title: Pain Modulation by Lignans (Phyllanthin and Hypophyllanthin) and Tannin (Corilagin) Rich Extracts of Phyllanthus amarus in Carrageenan-induced Thermal and Mechanical Chronic Muscle Hyperalgesia.
abstract: The current study was aimed at evaluating the antihyperalgesic effects of lignans (phyllanthin and hypophyllanthin) and tannin (corilagin) rich three standardized extracts of Phyllanthus amarus in a model of chronic musculoskeletal inflammatory pain. Three percent carrageenan injected in the gastrocnemius muscle produced hyperalgesia to mechanical and heat stimuli ipsilaterally, which spreads to the contralateral side within 7 to 9 days. To investigate the effects on chronic thermal and mechanical hypersensitivity, three extracts of P. amarus in three doses (100, 200, and 400 mg/kg) were administered to animals intraperitoneally from 14th day to 22nd day after intramuscular injection of carrageenan. It was observed that intraperitoneal administrations of Phyllanthus extracts showed antihyperalgesic activity, as they elevated thermal and mechanical threshold, which was supported by histopathological observations along with reduction in prostaglandin E2 (PGE2) concentration. In conclusion, we strongly suggest that the observed antihyperalgesic and antiinflammatory effects of P. amarus in current pain model are mediated via spinal or supraspinal neuronal mechanisms, mainly by inhibition of PGE2. Modulation of chronic muscular inflammation may be due to presence of phytoconstituents like phyllanthin, hypophyllanthin, and corilagin, which offers a promising means for treatment of chronic muscle pain.
authors.affiliation: Department of Pharmacology, Rajarambapu College of Pharmacy, Kasegaon, 415404, Maharashtra, India.|Department of Pharmacognosy and Pharmacology, Government College of Pharmacy, Karad, 41512, Maharashtra, India.
authors.forename: Atul R
authors.initials: AR
authors.lastname: Chopade
authors.affiliation: Department of Pharmacognosy and Pharmacology, Government College of Pharmacy, Karad, 41512, Maharashtra, India.
authors.forename: F J
authors.initials: FJ
authors.lastname: Sayyad
mesh_terms: D000818:Animals; D002351:Carrageenan / Q000009:adverse effects; D015232:Dinoprostone / Q000737:chemistry; D004195:Disease Models, Animal; D005960:Glucosides / Q000494:pharmacology*; D047348:Hydrolyzable Tannins / Q000494:pharmacology*; D006930:Hyperalgesia / Q000188:drug therapy*; D007249:Inflammation / Q000188:drug therapy; D017705:Lignans / Q000494:pharmacology*; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000473:pathology; D059352:Musculoskeletal Pain / Q000188:drug therapy*; D010146:Pain / Q000188:drug therapy*; D029803:Phyllanthus / Q000737:chemistry*; D017208:Rats, Wistar
chemical_list: D005960:Glucosides; D047348:Hydrolyzable Tannins; D017705:Lignans; C512682:hypophyllanthin; C049096:corilagin; C517985:phyllanthin; D002351:Carrageenan; D015232:Dinoprostone
keywords: Phyllanthus amarus; carrageenan; chronic; muscle and hyperalgesia