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Attenuation of Neuroinflammatory Responses in Lipopolysaccharide-Induced BV-2 Microglia by Suaeda asparagoides Miq. (Chenopodiaceae)
Kopalli, Spandana Rajendra & Koppula, Sushruta
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 proinflammatory
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 LPSstimulated
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 antineuroinflammatory
effect.
Keywords
Suaeda asparagoides; Chenopodiaceae; Microglia; Lipopolysaccharide; Neuroinflammation; Cytokines; Antioxidant
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