Peels of Citrus Fruits: A Potential Source of Anti-inflammatory and Anti-nociceptive Agents

Introduction: The present study was contemplated to evaluate the anti-inflammatory and analgesic potentials in peels of some commercially grown Citrus fruits of South India viz, Lime (Citrus aurantifolia), Orange (Citrus reticulata), Sour Orange (Citrus aurantium), Pomello (Citrus grandis) and Citron (Citrus medica). Methods: The peel of the fruits were separated and subjected to cold extraction using 70% alcohol. The extracts obtained were screened for the presence of phytoconstituents by qualitative phytochemical analysis; the anti-inflammatory activity of extracts at 250 and 500mg/Kg body weight concentrations were assessed by in vivo Carrageenan induced rat paw edema model and in vitro HRBC membrane stabilization assay whereas Tail immersion and Hot plate methods have been used to evaluate their analgesic property. Results: The results revealed that, all extracts treated animals have shown significant decrease in paw edema volume at 3^rd and 4^th hour of treatment and increase in reaction time in tail immersion and hot plate readings at 120 and 150 min and are comparable to the standards. From the results it was evident that Citron peel extract exhibited significant antiinflammatory and analgesic property in all models. Preliminary phytochemical investigation revealed that extracts were bestowed with presence of flavonoids, terpenoids, steroids, glycosides, alkaloids, carotenoids and phenolic compounds which might be responsible for the antinociceptive and anti-inflammatory activities. Conclusion: From the results it was evident that all citrus fruits have prominent activity in terms of parameters assessed in a dose dependent manner and are more effective in the later phase. The study thus documents that Citrus peels are good sources of anti-inflammatory and anti-nociceptive agents.