Key Findings
The objective of this study was to evaluate the dose dependent effect of flaxseed lignan complex (FLC) in DOCA-salt induced renal hypertension in Wistar rats. Histopathological examination revealed that DOCA salt induced hypertension damaged the heart and kidney tissues. The hearts and kidneys of the FLC-treated DOCA-salt hypertensive rats showed reduced cardiac and renal damage. Higher doses of FLC significantly decreased systolic, diastolic, and mean arterial blood pressures similar to those of standard ACE inhibitor drug captopril. FLC dose-dependently reduced EDP, dP/dt max, dP/dt min after 5 weeks of treatment suggesting that FLC provides sufficient contractile reserve in hypertensive condition. FLC significantly prevented the increase in kidney and heart weight associated with the hypertrophy and thus confirmed that the prevention of hypertrophy might be due to antihypertensive effects of FLC. After the treatment with FLC and captopril, significant decrease in serum sodium and significant increase in serum potassium was observed. The results showed that FLC reduced the increase in blood pressure, which may be due to antioxidant activity of FLC. In this study, antioxidant activity of FLC decreased lipid peroxidation, controlled abnormal lipid metabolism, and restored altered lipid profile values.
Abstract
Context: Earlier we reported cardioprotective, antihyperlipidemic, and in vitro antioxidant activity of flax lignan concentrate (FLC) obtained from the seeds of Linum usitatissimum L. (Linaceae). Objective: To investigate the effect of FLC in deoxycorticosterone acetate (DOCA)-salt induced experimental renal hypertension in rats. Materials and methods Hypertension was induced inuninephrectomized (UNTZD) male Wistar rats (230–280 g) by injecting DOCA (25 mg/kg, subcutaneously, twice weekly) and supplementing 1% NaCl in drinking water for 5 weeks. The rats were divided in six groups. Captopril (30 mg/kg, p.o.) and FLC (200, 400 and 800 mg/kg, p.o.) were administered daily to the rats of groups III–VI, respectively, for 5 weeks. Various hemodynamic and biochemical parameters were investigated as well as histology of kidney and heart were carried out. Results In this study, the FLC (400 and 800 mg/kg) significantly (p<0.01, p<0.001) decreased the systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure. It also significantly (p<0.01, p<0.001) decreased elevated end diastolic pressure (EDP), dP/dt max and dP/dt min, organs weights (kidney and heart) and activities of hepatic, renal and cardiac marker enzymes in the serum. Furthermore, FLC (400 and 800 mg/kg) significantly (p50.01, p50.001) restored altered antioxidant status, serum electrolyte level, lipid profile values, and histological abnormalities. Captopril (30 mg/kg) showed maximum antihypertensive effect but low dose of FLC (200 mg/kg) was not enough to show the antihypertensive activity. Conclusion FLC possessed antihypertensive effect via modulation of endogenous enzymes in DOCA-salt induced renal hypertension in rats.
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