Pharmacological Aspects of Phyllanthus fraternus Standardized Extract (Rich in Lignans and Tannins) as a Pain Modulator

Background: The standardized extracts of P. fraternus were previously reported by us for its anti-inflammatory, analgesic, and anti-arthritic biological potentials. However, we have not reported for a consequence of P. fraternus on chronic inflammatory muscle hyperalgesia. Herein, we have demonstrated chronic pain modulating effect of standardized extracts of P. fraternus. Materials and Methods: Firstly, we have collected various parts of P. fraternus plant including the dried stems, leaves, and roots. In order to produce chronic inflammations, we further allowed injection to the left gastrocnemius muscle belly of rats with a freshly prepared solution of 3% carrageenan in normal saline (100µL). Thermal/heat hyperalgesia, mechanical hyperalgesia and muscle circumferences were determined in the current experimental model. In order to estimate, chronic pain modulating potential of P. fraternus, we have also studied histopathological studies and measurement of prostaglandin E-2 (PGE2). Results: After administration of 3% carrageenan intramuscular injection, we investigated the chronic thermal and mechanical hypersensitivity of aforementioned test sample i.e. standardized extracts of P. fraternus in terms of adopting 2 gradual dosings of 200 and 400 mg/kg (administered intraperitoneally) from day 14th to 22nd. From our study, we observed significant antihyperalgesic activity; when we allowed administering standardized extracts of P. fraternus intraperitoneally. Conclusion: To conclude, we have investigated the antihyperalgesic and anti-inflammatory potentials of standardized extracts of P. fraternus. These effects might be having mediation via supraspinal or spinal neuronal mechanisms, and mainly observed due to evidence of PGE2 inhibitions.