Blood pressure lowering and cardio-protective effects of garlic (Allium sativum) and ginger (Zingiber officinale) extracts in some laboratory animals

Abstract

This study evaluated the blood pressure effects and cardio-protective function of ginger and garlic extracts in laboratory animals. Wistar rats of both sexes were assigned into the following groups: Group I: Served as control + distilled water; Group II: 20 mg/kg of garlic; Group III: 40 mg/kg of garlic; Group IV: 20 mg/kg of ginger; Group V: 40 mg/kg of ginger; Group VI: garlic 10 mg and ginger 10 mg/kg; Group VII: garlic 20 mg and ginger 20 mg/kg. Animals were euthanized after four weeks of treatment. Blood samples were collected and serum separated for lipid profile assay. The effect of extracts on perfused rabbit heart was also investigated. Moreover, the effect of extract on blood pressure was tested in anaesthetized cats. The results obtained in the study showed a statistically significant decrease (p<0.05) of serum total cholesterol (TC), triglyceride and low density lipoprotein-cholestero (LDL-C) levels at all single and combined doses of the extract when compared with the control group. The extract single and combined doses significantly increased (p<0.05) serum high density lipoprotein-cholesterol (HDL-C) level in the treated animals when compared with the control group. The results showed a significantly decreased rate and force of contraction at the combined doses when compared with the baseline line control level (p<0.05). The study also revealed that the administration of only garlic at dose of 0.1 and 1 mg/ml produced a significant decrease (p<0.05) in the diastolic blood pressure. There was a statistically significant decrease (p<0.05) in diastolic blood pressure in all single doses of garlic as well as the combined doses of garlic and ginger extract administered. The result obtained showed that administration of only single doses of ginger produced a significant decrease in p < 0.05. Administration of single doses of garlic (0.1 and 1 mg/ml) produced significant reduction (P < 0.05) in mean arterial pressure (MAP) when compared with control group. In conclusion, the findings suggest that the extract as well as its combination improved lipid profile and may have a cardio-protective effect.   Key words: Garlic, ginger, isolated perfuse heart, total cholesterol, triglyceride, low-density lipoprotein, blood pressure.