Exploration of molecular interactions responsible for anti-inflammatory attributes of GI friendly micro-sized formulation of flurbiprofen and clove oil.

Clove oil obtained from Syzygium aromaticum (L.) is traditionally employed to treat inflammation associated with rheumatism, gastric disorders, and as an analgesic. Chemo-herbal combinations are known to have potent anti-inflammatory and analgesic effects, while mitigating the drug related side effects. The purpose of this study was to evaluate anti-inflammatory, analgesic and antipyretic effects of a combination of flurbiprofen and clove oil in a micro-emulsion (FCM) form using various in vivo models. Micro-emulsion of flurbiprofen and clove oil (FCM) was prepared following reported protocols and three different dose combinations (25, 12.5 and 6.25 mg/kg) were evaluated in carrageenan and histamine-induced acute inflammation, CFA-induced arthritis, yeast-induced pyrexia, and acetic acid-induced writhing models. qPCR studies were conducted to explore the possible mechanism of action. GC-MS of clove oil was performed to explore its chemical composition. FCM 25 mg/kg treated group exhibited significantly better (p < 0.05) effects compared to clove oil (CM) and flurbiprofen (FBR) (25 mg/kg) treated groups in both acute and chronic models. Histopathological study of joints showed a reduction in infiltration of inflammatory cells, bone erosion, and tissue oedema in FCM (25 mg/kg) treated group as compared to other treatment groups. Significant up-regulation in mRNA expression of anti-inflammatory (IL-4, IL-10) and down-regulation of pro-inflammatory genes (NF-κB, IL-6, TNF-α, IL-1β and COX-2) was observed in all the FCM-treated groups but, 25 mg/kg-treated group showed comparatively better results. Gross macroscopic examination of stomach sections also showed relatively less deleterious effects of test treatments (CM and FCM) as compared with FBR treated group. Serum levels of liver enzymes (alanine aminotransferase (ALT), and alkaline phosphatase (ALP)), blood urea nitrogen (BUN) and creatinine were also found to be normal as compared to FBR and tween-water (TW) treated groups. GC-MS of clove oil revealed that it was rich in eugenol contents.  This study reveals that a combination of flurbiprofen and clove oil in a micro-emulsion form could be a promising approach to enhance therapeutic actions and to mitigate synthetic drugs related side effects in clinical settings. It might implicate a synergistic action on the modulation of inflammatory genes expression. Further research is warranted to explore the full potential of this combination in treating various inflammatory conditions.