Molecular mechanism of anti-inflammatory activity of Pluchea indica leaves in macrophages RAW 264.7 and its action in animal models ofinflammation.
BACKGROUND
PLUCHEA INDICA LESS.: (Asteraceae) is a Thai medicinal plant used in traditional medicine for the treatment of hemorrhoids, lumbago, leucorrhoea and inflammation. This study investigated the molecular mechanism of anti-inflammatory activity of Pluchea indica leaf extract in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and also determined its action in acute inflammation animal models.


METHODS
The inhibitory effect of Pluchea indica leaf extract on LPS-induced nitric oxide (NO) production was evaluated by Griess reaction. Protein and mRNA expressions were determined by real time RT-PCR and Western blotting analysis, respectively. Inducible nitric oxide synthase (iNOS) promoter activity was evaluated by iNOS promoter based reporter gene assay. In vivo anti-inflammatory effect was examined in ethylphenylpropiolate (EPP)-induced ear edema and carrageenan-induced paw edema in rat models.


RESULTS
Ethyl acetate fraction of ethanol extract of Pluchea indica leaves (EFPI) exhibited the potent inhibitory effect on NO production in LPS-induced macrophages and also inhibited PGE2 release. EFPI reduced iNOS mRNA and protein expression through suppressed iNOS promoter activity and nuclear translocation of subunit p65 of nuclear factor-κB, but did not inhibit phosphorylation of the mitogen-activated protein kinases (MAPKs). Moreover, EFPI possessed anti-inflammatory activities on acute phase of inflammation as seen in EPP-induced ear edema and carrageenan-induced paw edema inrats.


CONCLUSIONS
These data support the pharmacological basis of Pluchea indica plant as a traditional herbal medicine for treatment of inflammation.
Biological Science Program, Faculty of Science, Burapha University, Saensook, Muang, Chonburi 20131, Thailand.
Doungnapa
D
Buapool
Nadtaya
N
Mongkol
Jirapa
J
Chantimal
Sittiruk
S
Roytrakul
Ekaruth
E
Srisook
Kloakwan
K
Srisook
D000480:Alkynes; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology / Q000627:therapeutic use*; D019659:Asteraceae; D002351:Carrageenan; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D015232:Dinoprostone / Q000378:metabolism; D004195:Disease Models, Animal; D004487:Edema / Q000139:chemically induced / Q000188:drug therapy*; D007249:Inflammation / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism; D008070:Lipopolysaccharides; D008264:Macrophages; D008297:Male; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D018515:Plant Leaves; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D000480:Alkynes; D000893:Anti-Inflammatory Agents; D008070:Lipopolysaccharides; D009573:Nitrites; D010936:Plant Extracts; D012333:RNA, Messenger; C015202:ethylphenylpropiolate; D002351:Carrageenan; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D020928:Mitogen-Activated Protein Kinases; D015232:Dinoprostone