Dietary low-fat soy milk powder retards diabetic nephropathy progression via inhibition of renal fibrosis and renal inflammation

Reduction in Glomerular and Renal Tubular Damage in Kidneys of Diabetic Rats Supplemented with Alpha-Lipoic Acid

Chronic hyperglycemia caused by diabetes results in systemic damage to the body, and the kidney ends up being the target of tissue damage. The use of antioxidants such as alpha-lipoic acid (ALA) has been shown to improve clinical and biochemical parameters in diabetic patients as they help in the prevention of oxidative stress. The present study aimed to undertake a comparative evaluation of the renal morphology of normal and diabetes-induced Wistar rats supplemented with ALA. The experiment had 4 experimental groups (n=7): a control group and a diabetic group that were fed commercial food; an alpha-lipoic group and an alpha-lipoic diabetic group that received the ALA supplement. Diabetes was induced with a single intraperitoneal injection of alloxane monohydrate administered after fasting. After 60 days of the experiment, the kidneys were excised to study the histomorphometric and stereological parameters of the glomeruli and renal tubules and the immunohistochemical parameters with a podocyte count. In the evaluation, the ALA promoted improvement in all of the relevant parameters of the glomerular areas and attenuation of tubular lesions of diabetic animals (p<0.001). Supplementation with ALA also showed beneficial effects in diabetic animals, such as reducing hyperglycemia and the damage promoted by oxidative stress alongside promoting a protective effect on the renal parenchyma. The reduction of glomerular and tubular damage delayed the advance of diabetic nephropathy and its complications, preventing renal failure in diabetic groups.

Association of Dietary Fish and n-3 Unsaturated Fatty Acid Consumption with Diabetic Nephropathy from a District Hospital in Northern Taiwan

Nephropathy caused by diabetes mellitus (DM) is the main cause of end-stage renal disease (ESRD). To understand the association of dietary intake with renal function indicators among patients with diabetic nephropathy (DN), this cross-sectional study was conducted at the dietetic consultation clinic of the Taoyuan Armed Forces General Hospital in Taiwan. In total, 317 participants were recruited for this study. Patients with diabetes who had a urinary albumin–creatinine ratio (UACR) of ≥30 mg/g were defined as having DN. The anthropometric characteristics, blood biochemistry, and renal function of the participants were assessed. Furthermore, a semiquantitative food frequency questionnaire (SQFFQ) was administered to investigate the dietary intake of the participants in the DM and DN groups. The result showed that participants in the DN group were older, had longer diabetes duration and poorer glycemic control and renal function than those in the DM group. Logistic regression models revealed that intake of high-fat marine fishes had the lowest odds ratio (OR) for DN risk compared with other fishes (OR: 0.868; 95% CI: 0.781–0.965, p = 0.009). Shellfish, soybean products, and skim milk also provided better protective effects to decrease the risk of DN. A further analysis of polyunsaturated fatty acids revealed that Σn-3 PUFAs significantly reduced DN risk, while Σn-6 PUFAs did not, especially EPA (OR: 0.821; 95% CI: 0.688–0.979, p = 0.029) and DHA (OR: 0.903; 95% CI: 0.823–0.992, p = 0.033) regardless of whether the variables were adjusted, including diabetes duration, age, and HbA1c. Our findings suggest that a diet that incorporates high-fat fish, shellfish, soybean products, and a lower Σn-6/Σn-3 ratio can mitigate DN risk.

Soy Phospholipids Exert a Renoprotective Effect by Inhibiting the Nuclear Factor Kappa B Pathway in Macrophages

Complications associated with chronic kidney disease (CKD), which involves kidney inflammation, are a major health problem. Soy protein isolate (SPI) reportedly inhibits CKD exacerbation; however, its detailed action mechanism remains obscure. Therefore, the role of the polar lipid component of SPI in suppressing inflammation was investigated. Zucker fatty rats were divided into three groups and fed a diet containing casein, SPI, or casein + SPI ethanol extract (SPIEE) for 16 weeks. The isoflavones and phospholipids of SPIEE were evaluated for their anti-inflammatory effects. Rats in the SPI and casein + SPIEE groups showed reduced levels of the urinary N-acetyl-β-d-glucosaminidase and renal IL-1β mRNA (an inflammatory marker) compared with those in the casein group. In proximal tubular cells, genistein significantly inhibited monocyte chemoattractant protein-1 (MCP-1) expression induced by an IL-1β stimulus. In macrophages, soybean phospholipids suppressed lipopolysaccharide-induced IL-1β gene expression by inhibiting the phosphorylation of inhibitor κB and p65. Phosphatidylinositol (PI) was found to be essential for inhibition of IL-1β expression. SPIEE inhibited the exacerbation of kidney disease. Genistein and soybean phospholipids, especially soybean-specific phospholipids containing PI, effectively inhibited the inflammatory spiral in vitro. Hence, daily soybean intake may be effective for inhibiting chronic inflammation and slowing kidney disease progression.

Dietary protein sources and risk of diabetic nephropathy in women: A case-control study

BACKGROUND

Several studies have investigated the association between dietary protein and the risk of diabetic nephropathy (DN); however, there is no agreement on the type of dietary protein sources that might increase the risk of DN. This study was conducted to investigate the associations between different protein sources and the odds of DN developing in Iranian women with existing type 2 diabetes.

METHODS

In this case-control study, 105 women with DN and 105 controls, matched for age and diabetes duration, were selected from the Kowsar Diabetes Clinic in Semnan, Iran. Dietary intake was assessed using a validated and reliable food frequency questionnaire. Dietary protein patterns were estimated using the factor analysis method. Multivariate logistic regression was performed to examine the association between protein patterns and the odds of developing DN.

RESULTS

Two patterns were identified: the Mediterranean-based Dietary Protein Sources (MDPS) pattern which is rich in low-fat dairy, fish, poultry, soy, and legumes, and the Western-based Dietary Protein Sources (WDPS) pattern, rich in red and processed meats, eggs, and high-fat dairy. After adjusting for several confounders, greater adherence (third vs. the first tertile) to the MDPS pattern was associated with lower odds of DN (OR = 0.03; 95 % CI: 0.00, 0.10). In contrast, a strong positive association was observed between adherence to the WDPS pattern and DN (OR = 2.81; 95 % CI: 1.09-7.21).

CONCLUSIONS

Our results show that there is a potential association between the type of protein sources consumed and the odds of DN development in women with type 2 diabetes. Further studies are needed to confirm these findings.

Dietary Inflammatory Index and Ovarian Cancer Risk: A Meta-Analysis

Existing evidence suggests diet and chronic inflammation as risk factors in ovarian cancer (OC) development. We aim to conduct a meta-analysis exploring possible associations between dietary inflammatory potential and OC. A systematic search was conducted through PubMed, Scopus, Embase, and PMC databases for studies reporting relationships between dietary inflammatory potential and OC risk published up to September 2020. We included six studies for stepwise analysis, of which 5,468 among 197,086 individuals developed OC. Pooled odds ratios (ORs) were calculated by fixed-effects models, while heterogeneity was assessed by Q test and I² statistic. The results revealed a positive association between dietary inflammatory potential measured by the Dietary Inflammatory Index (DII) and OC(P < 0.05). Individuals with higher DII scores had a 42% increased risk of OC incidence [OR = 1.42, 95% confidence interval (CI): 1.19-1.65]. The analysis considering DII as a continuous variable showed an increased risk of 10% for 1-point increase of DII(OR = 1.10, 95% CI: 1.06-1.14). Subgroup analysis revealed that increased risk of OC in individuals with higher DII scores vs. those with lower DII was only significant among post-menopausal women(OR = 1.72, 95% CI: 1.26-2.21) rather than those pre/peri-menopausal(OR = 1.21, 95% CI: 0.63-1.79). Pro-inflammatory diets with higher DII score were significantly related to increased OC risk among post-menopausal women.

Potential Health Benefits Associated with Lunasin Concentration in Dietary Supplements and Lunasin-Enriched Soy Extract

Lunasin has demonstrated antioxidative, anti-inflammatory, and chemopreventive properties. The objectives were to evaluate the concentration of lunasin in different lunasin-based commercial dietary supplements, to produce a lunasin-enriched soy extract (LESE) using a two-step pilot-plant-based ultrafiltration process, and to evaluate their biological potential in vitro. LESE was produced using 30 and 1 kDa membranes in a custom-made ultrafiltration skid. Lunasin was quantified in eight products and LESE. Lunasin concentrations of the lunasin-based products ranged from 9.2 ± 0.6 to 25.7 ± 1.1 mg lunasin/g protein. The LESE extract contained 58.2 mg lunasin/g protein, up to 6.3-fold higher lunasin enrichment than lunasin-based dietary supplements. Antioxidant capacity ranged from 121.5 mmol Trolox equivalents (TE)/g in Now® Kids to 354.4 mmol TE/g in LESE. Histone acetyltransferase (HAT) inhibition ranged from 5.3% on Soy Sentials® to 38.3% on synthetic lunasin. ORAC and lunasin concentrations were positively correlated, and HAT and lunasin concentrations were negatively correlated (p < 0.05). Melanoma B16-F10 and A375 cells treated with lunasin showed dose-dependent inhibitory potential (IC50 equivalent to 330 and 370 μM lunasin, respectively). Lunasin showed protein kinase B expression (57 ± 14%) compared to the control (100%) in B16-F10. Lunasin concentration found in commercial products and lunasin-enriched soy extract could exert benefits to consumers.

The effects of soy supplementation on inflammatory biomarkers: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Soy products contain several compounds with anti-inflammatory properties like genistein and daidzein which reported to act through different pathways. Present study conducted considering the inconsistent results and lack of any comprehensive review regarding randomized controlled trials which assess the effect of soy products on inflammatory markers.

METHODS

Following electronic databases were searched up to March 2020: PubMed, Scopus, ISI web of science, and Cochrane Library All randomized trials which assessed the effect of soy product supplementation on c-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were included for last analysis. Treatment effects were expressed as mean difference (MD) and the standard deviation (SD) of outcomes. To estimate the overall effect the random-effects model was employed.

RESULTS

Finally, 51 randomized trial were included for present study. Last analysis showed that soy product supplementation lead to significant reduction in CRP (MD -0.27 mg/L; 95% CI: -0.51, -0.02, p = 0.028) but it did not affect IL-6 (MD 0.0 pg/ml; 95% CI: -0.06, 0.06, p = 0.970) and TNF-α (MD = -0.04 pg/ml; 95% CI: -0.11, 0.03, p = 0.252). Subgroup analysis showed that soy supplementation had a significant impact on decreasing IL-6 and TNF-α levels when studies had a long-term intervention (≥12 weeks) and used low dose isoflavone (<100 mg/day).

CONCLUSION

In conclusion, present systematic review and meta-analysis found a significant reduction in CRP levels after soy supplementation whiles IL-6 and TNF-α did not affect.

Synthesis, antidiabetic activity and molecular docking study of rhodanine-substitued spirooxindole pyrrolidine derivatives as novel α-amylase inhibitors

In a sustained search for novel α-amylase inhibitors for the treatment of type 2 diabetes mellitus (T2DM), we report herein the synthesis of a series of nineteen novel rhodanine-fused spiro[pyrrolidine-2,3'-oxindoles]. They were obtained by one-pot three component [3 + 2] cycloaddition of stabilized azomethine ylides, generated in situ by condensation of glycine methyl ester and the cyclic ketones 1H-indole-2,3-dione (isatin), with (Z)-5-arylidine-2-thioxothiazolidin-4-ones. The highlight of this protocol is the efficient high-yield construction of structurally diverse rhodanine-fused spiro[pyrrolidine-2,3'-oxindoles] scaffolds, including four contiguous stereocenters, along with excellent regio- and diastereoselectivities. The stereochemistry of all compounds was confirmed by NMR and corroborated by an X-ray diffraction study performed on one derivative. All cycloadducts were evaluated in vitro for their α-amylase inhibitory activity and showed good α-amylase inhibition with IC₅₀ values ranging between 1.49 ± 0.10 and 3.06 ± 0.17 µM, with respect to the control drug acarbose (IC₅₀ = 1.56 µM). Structural activity relationships (SARs) were also established for all synthesized compounds and the binding interactions of the most active spiropyrrolidine derivatives were modelledby means of molecular insilico docking studies. The most potent compounds 5 g, 5 k, 5 s and 5 l were further screened in vivo for their hypoglycemic activity in alloxan-induced diabetic rats, showing a reduction of the blood glucose level. Therefore, these spiropyrrolidine derivatives may be considered as promising candidates for the development of new classes of antidiabetic drugs.

Effects of soy milk consumption on gut microbiota, inflammatory markers, and disease severity in patients with ulcerative colitis: a study protocol for a randomized clinical trial

Background

Several strategies are recommended to alleviate clinical symptoms of ulcerative colitis (UC). Soy milk may affect UC through its anti-inflammatory properties. However, no study has examined the effects of soy milk consumption on gut microbiota and inflammatory biomarkers in patients with UC. The current study will be done to examine the effects of soy milk consumption on UC symptoms, inflammation, and gut microbiota in patients with UC.

Methods

This study is a randomized clinical trial, in which thirty patients with mild to moderate severity of UC will be randomly allocated to receive either 250 mL/day soy milk plus routine treatments (n = 15) or only routine treatments (n = 15) for 4 weeks. Assessment of anthropometric measures and biochemical indicators including serum concentrations of high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interferon gamma (IFN-γ) will be done at the study baseline and end of trial. In addition, the quantity of butyrate-producing bacteria including Clostridium cluster IV, Faecalibacterium prausnitzii, and Roseburia spp.; prebiotic bacteria including Lactobacillus spp. and Bifidobacteria spp.; and mucus-degrading bacteria including Akkermansia muciniphila, Bacteroides fragilis, and Ruminococcus spp., as well as calprotectin and lactoferrin levels, will be explored in fecal samples. Also, the Firmicutes to Bacteroidetes ratio which is of significant relevance in human gut microbiota composition will be assessed.

Discussion

Altered gut microbiota has been reported as an important contributing factor to inflammation in patients with inflammatory bowel disease (IBD). Soy milk contains several components such as phytoestrogens with potential anti-inflammatory properties. This product might affect gut microbiota through its protein and fiber content. Therefore, soy milk might beneficially affect systemic inflammation, gut microbiota, and then clinical symptoms in patients with UC.

Trial registration

Iranian Registry of Clinical Trials (www.irct.ir) IRCT20181205041859N1. Registered on 27 January 2019.

Gut microbiome-derived phenyl sulfate contributes to albuminuria in diabetic kidney disease

Diabetic kidney disease is a major cause of renal failure that urgently necessitates a breakthrough in disease management. Here we show using untargeted metabolomics that levels of phenyl sulfate, a gut microbiota-derived metabolite, increase with the progression of diabetes in rats overexpressing human uremic toxin transporter SLCO4C1 in the kidney, and are decreased in rats with limited proteinuria. In experimental models of diabetes, phenyl sulfate administration induces albuminuria and podocyte damage. In a diabetic patient cohort, phenyl sulfate levels significantly correlate with basal and predicted 2-year progression of albuminuria in patients with microalbuminuria. Inhibition of tyrosine phenol-lyase, a bacterial enzyme responsible for the synthesis of phenol from dietary tyrosine before it is metabolized into phenyl sulfate in the liver, reduces albuminuria in diabetic mice. Together, our results suggest that phenyl sulfate contributes to albuminuria and could be used as a disease marker and future therapeutic target in diabetic kidney disease.

Diabetes is a major cause of kidney disease. Here Kikuchi et al. show that phenol sulfate, a gut microbiota-derived metabolite, is increased in diabetic kidney disease and contributes to the pathology by promoting kidney injury, suggesting phenyl sulfate could be used a marker and therapeutic target for the treatment of diabetic kidney disease.

Dietary Inflammatory Index and Site-Specific Cancer Risk: A Systematic Review and Dose-Response Meta-Analysis

Existing evidence suggests a link between the inflammatory potential of diet and risk of cancer. This study aimed to test the linear and potential nonlinear dose-response associations of the Dietary Inflammatory Index (DII), as being representative of inflammatory features of the diet, and site-specific cancer risk. A systematic search was conducted with the use of PubMed and Scopus from 2014 to November 2017. Prospective cohort or case-control studies reporting the risk estimates of any cancer type for ≥3 categories of the DII were selected. Studies that reported the association between continuous DII score and cancer risk were also included. Pooled RRs were calculated by using a random-effects model. Eleven prospective cohort studies (total n = 1,187,474) with 28,614 incident cases and 29 case-control studies with 19,718 cases and 33,229 controls were identified. The pooled RRs for a 1-unit increment in the DII were as follows: colorectal cancer, 1.06 (95% CI: 1.04, 1.08; I2 = 72.5%; n = 9); breast cancer, 1.03 (95% CI: 1.00, 1.07; I2 = 84.0%; n = 7); prostate cancer, 1.06 (95% CI: 0.97, 1.15; I2 = 56.2%; n = 6); pancreatic cancer, 1.16 (95% CI: 1.05, 1.28; I2 = 61.6%; n = 2); ovarian cancer, 1.08 (95% CI: 1.03, 1.13; I2 = 0%; n = 2); esophageal squamous cell carcinoma, 1.24 (95% CI: 1.10, 1.38; I2 = 64.3%; n = 2); renal cell carcinoma, 1.08 (95% CI: 1.02, 1.13; I2 = 0%; n = 2); and esophageal adenocarcinoma, 1.26 (95% CI: 1.13, 1.39; I2 = 0%; n = 2). A nonlinear dose-response meta-analysis showed that, after a somewhat unchanged risk within initial scores of the DII, the risk of colorectal cancer increased linearly with increasing DII score. In the analyses of breast and prostate cancers, the risk increased with a very slight trend with increasing DII score. In conclusion, the results showed that dietary habits with high inflammatory features might increase the risk of site-specific cancers.

Impact of diet restriction in the management of diabetes: evidences from preclinical studies

The inappropriate dietary habits lead to the onset of age-related pathologies which include diabetes and cardiovascular ailments. Dietary restriction and nutritional therapy play an important role in the prevention of these chronic ailments. Preclinical research provides a basis for the therapeutic exploration of new dietary interventions for the clinical trials to potentiate the scientific management of diabetes and its related complications which further help in translating these nutritional improvements from bench to bedside. Within the same context, numerous therapeutically proved preclinical dietary interventions like high-fiber diet, caloric restriction, soy isoflavone-containing diets, etc., have shown the promising results for the management of diabetes and the associated complications. The focus of the present review is to highlight the various preclinical evidences of diet restriction for the management of diabetes and which will be helpful for enlightening the new ideas of nutritional therapy for future research exploration. In addition, some potential approaches are also discussed which are associated with various nutritional interventions to combat progressive diabetes and the associated disorders. Graphical abstract ᅟ.

Recombinant human GLP-1(rhGLP-1) alleviating renal tubulointestitial injury in diabetic STZ-induced rats

GLP-1-based treatment improves glycemia through stimulation of insulin secretion and inhibition of glucagon secretion. Recently, more and more findings showed that GLP-1 could also protect kidney from diabetic nephropathy. Most of these studies focused on glomeruli, but the effect of GLP-1 on tubulointerstitial and tubule is not clear yet. In this study, we examined the renoprotective effect of recombinant human GLP-1 (rhGLP-1), and investigated the influence of GLP-1 on inflammation and tubulointerstitial injury using diabetic nephropathy rats model of STZ-induced. The results showed that rhGLP-1 reduced urinary albumin without influencing the body weight and food intake. rhGLP-1 could increased the serum C-peptide slightly but not lower fasting blood glucose significantly. In diabetic nephropathy rats, beside glomerular sclerosis, tubulointerstitial fibrosis was very serious. These lesions could be alleviated by rhGLP-1. rhGLP-1 decreased the expression of profibrotic factors collagen I, α-SMA, fibronectin, and inflammation factors MCP-1 and TNFα in tubular tissue and human proximal tubular cells (HK-2 cells). Furthermore, rhGLP-1 significantly inhibited the phosphorylation of NF-κB, MAPK in both diabetic tubular tissue and HK-2 cells. The inhibition of the expression of TNFα, MCP-1, collagen I and α-SMA in HK-2 cells by GLP-1 could be mimicked by blocking NF-κB or MAPK. These results indicate that rhGLP-1 exhibit renoprotective effect by alleviation of tubulointerstitial injury via inhibiting phosphorylation of MAPK and NF-κB. Therefore, rhGLP-1 may be a potential drug for treatment of diabetic nephropathy.