Muscle relaxant and antipyretic effects of pentacyclic triterpenes isolated from the roots of Diospyros lotus L.

The present article describes the muscle relaxant and antipyretic effects of pentacyclic triterpenes, oleanolic acid (OA), ursolic acid (UA) and betulinic acid (BA) isolated from roots of Diospyros lotus in animal models. The muscle relaxant effects of isolated pentacyclic triterpenes were determined by chimney and inclined plane tests. In the chimney test, pretreatment of pentacyclic triterpenes evoked significant dose dependent influence on muscle coordination. When administered intraperitoneally (i.p.) to mice at 10 mg/kg for 90 minutes, OA, UA, and BA exhibited muscle relaxant effects of 66.72%, 60.21%, and 50.77%, respectively. Similarly, OA, UA, and BA (at 10 mg/kg) illustrated 65.74%, 59.84% and 51.40% muscle relaxant effects in the inclined plane test. In the antipyretic test, significant amelioration was caused by pretreatment of all compounds in dose dependent manner. OA, UA, and BA (at 5 mg/kg) showed 39.32%, 34.32% and 29.99% anti-hyperthermic effects, respectively 4 h post-treatment, while at 10mg/kg, OA, UA, and BA exhibited 71.59%, 60.99% and 52.44% impact, respectively. The muscle relaxant effect of benzodiazepines is well known for enhancement of GABA receptors. There may exist a similar mechanism for muscle relaxant effect of pentacyclic triterpenes. The in-silico predicted binding pattern of all the compounds reflects good affinity of compounds with GABAA receptor and COX-2. These results indicate that the muscle relaxant and antipyretic activities of these molecules can be further improved by structural optimization.