and Lactobacillus brevis after extraction of D. morbifera with distilled water. Antioxidant activity before and after fermentation was assessed via the α, α-diphenyl-β-picrylhydrazyl  (DPPH) radical scavenging assay, cytotoxicity analyzed with the MTT assay using 3T3-L1 cells and anti-diabetic activity measured based on inhibition of α-glucosidase activity. The D. morbifera extract exhibited substantial antioxidant activity. Moreover, FDE at 24 h exerted more significant antioxidant effects than NFDE (97.1 vs 89.8%) at a concentration of 5 mg/ml. Comparison of the effects of the non-fermented and fermented extracts on 3T3-L1 cell viability revealed slightly higher cytotoxicity of FDE than NFDE (85 vs 95% viability) at a concentration of 500 µg/ml. Both NFDE and FDE (100 µg/ml) exerted strong α-glucosidase inhibitory effects (98.9 and 97.6%, respectively). In view of the low cytotoxicity coupled with significant antioxidant and anti-diabetic effects, the D. morbifera extract presents a novel candidate for the production of functional anti-diabetic agents with minimal side-effects.   Key words: Dendropanax morbifera, fermented and non-fermented extracts, antioxidant activity, cytotoxicity, antidiabetic effects, health-oriented food.