Analgesic, Anti-inflammatory and Other Pharmacological Activities of Methanol Extract of Rhododendron campanulatum from Nepal

Aims: Rhododendron campanulatum D. Don is a plant of Ericaceae family that is found at an altitude of 3000-4200 meters. Traditionally, it has been used to cure rheumatism, hemicranias, sciatica and colds. This study aims to determine analgesic and anti-inflammatory activities and effect on gastrointestinal motility, brain function and skeletal muscle of Rhododendern campanulatum extracts in mice.

Methodology: Pharmacological activities were evaluated in mice. Analgesic activity was determined by hot plate and chemical writhing methods; anti-inflammatory activity by ability to cure carrageenan induced paw edema; effect on gastrointestinal motility by charcoal meal assay, effect on brain function by locomotor activity and skeletal muscle relaxant activity by traction test.

Results: Methanol extract from R. campanulatum increased the response time of mice from 6 secs to 20 secs in hot plate assay and reduced the stretching episodes from 49 to 14 in acetic acid induced writhing tests revealing its analgesic activity. The extract at a dose of 200 mg kg-1 inhibited carrageenan induced paw edema by 66.66% and reduced the gastrointestinal motility to 51.66%. The methanol extract inhibited locomotor activity and grasping power of mice suggesting its central nervous system depressant and skeletal muscle relaxant activities respectively.

Conclusion: The present study shows that Rhododendron campanulatum has analgesic, anti-inflammatory, anti-motility, central nervous system depressant and muscle relaxant properties. These results suggest that R. campanulatum could be a source for potential drug formulation.