Abstract:

Objective To discuss the antioxidant capacities of ten edible plant exosomes-like nanoparticles （ELNs） from ginger， green pepper， garlic， mushroom， lemon， yam， grapes， tomatoes， broccoli，and onions in vitro and their protective effects on oxidative injury of the PC12 cells induced by hydrogen peroxide，and to provide the basis for the further study on the ELNs. Methods The PC12 cells were divided into control group， exosome group， hydrogen peroxide group，and hydrogen peroxide+exosomes group. Ten types of ELNs were separated and extracted by using high-speed differential centrifugation. The in vitro antioxidant capacities of these 10 types of ELNs were detected by using 1，1-diphenyl-2-picryl-hydrazyl（DPPH） free radical scavenging system，2，2'-azinobis-（3-ethylbenzthiazoline-6-sulphonate（ABTS） cationic radical system， and ferric ion total reduction antioxidant power（FRAD） system. The viabilities of PC12 cells in various groups were detected by MTT method. Results The DPPH radical scavenging abilities of ten ELNs，from high to low， were mushroom， onion， ginger， lemon， grape， tomato， green pepper， broccoli， yam， and garlic； the capacities of ten ELNs to scavenge ABTS， from high to low， were ginger， mushroom， onion， lemon， yam， grape， green pepper， garlic， tomato， and broccoli； the total antioxidant capacities of ten ELNs in FRAP， from high to low， were ginger， green pepper， onion， mushroom， lemon， broccoli， grape， yam， tomato，and garlic. The antioxidant capacities of five ELNs with stronger antioxidant capacities were increased with the increasing concentration of the ELNs in the DPPH radical scavenging system， ABTS cationic radical system and FRAP system. The half maximal inhibitory concentration（IC₅₀） values of onion were 73.15， 123.02， and 83.00 g·L^－1， the IC₅₀ values of ginger were 124.07， 91.24， and 91.24 g·L^－1， the IC₅₀ values of mushroom were 310.44， 518.04，and 237.10 g·L^－1， the IC₅₀ of green pepper were 969.06， 847.32，and 237.10 g·L^－1 and the IC₅₀ values of lemon were 1 718.94， 544.38，and 962.12 g·L^－1； compared with control group， the viability of the PC12 cells in hydrogen peroxide group was decreased by about 30%. Compared with hydrogen peroxide group， the viability of the PC12 cells in hydrogen peroxide+ELNs groups （green pepper， lemon， yam， and broccoli） were increased by 21.08%， 26.2%， 11.72%， and 15.15%. Conclusion The ELNs from ginger， mushroom， lemon， and onion show stronger antioxidant capacities in the DPPH radical scavenging system， ABTS cationic radical system and FRAP system. The ELNs from green pepper， lemon， yam， and broccoli have protective effects on the oxidative damage of the PC12 cells induced by hydrogen peroxide.

Key words: Exosome, Edible plant-exosomes-like nanoparticles, Antioxidant evaluation, 1，1-diphenyl-2-picryl-hydrazyl free radical scavenging system, Ferric ion reducing antioxidant power