Anti-inflammatory effect of Mentha longifolia in lipopolysaccharide-stimulated macrophages: reduction of nitric oxide production through inhibition of inducible nitric oxide synthase.
Mentha longifolia is an aromatic plant used in flavoring and preserving foods and as an anti-inflammatory folk medicine remedy. The present study assessed the effects of M. longifolia extracts, including essential oil and crude methanol extract and its fractions (ethyl acetate, butanol and hexane), on nitric oxide (NO) production and inducible NO synthase (iNOS) mRNA expression in lipopolysaccharide (LPS)-stimulated J774A.1 cells using real-time polymerase chain reaction (PCR). The cytotoxic effects of the extracts on the cells were examined and non-cytotoxic concentrations (<0.2 mg/ml) were used to examine their effects on NO production and iNOS mRNA expression. Only the hexane fraction that contained high levels of phenolic and flavonoid compounds at concentrations from 0.05-0.20 mg/ml significantly reduced NO production in LPS-stimulated cells (p < 0.001). Real-time PCR analysis indicated the ability of this fraction at the same concentrations to significantly decrease iNOS as well as TNFα mRNA expression in the cells (p < 0.001). All extracts were able to scavenge NO radicals in a concentration-dependent manner. At concentrations greater than 0.2 mg/ml, total radicals were 100% scavenged. In conclusion, M. longifolia possibly reduces NO secretion in macrophages by scavenging NO and inhibiting iNOS mRNA expression, and also decreases TNFα pro-inflammatory cytokine expression, thus showing its usefulness in the inflammatory disease process.
Institute of Biotechnology, College of Agriculture, Shiraz University , Shiraz , and.
Parastoo
P
Karimian
Gholamreza
G
Kavoosi
Zahra
Z
Amirghofran
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D015536:Down-Regulation; D016166:Free Radical Scavengers / Q000008:administration & dosage*; D006801:Humans; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology; D027541:Mentha / Q000276:immunology*; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism*; D009822:Oils, Volatile / Q000008:administration & dosage*; D008517:Phytotherapy / Q000379:methods*; D010936:Plant Extracts / Q000008:administration & dosage*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
D000894:Anti-Inflammatory Agents, Non-Steroidal; D016166:Free Radical Scavengers; D009822:Oils, Volatile; D010936:Plant Extracts; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II