Adulterant profile of illicit street heroin and reduction of its precipitated physical dependence withdrawal syndrome by extracts of St John's wort (Hypericum perforatum).

The study evaluated the adulterants in a specimen of illicit street heroin supplied under strict control by the Pakistan Anti-Narcotic Force. It also examined the effects of Hypericum perforatum L. extracts on the naloxone-induced heroin withdrawal syndrome. The GC-MS analysis of the specimen showed that in addition to heroin (37.8%), the sample also contained caffeine (8.4%), phenobarbitone (12.7%), 6-acetyl codeine (5.3%), 6-acetyl morphine (10.9%) and noscapine (15.8%). Administration of the heroin to rats for 8 days induced physical withdrawal signs of abdominal constriction, diarrhoea and vocalization on touch after naloxone treatment. Aqueous Hypericum perforatum extracts (20 mg/kg twice daily chronically or as a single acute dose 90 min before naloxone) given orally to the heroin dependent rats attenuated abdominal constrictions both acutely and chronically while the hydroethanol and ethanol extracts were only effective in acutely treated animals. Diarrhoea was ameliorated by the hydroethanol and ethanol extracts following acute or chronic heroin treatment while the aqueous extract failed to show any effect. Vocalization on touch during withdrawal was reduced by all the extracts either chronically or acutely with the exception of chronic treatment with hydroethanol extracts. The findings suggest that Hypericum perforatum is capable of reducing the physical signs of opiate withdrawal.