Anti-neuroinflammatory effects of alkaloid-enriched extract from Huperzia serrata on lipopolysaccharide-stimulated BV-2 microglial cells

Abstract

Context

Alkaloid-enriched extract of Huperzia serrata (Thunb.) Trevis (Lycopodiaceae) (HsAE) can potentially be used to manage neuronal disorders.

Objective

This study determines the anti-neuroinflammatory effects of HsAE on lipopolysaccharide (LPS)-stimulated BV-2 microglial cells and the underlying mechanisms.

Materials and methods

BV-2 cells were pre- or post-treated with different concentrations of HsAE (25-150 µg/mL) for 30 min before or after LPS induction. Cell viability was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and no cytotoxicity was found. Nitric oxide (NO) concentration was determined using Griess reagent. The levels of prostaglandin E2 (PGE2), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 were determined using enzyme-linked immunosorbent assay. The levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 and the phosphorylation of mitogen-activated protein kinase (MAPK) were analyzed using western blotting.

Results

HsAE reduced LPS-induced NO production with half-maximal inhibitory concentration values of 99.79 and 92.40 µg/mL at pre- and post-treatment, respectively. Pre-treatment with HsAE at concentrations of 50, 100, and 150 µg/mL completely inhibited the secretion of PGE2, TNF-α, IL-6, and IL-1β compared to post-treatment with HsAE. This suggests that prophylactic treatment is better than post-inflammation treatment. HsAE decreased the expression levels of iNOS and COX-2 and attenuated the secretion of pro-inflammatory factors by downregulating the phosphorylation of p38 and extracellular signal-regulated protein kinase in the MAPK signaling pathway.

Discussion and Conclusions

HsAE exerts anti-neuroinflammatory effects on LPS-stimulated BV-2 cells, suggesting that it may be a potential candidate for the treatment of neuroinflammation in neurodegenerative diseases.

Keywords:

• Huperzine A
• neurodegenerative diseases

Author contributions

Thu Kim Dang: Conceptualization, Formal analysis, Data curation, Methodology, Writing - Original Draft. Seong-Min Hong: Conceptualization, Formal analysis, Data curation, Methodology, Writing - Review & Editing. Vui Thi Dao: Conceptualization, Supervision. Phuong Thi Thu Tran, Hiep Tuan Tran: Writing - Review & Editing, Investigation. Hai Thanh Nguyen, Giang Hoang Do, Hang Thi Nguyet Pham: Investigation, Data curation. Sun Yeou Kim: Conceptualization, Supervision, Funding acquisition.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Gachon University Research Fund of 2021 [grant number GCU-202102980001] and the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education [grant number NRF-2022R1I1A406891711].