Bioactivity of neolignans from fructus Schizandrae.

Fructus Schizandrae sinensis Baill, a traditional Chinese medicine, used as tonic and sedative, has been shown at the beginning of 70's to lower the elevated serum glutamic-pyruvic transaminase (SGPT) levels of patients suffering from chronic viral hepatitis. During past 20 years, a series of neolignans have been isolated and identified as effective principles. Pharmacological studies revealed that they increased liver protein and glycogen synthesis, antagonized liver injuries from CCl4 and thioacetamide. The mechanism of SGPT lowering was considered as a hepato-protective and membrane stabilize action, although inhibition of the activity of liver GPT may also be existed. It was found that some principles of Schizandrae have an inducing effect on hepatic microsomal drug-metabolizing enzyme system P-450, thus explained their anti-toxic, anti-carcinogenic and anti-mutagenic effects. A synthetic derivative compound of Schisandrin called DDB has most of the above mentioned actions now used widely in China as a hepato-protective drug with high effectiveness in normalizing liver functions and very low side effects. From natural Schisandrin to synthesized DDB, pointed out a successful way in the development of new drugs from natural products.