Passive opium smoking does not have beneficial effect on plasma lipids and cardiovascular indices in hypercholesterolemic rabbits with ischemic and non-ischemic hearts

BackgroundTo scientifically test a traditionally belief of some Asian countries residents that opium may prevent or have ameliorating effects on cardiovascular diseases (CVD) we investigated the effect of passive opium smoking (POS) on plasma lipids and some cardiovascular parameters in hypercholesterolemic rabbits with ischemic and non-ischemic hearts.Methods40 rabbits were fed for 2 weeks with cholesterol-enriched diet and divided to control (CTL), short-term opium (SO) and long-term opium (LO) groups. SO and LO groups were exposed to POS for 3 days and 4 weeks respectively. ECG, blood pressure (BP) and left ventricular pressure recorded and serum lipid and cardiac troponin I levels were measured. Isoproterenol (ISO) injected for induction of cardiac ischemia and after 4 h the above variables were measured along with cardiac histopathology assessment.ResultsHDL cholesterol decreased significantly in LO compared to CTL group (35 ± 5 vs 53 ± 5 mg/dl). Groups treated with ISO showed significantly higher increments in troponin I level (P < 0.05) except for LO group and reduction of BP was higher in ISO and SO + ISO groups compared to CTL and SO groups respectively (−38 ± 6 vs −23 ± 4 and −37 ± 11 vs −11 ± 3 percent respectively, P < 0.05). Reduction in BP was significantly lower in LO + ISO compared to ISO group. Opium exposure caused a trend of increase in blood pressure, LDL cholesterol and ECG disturbances, attenuated ISO induced myonecrosis but augmented tissue congestion and hemorrhage.ConclusionPOS can be considered as a CVD risk factor. Opium does not reduce BP or cholesterol level, as is anticipated by its users.

Graphical abstractOpium is a brown to black colour substance which is formed from a milky exudation obtained by incising the unripe capsules of Papaver somniferum (family Papaveraceae) when it is dried in air.Figure optionsDownload full-size imageDownload as PowerPoint slide