Comparison of the anti-inflammatory and anti-nociceptive effects of three medicinal plants known as "Snow Lotus" herb in traditional Uighur and Tibetan medicines

Abstract

Ethnopharmacological relevance: Saussurea involucrata (Kar. et Kir.) Sch.-Bip. (Compositae) has long been used under the herbal name "Snow Lotus" for the treatment of rheumatoid arthritis, stomachache and dysmenorrhea in Uighur folk medicine. In traditional Tibetan medicine, Saussurea laniceps Hand.-Mazz. and Saussurea medusa Maxim. have also been used under the name "Snow Lotus" and prescribed for the treatment of pain and inflammatory conditions.

Aim of the study: The present study evaluated the pharmacological effects of three species of "Snow Lotus" in experimental inflammation and pain models, and determined the chemical compounds that may correlate with their pharmacological activities.

Materials and methods: The anti-inflammatory activities of the three herbs were observed by using carrageenan-induced paw edema in rats and xylene-induced ear edema in mice. Investigations on the analgesic effects were conducted, including acetic acid-induced writhing and hot-plate test. An UPLC-MS method was developed to analyze the chemical composition of the three herbs and of plasma samples after herb administration.

Results: In rat paw edema model, the peak inhibitory effects of Saussurea laniceps and Saussurea involucrata (55.1% and 42.2%, respectively) were recorded with the dose of 400mg/kg at 3h post-carrageenan injection. In mouse ear edema model, oral administration of Saussurea laniceps, Saussurea involucrata and Saussurea medusa extract (400mg/kg) resulted in a significant inhibition of ear edema by 40.9%, 33.3%, and 9.1%, respectively. In the writhing test, oral administration of Saussurea laniceps extract (100, 200 and 400mg/kg) resulted in a significant inhibition of writhings by 13.5%, 22.3%, and 43.5%, respectively. In the hot-plate test, Saussurea laniceps extract significantly increased the latency of jumping response by 38.2% and 52.7% when treated orally at 200 and 400mg/kg in mice, respectively. Flavonoids, coumarins and lignins were found to be present in plasma after administration of the extracts and may be the basis of the observed pharmacological effects.

Conclusion: The results clearly demonstrated that Saussurea laniceps was most effective; Saussurea involucrata exhibited a moderate potency, whereas Saussurea medusa possessed little effect against the experimental edema and pains. This study also supported discrimination among the three herbs when using them in folk medicine.