Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Attenuation of Neuroinflammatory Responses in Lipopolysaccharide-Induced BV-2 Microglia by Suaeda asparagoides Miq. (Chenopodiaceae)

Spandana Rajendra Kopalli, Sushruta Koppula

College of Biomedical and Health Science, Konkuk University, Chungju, 380-701, Republic of Korea;

For correspondence:- Sushruta Koppula Email: sushrutak@gmail.com Tel:+82438403609

Received: 7 June 2014 Accepted: 1 August 2014 Published: 24 September 2014

Citation: Kopalli SR, Koppula S. Attenuation of Neuroinflammatory Responses in Lipopolysaccharide-Induced BV-2 Microglia by Suaeda asparagoides Miq. (Chenopodiaceae). Trop J Pharm Res 2014; 13(9):1407-1413 doi: 10.4314/tjpr.v13i9.5

© 2014 The authors.
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Abstract

Purpose: To investigate the protective effect of Suaeda asparagoides (Chenopodiaceae) extract on neuroinflammatory responses induced by lipopolysaccharide (LPS) in BV-2 microglial cells and its antioxidant effects.

Methods: Biochemical studies carried out include 3-(4, 5-dimethylthiazol-2-yl)-2, 5- diphenyl-tetrazolium bromide (MTT) assay and 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) assay for cell viability and radical scavenging activities, respectively. To evaluate the anti-neuroinflammatory effects of S. asparagoides (SAE) extract, LPS (1μg/ml)-stimulated BV-2 microglial cells were used and pro-inflammatory mediators and cytokines such as nitric oxide (NO), inducible NO (iNOS), cyclooxygenase (COX)-2, tumor necrosis factor-alpha (TNF-α) and nuclear factor-kappa B (NF-κB) were measured using Western blotting and enzyme-linked immunosorbent assay (ELISA).

Results: LPS-stimulation of BV-2 cells increased the levels of NO (25.2 ± 2.15, p < 0.001) and pro-inflammatory mediators such as iNOS, COX-2 and TNF- α. However, treatment with SAE extract (20, 40 and 80 µg/ml) to LPS-stimulated BV-2 cells significantly inhibited the excessive release of NO (p < 0.05 at 20 µg/ml and p < 0.001 at 40 and 80 µg/ml, respectively) and suppressed the increased levels of iNOS, COX-2 and TNF-α. SAE also concentration dependently inhibited the NF-κB activation in LPS-stimulated BV-2 microglia. Further, SAE significantly and concentration-dependently (p < 0.001 at 20 - 200 µg/ml, respectively) scavenged DPPH radicals with IC₅₀ of 36.33 ± 2.12 µg/ml.

Conclusion: The results strongly suggest that SAE exhibits protective activity against LPS-stimulated neuroinflammatory responses. Mechanistic study reveals that SAE might by regulating NF-κB signaling. The antioxidant activity exhibited by SAE extract might also play a role in the plant’s significant anti-neuroinflammatory effect.

Keywords: Suaeda asparagoides, Chenopodiaceae, Microglia, Lipopolysaccharide, Neuroinflammation, Cytokines, Antioxidant