Ocimum gratissimum L. leaf flavonoid-rich fraction suppress LPS-induced inflammatory response in RAW 264.7 macrophages and peritonitis in mice.

Abstract

ETHNOPHARMACOLOGICAL RELEVANCE:

Ocimum gratissimum L. is a herbaceous plant that has been reported in several ethnopharmacological surveys as a plant readily accessible to the communities and widely used for the treatment of inflammatory diseases. The main goal of this study was to investigate the in vitro and in vivo anti-inflammatory activity and mechanism of action of the ethylacetate fraction of O. gratissimum leaf (EAFOg) and to chemically characterize this fraction.

MATERIALS AND METHODS:

EAFOg was obtained from a sequential methanol extract. The safety profile was evaluated on RAW 264.7 cells, using the alamarBlue® assay. Phenolic contents were determined by spectrophotometry, and metabolites quantified by high performance liquid chromatography. The anti-inflammatory activity of EAFOg and its ability to acts on leucocytes infiltration, inflammatory mediators as NO, IL-1β, TNF-α, and IL-10 in lipopolysaccharide-induced peritonitis in mice and LPS-stimulated RAW 264.7 macrophage were evaluated. In addition, the anti-inflammatory activity of EAFOg was also investigated in arachidonic acid-related enzymes.

RESULTS:

Total phenolic and flavonoid contents of EAFOg were 139.76±1.07mg GAE/g and 109.95±0.05mg RE/g respectively. HPLC analysis revealed the presence of rutin, ellagic acid, myricetin and morin. The fraction exhibited no cytotoxic effects on the RAW 264.7 cells. The EAFOg (10, 50 and 200mg/kg) significantly reduced (p<0.05) neutrophils (38.8%, 58.9%, and 66.5%) and monocytes (38.9%, 58.0% and 72.8%) in LPS-induced peritonitis. Also, EAFOg (5, 20 and 100µg/mL) produced significant reduction in NO, IL-1β, and TNF-α in RAW 264.7 cells. However, IL-10 level was not affected by the EAFOg, and it preferentially inhibits COX-2 (IC50 =48.86±0.02µg/mL) than COX-1 and 15-LO (IC50 >100µg/mL).

CONCLUSION:

The flavonoid-rich fraction of O. gratissimum leaves demonstrated anti-inflammatory activity via mechanisms that involves inhibition of leucocytes influx, NO, IL-1β, and TNF-α in vivo and in vitro, thus supporting its therapeutic potential in slowing down inflammatory processes in chronic diseases.

• Authors: Abayomi Mayowa Ajayi, Domingos Tabajara de Oliveira Martins, Sikiru Olaitan Balogun, Ruberlei Godinho de Oliveira, Sérgio Donizeti Ascêncio, Ilsamar Mendes Soares, Robson Dos Santos Barbosa, Olusegun George Ademowo
• Journal: Journal of ethnopharmacology (J Ethnopharmacol) Vol. 204 Pg. 169-178 (May 23 2017) ISSN: 1872-7573 [Electronic] Ireland
• PMID: 28400288 (Publication Type: Journal Article)
• Copyright: Copyright © 2017. Published by Elsevier B.V.

Chemical References

• Anti-Inflammatory Agents
• Cytokines
• Lipopolysaccharides
• Membrane Proteins
• Plant Extracts
• Nitric Oxide
• Ptgs2 protein, mouse
• Cyclooxygenase 1
• Cyclooxygenase 2
• Ptgs1 protein, mouse

Topics

• Animals
• Anti-Inflammatory Agents (pharmacology, therapeutic use)
• Ascitic Fluid (metabolism)
• Cell Survival (drug effects)
• Cyclooxygenase 1 (metabolism)
• Cyclooxygenase 2 (metabolism)
• Cytokines (metabolism)
• Female
• Lipopolysaccharides
• Macrophages (drug effects)
• Membrane Proteins (metabolism)
• Mice
• Nitric Oxide (metabolism)
• Ocimum
• Peritoneal Lavage
• Peritonitis (drug therapy, metabolism)
• Phytotherapy
• Plant Extracts (pharmacology, therapeutic use)
• Plant Leaves
• RAW 264.7 Cells