Inflammation and kidney injury attenuated by prior intake of Brazil nuts in the process of ischemia and reperfusion

Brazil nut (Bertholletia excelsa Bonpl.) in health and disease: A narrative review

Brazil nut is one of the most consumed nut-producing species from South America. This narrative review evaluates the potential benefits of Brazil nut in health and disease. Various preclinical studies have shown that Brazil nut possesses antioxidant and anti-inflammatory actions and may be associated with antihypertensive, anti-nephrotoxic, cardioprotective (by reversing obesity, diabetes, hypertension, and dyslipidemia), and antineoplastic properties. Additionally, several clinical trials showed that Brazil nut can improve antioxidant defense, reduce inflammatory processes, attenuate glycemia, prevent obesity and hypertension, reduce visceral adiposity, reduce endothelial dysfunction, and improve vascular tone. Besides its various health benefits, Brazil nut can be a promising agent in the food industry for enhancing products with a better nutritional profile and meeting the growing demand for functional and sustainable foods. Moreover, secondary products derived from the Brazil nut, such as Brazil nut oil and phytocompounds, have potential for use in multiple pharmaceutical and cosmetics industries.

Brazil nut (Bertholletia excelsa) and metformin abrogate cardiac complication in fructose/STZ-induced type 2 diabetic rats by attenuating oxidative stress and modulating the MAPK-mTOR/NFkB/IL-10 signaling pathways

Background

The global prevalence of diabetic heart complication has been on the increase, and some of the drugs that are currently used to treat diabetes mellitus (DM) have not been able to mitigate this complication.

Objective

This study determines the effect of Brazil nut (Bertholletia excelsa) and metformin on diabetic cardiomyopathy (DCM) in fructose/streptozotocin (STZ)-induced type 2 diabetic rats and also characterizes using Gas Chromatography Mass Spectrophotometry and Fourier Transform Infrared the bioactive compounds in 50% aqueous ethanol extract of Brazil nut.

Design

After inducing type 2 DM, 30 male albino Wistar rats were separated into five groups that comprised of six rats per group, and they were treated as follows: groups 1 (Control) and 2 (Diabetic control) rats received rat pellets and distilled water; group 3 (Diabetic + Brazil nut) received rat pellets and Brazil nut extract (100 mg/kg, orally) dissolved in distilled water, group 4 (Diabetic + metformin) received metformin (100 mg/kg, orally) dissolved in distilled water, while group 5 (Diabetic + Brazil nut + metformin) received oral administrations of Brazil nut (100 mg/kg) and metformin (100 mg/kg) dissolved in distilled water. This study lasted for 6 weeks. The dose of Brazil nut used was selected from our pilot study on the minimum therapeutic dose of different concentrations of Brazil nut extract.

Results

STZ administration induced insulin resistance, hyperglycemia, loss of weight, dyslipidemia, oxidative stress, inflammation, apoptosis, alteration of mammalian target of rapamycin, mitogen-activated protein kinase, heart function markers (creatine kinase MB, lactate dehydrogenase, and aspartate amino transaminase), and heart histology of the diabetic control, which was ameliorated after treatment with Brazil nut and metformin, but their combined treatment was better than the single treatments.

Conclusion

This study shows that Brazil nut contains several bioactive compounds that support its biological properties as well as its candidature as a complementary therapy to metformin in mitigating cardiac complications arising from DM in rats.

Brazil nuts potential: effects on lipid peroxidation and heart health in nephrectomized rats

OBJECTIVES

To investigate the effects of a Brazil nut-enriched diet on the wall thickness and the left ventricular chamber diameter of the heart, and lipid peroxidation in a CKD-induced model.

METHODS

Male Wistar rats at 12 weeks of age were divided into two groups (n=16/group): the Nx group, which underwent 5/6 nephrectomy, and the Sham group, as a control. After 5 weeks, the groups were subdivided according to diet (n=8/group): the Nx and Sham groups received a control diet; the Nx5% and Sham5% groups received a diet enriched with 5 % Brazil nuts for 8 weeks. The left ventricular thickening and chamber diameter were determined. Plasma biochemical parameters were evaluated. Analysis of thiobarbituric acid reactive substances (TBARS) and antioxidant enzyme activity was performed in the plasma and the left ventricle (LV). LV mRNA expression of nuclear factor-kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) was evaluated by reverse transcription-polymerase chain reaction.

RESULTS

The Nx5% group showed a remodeled LV wall with decreased thickness compared to the Nx group (p=0.016). Furthermore, LV TBARS concentration was reduced in the Nx5% group (p=0.0064). In addition, the Nx5% group showed an increase in plasma GPx activity (p=0.0431). No significant results were found concerning the LV mRNA expression of NF-κB and Nrf2 genes.

CONCLUSIONS

A Brazil nut-enriched diet decreased LV thickness and LV TBARS concentration and increased GPx activity in a 5/6 nephrectomy experimental model, making it a promising adjuvant therapy to improve antioxidant status and cardiovascular outcomes in chronic kidney disease.

Brazil Nut-Enriched Diet Modulates Enteric Glial Cells and Gut Microbiota in an Experimental Model of Chronic Kidney Disease

Introduction: Chronic kidney disease (CKD) promotes gut dysbiosis, and enteric glial reactivity, a feature of intestinal inflammation. Brazil nut modulated enteric glial profile in healthy animals and could modulate these cells in 5/6 nephrectomized rats.Methods: A 5/6 nephrectomy-induced CKD and Sham-operated rats were divided as follows: CKD and Sham received a standard diet and CKD-BN and Sham-BN received a 5% Brazil nut enriched-diet. The protein content of glial fibrillary acid protein (GFAP), enteric glial marker, and GPx protein content and activity were assessed in the colon. The major phyla of gut microbiota were assessed.Results: CKD-BN group presented a decrease in GFAP content (p = 0.0001). The CKD-BN group modulated the abundance of Firmicutes, increasing its proportion compared to the CKD group. The CKD-BN group showed increased GPx activity in the colon (p = 0.0192), despite no significant difference in protein content.Conclusion: Brazil nut-enriched diet consumption decreased enteric glial reactivity and modulated gut microbiota in the CKD experimental model.

Renoprotective effect of vildagliptin following hepatic ischemia/reperfusion injury

Remote renal injury is a drastic consequence of hepatic ischemia/reperfusion (IR) injury. Vildagliptin (V) is a dipeptidyl peptidase-4 inhibitor that has a hepatorenal protective effect against models of liver and renal IR. This research was done to explore the protective role of vildagliptin against renal injury following hepatic IR injury as well as the possible involvement of transforming growth factor-beta (TGF-β)/Smad/alpha-smooth muscle actin (α-SMA) expressions in the pathophysiological mechanism of the remote renal injury. Three groups of male Wistar rats were organized into: sham group, IR group, and V + IR group in which 10 mg/kg/day of vildagliptin was pretreated for 10 days intraperitoneally. Blood in addition to renal and hepatic tissue samples was used for biochemical and histopathological studies. Hepatic IR induced a marked increase in serum creatinine, blood urea nitrogen, liver enzymes, renal nitric oxide, malondialdehyde, tumor necrosis factor-alpha levels with a marked upregulation of renal mRNA expressions of TGF-β, Smad2, Smad3, and α-SMA in addition to a marked decline in renal catalase content comparing to the sham group. Abnormal histopathological findings of hepatic and renal injury were detected in the IR group. Vildagliptin significantly improved these biochemical markers as well as the histopathological changes. The upregulation of renal TGF-β/Smad/α-SMA mRNA expressions was involved for the first time in the pathogenesis of the renal injury following hepatic IR and vildagliptin ameliorated this renal injury through blocking these expressions.

Protective effects of therapeutic hypothermia on renal injury in an asphyxial cardiac arrest rat model

Cardiac arrest (CA) is a leading cause of mortality worldwide. Most of post-resuscitation related deaths are due to post-cardiac arrest syndrome (PCAS). After cardiopulmonary resuscitation (CPR), return of spontaneous circulation (ROSC) leads to renal ischemia-reperfusion injury, also known as PCAS. Many studies have focused on brain and heart injuries after ROSC, but renal failure has largely been ignored. Therefore, we investigated the protective effects of therapeutic hypothermia (TH) on asphyxial CA-induced renal injury in rats. Thirty rats were randomly divided into five groups: 1) the control group (sham); 2) the normothermic CA (nor.); 3) a normothermic CA group that received TH immediately within 2 h after CPR (Hypo. 2 hrs); 4) a normothermic CA group that received TH within 4 h after CPR (Hypo. 4 hrs); and 5) a normothermia CA group that received TH within 6 h after CPR (Hypo. 6 h). One day after CPR, all rats were sacrificed. Compared with the normothermic CA group, the TH groups demonstrated significantly increased survival rate (P < 0.05); decreased serum blood urea nitrogen, creatinine, and lactate dehydrogenase levels; and lower histological damage degree and malondialdehyde concentration in their renal tissue. Terminal deoxynucleotidyl transferase dUTP nick end labeling stain revealed that the number of apoptotic cells significantly decreased after 4 h and 6 h of TH compared to the results seen in the normothermic CA group. Moreover, TH downregulated the expression of cyclooxygenase-2 in the renal cortex compared to the normothermic CA group one day after CPR. These results suggest that TH exerts anti-apoptotic, anti-inflammatory, and anti-oxidative effects immediately after ROSC that protect against renal injury.