Evaluation of Anti-nociceptive and Anti-Inflammatory Effects of Markhamia tomentosa Cream Co-Formulated with Eucalyptus Oil

Abstract

Background: Pain is a noxious, sensory, and emotional experience due to intense stimuli. Pain is intimately linked with nociception. The clinical therapies available at the moment for pain are tricyclic antidepressants, non -steroidal anti-inflammatory drugs, and opioids. There is a need to develop and investigate safer alternatives that minimise the chances of psychological or physical drug dependence and drug dose tolerance. The purpose of this research is to develop an anti-inflammatory and anti-nociceptive formulation (Markhamia tomentosa cream co-formulated with Eucalyptus oil as a permeation enhancer) and evaluate its efficacy. Methods: In this study, Markhamia tomentosa was extracted from its leaves using maceration technique. A qualitative screening of the Markhamia tomentosa ethanolic extract (EEMT) was carried out. Five emulsions (A1-A5) containing varying compositions of Markhamia tomentosa were developed, and a negative control (an emulsion that did not contain Markhamia tomentosa or Eucalyptus oil) was also developed using fusion method. The anti-inflammatory and anti-nociceptive properties of the topical creams were evaluated using mice paw-licking and xylene-induced ear oedema tests. Diclofenac and aspirin administered at 20 mg/kg and 50mg/kg orally, respectively, were used as standards. All experiments were carried out in triplicates. Results: The phytochemical investigation of the Markhamia tomentosa extract showed a marked presence of key phyto-constituents such as saponins, flavonoids, alkaloids, and terpenoids. A1 and A2 had significantly higher percentage of nociception inhibition at phase I—neurogenic and phase II—inflammatory stages compared to Diclofenac 20 mg/kg. A1 and A3 had anti-inflammatory properties more potent than Aspirin 50mg/kg. In both tests, the negative controls did not show any level of potency. All results in this investigation were expressed as mean ± S.D (n=3) and (p<0.05) for all data sets. Formulation A1 had the highest concentration of EEMT. No rash, erythema, or oedema was observed in the Draize test implying that the formulations are safe for topical application. Conclusion: Markhamia tomentosa and eucalyptus oil cream showed potent anti-nociceptive and anti-inflammatory activity. Markhamia tomentosa cream co-formulated with Eucalyptus oil as a permeation enhancer can be used effectively as a non-opioid, anti-nociceptive, and anti-inflammatory cream topically for pain and its symptoms