Hop (Humulus lupulus L.) extract reverts glycaemic imbalance and cognitive impairment in an animal model of obesity.

The rates of overweight and obesity around the world have increased in past years. The body's adipose tissue stimulates the antioxidant and oxidation imbalance capacity at the cellular level. This scenario favors an inflammatory low-grade systemic condition starting with insulin resistance, which in turn may involve diabetes mellitus type 2 and cognitive decline afterward. Neurological diseases have been correlated to senile age diseases over time. This scenario calls for a change in the incidence of obesity in the younger generation. An unhealthy dietary consumption together with sedentary habits might lead to poor gut absorption of nutrients. Several plants and foods have bioactive compounds that can reduce or inhibit radical scavengers, reactive oxygen species, and metal ion complexes that threaten the cerebral defense system. The bitter acids from hops (Humulus lupulus L.) have been demonstrated to have promising effects on lipid and carbohydrate metabolism improvement, reducing inflammatory responses through alpha acids, beta acids, and analogs action. Therefore, the current study aimed to investigate the bioactivity of hop bitter acids in obese and lean mice. For that, a dry hop extract (DHE) was obtained by applying carbon dioxide as the fluid of supercritical extraction. Afterward, seventy-eight male mice of the C57BL/6J strain were weighed and randomly distributed into six groups of 13 animals each according to the diet offered: (NO) normolipidic diet, (NO1) normolipidic diet containing 0.35% alpha acids, (NO2) normolipidic diet containing 3.5% alpha acids, (HP) hyperlipidic diet, (HP1) hyperlipidic diet containing 0.35% alpha acids, and (HP2) hyperlipidic diet containing 3.5% alpha acids. After applying the glycemic tolerance and insulin tolerance tests, a better stabilization of glycemia levels and weight gain among those animals fed with DHE (NO2 and HP2) were observed in comparison to the obese control group (HP) (p < 0.05). There was also an amelioration of antioxidant capacity observed by checking the enzymatic profile by SOD and an apparent mitigation of brain degeneration by checking GSK3ß and p-IRS1 proteins expression (p < 0.05). The y-maze cognitive test applied to highlight possible obesity-harmful animal brains did not indicate a statistical difference between the groups. Although the weekly dietary intake between the obese HP2 group (33.32 ± 4.11, p < 0.05) and control HP (42.3 ± 5.88, p < 0.05) was different. The bioactive compounds present in DHE have demonstrated relevant effects on glycemic control, insulin signaling, and the consequent modulatory action of the obesity-related markers with the brain's inflammatory progression.

White tea modulates antioxidant defense of endurance-trained rats.

The interest in nutritional strategies that may counteract the deleterious oxidative effects induced by strenuous exercises is remarkable. Herein, the impact of white tea (Camellia sinensis) (WT), a polyphenol-rich beverage, on antioxidant status in endurance-trained rats after one session of exhaustive exercise were evaluated. Male Wistar rats were divided into groups, which received: control groups - water, and testing groups - WT1 (0.25%; w/v) or WT2 (0.5%; w/v). Drinks were consumed, ad libitum, for 5 or 10 weeks, concomitantly with the running training. Exhaustive running tests were applied before and after the experimental periods. WT intake increased the serum antioxidant capacity of rats in a dose-dependent manner (P < 0.001), which was unaccompanied by the activity of endogenous antioxidant enzymes SOD, GPx, and GR, and GSH content. Inflammatory markers in serum [IL-1ß (P = 0.004) and IL-6 (P = 0.001)] could be downregulated by tea intake. In liver tissue, lower levels of lipid oxidation (P < 0.05) and improved antioxidant defenses (SOD, GPx, GR, and GSH, P < 0.05) were related to the consumption of WT in both doses, supporting protective effects in this responsible metabolic organ. In conclusion, long-term consumption of WT could be a promising adjuvant to exercise-stress management, emphasizing its ability to regulate antioxidant responses and prevent oxidative tissue damage.