Anti-hepatotoxic activity of extracts and constituents of Buddleja species

The aqueous extracts of three species of Buddleja which are used in traditional medicine for the treatment of liver ailments have shown an inhibitory effect against induced cytotoxicity of cultured hepatocytes. Fractionation of one of these extracts, from B. globosa leaves, resulted in the isolation of five iridoids, two phenylpropide glycosides, and a flavonoid glycoside. Two of the iridoids were found to be novel compounds, 7-p-methoxycinnamoylaucubin (1) and 7-p-methoxycinnamoylcatalposide (2). One of the phenylpropides, echinacoside, has not previously been reported from Buddleja. Testing of the isolated compounds in the cultured hepatocyte system indicated that the activity is most likely due to the flavonoid and phenylpropide constituents. Phenylpropide glycosides have not previously been shown to have a liver-protectant effect.