Indole alkaloids of Alstonia scholaris (L.) R. Br. alleviated nonalcoholic fatty liver disease in mice fed with high-fat diet

Alstonia scholaris (L.) R. Br. ameliorated diabetic nephropathy through PPAR-δ pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Alstonia scholaris was utilized as a medicinal herb for the management of diabetes traditionally, with diabetic nephropathy (DN) was one of its major complications. However, the effect of A. scholaris on DN have yet to be explored.

AIM OF THE STUDY

To investigate the effect and mechanism of A. scholaris in treating DN.

MATERIALS AND METHODS

The high glucose (HG)-induced renal podocyte (MPC5) injury model was conducted in vitro, and DN mice induced by high fat diet and combined with streptozotocin (HFD + STZ) was employed to evaluate bioactivity in vivo. Transcriptome analysis was conducted to explore the potential targets of vallesamine, with findings further validated by RT-qPCR and WB analysis. Furthermore, the binding affinity of vallesamine to its potential target was investigated through molecular docking and dynamics simulation.

RESULTS

Four major alkaloids of A. scholaris demonstrated significant efficacy in mitigating HG-induced MPC5 cell damage, and they also restored oxidation balance while reducing the release of nitric oxide and lactate dehydrogenase. Oral administration of the total alkaloids and the four compounds for 6 weeks, respectively, could ameliorate proteinuria, urinary protein-to-creatinine ratio, hyperglycemia and hyperlipidemia significantly, and as well elevate serum levels of total protein and albumin concurrently in HFD + STZ induced mice. Moreover, renal injury and matrix hyperplasia were also improved after the treatment. Notably, vallesamine (5 mg/kg) exerted a pronounced effect on DN through upregulating Ppar-δ, Fads2, Me1, Ehhadh, Lpl, Scd1, Acsl1, and downregulating Hmgcs5, Slc27a1, Dbil5 and Plin5 gene expressions of PPAR pathway. Meanwhile, proteins related to lipid metabolism (PPAR-δ and ACSL1, HMGCS2) as well as the associated with renal inflammation (PODOCIN, BCL-2, and IL-6) were regulated by vallesamine intervention. In addition, vallesamine-PPAR-δ complexes maintained structural integrity, with the binding free energy of -25.84 kJ/mol, indicating a particularly high affinity between the ligand and the receptor in molecular dynamics and docking.

CONCLUSION

Total alkaloids from A. scholaris and its main components vallesamine alleviated kidney injury induced by HFD + STZ through modulation the PPAR-δ pathway, providing a potential strategy for the development of new botanical drug to treat DN.

Comparative efficacy and safety of antidiabetic drugs for obese patients with knee osteoarthritis: a network meta-analysis of randomized controlled trials

BACKGROUND

Obesity-related knee osteoarthritis (KOA) is a significant public health concern, affecting quality of life. Recent evidence suggests some antidiabetic drugs may help manage KOA in obese patients due to their anti-inflammatory and weight-reducing effects.

OBJECTIVE

This study aimed to compare the efficacy and safety of antidiabetic drugs for managing pain and adverse events in obese KOA patients through a network meta-analysis of randomized controlled trials (RCTs).

METHODS

A systematic search of multiple databases identified relevant RCTs on antidiabetic drugs for KOA. Treatment efficacy was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score improvement, and safety was evaluated based on the incidence of serious adverse events. The Surface Under the Cumulative Ranking Curve (SUCRA) scores were used to rank the treatments, and effect sizes were reported as mean differences (MD) with 95% confidence intervals (CI).

RESULTS

A total of nine RCTs were included in the analysis. For pain relief, metformin demonstrated the largest effect size with a mean difference of - 1.13 (95% CI - 1.48, - 0.78) compared to usual care, followed by Metformin-Phosphatidylcholine (MFPH) (- 0.92, 95% CI - 1.70, - 0.13) and semaglutide (- 0.90, 95% CI - 1.48, - 0.32). In terms of safety, usual care exhibited the lowest risk of adverse events, with liraglutide (0.09, 95% CI - 0.74, 0.92) and semaglutide (0.21, 95% CI - 0.46, 0.88) also showing favorable safety profiles. The SUCRA rankings further supported these findings, with metformin ranking highest for efficacy (SUCRA: 86.8%) and usual care ranking highest for safety (SUCRA: 75.7%). However, these rankings should be interpreted alongside the effect sizes and clinical context to fully assess the trade-offs between efficacy and safety across interventions.

CONCLUSIONS

Metformin and MFPH are promising for managing KOA pain in obese patients. Semaglutide offers a balanced efficacy and safety profile, while liraglutide may be a safe option for selected patients. Further research is needed to confirm these findings and assess long-term outcomes.

Impacts of live and artificial feed on histology, biochemical indicators, gene expression, and bacterial resistance in mandarin fish (Siniperca chuatsi)

The mandarin fish (Siniperca chuatsi) is a significant freshwater carnivorous species in Chinese aquaculture industry, and its farming scale is continuously expanding. The use of feed in aquaculture has become an increasingly common practice. However, the impacts of substituting artificial feed for live bait on fish's biochemical and immune responses are poorly understood. In this study, two hundred forty mandarin fish (weight: 5.60 ± 0.41 g) were divided into two groups and fed live bait or artificial feed (LB and AF groups) over a 63-day aquaculture experiment. We compared the differences between the two groups in terms of histology, biochemical indicators, gene expression, and bacterial resistance. The results showed that artificial feed promoted enhanced growth, evidenced by higher weight (p < 0.05). The AF group exhibited higher liver and intestinal somatic indices (p < 0.05), and histological examination revealed denser cytoplasmic content in liver cells, less fragmentation of renal tubular epithelial cells, and less detachment of intestinal epithelial cells in the AF group. Regarding biochemical indicators and gene expression, the AF group showed better performance in glucose regulation and lipid metabolism. The AF group maintained glucose balance (p < 0.05) and effectively regulated cholesterol transport (p < 0.05), promoting lipolysis (p < 0.05) while inhibiting lipogenesis (p < 0.05). In contrast, live bait consumption resulted in reduced lipolysis (p < 0.05), increased lipogenesis (p < 0.05), impaired endoplasmic reticulum function (p < 0.05), heightened inflammation (p < 0.05), and diminished antioxidant capacity (p < 0.05). Additionally, the LB group exhibited lower survival rates and lysozyme levels during bacterial challenges. Overall, artificial feed was more beneficial for the growth, regulate physiology and enhance disease resistance of S. chuatsi, highlighting its potential to improve fish health and increase aquaculture yield.

Oxymatrine reduces hepatic lipid synthesis in rat model of nonalcoholic steatohepatitis by regulating Sirt1/AMPK and LXR/Plin2/SREBP-1c pathways

Nonalcoholic Steatohepatitis (NASH) is a common liver disease with limited treatment options. Oxymatrine (OMT) has been reported to treat liver diseases effectively. This study aims to explore the mechanisms of OMT in NASH. Male Sprague-Dawley rats were fed a high-fat and high-sucrose diet and hepatocytes were stimulated with oleic acid (OA) to establish NASH models, then, NASH models were intervened with OMT. In vivo, liver injury and lipid accumulation extents were evaluated by serum and liver biochemical indexes, and histological analysis. In vitro, cell viability and lipid accumulation degrees were measured. Additionally, the relationships between perilipin 2 (Plin2) and liver X-activated receptor alpha (LXRα) as well as Plin2 and sterol regulatory element binding protein-1c (SREBP-1c), sirtuin 1 (Sirt1)/adenosine 5'-monophosphate-activated protein kinase (AMPK) pathway-, liver X-activated receptor (LXR)/Plin2/SREBP-1c pathway- and lipid synthesis-related proteins were detected both in vivo and in vitro. Finally, Sirt1 was knocked down in hepatocytes. OMT not only reduced serum alanine aminotransferase activity and triglyceride content, liver triglyceride and free fatty acid levels in NASH rats, but also improved hepatic injury and lipid accumulation. In vitro, OMT enhanced viability, and downregulated lipid accumulation in OA-induced hepatocytes. Both in vivo and in vitro results revealed Plin2 directly interacted with LXRα and SREBP-1c, and OMT activated Sirt1/AMPK pathway but inhibited the expressions of LXR/Plin2/SREBP-1c pathway and lipid synthesis (acetyl-CoA carboxylase, fatty acid synthase, stearoyl-Coenzyme A desaturase 1) related proteins in NASH models. Importantly, Sirt1 knockdown reversed the protective effects of OMT in OA-stimulated hepatocytes. OMT may reduce hepatic lipid synthesis in NASH by activating the Sirt1/AMPK pathway and inhibiting the LXR/Plin2/SREBP-1c pathway, suggesting that OMT may be a promising strategy for treating NASH.

Kakuol and asarinin protecting liver injury via HSP90AA1/CDK2/mTOR signaling pathway

Drug-induced liver injury caused acute hepatic failure and hepatitis frequently. In this investigation, kakuol and asarinin reduced the levels of serum alanine transaminase (ALT), aspartate transaminase (AST) and malondialdehyde (MDA) dramatically, and ameliorated the pathological damage of liver tissues in APAP-induced mice. Furthermore, both compounds increased the viabilities of APAP-induced L-O2 cells and extracellular glutathione (GSH) levels accompanied significantly by reducing the level of intracellular ROS in vitro. In addition, HSP90AA1/CDK2/mTOR signaling pathway and five target proteins (CDK2, HSP90AA1, HRAS, MMP1, mTOR) were proposed from network pharmacology and molecular docking prediction, and then the up-regulation of protein expression of CDK2, mTOR and down-regulation of HSP90AA1, HRAS, MMP1 by kakuol and asarinin in western blotting supported their mechanism.

Multiomics analysis investigating the impact of a high-fat diet in female Sprague-Dawley rats: alterations in plasma, intestinal metabolism, and microbial composition

Introduction

With improvements in living conditions, modern individuals exhibit a pronounced inclination towards a high-fat diet, largely because of its distinctive gustatory appeal. However, the association between high-fat diets and metabolic complications has largely been ignored, and metabolic diseases such as obesity and non-alcoholic fatty liver disease now constitute a major public health concern. Because high-fat diets increase the risk of metabolic diseases, a thorough investigation into the impact of high-fat diets on gut microbiota and metabolism is required.

Methods

We utilize 16S rRNA sequencing and untargeted metabolomics analysis to demonstrate that SD rats fed a high-fat diet exhibited marked alterations in gut microbiota and plasma, intestinal metabolism.

Results

Changes in gut microbiota included a decreased abundance at phylum level for Verrucomicrobiota, and a decreased abundance at genus level for Akkermansia, Ralstonia, Bacteroides, and Faecalibacterium. Additionally, significant changes were observed in both intestinal and plasma metabolite levels, including an upregulation of bile acid metabolism, an upregulation of glucose-lipid metabolism, and increased levels of metabolites such as norlithocholic acid, cholic acid, D-fructose, D-mannose, fructose lactate, and glycerophosphocholine. We also investigated the correlations between microbial communities and metabolites, revealing a significant negative correlation between Akkermansia bacteria and cholic acid.

Discussion

Overall, our findings shed light on the relationship between symbiotic bacteria associated with high-fat diets and metabolic biomarkers, and they provide insights for identifying novel therapeutic approaches to mitigate disease risks associated with a high-fat diet.

Undescribed indole lactones from Alstonia scholaris protecting hepatic cell damage

Six previously undescribed rigidly monoterpenoid indole alkaloids, alstolactines F-K (1-6), were isolated from Alstonia scholaris. Among them, a pair of cage-like epimers, 1 and 2, featuring a rare 6/5/6/6/7 ring system, represent the first example of C5→C20-olide, while compound 3 possesses unique degraded C18 and C19. The structures of the isolates were established by multiple spectroscopic analyses, quantum computational chemistry methods, and X-ray diffraction. Furthermore, the expression levels of proteins including NLRP3, TLR4, P-p65, NF-ĸB, Notch-2, IL-18, P-p38, and p38 in LPS-induced human normal hepatocyte (LO2) cells could be significantly downregulated by compounds 1-6, which showed potent anti-inflammatory bioactivity.

Uncarialines A-E, new alkaloids from Uncaria rhynchophylla and their anticoagulant activity

Uncarialines A-E (1-5), five undescribed monoterpene indole alkaloids, together with five known analogues were obtained from the stems of Uncaria rhynchophylla. Alkaloids 1-3 were unique 3,4-seco-tricyclic alkaloids with a 6/5/10 ring system, while 4 and 5 possessed a rare rearranged scaffold originated from corynantheine-type alkaloids with C-2/C-7 oxidation. Their structures were characterized by a comprehensive analysis of MS, NMR, and ECD. Their effects on blood clotting times of human plasma were evaluated and alkaloid 5 had a slight prolongation effect on both thrombin time and activated partial thromboplastin time (p < 0.001).

The Protective Effect of (-)-Tetrahydroalstonine against OGD/R-Induced Neuronal Injury via Autophagy Regulation

Here, (-)-Tetrahydroalstonine (THA) was isolated from Alstonia scholaris and investigated for its neuroprotective effect towards oxygen-glucose deprivation/re-oxygenation (OGD/R)-induced neuronal damage. In this study, primary cortical neurons were pre-treated with THA and then subjected to OGD/R induction. The cell viability was tested by the MTT assay, and the states of the autophagy-lysosomal pathway and Akt/mTOR pathway were monitored by Western blot analysis. The findings suggested that THA administration increased the cell viability of OGD/R-induced cortical neurons. Autophagic activity and lysosomal dysfunction were found at the early stage of OGD/R, which were significantly ameliorated by THA treatment. Meanwhile, the protective effect of THA was significantly reversed by the lysosome inhibitor. Additionally, THA significantly activated the Akt/mTOR pathway, which was suppressed after OGD/R induction. In summary, THA exhibited promising protective effects against OGD/R-induced neuronal injury by autophagy regulation through the Akt/mTOR pathway.

Therapeutic roles of plants for 15 hypothesised causal bases of Alzheimer's disease

Alzheimer's disease (AD) is progressive and ultimately fatal, with current drugs failing to reverse and cure it. This study aimed to find plant species which may provide therapeutic bioactivities targeted to causal agents proposed to be driving AD. A novel toolkit methodology was employed, whereby clinical symptoms were translated into categories recognized in ethnomedicine. These categories were applied to find plant species with therapeutic effects, mined from ethnomedical surveys. Survey locations were mapped to assess how this data is at risk. Bioactivities were found of therapeutic relevance to 15 hypothesised causal bases for AD. 107 species with an ethnological report of memory improvement demonstrated therapeutic activity for all these 15 causal bases. The majority of the surveys were found to reside within biodiversity hotspots (centres of high biodiversity under threat), with loss of traditional knowledge the most common threat. Our findings suggest that the documented plants provide a large resource of AD therapeutic potential. In demonstrating bioactivities targeted to these causal bases, such plants may have the capacity to reduce or reverse AD, with promise as drug leads to target multiple AD hallmarks. However, there is a need to preserve ethnomedical knowledge, and the habitats on which this knowledge depends.