Abstract: Objective: To evaluate the effect of Goji berries (Lycium barbarum) on the lifespan and spawning of Caenorhabditis elegans, and to explore its antioxidant capacity. Methods: The ferric reducing/antioxidant power (FRAP) method was used to assess and compare the antioxidant capacity of Goji berries from three different areas of Ningxia, Qinghai and Gansu provinces. The effect of Goji berries on the level of reactive oxygen species (ROS) in nematodes was detected using the fluorescent dye 2’,7’-dichlorofluorescein diacetate, and the effect on the expression of antioxidant enzymes in nematodes was evaluated by real-time quantitative polymerase chain reaction. In addition, in order to determine the effect of Goji berries on the lifespan and spawning, L4 stage nematodes were placed on NGM plates and incubated with and without added Goji berries. The scavenging capacity of Goji berries against H2O2 in the cytoplasm was detected using two transgenic nematodes: Pmyo3::HyPer and roGFP2::Orp1. The fluorescent dye MitoSox Red was used to measure the scavenging capacity against superoxide anion radical in the mitochondria. Results: Goji berries from all three areas had strong antioxidant activity in vitro with no significant difference being found between them. Goji berries could reduce the level of ROS and increase the levels of antioxidant enzymes in nematodes. However, Goji berries had no significant effect on the lifespan or spawning ability. Goji berries could scavenge mitochondrial superoxide anion radicals but not cytoplasmic H2O2. Conclusion: Goji berries can exert antioxidant capacity in vitro and in vivo, and its antioxidant effect in vivo is achieved by reducing the level of mitochondrial superoxide anion radicals. In addition, Goji berries do not dramatically affect the lifespan or the total number of eggs laid in nematodes.

Key words: Lycium barbarum, Caenorhabditis elegans, antioxidant capacity