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.
Sripanidkulchai
Bungorn
B
Center for Research and Development of Herbal Health Products, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002 Thailand. bungorn@kku.ac.th
Junlatat
Jintana
J
Wara-aswapati
Nawarat
N
Hormdee
Doosadee
D
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