Antiradical Capacity and Induction of Apoptosis on HeLa Cells by a <Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> Extract

Jamapa bean is a black Phaseolus vulgaris variety rich in condensed tannins, anthocyanins and flavonols with interesting biological activities. The objective of this work was to evaluate the antiradical capacity (ARC) of a Jamapa bean methanolic extract (BME) and some of the proanthocyanidin-rich fractions derived from it, using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The effect of the BME on some proteins involved in apoptosis on HeLa cells was also evaluated. A strong correlation between proanthocyanidin concentration in BME and antiradical capacity was found, suggesting that these compounds contribute significantly to antiradical activity. BME was a better radical scavenger than butylated hydroxytoluene (45.6 and 33.9% ARC at 400 μM, respectively). Two proanthocyanidin-rich fractions obtained after a preliminary separation of the BME using Toyopearl (TP4 and TP6) exhibited a higher antiradical activity than the parent extract. The treatment of HeLa cells with 35 μg BME/ml/24 h increased the expression of Bax and Caspase-3, pro-apoptotic proteins (6.13 and 1.2 times for Caspase-3 and Bax, respectively). The mechanism of action of some proteins involved in apoptosis was also evaluated, and the results suggest that black Jamapa bean could be an important source of polyphenolic compounds with potential biological use as antioxidant and anticancer agents.     

Effect of cultivar and growing location on the trypsin inhibitors, tannins, and lectins of common beans (Phaseolus vulgaris L.) grown in the semiarid highlands of Mexico

Trypsin inhibitors (TI), tannins, and lectins appear to have a role in preventing chronic diseases in humans. The genetic variability of these traits in common bean needs to be ascertained in order to increase levels through breeding. The variability of TI, tannin, and lectins was determined in five bean cultivars grown at five locations in Mexico. TI and tannins contents in colored beans that belong to the Jalisco race were higher (11.1-11.9 trypsin units inhibited (TUI)/mg and 29.0-38.1 mg catechin equivalent (CE)/g, respectively) than cultivars of the Durango race (7.9-8.3 TUI/mg and 16.8-19.9 CE/mg, respectively). Bayo Victoria, a Durango race cultivar, had three times more lectins than levels reported for soybean. Cultivar influenced TI and tannins contents (p < 0.001), whereas site affected lectins (p < 0.001). An increase in levels of TI and tannins could be enhanced through breeding.     

Cooked Common Beans (Phaseolus vulgaris) Protect Against β-cell Damage in Streptozotocin-Induced Diabetic Rats

Diabetes is a disease characterized by a hyperglycemic stage that leads to a chronic inflammatory state. We evaluated the in vivo effect of a diet supplemented with 25 % cooked black bean cultivar Negro 8025 (N8025) flour in streptozotocin-induced diabetic rats. The effect was assessed before (preventive-treatment) and after (treatment) the onset of diabetes. There is a significant decrease of total phenolic, tannins and anthocyanins content after cooking, and the concentration of most of the single phenols analyzed are only slightly decreased. The treatment group showed a significant reduction of glucose (22.8 %), triglycerides (21.9 %), total cholesterol (29.9 %) and LDL (56.1 %) that correlates with a protection of pancreatic ß-cells. The diet with N8025 flour before the induction of diabetes did not exert a protective effect (glucose levels are similar to the diabetic control) but they have low levels of total cholesterol (47.5 %) and LDL (56.1 %). The preventive-treatment group did not inhibit the increase of TNF-α and IL-1β, whereas the treatment group did, compared to the diabetic control. Therefore, N8025 bean supplementation can be recommended to control diabetes.     

Tannins,Trypsin Inhibitors and Lectin Cytotoxicity in Tepary (<Emphasis Type="Italic">Phaseolus acutifolius</Emphasis>) and Common (<Emphasis Type="Italic">Phaseolus vulgaris</Emphasis>) Beans

This study compared the levels of antinutritional components and cytotoxic effect of extracts, from tepary (Phaseolus acutifolius) and common (Phaseolus vulgaris) beans. Antinutritional factors were evaluated by determining their effect on the viability of epithelial cells isolated from rat small intestine. The protein and carbohydrates content were similar in all the genotypes studied (20 and 60%, respectively). Common beans presented higher content of trypsin inhibitors, tannins and lectins than tepary beans. There was not a significant correlation between tannins and cooking time. However, water absorption and cooking time correlated significantly (p < 0.05). Considerable variation was observed in lectin activity (1302–18161 Ul/mg) of extracts from different beans. Tannins, lectins, trypsin inhibitors and fat content differed between bean varieties whereas protein content was similar. The percent cellularity on rat epithelial cells was significantly different among protein extracts from different bean cultivars and ranged between 53.5% and 87.4% (p < 0.05). These results suggest that the incorporation of tepary beans in the diet would not alter the current nutritional contribution of common beans or introduce adverse toxic effects. The agronomic characteristics of tepary beans make them attractive for cultivation. However, the harder to cook phenomenon may be a limiting factor that needs further consideration.     

Antioxidant Capacity and Antimutagenic Activity of Anthocyanin and Carotenoid Extracts from Nixtamalized Pigmented Creole Maize Races (Zea mays L.)

Nixtamalization process is the first step to obtain maize based products, like tortillas; however, in both the traditional and commercial processes, white grain is generally preferred. Creole maize races, mainly pigmented varieties, have increasingly attention since these are rich in anthocyanins and carotenoids. The aim of this investigation was to evaluate the antioxidant and antimutagenic activity of rich anthocyanins and carotenoids extracts from creole maize races before (grain) and after (masa and tortilla) the nixtamalization process. Most anthocyanins and carotenoids were lost during nixtamalization. Before nixtamalization, blue and red genotypes contained either higher antioxidant capacity and anthocyanin contents (963?±?10.0 and 212.36?±?0.36 mg of cyanidin-3-glucoside eq/100 g, respectively) than the white and yellow genotypes. However, the highest carotenoid levels were displayed by red grains (1.01?±?0.07 to 1.14?±?0.08 μg of β-carotene eq/g extract). Anthocyanins losses were observed when the blue grains were processed into masa (83 %) and tortillas (64 %). Anthocyanins content correlated with antiradical activity (r?=?0.57) and with 2-aminoanthracene -induced mutagenicity inhibition on TA98 and TA100 (r?=??0.62 and r?=??0.44, respectively). For white grains, nixtamalization also reduced carotenoids (53 to 56 %), but not antioxidant activity and 2-Aa-induced mutagenicity. Throughout the nixtamalization process steps, all the extracts showed antimutagenic activity against 2-aminoanthracene—induced mutagenicity (23 to 90 %), displaying higher potential to inhibit base changes mutations than frameshift mutations in the genome of the tasted microorganism (TA100 and TA98, respectively). The results suggest that even though there were pigment losses, creole maize pigments show antioxidant and antimutagenic activities after nixtamalization process.     

Chia Sprouts Elicitation with Salicylic Acid and Hydrogen Peroxide to Improve their Phenolic Content,Antioxidant Capacities In Vitro and the Antioxidant Status in Obese Rats

Elicitation is a biotechnological approach to improve phenolic compounds content and antioxidant properties of ready-to-eat functional foods. This study aimed to evaluate the chemical elicitation effects using salicylic acid (SA) and hydrogen peroxide (H₂O₂) in optimized-germination conditions on seedling vigor, phenolic content, and their antioxidant capacities in vitro and serum and urine of Wistar obese rats. Optimized-germination conditions of 26.5 °C and 178 h produced a 64% of germination and a sprout length of 56 mm. Only, the elicitation with H₂O₂ (20 mM) enhanced the germination (75%) and H₂O₂ (10 and 20 mM) the sprout length (69 and 59 mm, respectively). In contrast, both elicitors enhanced phenolic contents, being more significant total phenolic compounds content for SA (1 and 2 mM), up to 65.5–73.5%. SA and H₂O₂ improved total flavonoids content (36.5–64.1%), ABTS (19.3–61.1%), and DPPH capacities (51–86%), depending on SA and H₂O₂ concentration, compared with non-elicited chia sprouts. The QUENCHER antioxidant capacities of elicited chia sprouts increased up to three times more than extracts capacities, principally Q-ABTS, which could be attributed to phenolic bounds to dietary fiber. Rats fed with a high-fat and fructose diet (HFFD) and supplemented with chia sprouts, especially 1-mM SA, improve the obesity-related oxidative stress through an increase of antioxidant capacities, using DPPH and ABTS test, on serum (70–118%) and urine samples (80–116%). These results suggest that chia sprouts elicited with 1-mM SA are a source of antioxidant compounds that can be used to decrease obesity related oxidative stress.