Assessment of Comparative COX-1 and COX-2 Inhibition Efficacy of Ehretia Laevis Roxb. (Khandu Chakka/Ajan Vruksha) Leaves versus Diclofenac Sodium: An In-vitro Study

Introduction: Pain is a significant problem globally. Ehretia laevis Roxb has pain-relief and anti-inflammatory properties. Cyclooxygenase (COX) is responsible for the production of prostaglandins, which control pain and inflammation. Nonsteroidal anti-inflammatory drugs (NSAIDs) reduce pain and inflammation by acting on COX. Aim: To assess the comparative COX-1 and COX-2 inhibition efficacy of Ehretia laevis Roxb leaves versus diclofenac sodium. Materials and Methods: This study is an analytical, experimental in-vitro study. Which was performed at Sciore Research Private Limited and affiliated with Bajaj College of Science, Wardha, and Mahatma Gandhi Ayurved College, Hospital, and Research Centre at Datta Meghe Institute of Higher Education and Research, Wardha, Maharashtra, India from May 2023 to June 2023. The study was performed according to the manufacturer’s protocol from Cayman Chemical (item No: 701070) and the standard operating procedures of the test facility. For in-vitro processing, Ehretia laevis Roxb powder was mixed with a 10% Dimethyl Sulfoxide (DMSO) solution to obtain a concentration of 1 mg/mL and filtered. All assays were performed in triplicate. GraphPad Prism (Version 8.4.2) was used to calculate the IC50 values by plotting log (inhibitor) vs. normalised response/variable slope. Results: Diclofenac sodium was a significantly more potent inhibitor of both COX-1 and COX-2 enzymes compared to Ehretia laevis Roxb powder. To achieve 50% inhibition of COX-1, diclofenac sodium required only 59.49 nanograms per milliliter (ng/mL), whereas Ehretia laevis Roxb powder needed a significantly higher dose of 301.6 micrograms per milliliter (µg/ mL). This indicates that diclofenac sodium is roughly five times more potent for COX-1 inhibition. Similarly, for COX-2 inhibition, diclofenac sodium had an IC50 value of 14.23 ng/mL, while Ehretia laevis Roxb powder had an IC50 value of 245.0 µg/mL, indicating that diclofenac sodium is approximately 17 times more potent for COX-2 inhibition. Overall, the data suggested that diclofenac sodium has a stronger and more selective inhibitory effect on both COX-1 and COX-2 enzymes compared to Ehretia laevis Roxb powder. Conclusion: The IC50 values for diclofenac sodium for COX-1 inhibition is 59.49 ng/mL and for COX-2 inhibition is 14.23 ng/ mL. The IC50 value for Ehretia laevis Roxb for COX-1 inhibition is 301.6 µg/mL and for COX-2 inhibition is 245.0 µg/mL. Various extracts of Ehretia laevis Roxb should be tested further for their COX inhibition activities.