Smooth muscle relaxing compounds from Dodonaea viscosa

Area of Science:

• Pharmacology
• Natural Products Chemistry

Background:

• Dodonaea viscosa (Sapindaceae) is traditionally used as an antispasmodic agent.
• Investigating the plant's bioactive constituents is crucial for validating its medicinal applications.

Purpose of the Study:

• To isolate and identify spasmolytic compounds from Dodonaea viscosa.
• To elucidate the mechanism of action of the isolated compounds on smooth muscle contractions.

Main Methods:

• Bioassay-directed fractionation of a chloroform-methanol extract of Dodonaea viscosa.
• In vitro assays using guinea-pig ileum and rat uterus preparations to assess spasmolytic activity.
• Evaluation of compound effects on spontaneous, electrically-induced, and agonist-induced contractions, as well as Ca2+ influx.

Main Results:

• Four spasmolytic compounds were isolated: sakuranetin (1), 6-hydroxykaempferyl 3,7-dimethyl ether (2), hautrivaic acid (3), and ent-15,16-epoxy-9 alpha H-labda-13(16)14-diene-3 beta, 8 alpha-diol (4).
• Sakuranetin and the ent-labdane derivative demonstrated significant inhibition of guinea-pig ileum contractions induced by acetylcholine, histamine, and barium chloride.
• Both sakuranetin and the ent-labdane relaxed rat uterus contractions induced by Ca2+, indicating interference with calcium metabolism in smooth muscle cells.

Conclusions:

• Sakuranetin and ent-15,16-epoxy-9 alpha H-labda-13(16)14-diene-3 beta, 8 alpha-diol possess potent spasmolytic activity.
• The mechanism involves interference with calcium ion influx into smooth muscle cells.
• These findings provide a scientific basis for the ethnopharmacological use of Dodonaea viscosa as an antispasmodic remedy.