Anti-inflammatory effect of Streblus asper leaf extract in rats and its modulation on inflammation-associated genes expression in RAW 264.7 macrophage cells.
OBJECTIVE
Streblus asper is a medicinal plant from Thailand used in folk medicine for the treatment of several inflammatory diseases. In this study, we investigated the anti-inflammatory effect of Streblus asper leaf ethanolic extract (SAE).


METHODS
The experimental carrageenan-induced paw edema in rats was performed in which the SAE at doses of 125, 250, 500 mg/kg body weight was intraperitoneally administered to the rats. Then, reverse transcriptive polymerase chain reaction (RT-PCR) technique was also performed to determine the effect of SAE on the expression of inflammation-associated genes in RAW 264.7 macrophage cells stimulated with lipopolysaccharide (LPS).


RESULTS
The SAE at all given doses caused a significant dose-dependent inhibition of edema (p<0.05). Moreover, the significant and dose-dependent LPS-induced cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) mRNA expressions were demonstrated in RAW 264.7 cells treated with SAE. The inhibition is selective, since COX-1 mRNA expression did not change in the presence of SAE.


CONCLUSIONS
The results of this study are the first scientific evidence on the molecular effects of Streblus asper as a potential anti-inflammatory agent, which supports the fact that the plant is employed in traditional remedies.
Center for Research and Development of Herbal Health Products, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002 Thailand. bungorn@kku.ac.th
Bungorn
B
Sripanidkulchai
Jintana
J
Junlatat
Nawarat
N
Wara-aswapati
Doosadee
D
Hormdee
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D002351:Carrageenan; D002470:Cell Survival / Q000187:drug effects; D051545:Cyclooxygenase 1 / Q000096:biosynthesis; D051546:Cyclooxygenase 2 / Q000096:biosynthesis; D004487:Edema / Q000473:pathology / Q000517:prevention & control; D015870:Gene Expression / Q000187:drug effects; D007249:Inflammation / Q000235:genetics*; D008070:Lipopolysaccharides; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D051379:Mice; D029586:Moraceae / Q000737:chemistry*; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors; D010936:Plant Extracts / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000894:Anti-Inflammatory Agents, Non-Steroidal; D008070:Lipopolysaccharides; D010936:Plant Extracts; D012333:RNA, Messenger; D002351:Carrageenan; D052247:Nitric Oxide Synthase Type II; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2