Quantification of quercetin from red onion (Allium cepa L.) powder via high-performance liquid chromatography-ultraviolet (HPLC-UV) and its effect on hyperuricemia in male healthy Wistar albino rats

Onions (Allium cepa L.) contain various flavonols, including quercetin, kaempferol, anthocyanin, luteolin, and myricetin. Quercetin in onions is considered the primary bioactive component. To assess the impact of quercetin on hyperuricemia in healthy Wistar albino rats, this study used high-performance liquid chromatography with ultraviolet (HPLC-UV) to identify and measure quercetin in onion powder. Twenty-four 160 ± 10 g, six wistar albino male rats in each group were kept: NC (control sample, no onion powder), OT1, OT2, and OT3, which contained 11.13, 14.84, and 18.61 g/100 g onion powder, respectively. The treatment lasted 28 days, during which the last 7 days were for urine, feces, and blood collection. The results showed a trend of decreasing levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, total bilirubin, total cholesterol, and low-density lipoprotein in rats fed OT1, OT2, and OT3 diets. Improvements were observed in feed, water, and nutrient intake, feed conversion ratio, feed efficiency ratio, nutrient digestibility, nitrogen balance, body weight, blood urea nitrogen, creatinine, and uric acid levels (p ≤ .05). In contrast, high-density lipoprotein, triglycerides, serum total protein, neutrophils, and lymphocytes did not change (p ≥ .05). White blood cells, red blood cell count, platelet count, hemoglobin, and monocytes showed an upward trend. Based on our calculations, we determined the optimal human dosage from the most effective amount of onion powder. By taking into account the ratio of human-to-rat surface area, we estimate that the equivalent human dose of onion is 181.04 grams with 204 mg of quercetin. Additionally, when factoring in the dry matter content, the recommended dose of onion is 29.19 grams with 220 mg of quercetin.

Quercetin Application for Common Carp (Cyprinus carpio): I. Effects on Growth Performance, Humoral Immunity, Antioxidant Status, Immune-Related Genes, and Resistance against Heat Stress

This study was done to evaluate the effect of different quercetin levels on growth performance, immune responses, antioxidant status, serum biochemical factors, and high-temperature stress responses in common carp (Cyprinus carpio). A total number of 216 common carp with an average weight of 27.21 ± 53 g were divided into 12 tanks (four treatments × three replications) and fed 0 mg/kg quercetin (T0), 200 mg/kg quercetin (T1), 400 mg/kg quercetin (T2), and 600 mg/kg quercetin (T3) for 60 days. There were significant differences in growth performance, and the highest final body weight (FBW), weight gain (WG), specific growth rate (SGR), and feed intake (FI) were observed in T2 and T3 (P < 0.05). Different quercetin levels significantly increased complement pathway activity (ACH50) and lysozyme activity both before and after heat stress (P < 0.05). Catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) were significantly increased in fish exposed to heat stress, but fish fed with a supplemented diet with quercetin showed the lowest levels both before and after heat stress (P < 0.05). Superoxide dismutase (SOD) levels were significantly enhanced in fish fed diets supplemented with quercetin in both phases (P < 0.05). Different quercetin levels led to a significant decrease in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) before and after the challenging test (P < 0.05). Glucose and cortisol levels were significantly higher in the control group compared to the other treatments in both phases (P < 0.05). The expression of glutathione peroxidase (GPx) and lysozyme was markedly upregulated in fish fed with quercetin-supplemented diets (P < 0.05). No marked effects were observed for growth hormone (GR) and interleukin-8 (IL8) (P > 0.05). In conclusion, dietary quercetin supplementations (400-600 mg/kg quercetin) improved growth performance, immunity, and antioxidant status and increased tolerance to heat stress.

Quercetin ameliorates chicken quality by activating the PI3K/PKB/AMPK signaling pathway in broilers

This study was conducted to investigate the effects and mechanism of quercetin on chicken quality in broilers. We selected 480 AA broilers (1 day old) and randomly allotted those to four treatments (negative control and 0.2, 0.4, or 0.6 g of quercetin per kg of diet) for 42 days. Compared with the control group, the supplementation with 0.4 g of quercetin significantly increased the pH_45min and L ^* value of the thigh muscle and decreased the shearing force of the thigh muscle and breast muscle and drip loss of the thigh muscle (P < 0.05). The supplementation with 0.6 g/kg of quercetin significantly increased the pH_45min and L ^* value of the thigh muscle, and pH_45min of breast muscle and decreased the drip loss of the thigh muscle (P < 0.05). Sensory scores of meat color, tenderness, and juiciness also were improved with increasing quercetin concentration (P < 0.05). The inosinic acid (IMP) content of the breast and thigh muscles of broilers was significantly increased by supplementation with 0.6 g/kg of quercetin (P < 0.05). Supplementation with 0.2, 0.4, and 0.6 g of quercetin significantly reduced mRNA expression of L-FABP (P < 0.05, P < 0.05, and P < 0.05); supplementation with 0.4 and 0.6 g/kg of quercetin significantly increased mRNA expression of PKB and AMPKα1 (P < 0.05 and P < 0.05); supplementation with 0.6 g/kg of quercetin in the diet significantly reduced mRNA expression of SREBP1 and HMGR (P < 0.05 and P < 0.05) and significantly increased mRNA expression of CPT1 and PPARγ (P < 0.05 and P < 0.05); and supplementation with 0.2, 0.4, and 0.6 g/kg of quercetin significantly increased mRNA expression of PI3K, LPL, and Apo A1 and significantly reduced mRNA expression of ACC and FATP1 in the breast muscle of broilers (P > 0.05). PI3k, PKB, AMPK, SREBP1, and L-FABP were significantly and positively correlated with pH_45min (P < 0.05); PPARγ was significantly and positively correlated with shear force (P < 0.05); CPT1 was significantly and positively correlated with the L ^* value (P < 0.05); and HMGR was significantly and positively correlated with drip loss (P < 0.05). In conclusion, quercetin improved the meat quality, protecting it against lipid oxidation and deposition by regulating the PI3K/PKB/AMPK_α1 signaling pathway in the breast muscle of broilers.

Selection of Forage Resources by Juvenile Goats in a Cafeteria Trial: Effect of Browsing Experience, Nutrient and Secondary Compound Content

Simple Summary

Grazing/browsing goats ingest a diverse diet selected from the forage resources available in the range/paddock intending to meet their nutritional requirements. Intake and selection of any given forage can be modified by several factors, such as its nutrient content, including secondary compounds, as well as its biomass availability in the environment. The animal’s previous browsing experience can also be an important factor driving intake and selection. Therefore, the present study evaluated all these factors as well as their interaction. The results showed that the goats’ browsing experience guided the selection and intake towards those forage resources of better nutritional quality when there was no restriction in forage supply, as is the case for cafeteria trials. Goats with browsing experience showed their ability to limit secondary compounds and optimize their selection and intake for plants with better digestibility. This cafeteria protocol made it possible to identify the selection and consumption pattern of plant species with limited availability in the natural vegetation. This methodology could help identifying the forage resources that may be useful for small ruminant feeding, versus those resources that are not consumed by goats despite having a suitable chemical composition and in vitro digestibility or a high abundance.

Abstract

We evaluated the effect of browsing experience, nutritional quality and secondary compounds of forage resources, and the interaction between these factors on the selection and intake of goats in a cafeteria trial. Twelve juvenile Criollo goats from 7 to 9 months of age, weighing 22 ± 3 kg, were divided into two groups: (a) browser goats group (n = 6, BG), and (b) naïve goats group (n = 6, NG), formed according to their previous browsing experience (with and without, respectively). Animals were housed in individual pens. The cafeteria experiment lasted 21 days considering pen adaptation, foliage adaptation, and measurements, which included the selection index (SI) of experimental forage resources (Chesson’s alpha) and their dry matter intake (DMI/Kg^0.75), using a multiple Latin square design. Furthermore, correlation and regression analyses were used to assess the relationship between the aforementioned factors. The NG did not show any selection pattern, while the BG selected Piscidia piscipula and Senegalia gaumeri (p = 0.0002). The BG consumed smaller amounts of secondary compounds compared to NG (p = 0.0001). In the BG, the flavonoids affected negatively their selection (R² = 97.51, p = 0.0001), while the DMI was affected by in vitro DM digestibility and flavonoids (R² = 99.85; p = 0.0001). For the NG, the crude protein and organic matter contents were associated with DMI, but none had a significant relationship with SI. The BG selected and consumed forages with suitable nutritional quality avoiding those with high content of secondary compounds such as flavonoids. Conversely, NG did not show a clear pattern for their selection or intake.