Glutamate is an excitatory neurotransmitter distributed in the central nervous system of mammals. However, high concentrations of glutamate are known to cause neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and stroke by causing nerve cell death. In this study, the antioxidant activity and neuroprotective effect of subtropical natural products were analyzed. Among 11 subtropical plant extracts mainly tested, Sallacca wallichiana extract (SE) showed the greatest free radical scavenging activity. Then, we confirmed through WST-1 assay that SE protected HT22 cells against glutamate-induced cell death in a concentration-dependent manner. The protective effects of SE against glutamate-induced apoptosis in HT22 cells were also confirmed by flow cytometry analysis using Annexin V/PI double staining. We also confirmed using H 2 DCF-DA single staining that SE inhibits glutamate-induced intracellular reactive oxygen species. And we were confirmed through that SE inhibited glutamateinduced phosphorylation of Mitogen-activated Protein kinases. Consequently, our results propose that SE may contribute to the development of therapeutics to prevent neurodegenerative diseases.

The present study aimed to investigate the antioxidant and anti-inflammatory effects of red beet (Merlin sprout and root) extract. The free radical scavenging activity, EC50 of Merlin sprout extract and Merlin root extract were measured at 1.687 μg/mL and 7.457 μg/mL, respectively. The total polyphenol content of the Merlin sprout extracts was observed to higher than that of the Merlin root extracts. Next, we investigated the effect of Merlin sprout and Merlin root extract on nitric oxide (NO) production in LPS-induced RAW264.7 cells. The Merlin sprout extract showed a higher NO production inhibitory effect compared to the Merlin root extract at 400 μg/mL concentration. In addition, treatment with the Merlin sprout extract significantly suppressed inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression levels. Furthermore, the Merlin sprout extract reduced interleukin-6 (IL-6) production in a concentration-dependent manner. From these results, it appears that it would be beneficial to use the Merlin sprout extract in the food industry and for the development of safe antioxidant and anti-inflammatory substances.