EFFECT OF POLYPHENOL‐CONTAINING AZUKI BEAN (VIGNA ANGULARIS) EXTRACT ON BLOOD PRESSURE ELEVATION AND MACROPHAGE INFILTRATION IN THE HEART AND KIDNEY OF SPONTANEOUSLY HYPERTENSIVE RATS

Abstract

1. Hypertension is a major risk factor for myocardial infarction and renal damage, and it has also been shown to have pro-inflammatory actions that increase the formation of reactive oxygen species. Macrophage infiltration has been suggested to play a role in the pathogenesis of hypertension. Azuki beans are known to contain pro-anthocyanidins, a group of polyphenolic bioflavonoids with remarkable radical-scavenging activities in vitro. Therefore, the aim of the present study was to investigate the effect of polyphenol-containing azuki bean extract (ABE) on systolic blood pressure (SBP) and macrophage infiltration in the heart and kidney of spontaneously hypertensive rats (SHR). 2. Spontaneously hypertensive rats and control normotensive Wistar-Kyoto (WKY) rats were divided into two groups fed either 0 or 0.8% ABE in their diets. Tail SBP and macrophage kinetics in the heart and kidney were examined. 3. The SBP of the SHR group was higher than that of age-matched WKY rats throughout the treatment period. After 8 weeks of treatment, the increased SBP in ABE-treated SHR was significantly less than that in untreated SHR. 4. Nicotinamide adenine dinucleotide (NADH) or nicotinamide adenine dinucleotide phosphate (NADPH)-stimulated superoxide (O2-) production was enhanced in the kidney and heart in SHR and WKY rats compared with levels in the absence of NADH or NADPH. The NADPH-stimulated superoxide (O2-) levels in the kidney in untreated SHR was significantly higher than that in untreated WKY rats. The (O2-) levels in ABE-treated SHR were significantly decreased compared with the untreated SHR group. 5. In immunohistochemical analyses, the number of macrophages in the heart and in the glomeruli and tubulointerstitium of the kidney was significantly higher in ABE-untreated SHR than in ABE-untreated WKY rats. Conversely, there was a significant decrease in the number of macrophages in ABE-treated SHR compared with the untreated SHR. There were significant positive correlations between SBP and the number of ED1-positive macrophages in the heart and tubulointerstitial and glomerular areas of the kidney in WKY rats and SHR. 6. In conclusion, the results of the present study suggest that ABE attenuates the elevation of SBP and macrophage infiltration in the heart, as well as in the glomeruli and tubulointerstitium of the kidney, in our SHR model.

Antioxidant and immunoregulatory activity of polysaccharides from adzuki beans (Vigna angularis)

“…Adzuki bean seed coats have been reported to attenuate vascular oxidative stress and inflammation during the progression of hypertension (Mukai & Sato, 2011). Although adzuki bean extracts have been demonstrated to have free radical scavenging activity and to attenuate the elevation blood pressure (Sato et al, 2008), no investigation has been performed on the antioxidant activity of the polysaccharides isolated and purified from the adzuki bean.…”

The health benefits of sweet lupin seed flours and isolated proteins

“…In particular, surprisingly, the health benefits provided by lupin polyphenols have been rarely investigated, although these phytochemicals are main bioactive food components, providing numerous health benefits. In particular, they are strong antioxidants, useful for preventing lipid oxidation and atherosclerosis formation, and efficient ACE-inhibitors (Sato, Mukai, Yamate, Kato, Kurasaki, Hatai, et al, 2008;Shahidi & Chandrasekara, 2013;Taku, Umegaki, Sato, Taki, Endoh, & Watanabe, 2007). As already indicated in the introduction, the two most abundant polyphenols in lupin are apigenin-6,8-di-C-β-glucopyranoside H and apigenin 7-O-β-apiofuranosyl-6,8-di-C-β-glucopyranoside I.…”

Effect of aqueous extract of the Vigna angularis in rats subjected to an experimental model of moderate chronic kidney disease

“…These results suggest that the extract or the compounds of the plant could be a useful treatment to illnesses related to IL -6 16 . Furthermore, in studies with hypertensive and hyperglycemic animal, it has been observed that this kind of treatment plays an important role in suppressing increases of oxidative stress and macrophage infiltration on kidneys 17 .…”