Ethylacetate extract of red onion (Allium cepa L.) tunic affects hemodynamic parameters in rats

Abstract

The effect of ethylacetate extract of red onion (Allium cepa) tunic (ACTE) on some hemodynamic and biochemical parameters were evaluated in normotensive albino rats.Blood pressure parameters were determined in anaesthetized rats orally administered ACTE (10-, 20-, or 40 mg/kg) or ramipril (1 mg/kg) once daily for 14 days. Respectively, 10-, 20-, or 40 mg/kg ACTE produced significant (P<0.01), dose-dependent fall in systolic blood pressure, SBP (21%, 27%, 33%), diastolic blood pressure, DBP (6%, 10%, 16%), pulse pressure, PP (42%, 49%, 56%), mean arterial blood pressure, MAPB (13%, 18%, 23%) and heart rate, HR (4%, 5%, 7%). The highest effective dose (40 mg/kg) compared well with ramipril (1 mg/kg) with regards to SBP (41%), DBP (19%), PP (70%), MABP (29%) and HR (10%). Similar trends (decreases) were recorded for 40 mg/kg ACTE and ramipril respectively as regards the activities of serum enzymes: creatine kinase (60% and 65%), ALT (18% and 14%) and ALP (28% and 16%). HPLC fingerprints of the flavonoid-rich ACTE revealed that flavonols: quercetin, quercitrin, isoquercitrin, rutin and kaempferol are the active flavonoids. The results demonstrate the hypotensive effect of Allium cepa tunic flavonoids initiating further investigation of their individual or synergistic contribution(s) to the observed effects.

Allium Flavonols: Health Benefits, Molecular Targets, and Bioavailability

“…A number of recent meta-analyses of prospective cohort studies have indicated that individuals with the highest flavonoid intakes have lower relative risk of mortality from CVD and all-causes compared with that of individuals with the lowest intakes [111][112][113]. Several studies evidenced the beneficial effects of Allium flavonols on the cardiovascular system via their regulatory effects on platelet aggregation [83,84,96], atherogenesis [78], thrombotic activities [79], endothelial function [81], hypertension [77,82], lipid metabolism [77], and oxidative stress [42] (Table 3). Ingestion of quercetin rich onion soup (69 mg total quercetin) inhibits platelet aggregation and essential components of the collagen-stimulated platelet activation pathway in human and may reduce the risk of thrombosis, a common pathology of CVD [114].…”

“…In addition, OPE also elevates cAMP levels, which might be related to the regulation of protein kinase activities [83]. Olayeriju et al [42] showed that the ethyl acetate extract of red onion tunic affects hemodynamic parameters in rats. The active flavonols in the extract are identified as quercetin, quercitrin, isoquercitrin, rutin, and kaempferol, which might potentially reduce systolic and diastolic pressure, mean arterial blood pressure, pulse rate, and heart rate via modulating the oxidative stress [42].…”

Angiotensin‐1‐converting enzyme inhibition, antioxidant activity, and modulation of cerebral Na+/K+ ATPase by free phenolics of African locust bean (Parkia biglobosa)

“…Both FPPB and BPPB could protect against HgCl 2 ‐provoked lysis of human erythrocytes at a specific concentration range. The observed decrease in the antihemolytic effect of the extracts and ascorbic acid at higher concentrations could be due to the prooxidative tendency of phenolics and antioxidant molecules, including ascorbic acid, at concentrations above a particular threshold …”

“…The observed decrease in the antihemolytic effect of the extracts and ascorbic acid at higher concentrations could be due to the prooxidative tendency of phenolics and antioxidant molecules, including ascorbic acid, at concentrations above a particular threshold. 28,29 Phenolic compounds have been speculated to contribute towards lowering the incidence of neurodegenerative diseases. 30 Of considerable importance to neuronal functions are the acetylcholinesterase and Na + /K + -ATPase enzymes.…”

Phytochemical constituents of sterol‐rich fraction from Allium cepa L. and its cytotoxic effect on human embryonic kidney (HEK293) cells

“…A. cepa has also been reported for its medicinal properties owing to its phytochemical components, with quercetin being the key flavonoid (Albishi et al., 2013; Kwak et al., 2017), and pyruvic acid, its major sulfur compounds (Gîtin et al., 2014). A. cepa has been well documented for its potent antioxidant activities as evident by its free radicals scavenging and redox imbalance ameliorative abilities in several diseases (Albishi et al., 2013; Corzo‐Martínez et al., 2007; Olayeriju et al., 2015). Its antimicrobial, antiallergenic, and anti‐inflammatory properties have been described and associated with the presence of sulfur–oxygen or sulfur–sulfur linkages (Block et al., 1997; Pareek et al, 2017).…”