Methanolic Extract of Leathery Murdah, Terminalia coriacea (Roxb.) Wight and Arn. Leaves Exhibits Anti-Inflammatory Activity in Acute and Chronic Models.

OBJECTIVE: The aim of the present study was to evaluate anti-inflammatory activity of methanolic extract of Terminalia coriacea. MATERIALS AND METHODS: A methanolic extract of T. coriacea leaves was studied in albino Wistar rats with carrageenan-induced paw edema, an acute model, and cotton pellet-induced granuloma, a chronic model, at 3 oral test doses (125, 250, and 500 mg/kg). Aspirin 100 mg/kg was used as a positive control. Paw volume and wet and dry weights of cotton pellets were determined. The data were analyzed by one-way ANOVA followed by Dunnett's multiple comparison test. RESULTS: The test extract at doses of 125 and 250 mg/kg decreased paw volume and wet and dry weights of cotton pellets. The highest test dose (500 mg/kg) displayed a response comparable to that of the standard drug (p < 0.01) on paw volume. The extract produced similar (p < 0.05) decrease in wet weight of the cotton pellet at 125 and 250 mg/kg, whereas the effect of 500 mg/kg of the extract was comparable to that of aspirin 100 mg/kg (p < 0.01). The extract of T. coriacea at 500 mg/kg induced the most significant (p < 0.01) effect on wet weight of granulomatous tissue. CONCLUSION: The methanolic extract of T. coriacea leaves successfully decreased paw edema as well as dry and wet weights of granulomatous tissue in both acute and chronic inflammatory models thus confirming the anti- edematogenic, antitransudative, and antiproliferative properties of T. coriacea.

Anti-nociceptive mechanisms of flavonoids-rich methanolic extract from Terminalia coriacea (Roxb.) Wight & Arn. leaves.

In view of the report on anti-nociceptive activity of Leathery Murdah, Terminalia coriacea {Roxb.} Wight & Arn. (Combretaceae) leaves, the present study was conducted to isolate the active constituents and identify the underlying mechanisms. The methanolic extract of T. coriacea leaves (TCLME) at doses 125, 250 and 500 mg/kg orally, was subjected to various in-vivo assays in acetic acid induced writhing and formalin induced paw-licking tests with aspirin (100 mg/kg) and morphine (5 mg/kg) as reference drugs. Three flavonoids, rutin, robinin and gossypetin 3-glucuronide 8-glucoside were isolated and characterized from TCLME for the first time. The extract showed significant (p < 0.001) dose-dependent anti-nociceptive activity in glutamate induced paw licking in mice. The involvement of opioid pathway was confirmed as naloxone (5 mg/kg, i.p) treatment blocked the analgesic activity of the test extract. Similarly, glibenclamide (an ATP - sensitive potassium channel inhibitor) at dose of 10 mg/kg, i.p increased writhing in acetic acid model. It reversed the inhibitory effects of TCLME when administered in combination. Treatment of TCLME alone and in combination with l-arginine (100 mg/kg, i.p) significantly (p < 0.001) reduced writhing while pre-treatment with l-NAME (20 mg/kg, i.p) further enhanced the analgesic action of TCLME indicating involvement of nitric oxide pathway.