Isolation of embelin from embeliaribes berries for the development of topical anti–inflammatory preparation

Abstract

Purpose: Embelin is a natural benzoquinone compound, isolated from Embeliaribes berries, known extensively for its anti-inflammatory properties. Due to its hydrophobic nature, it was less explored for topical preparation. Therefore, the purpose of this study was to explore the potential of embelin as an anti-inflammatory agent for topical preparations as well as assess its potential to replace synthetic drugs, which can be resistant to bacterial strains. A topical preparation with embelin would be potentially more effective as well as safer than synthetic drugs. Method: Embelin has been converted into its potassium salt, and a cream was developed, which was then subjected to physiochemical evaluation. The isolated Embelin and Embelin Potassium salts were characterised by various spectral analysis. The in vitro anti-inflammatory activity was determined by the heat-induced hemolysis and albumin denaturation. Docking scores of embelin and diclofenac were compared and the drug content per gram of cream was estimated. Result: The UV spectral absorption peak of Embelin  was determined to be at 274 nm, while that of the potassium salt of Embelin was at 515 nm.. The IR  bands were found at 1328.951cm-1,361.74 cm-1, 1616.35 cm -1,1616.35 cm -1 ,1452.4 cm -1, 748.28 cm -1  and 2947.23 cm -1  respectively due to phenolic OH bending, C=O stretching, aromatic ring bending, methylene bending and methyl stretching  . The IR spectra of Embelin potassium salt exhibited similar pattern as that of Embelin but with shifted band due to presence of potassium salt. Heat-induced hemolysis  using diclofenac as standard and embelin potassium salt as test showed  98.01% inhibition and 92% inhibition, respectively, at50µg/ml. The  binding affinity of diclofenac was determined to be -4.9, while the binding affinity of embelin was -5.7, indicating a higher affinity for embelin. Lastly, the drug content per gram of cream was found to be 95%, indicating the amount of active drug (embelin or embelin potassium salt) present in the cream formulation. Conclusion: Embelin was isolated from Embeliaribes berries and formulated into a herbal cream. The in-vitro studies conducted on the cream showed that it has a significant effect on inflammation . However, in–vivo studies are required for the prepared topical cream to confirm its effectiveness.