Metabolic Profiling of Carbonyl Compounds for Unveiling Protective Mechanisms of Pueraria lobata against Diabetic Nephropathy by UPLC-Q-Orbitrap HRMS/MS Analysis

Proteomic and lipidomic analysis of the mechanism underlying astragaloside IV in mitigating ferroptosis through hypoxia-inducible factor 1α/heme oxygenase 1 pathway in renal tubular epithelial cells in diabetic kidney disease

ETHNOPHARMACOLOGICAL RELEVANCE

The limitations of modern medicine in mitigating the pathological process of diabetic kidney disease (DKD) necessitate novel, precise, and effective prevention and treatment methods. Huangqi, the root of Astragalus membranaceus Fisch. ex Bunge has been used in traditional Chinese medicine for various kidney ailments. Astragaloside IV (AS-IV), the primary pharmacologically active compound in A. membranaceus, is involved in lipid metabolism regulation; however, its potential in ameliorating renal damage in DKD remains unexplored.

AIM OF THE STUDY

To elucidate the specific mechanism by which AS-IV moderates DKD progression.

MATERIALS AND METHODS

A murine model of DKD and high glucose-induced HK-2 cells were treated with AS-IV. Furthermore, multiomics analysis, molecular docking, and molecular dynamics simulations were performed to elucidate the mechanism of action of AS-IV in DKD, which was validated using molecular biological methods.

RESULTS

AS-IV regulated glucose and lipid metabolism in DKD, thereby mitigating lipid deposition in the kidneys. Proteomic analysis identified 12 proteins associated with lipid metabolism regulated by AS-IV in the DKD renal tissue. Additionally, lipid metabolomic analysis revealed that AS-IV upregulated and downregulated 4 beneficial and 79 harmful lipid metabolites, respectively. Multiomics analysis further indicated a positive correlation between the top-ranked differential protein heme oxygenase (HMOX)1 and the levels of various harmful lipid metabolites and a negative correlation with the levels of beneficial lipid metabolites. Furthermore, enrichment of both ferroptosis and hypoxia-inducible factor (HIF)-1 signaling pathways during the AS-IV treatment of DKD was observed using proteomic analysis. Validation results showed that AS-IV effectively reduced ferroptosis in DKD-affected renal tubular epithelial cells by inhibiting HIF-1α/HMOX1 pathway activity, upregulating glutathione peroxidase-4 and ferritin heavy chain-1 expression, and downregulating acyl-CoA synthetase long-chain family member-4 and transferrin receptor-1 expression. Our findings demonstrate the potential of AS-IV in mitigating DKD pathology by downregulating the HIF-1α/HMOX1 signaling pathway, thereby averting ferroptosis in renal tubular epithelial cells.

CONCLUSIONS

AS-IV is a promising treatment strategy for DKD via the inhibition of ferroptosis in renal tubular epithelial cells. The findings of this study may help facilitate the development of novel therapeutic strategies.

Huang-Lian-Jie-Du Decoction Alleviates Diabetic Encephalopathy by Regulating Inflammation and Pyroptosis via Suppression of AGEs/RAGE/NF-κB Pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Cognitive dysfunction associated with diabetes, known as diabetic encephalopathy (DE), is a grave neurodegenerative condition triggered by diabetes, and persistent inflammation plays a vital role in its development. The renowned traditional Chinese medicine Huang-Lian-Jie-Du Decoction (HLJDD) is clinically proven to manage diabetes mellitus and Alzheimer's disease and is famous for its heat-clearing and detoxifying effects. However, the underlying mechanisms through which HLJDD affects DE remain to be elucidated.

AIM OF THE STUDY

To explore the beneficial effects of HLJDD on improving cognitive dysfunction in DE mice.

STUDY DESIGN AND METHODS

A diabetic mouse was established through a high-fat diet and subsequent administration of streptozotocin over five consecutive days. After the animals were confirmed to have diabetes, they were treated with HLJDD. After oral administration of HLJDD or metformin for 14 weeks, behavioral tests were used to assess their cognitive capacity. Biochemical analyses were then performed to detect levels of glucose metabolism, followed by histological analyses to assess pathological damage. Furthermore, AGEs/RAGE/NF-κB axis related proteins were detected by Western blot or immunofluorescence techniques. An advanced UPLC-Q-Orbitrap HRMS/MS analytical technique utilizing a chemical derivatization strategy was employed for comprehensive metabolic profiling of carbonyl compounds in the plasma of DE mice.

RESULTS

Pharmacological assessment revealed that HLJDD effectively mitigated cognitive dysfunction, normalized glucose metabolic imbalances, and repaired neuronal damage in DE mice. It reduced neuroinflammation by attenuating carbonyl stress, deactivating astrocytes and microglia, and preserving dopaminergic neurons. Additionally, metabolomics analysis revealed 18 carbonyl compounds with marked disparities between DE and control mice, with 12 metabolites approaching normal levels post-HLJDD intervention. Further investigations showed that HLJDD regulated inflammation and pyroptosis through suppressing AGEs/RAGE/NF-κB pathways.

CONCLUSION

Our study indicated that HLJDD could ameliorate carbonyl stress via the regulation of carbonyl compound metabolism profiling, and inhibiting the AGEs/RAGE/NF-κB pathway, thereby alleviating inflammation and pyroptosis to exert beneficial effects on DE.

Profiling of Antidiabetic Bioactive Flavonoid Compounds from an Edible Plant Kudzu (Pueraria lobata)

Pueraria lobata (Willd.) Ohwi, known as kudzu and used as a "longevity powder" in China, is an edible plant which is rich in flavonoids and believed to be useful for regulating blood sugar and treating diabetes, although the modes of action are unknown. Here, a total of 53 flavonoids including 6 novel compounds were isolated from kudzu using multidimensional preparative liquid chromatography. The flavonoid components were found to lower blood sugar levels, promote urine sugar levels in mice, and reduce the urine volume. Molecular docking and in vitro assays suggested that the antidiabetic effect of kudzu was attributed to at least three targets: sodium-dependent glucose transporter 2 (SGLT2), protein tyrosine phosphatase-1B (PTP1B), and alpha-glucosidase (AG). This study suggests a possible mechanism for the antidiabetic effect that may involve the synergistic action of multiple active compounds from kudzu.

Protein Tyrosine Phosphatase 1B Inhibitors of Pueraria lobata Based on the Spectrum-Effect Relationship by Q-Marker Selection

Pueraria lobata (P. lobata), a traditional anti-diabetic medicine mainly composed of flavonoids and isoflavones, has a long history in diabetes treatment in China. However, the anti-diabetic active component is still unclear. Recently, protein tyrosine phosphatase 1B (PTP1B) has been a hot therapeutic target by negatively regulating insulin signaling pathways. In this study, the spectrum-effect relationship analysis method was first used to identify the active components of P. lobata that inhibit PTP1B. The fingerprints of 12 batches of samples were established using high-performance liquid chromatography (HPLC), and sixty common peaks were identified. Meanwhile, twelve components were identified by a comparison with the standards. The inhibition of PTP1B activity was studied in vitro by using the p-nitrophenol method, and the partial least squares discriminant analysis, grey relational analysis, bivariate correlation analysis, and cluster analysis were used to analyze the bioactive compounds in P. lobata. Peaks 6, 9 (glycitin), 11 (genistin), 12 (4'-methoxypuerarin), 25, 34, 35, 36, 53, and 59 were considered as potentially active substances that inhibit PTP1B. The in vitro PTP1B inhibitory activity was confirmed by glycitin, genistin, and 4'-methoxypuerarin. The IC50s of the three compounds were 10.56 ± 0.42 μg/mL, 16.46 ± 0.29 μg/mL, and 9.336 ± 0.56 μg/mL, respectively, indicating the obvious PTP1B inhibitory activity. In brief, we established an effective method to identify PTP1B enzyme inhibitors in P. lobata, which is helpful in clarifying the material basis of P. lobata on diabetes. Additionally, it is evident that the spectrum-effect relationship method serves as an efficient approach for identifying active compounds, and this study can also serve as a reference for screening bioactive constituents in traditional Chinese medicine.

Comparative study on Angelica sinensis after different processing with yellow rice wine in color, aromas, chemical components, and antioxidant activities

This study aimed to explore the differences in raw Angelica Sinensis (RAS), wine washing AS (WAS), and wine stir-frying AS (WSAS). The results showed there were differences among the three AS in color and aroma, and 34 aroma compounds were identified. The content determination results revealed the ferulic acid and Z-ligustilide levels of RAS decreased after processing, and those in WAS were higher than in WSAS. Furthermore, 85 representative common components and 37 unique components were tentatively identified in three AS. Finally, the free radical scavenging assay results indicated the antioxidant capacity of RAS was reduced after processing, and the antioxidant capacity of WAS was better than WSAS. Collectively, the RAS undergoes significant changes in color, aromas, components, and antioxidant ability after processing, and the different processing methods also result in significant differences between WAS and WSAS.

Pterostilbene could alleviate diabetic cognitive impairment by suppressing TLR4/NF-кB pathway through microbiota-gut-brain axis

Diabetic cognitive impairment (DCI) is a serious neurodegenerative disorder caused by diabetes, with chronic inflammation being a crucial factor in its pathogenesis. Pterostilbene is a well-known natural stilbene derivative that has excellent anti-inflammatory activity, suggesting its potential medicinal advantages for treating DCI. Therefore, this study is to explore the beneficial effects of pterostilbene for improving cognitive dysfunction in DCI mice. A diabetic model was induced by a high-fat diet plus streptozotocin (40 mg·kg-1 ) for consecutive 5 days. After the animals were confirmed to be in a diabetic state, they were treated with pterostilbene (20 or 60 mg·kg-1 , i.g.) for 10 weeks. Pharmacological evaluation showed pterostilbene could ameliorate cognitive dysfunction, regulate glycolipid metabolism disorders, improve neuronal damage, and reduce the accumulation of β-amyloid in DCI mice. Pterostilbene alleviated neuroinflammation by suppressing oxidative stress and carbonyl stress damage, astrocyte and microglia activation, and dopaminergic neuronal loss. Further investigations showed that pterostilbene reduced the level of lipopolysaccharide, modulated colon and brain TLR4/NF-κB signaling pathways, and decreased the release of inflammatory factors, which in turn inhibited intestinal inflammation and neuroinflammation. Furthermore, pterostilbene could also improve the homeostasis of intestinal microbiota, increase the levels of short-chain fatty acids and their receptors, and suppress the loss of intestinal tight junction proteins. In addition, the results of plasma non-targeted metabolomics revealed that pterostilbene could modulate differential metabolites and metabolic pathways associated with inflammation, thereby suppressing systemic inflammation in DCI mice. Collectively, our study found for the first time that pterostilbene could alleviate diabetic cognitive dysfunction by inhibiting the TLR4/NF-κB pathway through the microbiota-gut-brain axis, which may be one of the potential mechanisms for its neuroprotective effects.

LC-MS Profiling of Kakkonto and Identification of Ephedrine as a Key Component for Its Anti-Glycation Activity

A total of 147 oral Kampo prescriptions, which are used clinically in Japan, were evaluated for their anti-glycation activity. Kakkonto demonstrated significant anti-glycation activity, prompting further analysis of its chemical constituents using LC-MS, which revealed the presence of two alkaloids, fourteen flavonoids, two but-2-enolides, five monoterpenoids, and four triterpenoid glycosides. To identify the components responsible for its anti-glycation activity, the Kakkonto extract was reacted with glyceraldehyde (GA) or methylglyoxal (MGO) and analyzed using LC-MS. In LC-MS analysis of Kakkonto reacted with GA, the peak intensity of ephedrine was attenuated, and three products from ephedrine-scavenging GA were detected. Similarly, LC-MS analysis of Kakkonto reacted with MGO revealed two products from ephedrine reacting with MGO. These results indicated that ephedrine was responsible for the observed anti-glycation activity of Kakkonto. Ephedrae herba extract, which contains ephedrine, also showed strong anti-glycation activity, further supporting ephedrine's contribution to Kakkonto's reactive carbonyl species' scavenging ability and anti-glycation activity.

The chemistry and activity-orientedcharacterization of isoflavones difference between roots of Pueraria lobata and P. thomsonii guided by feature-based molecular networking

Isoflavones are important chemical components in Pueraria species with various biological activities. This study proposed an integrated strategy combining feature-based molecular networking (FBMN), chemometrics and activity evaluation for isoflavone analysis in the roots of P. lobate (PLR) and P. thomsonii (PTR). Based on the strategy, a total of 68 isoflavones were annotated in the two Pueraria species, and 11 significant difference isoflavones between PLR and PTR were identified by chemometric methods. Additionally, the correlation coefficient between the characteristic isoflavones and hypoglycemic activity were calculated, and 7 isoflavones were further confirmed as bioactive marker compounds. This approach provided guidance for the discovery of active markers among different products.

Analysis of Isoflavones in Pueraria by UHPLC-Q-Orbitrap HRMS and Study on α-Glucosidase Inhibitory Activity

Pueraria is a rich source of bioactive compounds, but there is a lack of comprehensive information concerning its composition. Therefore, a UHPLC-Q-Orbitrap HRMS method was developed to identify and quantify bioactive compounds in pueraria. Twelve isoflavones were quantified, with puerarin being the most abundant, followed by puerarin 6″-O-xyloside, 3′-methoxy puerarin, and 3′-hydroxy puerarin. A further 88 bioactive components in eight categories were also tentatively identified. The 12 isoflavones, except for genistein, exhibited α-glucosidase inhibitory activity. The binding of these compounds to the active site of α-glucosidase was confirmed via molecular docking analysis. These findings provide a basis for identifying pueraria as a promising functional food ingredient.

Trilobatin alleviates non-alcoholic fatty liver disease in high-fat diet plus streptozotocin-induced diabetic mice by suppressing NLRP3 inflammasome activation

Diabetes mellitus (DM) is a factor with great risk in the course of non-alcoholic fatty liver disease (NAFLD) due to its high glucotoxicity and lipotoxicity. Trilobatin, a glycosylated dihydrochalcone derived from the leaves of the Chinese sweet tea Lithocarpus polystachyus Rehd, is reported to possess various pharmacological activities. Nevertheless, it is still unclear regarding if trilobatin can alleviate liver injury in diabetic mice with NAFLD and its mechanism. Our aim was to investigative the protective effects of trilobatin against DM with NAFLD and its mechanism of action. A DM mice model was established by high-fat diet (HFD) feeding with streptozocin (STZ) injections, and treated with trilobatin for 10 weeks. The biochemical results showed that trilobatin restored glucose metabolic disorder and liver function in diabetic mice. The histopathological evaluation revealed that trilobatin improved liver injury by alleviating lipid accumulation and liver fibrosis. Mechanistically, trilobatin decreased expression of NLRP3, p65 NF-κB, cleaved-Caspase-1 and N-GSDMD, as well as the release of IL-18 and IL-1β, leading to a alleviation of inflammation and pyroptosis. Taken together, we determined for the first time found that trilobatin could prevent liver injury in diabetic mice with NAFLD by suppressing NLRP3 inflammasome activation to reduce inflammation and pyroptosis.

Hesperetin, a Promising Treatment Option for Diabetes and Related Complications: A Literature Review

The morbidity and mortality of diabetes have increased dramatically in recent decades. Novel strategies for treating diabetes and its complications with minimal side effects are in urgent need. New monomeric molecules extracted from herbal medicine, which is a form of alternative medicine, are being sought as drug candidates for the treatment of diabetes and its complications. Hesperetin (Hst), a citrus flavonoid, is of increasing interest in scientific studies recently due to its properties in combating diabetes and its complications, whereas existing studies are scattered and unsystematic. Here, we summarized the literature studies over the last 10 years to review the potential therapeutic role of Hst in the prevention and mitigation of diabetes and its complications, intending to provide promising strategies for the clinical management of diabetes and its complications.

Effects of natural dihydrochalcones in sweet tea (Lithocarpus polystachyus) on diabetes: a systematical review and meta-analysis of animal studies

Sweet tea (Lithocarpus polystachyus Rehd.), a natural functional food highly rich in dihydrochalcones including trilobatin, phlorizin and phloretin, is reported to possess numerous biological activities especially for treating diabetes. Here, the aim of this systematical review and meta-analysis is to assess the effect of dihydrochalcones in sweet tea (DST) on diabetes and summarize their possible mechanisms. We searched in eight databases including Embase, PubMed, Cochrane, Web of Science, WanFang database, VIP database, China National Knowledge Infrastructure and China Biology Medicine from Jan 2000 to Nov 2021 and ultimately included 21 animal studies in this review. A total of 10 outcome measurements including blood lipid indexes, blood glucose, insulin resistance indicators and oxidative stress biomarkers were extracted for meta-analysis using RevMan 5.4 software. DST significantly decreased the levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), blood glucose (BG), homeostasis model assessment of insulin resistance (HOMA-IR) and malondialdehyde (MDA), and increased high-density lipoprotein cholesterol (HDL-c), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity in diabetic animal models. In summary, DST could treat diabetes by regulation of blood glucose/lipid metabolism, oxidative/carbonyl stress, inflammatory response etc.