Ethanolic extract of Puhuang (Pollen Typhae) modulates lipopoly- saccharide-induced inflammatory response through inducible nitric oxide synthase / cyclooxygenase-2 signaling in RAW 264.7 macro- phages

OBJECTIVE: To evaluate the immune modulatory response of Puhuang (Pollen Typhae), ethanolic extract of dried pollens (TP-E) and charcoal activated pollens (CTP-E) were used for their phytochemical evaluation and their modulatory response against lipopolysaccharide (LPS) induced inflammatory activity on RAW264.7 macrophage cells. METHODS: Biochemical assays were carried out to quantify the 1,1-Diphenyl-2-picrylhydrazyl Radical Scavenging Activity, Reducing Power, Ferrous ion chelating ability and total polyphenol content and flavonoids. Non-toxic dose of the extract (TP-E and CTP-E) was chosen based on 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Effect of TP-E and CTP-E on lipopolysaccharides-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression was measured by Western blot and quantitative PCR (qRT-PCR). Expression of inflammatory cytokines, such as interleukins (IL-113 and IL-6) and tumor necrosis factor alpha (TNF-alpha), was quantified using qRT-PCR. Mitogen-activated protein kinase pathway was analyzed using Western blot. RESULTS: Phytochemical analysis revealed that both TP-E and CTP-E have strong antioxidant activities and high flavonoid and phenolic contents. TP-E and CTP-E effectively inhibit the expression of iNOS and COX-2, thereby inhibiting its downstream pro inflammatory regulators, the extracellular signal -related kinase-1/2, that decreases the expression of IL-113, IL-6 and TNF-alpha. CONCLUSION: Phytochemical constituents present in Typha angustifolia Linn could be used for treating inflammation-related diseases. (c) 2021 JTCM. All rights reserved.

Automated summary

The study evaluated the immune modulatory response of Puhuang, showing that its extracts have inhibitory effects on inflammatory activity of macrophage cells and work by inhibiting the expression of inflammatory regulators. The phytochemical constituents present in Typha angustifolia Linn exhibit strong antioxidant activities and high levels of flavonoids and phenolic contents.