Antihypertensive effects of Ocimum basilicum L. (OBL) on blood pressure in renovascular hypertensive rats

Abstract

Ocimum basilicum L. (OBL), sweet basil, is a medicinal herb used in traditional Chinese medicine to treat cardiovascular diseases including hypertension. The objective of the study was to investigate the possible antihypertensive effects of OBL extract in renovascular hypertensive rats. The two-kidney one-clip (2K1C) Goldblatt model of renovascular hypertension was used in Wistar rats. Rats were randomized into sham, untreated 2K1C, captopril-(30 mg kg À1 per day orally) and OBL-(100, 200, 400 mg kg À1 per day orally) (low (L)-, medium (M)-, high (H)-OBL) treated 2K1C groups (n¼10-12 per group), followed up for 4 weeks. Blood pressure, heart weight/body weight, plasma angiotensin-II and endothelin (ET)-1 were studied. OBL reduced systolic and diastolic blood pressure by about 20 and 15 mm Hg, respectively, compared with 35 and 22 mm Hg for captopril, from the lowest dose tested with no dose dependency. Cardiac hypertrophy was reduced from 3.6±0.7 mg g À1 for untreated 2K1C to 3.0 ± 0.6, 2.9 ± 0.6 and 2.4 ± 0.4 mg g À1 for L-, M-and H-OBL, respectively, compared with 2.6 ± 0.5 for sham and 3.1 ± 0.4 mg g À1 for captopril (Po0.05). Renal function was improved with captopril. Angiotensin was reduced to a lesser extent than with captopril. ET was reduced to lower concentrations (78±15, 80±22, 82±15 pg ml À1 for L-, M-, H-OBL, respectively) than in sham (116 ± 31 pg ml À1 ), untreated 2K1C (174 ± 72 pg ml À1 ) or captopril (117 ± 72 pg ml À1 ) groups. The effects of OBL on blood pressure, cardiac hypertrophy and ET, are consistent with an effect on ET-converting enzyme, and warrant further exploration. , sweet basil, is used in traditional Asian medicine to treat chronic effects related to the cardiovascular system, in particular hypertension and coronary heart disease. Sweet basil is also a major constituent of traditional recipes in the Mediterranean diet, which has been associated with reduced cardiovascular morbidity.We have shown in previous studies that OBL possesses an inhibitory effect on human platelet aggregation induced by adenosine diphosphate and thrombin, which is dose dependent and results in an antithrombotic effect in vivo. 1 It also has effects on experimental hyperlipidemia and cholesterol metabolism. 2,3 Hypertension is with dyslipidemia and platelet activation a major contributor to cardiovascular risk 4 with clinical consequences, such as heart failure, acute coronary syndrome and ischemic stroke. 5,6 It was therefore thought useful to test whether OBL also had any effects on blood pressure in a model of experimental hypertension and cardiac hypertrophy.

Eugenol Dilates Rat Cerebral Arteries by Inhibiting Smooth Muscle Cell Voltage-dependent Calcium Channels

“…In addition to being used as food flavorings, these plants are also used as folk medicines to alleviate diseases, including hypertension 1-4 . However, mechanisms by which these plants and, in particular, eugenol are clinically beneficial are unclear.…”

Eugenol dilates mesenteric arteries and reduces systemic BP by activating endothelial cell TRPV4 channels

“…These plants possess antihypertensive properties, although the chemicals mediating this effect have not been elucidated (Grover et al, 2002;Umar et al, 2010;Ranasinghe et al, 2013). Eugenol and capsaicin share a vanillyl group as an important structural motif for bioactivity.…”

Anti-hypertensive medicinal plants and their mode of action

“…In another study, the hypotensive action of Capparis cartilaginea has been suggested to be mediated through direct relaxant action on myocardium and blood vessels (Gilani and Aftab, 1994). A similar mechanism has been suggested for the hypotensive effect of Ocimum basilicum (Aftab, 2006) along with involvement of Endothelin converting enzymes (ECEs) (Umar et al , 2010). Eugenol from the plant was isolated and was shown to be responsible for observed effects.…”