Antinociceptive activity of Quillaja saponaria Mol. saponin extract, quillaic acid and derivatives in mice

Ethnopharmacological relevance: Quillaja saponaria bark contains a high percentage of triterpene saponins and has been used for centuries as a cleansing and analgesic agent in Chilean folk medicine.

Aim of the study: The topical and systemic analgesic effects of a commercial partially purified saponin extract, 3β,16α-dihydroxy-23-oxoolean-12-en-28-oic acid (quillaic acid), methyl 3β,16α-dihydroxy-23-oxoolean-12-en-28-oate and methyl 4-nor-3,16-dioxoolean-12-en-28-oate.

Materials and methods: The samples were assessed in mice using the topical tail-flick and i.p. hot-plate tests, respectively.

Results: All the samples showed activity in both analgesic tests in a dose-dependent manner. The most active against tail flick test was commercial partially purified saponin extract (EC50 27.9 mg%, w/v) and more than the ibuprofen sodium. On hot-plate test, methyl 4-nor-3, 16-dioxoolean-12-en-28-oate was the most active (ED50 12.2 mg/kg) and more than the ibuprofen sodium.

Conclusions: The results of the present study demonstrated that Quillaja saponaria saponins, quillaic acid, its methyl ester, and one of the oxidized derivatives of the latter, elicit dose-dependent antinociceptive effects in two murine thermal models.