| Abstract: |
Ancient Egyptian medicine of 1000 B.C. are known to have used garlic, opium, castor oil, coriander, mint, and other herbs for medicine. Many of the pharmaceuticals currently available to physicians have a long history of use as herbal remedies, including opium, digitalis, and quinine. The World Health Organization (WHO) estimates that 80 percent of the world’s population presently uses herbal medicine for some aspect of primary health care (Aggarwal et al., 2007).The use of, and search for, drugs and dietary supplements derived from plants have accelerated in recent years. Pharmacologists, microbiologists, botanists, and natural-products chemists are combing the earth for phytochemicals and herbs that could be developed for treatment of various diseases (Eisenberg et al., 1998).The present investigation was done in a trial to investigate the effect of HS in the protection against and treatment of renovascular hypertension, taking the advantages of being cheap, available and safe alternative to the chemically synthesized drugs, avoiding their various side effects. In addition, a standard drug valsartan as an angiotensin II receptor blocker was used for comparison to provide approximate indication about the potency of the HS extract. Valsartan was compared with HS.This study was divided into 2 major parts:I- Part I:It was carried out to demonstrate the role of HS in the protection against renovascular hypertension induced by ligation of renal artery through the determination of B.P ,heart rate, E.C.G, serum TC, TGs, HDL, LDL, VLDL, Ca++, K+, Na+ and NO levels and aortic SOD and GSH content in addition to histopathological examination of aorta, heart and carotid artery.II- Part II:It was carried out to investigate the role of HS, valsartan and their combination in the treatment of RVH induced by ligation of renal artery. B.P, heart rate, E.C.G, serum TC, TGs, HDL, LDL, VLDL, Ca++, K+, Na+ and NO levels and aortic SOD and GSH content were measured. Also histopathological examination of aorta, heart and carotid artery were done.The results obtained can be summarized as follows:1- Induction of renovascular hypertension by ligation of renal artery for 30 and 45 days caused a significant increase in MAP, heart rate, serum TC, TGs, LDL, VLDL and K+. While, it reduced serum HDL and NO levels and aortic SOD and GSH content when compared with sham operated rats. The results were confirmed with histopathological examination of the aorta and carotid artery which showed dilatation of the lumen with blood inside it and the heart showed dilated coronaries and myocardial blood vessels that engorged with blood. E.C.G showed ventricular tachycardia.2- The increase in MAP noticed after 45 days after induction of hypertension was significantly higher than the increase in MAP after 30 days of induction of hypetension.I- Part A:1- Administraion of HS (250 mg/kg/day orally) for 30 days before ligation of renal artery and for 30 and 45 days along with the induction of hypertension caused a significant decrease in MAP, heart rate, serum TC, TGs, LDL and VLDL when compared with hypertensive rats. On the other hand, it caused a significant increase in serum HDL and NO levels and aortic SOD and GSH content. It had no significant effect on serum levels of Ca++, K+ and Na+. E.C.G was normal. Histopathological examination of aorta showed mild dilatation of lumen with normal tunics without blood inside its lumen. Carotid artery showed partially damaged tunica intima and a few blood sticked on the intima. Heart showed dilated and engorged coronaries and myocardial blood vessels with blood.2- Administration of HS (250 mg/kg/day orally) for 30 days before ligation of renal artery and valsartan (5 mg/kg/day orally) for 30 and 45 days along with the induction of hypertension caused a significant decrease in MAP while caused a significant increase in serum NO level and aortic SOD and GSH content when compared with hypertensive rats. There was no significant change in heart rate and serum levels of Ca++, K+, Na+, TC, TGs, LDL and VLDL. E.C.G showed sinus tachycardia. Histopathological examination showed slightly dilated lumen of aorta and carotid artery with engorged blood inside it. Heart showed dilated and engorged blood vessels, coronaries and capillaries with blood.3- Rats given combination of HS(250 mg/kg/day orally) for 30 days before ligation of renal artery and combination of HS (250 mg/kg/day orally) and valsartan (5 mg/kg/day orally) for 30 and 45 days along with the induction of hypertension caused a significant decrease in MAP, heart rate, serum TC, TGs, LDL and VLDL. On the other hand, it caused a significant increase in serum HDL and NO levels and aortic SOD and GSH content when compared with hypertensive rats. E.C.G was normal. Histopathological examination of aorta showed mild dilated lumen, irregular tunica intima and partially stretched vascular wall with a few blood inside its lumen. Carotid artery showed normal or slightly dilated lumen. Heart showed slightly dilated coronaries, myocardial blood vessels with perivascular hemorrhages.
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