Abstract
Introduction: Osteospermum imbricatum is used traditionally in Eastern Cape, South Africa for the management of hypertension, chest and stomach complaints. This study was aimed at investigating the antioxidant and antihypertensive effects of this plant. Methods: Antioxidant capacity was determined by radical scavenging assays and ferric reducing antioxidant power. Antihypertensive effects after once off treatment with the leaf/root extracts (500 mg/kg) were evaluated in spontaneously hypertensive rats (SHR). The effect of the extracts on established hypertension was determined in Wistar rats treated with Nω-Nitro-L-arginine methyl ester (L-NAME) (40 mg/kg/day) for 4 weeks followed by co-treatment with L-NAME and extracts (200 mg/kg and 400 mg/kg) or amlodipine (5 mg/kg) or normal saline for 4 more weeks. Results: The concentration at which there was 50 % inhibition (IC50) of DPPH radical by the extracts was lower for the leaf extract (0.79 mg/mL) compared to the root extract (1.15 mg/mL). The leaf extract significantly (p<0.01) decreased systolic and diastolic blood pressures in both rat models. Conclusion: The extracts of Omsteospermum imbricatu have moderate antioxidants and antihypertensive properties.
Highlights
Osteospermum imbricatum is used traditionally in Eastern Cape, South Africa for the management of hypertension, chest and stomach complaints
Results from the DPPH assay indicated that the leaf extract had lower absorbance and lower IC50 values compared to the root extract indicating that the leaf extract had better free radical scavenging activity
This indicates that the leaf extract had higher antioxidant capacity compared to the root extract reason being that it had more phenols and flavonoid compounds
Summary
Osteospermum imbricatum is used traditionally in Eastern Cape, South Africa for the management of hypertension, chest and stomach complaints. Antihypertensive effects after once off treatment with the leaf/root extracts (500 mg/kg) were evaluated in spontaneously hypertensive rats (SHR). The effect of the extracts on established hypertension was determined in Wistar rats treated with Nω-Nitro-L-arginine methyl ester (L-NAME) (40 mg/kg/day) for 4 weeks followed by co-treatment with L-NAME and extracts (200 mg/kg and 400 mg/kg) or amlodipine (5 mg/kg) or normal saline for 4 more weeks. Other possible causes of systemic vasoconstriction in NO-deficient rats may include enhancements of sympathetic nerve activity, reninangiotensin system and oxidative stress.[6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
