Ocimum gratissimum Linn. Leaf extract inhibits free radical generation and suppressed inflammation in carrageenan-induced inflammation models in rats.
BACKGROUND
Ocimum gratissimum leaf is used in managing rheumatism and other inflammatory conditions. In this study, we investigated the antioxidant and anti-inflammatory effects of phenolic extract obtained by sequential methanol extraction of O. gratissimum leaves (MEOg).


METHODS
The methanol extract (MEOg) was obtained after sequential maceration (n-hexane, chloroform and methanol) of dried O. gratissimum leaves. The fingerprint of the extract was obtained using a high-performance liquid chromatrographic method. In vitro effects were tested by 1,1-Diphenyl-2-picryl-hydrazyl (DPPH), nitric oxide (NO) free radical scavenging, lipoxygenase, and xanthine oxidase inhibitory assays. MEOg was studied for anti-inflammatory activity in carrageenan-induced paw edema and air pouch inflammation in rats.


RESULTS
HPLC fingerprint of the extract shows the presence of caffeic acid, rutin, ferulic acid, apigenin, and quercetin. Antioxidant activity of MEOg revealed an IC50 value in DPPH (31.5±0.03 μg/mL) and NO assay (201.6±0.01 μg/mL), respectively. The extract demonstrated strong xanthine oxidase inhibitory and weak antilipoxygenase activities. MEOg (100 mg/kg) significantly inhibited carrageenan-induced paw edema by 43.2%. Furthermore, MEOg (50 and 100 mg/kg) significantly reduced exudate volume, leucocyte count, neutrophil infiltration, TNF-α, nitrites, myeloperoxidase, and malondialdehyde in carrageenan-induced air pouch inflammation. MEOg also elevated the glutathione levels in the inflammatory exudates.


CONCLUSIONS
MEOg shows potential therapeutic benefits in slowing down inflammation and oxidative stress in chronic diseases, such as arthritis.
.
Abayomi M
AM
Ajayi
.
Mary O
MO
Ologe
.
Benneth
B
Ben-Azu
.
Samuel E
SE
Okhale
.
Bulus
B
Adzu
.
Olusegun G
OG
Ademowo
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D002351:Carrageenan; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004487:Edema / Q000517:prevention & control*; D005609:Free Radicals / Q000378:metabolism*; D007249:Inflammation / Q000517:prevention & control*; D008297:Male; D000432:Methanol / Q000737:chemistry; D031339:Ocimum / Q000737:chemistry*; D019800:Phenol; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D051381:Rats
D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D005609:Free Radicals; D010936:Plant Extracts; D019800:Phenol; D002351:Carrageenan; D000432:Methanol
anti-inflammatory; antioxidant; apigenin; carrageenan; phenolic; xanthine oxidase