Investigating the anti-inflammatory and analgesic properties of leaves ethanolic extracts of Cedrus libani and Pinus brutia

Abstract

This investigation aimed to assess the anti-inflammatory and analgesic effects of Cedrus libani and Pinus brutia leaves. The anti-inflammatory property was evaluated by Human Red Blood Cells (HRBC) membrane stabilization assay and Albumin denaturation assay using Sodium diclofenac as a positive control. To evaluate the analgesic property, formalin and tail flick tests were carried out using ethanolic extracts at a dose of 30 mg/kg and gel containing 2% (w/v) of ethanolic extract of each plant. Diclofenac sodium, diclofenac gel 1% and lidocaine gel 2 % were used as positive controls. Results: The effect of inhibiting hemolysis was observed at concentrations (2.5–12.5) μg/ml for P. brutia, and (2.5–25) μg/ml for C. libani. Moreover, albumin denaturation test showed protection effect for both plant extracts with IC50 of 47.74 and 81.50 μg/ml for C. libani and P. brutia extract, consecutively. In Formalin test, both extracts could significantly reduce paw licking time, and in tail flick test, each plant extract gel showed greater efficacy than diclofenac gel by calculating the maximum possible effect (MPE %) for both extracts and Diclofenac. Conclusion: We concluded that both extracts showed in vitro anti-inflammatory activity at different concentrations when compared to standard drug of diclofenac as well as analgesic activity in formalin and tail flick tests.

Keywords

• HRBC test
• Albumin denaturation assay
• Formalin test
• Tail flick
• Albino rats
• Cedrus libani