Humulus japonicus extract alleviates oxidative stress and apoptosis in 6-hydroxydopamine-induced PC12 cells

Objective: To explore the possible neuroprotective activities of Humulus japonicus extract against Parkinson's disease (PD) in a cellular model. Methods: PD was modeled in PC12 cells using 6-hydroxydopamine (6-OHDA). The cell activity, intracellular levels of reactive oxygen species (ROS), anti-oxidative and anti-apoptotic effects, and other related indicators and related signaling pathways were evaluated to elucidate the neuroprotective effects of Humulus japonicus extract. Results: Humulus japonicus extract exhibited anti-oxidative and anti-apoptotic effects in 6-OHDA-stimulated PC12 cells. It also reduced oxidative stress-induced ROS accumulation; upregulated antioxidant enzymes, such as glutathione, catalase, heme oxidase-1, and 8-oxguanine glycosylase 1; promoted cell survival by decreasing BAX and increasing Bcl-2 and sirtuin 1 expression via the MAPK and/or Nrf2 signaling pathways. Conclusions: Humulus japonicus extract has antioxidative and anti-apoptotic effects and could be developed as a promising candidate for preventing and treating oxidative stress-related neurodegenerative diseases.