Metformin and digestive disorders

Senotherapeutic repurposing of metformin for age-related diseases and their signaling pathways

Drug repurposing is the process of using currently approved drugs for a novel treatment or medical condition for which it was not previously indicated. Despite promising preclinical and clinical results, most of the newly designed senotherapeutic agents synthesized have limited clinical utility due to individual and organ-specific variations in aging phenotype and adverse side effects. All these limitations indicate that further clinical research is required to determine the effectiveness of repurposed senotherapeutic drug interventions, such as metformin, for age-related diseases. Metformin exerts diverse senotherapeutic effects on various aging tissues at different metabolic conditions. Although not exhibiting senolytic properties, metformin has effectively suppressed cellular senescence and senescence-associated secretory phenotype (SASP) in age-related diseases (ARDs). Targeting specific SASP-related signaling pathways with metformin may offer new therapeutic benefits to alleviate the detrimental effects of senescent cells accumulated in most common ARDs in the elderly. Metformin was also the first drug evaluated for its senescence-targeting effects in a large clinical trial named "Targeting Aging with Metformin (TAME)". In this review, we critically evaluate the literature to highlight senotherapeutic mechanisms in which metformin can be therapeutically repurposed for the prevention and treatment of ARDs.

Metabolic anomalies in vitiligo: a new frontier for drug repurposing strategies

Vitiligo is a chronic autoimmune condition characterized by the destruction of melanocytes, leading to patchy loss of skin depigmentation. Although its precise cause remains unclear, recent evidence suggests that metabolic disturbances, particularly oxidative stress and mitochondrial dysfunction, may play a significant role in the pathogenesis of the disease. Oxidative stress is thought to damage melanocytes and trigger inflammatory responses, culminating in melanocyte immune-mediate destruction. Additionally, patients with vitiligo often exhibit extra-cutaneous metabolic abnormalities such as abnormal glucose metabolism, dyslipidemia, high fasting plasma glucose levels, high blood pressure, out of range C-peptide and low biological antioxidant capacity, suggesting a potential link between metabolic impairment and vitiligo development. This implies that the loss of functional melanocytes mirrors a more general systemic targetable dysfunction. Notably, therapies targeting metabolic pathways, particularly those involving mitochondrial metabolism, such as the peroxisome proliferator-activated nuclear receptor γ (PPARγ) agonists, are currently being investigated as potential treatments for vitiligo. PPARγ activation restores mitochondrial membrane potential, mitochondrial DNA copy number and, consequently, ATP production. Moreover, PPARγ agonists counteract oxidative stress, reduce inflammation, inhibit apoptosis, and maintain fatty acid metabolism, in addition to the well-known capability to enhance insulin sensitivity. Additionally, increasing evidence of a strong relationship between metabolic alterations and vitiligo pathogenesis suggests a role for other approved anti-diabetic treatments, like metformin and fibrates, in vitiligo treatment. Taken together, these data support the use of approaches alternative to traditional immune-suppressive treatments for the treatment of vitiligo.

Study on the mechanism of the Chinese herbal pair Banxia-Chenpi in ameliorating polycystic ovary syndrome based on the CYP17A1 gene

ETHNOPHARMACOLOGICAL RELEVANCE

As a typical Traditional Chinese Medicine (TCM) couplet medicine, Arum Ternatum Thunb. (Pinellia ternata (Thunb.) Makino, known as Banxia in Chinese) and Citrus Reticulata (pericarps of Citrus reticulata Blanco, known as Chenpi in Chinese) has been widely used in clinical practice for their properties of drying dampness, resolving phlegm, relieving oppression and masses. According to the TCM theories, the imbalance in fluid metabolism could lead to the accumulation of the excess dampness and phlegm, resulting in the pathological phenotype as 'damp-phlegm syndrome'. It can further lead to polycystic ovary syndrome (PCOS) when this accumulation of the excess fluid presents in uterus, affecting women's fertility and endocrine function. Recent studies have indicated that Banxia-Chenpi herbal pair (BXCP) exhibits significant therapeutic effects on damp-phlegm syndrome, yet the precise mechanisms underlying its anti-PCOS actions remain to be fully elucidated.

AIM OF THE STUDY

The objective was to investigate the signaling pathway involved in steroid biosynthesis, particularly the cytochrome P450 family 17, subfamily A, member 1 (CYP17A1), and to evaluate the effects and mechanisms of BXCP in ameliorating PCOS through both in vivo and in vitro experiments.

MATERIALS AND METHODS

A systematic evaluation was conducted to assess BXCP's effects on serum biochemical indicators and ovarian tissue pathology in a PCOS rat model (induced by high-fat diet + letrozole) and a DHT-induced human granulosa cells (KGN) model. Core targets were screened using absorbed components analysis, bioinformatics, metabolomics, and network analysis. RT-qPCR and Western blot techniques were employed to confirm the expression of CYP17A1 and related signaling molecule expression during BXCP's amelioration of PCOS, both in vivo and in vitro.

RESULTS

BXCP significantly ameliorated PCOS in vivo by mitigating weight gain, regulating estrus cycles, and normalizing sex hormone levels in rats. It upregulated metabolites related to steroid biosynthesis, including cortolone and progesterone, with CYP19A1, AKR1C3, and HSD17B1 as key regulators of CYP17A1. The main BXCP components, Naringenin and Nobiletin, increased CYP17A1 and CYP19A1 protein expression while decreased AKR1C3 and HSD17B1.

CONCLUSION

In conclusion, BXCP ameliorates PCOS by activating the CYP17A1-centered steroid biosynthesis pathway. These findings provide new insights into BXCP's clinical potentials in the management of patients with PCOS, highlighting the importance of TCM in modern medicine.

Disparities in Antidiabetic Medication Discontinuation Between Non-Hispanic White and Black Beneficiaries in Medicare Across Diabetes Belt and Surrounding Area

OBJECTIVE

To assess racial and geographic disparities in antidiabetic medication discontinuation among Medicare beneficiaries with type 2 diabetes (T2D) in or around Diabetes Belt (DB) areas, with a specific focus on differences between non-Hispanic (NH) white and NH Black individuals.

STUDY DESIGN

A retrospective cohort analysis was conducted on Medicare beneficiaries who initiated metformin and used antidiabetic medications during 2011-2015, including metformin, sulfonylureas, insulin, DPP-4 inhibitors, GLP-1 receptor agonists, SGLT2 inhibitors, and thiazolidinediones. Medication discontinuation was defined as a gap of 90 days or more without any antidiabetic medications.

METHODS

Multivariable Cox regression was used to examine the influence of racial and geographic factors on medication discontinuation, controlling for demographic, socioeconomic, and contextual factors. The interaction between race and DB status was also examined.

RESULTS

Among 21,159 Medicare beneficiaries initiating metformin during the study period, 8710 (41.2%) experienced medication discontinuation. NH Black individuals had a significantly higher discontinuation risk (HR: 1.22, 95% CI: [1.162, 1.286]) compared to NH White individuals. No significant geographic difference (HR: 1.02, 95% CI: [0.973, 1.072]) was observed between DB and Non-Diabetes Belt (NDB). NH Black patients consistently showed significantly higher discontinuation risks within both DB and NDB. No significant difference was found within the same race across counties.

CONCLUSION

We found significant racial but no geographic disparities in antidiabetic medication discontinuation among Medicare beneficiaries with T2D. Further research is needed to understand the underlying factors to improve equitable diabetes care management.

Acupuncture and Drug Combination Therapy for Abnormal Glucose Metabolism: Exploring Synergistic Enhancement and Reduced Toxicity Mechanisms

This review examines the impact of combining acupuncture with drug therapy on abnormal glucose metabolism and investigates their underlying mechanisms. Conditions like diabetes pose significant health risks due to irregular glucose metabolism. Traditional drug treatments often encounter challenges related to side effects and drug resistance. Acupuncture, as a non-pharmacological intervention, is thought to enhance glucose metabolism and mitigate medication side effects. We selected the relevant studies of acupuncture or electroacupuncture combined with drugs in the treatment of abnormal glucose metabolism in the past five years, and the results indicate that the combination of acupuncture or electroacupuncture and drug therapy markedly enhances glucose metabolism and mitigates medication-related side effects such as gastrointestinal discomfort and hypoglycemia. Overall, this review underscores the synergistic benefits of acupuncture and drug therapy in improving treatment efficacy and reducing adverse effects, offering promising new approaches for managing abnormal glucose metabolism. Our review provides evidence for the potential benefits of combining acupuncture with drug therapy for abnormal glucose metabolism, which could lead to improved treatment outcomes and reduced side effects for patients with type 2 diabetes mellitus.

Metformin: Diverse molecular mechanisms, gastrointestinal effects and overcoming intolerance in type 2 Diabetes Mellitus: A review

Metformin, the first line treatment for patients with type 2 diabetes mellitus, has alternative novel roles, including cancer and diabetes prevention. This narrative review aims to explore its diverse mechanisms, effects and intolerance, using sources obtained by searching Scopus, PubMed and Web of Science databases, and following Scale for the Assessment of Narrative Review Articles reporting guidelines. Metformin exerts it actions through duration influenced, and organ specific, diverse mechanisms. Its use is associated with inhibition of hepatic gluconeogenesis targeted by mitochondria and lysosomes, reduction of cholesterol levels involving brown adipose tissue, weight reduction influenced by growth differentiation factor 15 and novel commensal bacteria, in addition to counteraction of meta-inflammation alongside immuno-modulation. Interactions with the gastrointestinal tract include alteration of gut microbiota, enhancement of glucose uptake and glucagon like peptide 1 and reduction of bile acid absorption. Though beneficial, they may be linked to intolerance. Metformin related gastrointestinal adverse effects are associated with dose escalation, immediate release formulations, gut microbiota alteration, epigenetic predisposition, inhibition of organic cation transporters in addition to interactions with serotonin, histamine and the enterohepatic circulation. Potentially effective measures to overcome intolerance encompasses carefully objective targeted dose escalation, prescription of fixed dose combination, microbiome modulators and prebiotics, in addition to use of extended release formulations.

Apoptotic and proliferative processes in the small intestine of rats with type 2 diabetes mellitus after metformin and propionic acid treatment

Background

Propionic acid (PA) is an intermediate product of metabolism of intestinal bacteria and may protect the intestinal barrier from disruption. The aim of the study was to investigate the apoptotic and proliferative processes in the small intestine (SI) of rats with type 2 diabetes mellitus (T2DM) on the background of metformin monotherapy and its combination with PA.

Methods

Male Wistar rats were divided: 1) control; 2) T2DM (3-month high-fat diet followed by streptozotocin injection of 25 mg/kg of body weight); 3) T2DM + metformin (60 mg/kg, 14 days, orally); 4) T2DM + PA (60 mg/kg, 14 days, orally); 5) T2DM + PA + metformin. Western blotting, RT-PCR, and scanning electron microscopy were performed.

Results

We observed profound changes in the SI of diabetic rats suggesting the disturbed intestinal homeostasis: impaired mitochondrial ultrastructure, increased cristae volume, and decreased content of proliferative marker Ki67 with almost unchanged proapoptotic caspase-3 and its p17 subunit levels. Metformin and PA monotherapies also led to an increased cristae volume, however, after their combination, a tendency to normalization of ultrastructure of mitochondria was observed. While there was a significant inhibition of proliferation in T2DM and, in greater extent, after metformin and PA monotherapies, differential influence on apoptosis in the SI was observed. While metformin inhibited apoptosis via Bax declining, PA mainly acted via caspase-3-dependent mechanism elevating its active p17 subunit.

Conclusion

PA supplementation for the improvement of diabetes-induced gastrointestinal complications concurrently with metformin may be consider as a perspective supportive therapy. Data related to PA action on SI may be valuable during the development of new treatment strategies for diabetes-induced intestinal disturbances raised after metformin treatment.

Metformin-Induced Invertase Unfolding: Enzyme Kinetics and Activity Regulation

The effects of metformin on invertase activity and its inhibition on sucrose digestion were studied. The rapid unfolding kinetics of invertases, followed a two-state model with an inactive intermediate formation. The dynamic interaction between metformin and invertase caused the secondary structure of the enzyme to become less β-sheet, more α-helix, and random coiling oriented, which weakened the binding force between enzyme and its substrate. Metformin acted as a chaotrope and disrupted the hydrogen bonds of water, which facilitated the unfolding of invertase. However, some sugar alcohols, which promoted the H-bond formation of water, could repair the secondary structure of metformin-denatured invertase and therefore regulate the enzyme activity. This research enriches our understanding of the mechanism of enzyme unfolding induced by guanidine compounds. Moreover, because metformin and sugar substitutes are of concern to diabetes, this research also provides useful information for understanding the activity of the digestive enzyme that coexists with metformin and sugar alcohols.

Metformin-Associated Gastrointestinal Adverse Events Are Reduced by Probiotics: A Meta-Analysis

Metformin, one of the most frequently used oral glucose-lowering drugs (GLDs), is associated with the occurrence of gastrointestinal (GI) adverse events in approximately 20% of users. These unwanted actions result in non-compliance or even discontinuation of metformin therapy. The aim of the presented meta-analysis was to determine whether adding a drug from the group of sulfonylureas, glitazones, DPP-IV inhibitors, or probiotics to metformin monotherapy may affect the risk of GI side effects. The material for this meta-analysis comprised data from 26 randomized controlled clinical trials (RCTs) published in English. This meta-analysis included 41,048 patients. The PubMed, Cochrane Library, and Clinical Trials databases were thoroughly searched to find relevant RCTs. The Population, Intervention, Comparison, Outcomes, and Study Type (PICOT) structure was used to formulate study selection criteria and the research question. Cochrane Review Manager Software 5.4 was used to carry out analysis of collected data. The results were presented as relative risk (RR) and 95% confidence interval (95% CI) for each group, and p < 0.05 was considered as statistically significant. As expected from clinical practice, metformin was associated with a markedly increased risk of abdominal pain, nausea, and vomiting compared to placebo. In comparison to other GLDs, taking metformin was related to an elevated risk of diarrhea and abdominal pain and to a lowered risk of vomiting and bloating. In turn, adding other GLDs to metformin treatment was associated with an elevated risk of nausea and vomiting than treatment with metformin in monotherapy. However, adding probiotics to metformin therapy was related to a decreased risk of diarrhea, bloating, and constipation. The obtained results demonstrate that the combination of metformin with other GLDs may elevate the risk of nausea and vomiting, whereas combination with probiotics decreases the risk of diarrhea, bloating, and constipation. Thus, the results of our meta-analysis suggest that probiotics may reduce the risk of some GI side effects in people with type 2 diabetes mellitus (T2DM) who started treatment with metformin.

Lab-on-chip technologies for exploring the gut-immune axis in metabolic disease

The continued rise in metabolic diseases such as obesity and type 2 diabetes mellitus poses a global health burden, necessitating further research into factors implicated in the onset and progression of these diseases. Recently, the gut-immune axis, with diet as a main regulator, has been identified as a possible role player in their development. Translation of conventional 2D in vitro and animal models is however limited, while human studies are expensive and preclude individual mechanisms from being investigated. Lab-on-chip technology therefore offers an attractive new avenue to study gut-immune interactions. This review provides an overview of the influence of diet on gut-immune interactions in metabolic diseases and a critical analysis of the current state of lab-on-chip technology to study this axis. While there has been progress in the development of "immuno-competent" intestinal lab-on-chip models, with studies showing the ability of the technology to provide mechanical cues, support longer-term co-culture of microbiota and maintain in vivo-like oxygen gradients, platforms which combine all three and include intestinal and immune cells are still lacking. Further, immune cell types and inclusion of microenvironment conditions which enable in vivo-like immune cell dynamics as well as host-microbiome interactions are limited. Future model development should focus on combining these conditions to create an environment capable of hosting more complex microbiota and immune cells to allow further study into the effects of diet and related metabolites on the gut-immune ecosystem and their role in the prevention and development of metabolic diseases in humans.

Clinical Trial: Probiotics in Metformin Intolerant Patients with Type 2 Diabetes (ProGasMet)

BACKGROUND

For decades, metformin has been the drug of first choice in the management of type 2 diabetes. However, approximately 2-13% of patients do not tolerate metformin due to gastrointestinal (GI) side effects. Since metformin influences the gut microbiota, we hypothesized that a multi-strain probiotics supplementation would mitigate the gastrointestinal symptoms associated with metformin usage.

METHODS AND ANALYSIS

This randomized, double-blind, placebo-controlled, single-center, cross-over trial (ProGasMet study) assessed the efficacy of a multi-strain probiotic in 37 patients with metformin intolerance. Patients were randomly allocated (1:1) to receive probiotic (PRO-PLA) or placebo (PLA-PRO) at baseline and, after 12 weeks (period 1), they crossed-over to the other treatment arm (period 2). The primary outcome was the reduction of GI adverse events of metformin.

RESULTS

37 out of 82 eligible patients were enrolled in the final analysis of whom 35 completed the 32 weeks study period and 2 patients resigned at visit 5. Regardless of the treatment arm allocation, while on probiotic supplementation, there was a significant reduction of incidence (for the probiotic period in PRO-PLA/PLA-PRO: P = 0.017/P = 0.054), quantity and severity of nausea (P = 0.016/P = 0.024), frequency (P = 0.009/P = 0.015) and severity (P = 0.019/P = 0.005) of abdominal bloating/pain as well as significant improvement in self-assessed tolerability of metformin (P < 0.01/P = 0.005). Moreover, there was significant reduction of incidence of diarrhea while on probiotic supplementation in PRO-PLA treatment arm (P = 0.036).

CONCLUSION

A multi-strain probiotic diminishes the incidence of gastrointestinal adverse effects in patients with type 2 diabetes and metformin intolerance.

Calorie restriction mimetic drugs could favorably influence gut microbiota leading to lifespan extension

Calorie restriction (CR) can prolong human lifespan, but enforcing long-term CR is difficult. Thus, a drug that reproduces the effects of CR without CR is required. More than 10 drugs have been listed as CR mimetics (CRM), and some of which are conventionally categorized as upstream-type CRMs showing glycolytic inhibition, whereas the others are categorized as downstream-type CRMs that regulate or genetically modulate intracellular signaling proteins. Intriguingly, recent reports have revealed the beneficial effects of CRMs on the body such as improving the host body condition via intestinal bacteria and their metabolites. This beneficial effect of gut microbiota may lead to lifespan extension. Thus, CRMs may have a dual effect on longevity. However, no reports have collectively discussed them as CRMs; hence, our knowledge about CRM and its physiological effects on the host remains fragmentary. This study is the first to present and collectively discuss the accumulative evidence of CRMs improving the gut environments for healthy lifespan extension, after enumerating the latest scientific findings related to the gut microbiome and CR. The conclusion drawn from this discussion is that CRM may partially extend the lifespan through its effect on the gut microbiota. CRMs increase beneficial bacteria abundance by decreasing harmful bacteria rather than increasing the diversity of the microbiome. Thus, the effect of CRMs on the gut could be different from that of conventional prebiotics and seemed similar to that of next-generation prebiotics.

Pterostilbene ameliorates type-2 diabetes mellitus - Induced depressive-like behavior by mitigating insulin resistance, inflammation and ameliorating HPA axis dysfunction in rat brain

One of the most serious mental health comorbidities associated with diabetes mellitus is depression. The occurrence is almost double in type 2 diabetes mellitus (T2DM) compared with the general population. Pterostilbene (PTE), a dimethylated analog of resveratrol, has been reported for significant neuroprotective, anti-inflammatory, hypolipidemic, hypoglycaemic and antioxidant effects. However, its effect on diabetes-induced depression-like behavior (DID) has not been studied. The current study aimed at studying the effects of PTE on depressive-like behavior in male Wistar rats with T2DM. It was induced by single dose administration of nicotinamide (NA) and streptozotocin (STZ). On day 21, forced swim test (FST) was conducted for the confirmation of DID. Rats demonstrating depressive-like behavior were treated with PTE (10, 20 and 40 mg/kg), metformin (MET; 500 mg/kg) and fluoxetine (FLX; 10 mg/kg) for 28 days, orally. At the end of the treatment, behavioral assessment for depression, blood glucose (BG) and lipid profile, oxidative stress markers, gene expression of Sirtuin 1 (SIRT1) and histopathological parameters were investigated. PTE significantly reduced weight loss and mitigated depressive-like behavior paradigms such as sucrose preference test (SPT), resident intruder test (RIT) and open field test (OFT). It significantly restored BG, lipid and liver profile, creatinine and antioxidant level. It Improved glucose tolerance, insulin resistance (IR) and reduced cortisol level as well as inflammatory markers. It showed improved morphology of the pancreas, brain, liver and kidney. Gene expression studies revealed that, PTE significantly increased SIRT1 expression. PTE by its virtue to maintain BG, reduced IR, amelioration of the HPA axis, anti-inflammatory, antioxidant activity and improvement of SIRT1 gene expression proved to be effective in the treatment of DID-like behavior in rats.

Research Progress of Metformin in the Treatment of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies and has a high mortality, posing a great threat to both human physical and mental health. With the advancement of scientific research, a variety of cancer therapies have been used for OSCC treatment. However, the prognosis of OSCC shows no significant improvement. Metformin has been recognized as the first-line drug for the treatment of diabetes, and recent studies have shown that metformin has a remarkable suppressive effect on tumor progression. Metformin can not only affect the energy metabolism of tumor cells but also play an antitumor role by modulating the tumor microenvironment and cancer stem cells. In this review, the molecular mechanism of metformin and its anticancer mechanism in OSCC are summarized. In addition, this article summarizes the side effects of metformin and the future prospects of its application in the treatment of OSCC.

Predictors of Metformin Side Effects in Patients with Newly Diagnosed Type 2 Diabetes Mellitus

Introduction Metformin has become the first-line agent for the treatment of type 2 diabetes mellitus (T2DM) in several international guidelines. Up to 25% of patients suffer from gastrointestinal side-effects, with approximately 5% unable to tolerate metformin at all.

Objective We aimed to study the effect of variables that may influence the development of metformin side effects and/or intolerance.

Method A prospective study was conducted from April 1, 2021 to March 30, 2022. One-hundred and forty-eight patients newly diagnosed with T2DM were enrolled in the study, and divided into two groups—those who were escalate to the maximum dose of metformin over 2 weeks (n = 43) and the other group over 4 weeks (n = 105). We studied the variables that may affect the development of side effects including age, gender, body mass index (BMI), lipid profile, glycemic level, and the use of other antidiabetic medications besides the duration of dose escalation.

Results Total number of patients who developed side effects was 59 (39.9%). Twenty-four (55.8%) and 35 (33.3%) patients were put in the rapid and slow escalation groups, respectively. Twenty-six (17.6%) patients developed diarrhea that was the most common side effect. Two (2.7%) men and ten women (13.5%) had stopped metformin due to severe side effects developed after initiation (p = 0.016). The mean BMI for the patients who discontinued metformin was 34.7 ± 4.1 kg/m2 in the rapid escalation arm and 31.6 ± 3.3 kg/m2 in the slow escalation arm (p = 0.003). The mean of fasting blood glucose for the patients who discontinued metformin in the rapid and slow escalation arms was 200.6 ± 25.6 and 173.4 ± 36.5 mg/dL, respectively (p = 0.022).

Conclusion The severity of metformin side effects is higher in women than in men, making more women to discontinue the drug. Besides, a higher fasting blood sugar and BMI are associated with a higher rate of discontinuation. A rapid dose escalation is associated with a higher frequency of side effects. Diarrhea is the commonest side effect encountered.

Identification of Transporter Polymorphisms Influencing Metformin Pharmacokinetics in Healthy Volunteers

For patients with type 2 diabetes, metformin is the most often recommended drug. However, there are substantial individual differences in the pharmacological response to metformin. To investigate the effect of transporter polymorphisms on metformin pharmacokinetics in an environment free of confounding variables, we conducted our study on healthy participants. This is the first investigation to consider demographic characteristics alongside all transporters involved in metformin distribution. Pharmacokinetic parameters of metformin were found to be affected by age, sex, ethnicity, and several polymorphisms. Age and SLC22A4 and SLC47A2 polymorphisms affected the area under the concentration-time curve (AUC). However, after adjusting for dose-to-weight ratio (dW), sex, age, and ethnicity, along with SLC22A3 and SLC22A4, influenced AUC. The maximum concentration was affected by age and SLC22A1, but after adjusting for dW, it was affected by sex, age, ethnicity, ABCG2, and SLC22A4. The time to reach the maximum concentration was influenced by sex, like half-life, which was also affected by SLC22A3. The volume of distribution and clearance was affected by sex, age, ethnicity and SLC22A3. Alternatively, the pharmacokinetics of metformin was unaffected by polymorphisms in ABCB1, SLC2A2, SLC22A2, or SLC47A1. Therefore, our study demonstrates that a multifactorial approach to all patient characteristics is necessary for better individualization.

Increased expression of glucagon-like peptide-1 and cystic fibrosis transmembrane conductance regulator in the ileum and colon in mouse treated with metformin

Metformin, an oral medication, is prescribed to patients with type 2 diabetes mellitus. Although the efficacy, safety, and low economic burden of metformin on patients have long been recognized, approximately 5% of the patients treated with this drug develop severe diarrhea and discontinue the treatment. We previously reported that 1,000 mg·kg^-1·day^-1 of metformin induced diarrhea in diabetic obese (db/db) mice and wood creosote (traditional medication for diarrhea) ameliorated the symptoms. In this study, we attempted to elucidate the molecular mechanisms by which metformin induces diarrhea. Cystic fibrosis transmembrane conductance regulator (CFTR) is a key ion (chloride) channel in cyclic adenosine monophosphate (cAMP)-induced diarrhea. Metformin treatment increased bile flow (bile acids and bilirubin) in the ileum of mice. In addition, the treatment was accompanied by an increase in mRNA and protein levels of CFTR in the mucosa of the ileum and colon in both wild-type (C57BL/6J) and db/db mice. Glucagon-like peptide-1 (GLP-1), as well as cholic acid, induces CFTR mRNA expression in human colon carcinoma Caco-2 cells through cAMP signaling. Although wood creosote (10 mg/kg) ameliorated diarrhea symptoms, it did not alter the mRNA levels of Glp-1 or Cftr. Similar to overeating, metformin upregulated GLP-1 and CFTR expression, which may have contributed to diarrhea symptoms in mice. Although we could not identify db/db mouse-specific factors associated with metformin-induced diarrhea, these factors may modulate colon function. Wood creosote may not interact with these factors but ameliorates diarrhea symptoms.

An investigation into the potential action of polyphenols against human Islet Amyloid Polypeptide aggregation in type 2 diabetes

Type 2 diabetes (T2D), a chronic metabolic disease characterized by hyperglycemia, results in significant disease burden and financial costs globally. Whilst the majority of T2D cases seem to have a genetic basis, non-genetic modifiable and non-modifiable risk factors for T2D include obesity, diet, physical activity and lifestyle, smoking, age, ethnicity, and mental stress. In healthy individuals, insulin secretion from pancreatic islet β-cells is responsible for keeping blood glucose levels within normal ranges. T2D patients suffer from multifactorial onset of β-cell dysfunction and/or loss of β-cell mass owing to reactive oxygen species (ROS) production, mitochondrial dysfunction, autophagy, and endoplasmic reticulum (ER) stress. Most predominantly however, and the focus of this review, it is the aggregation and misfolding of human Islet Amyloid Polypeptide (hIAPP, also known as amylin), which is detrimental to β-cell function and health. Whilst hIAPP is found in healthy individuals, its misfolded version is cytotoxic and able to induce β-cell dysfunction and/or death through various mechanisms including membrane changes in β-cell causing influx of calcium ions, arresting complete granule membrane recovery and ER stress. There are several existing therapeutics for T2D. However, there is a need for alternative or adjunct therapies for T2D with milder adverse effects and greater availability. Foremost among the potential natural therapeutics are polyphenols. Extensive data from studies evaluating the potential of polyphenols to inhibit hIAPP aggregation and disassemble aggregated hIAPP are promising. Moreover, in-vivo, and in-silico studies also highlight the potential effects of polyphenols against hIAPP aggregation and mitigation of larger pathological effects of T2D. Whilst there have been some promising clinical studies on the therapeutic potential of polyphenols, extensive further clinical studies and in-vitro studies evaluating the mechanisms of action and ideal doses for many of these compounds are required. The need for these studies is made more important by the postulated link between Alzheimer's disease (AD) and T2D pathophysiology given the similar aggregation process of their respective amyloid proteins, which evokes thoughts of cross-reactive polyphenols which can be effective for both AD and T2D patients.

Metformin in therapeutic applications in human diseases: its mechanism of action and clinical study

Metformin, a biguanide drug, is the most commonly used first-line medication for type 2 diabetes mellites due to its outstanding glucose-lowering ability. After oral administration of 1 g, metformin peaked plasma concentration of approximately 20-30 μM in 3 h, and then it mainly accumulated in the gastrointestinal tract, liver and kidney. Substantial studies have indicated that metformin exerts its beneficial or deleterious effect by multiple mechanisms, apart from AMPK-dependent mechanism, also including several AMPK-independent mechanisms, such as restoring of redox balance, affecting mitochondrial function, modulating gut microbiome and regulating several other signals, such as FBP1, PP2A, FGF21, SIRT1 and mTOR. On the basis of these multiple mechanisms, researchers tried to repurpose this old drug and further explored the possible indications and adverse effects of metformin. Through investigating with clinical studies, researchers concluded that in addition to decreasing cardiovascular events and anti-obesity, metformin is also beneficial for neurodegenerative disease, polycystic ovary syndrome, aging, cancer and COVID-19, however, it also induces some adverse effects, such as gastrointestinal complaints, lactic acidosis, vitamin B12 deficiency, neurodegenerative disease and offspring impairment. Of note, the dose of metformin used in most studies is much higher than its clinically relevant dose, which may cast doubt on the actual effects of metformin on these disease in the clinic. This review summarizes these research developments on the mechanism of action and clinical evidence of metformin and discusses its therapeutic potential and clinical safety.

Metformin in pregnancy and risk of abnormal growth outcomes at birth: a register-based cohort study

We previously reported an increased risk of being small for gestational age (SGA) and a decreased risk of being large for gestational age (LGA) after in utero exposure to metformin compared with insulin exposure. This follow-up study investigated if these observations remain when metformin exposure (henceforth, metformin cohort) is compared with non-pharmacological antidiabetic treatment of gestational diabetes mellitus (GDM; naïve cohort), instead of insulin. RESEARCH DESIGN AND METHODS : This was a Finnish population register-based cohort study from singleton children born during 2004-2016. Birth outcomes from metformin cohort (n=3964) and the naïve cohort (n=82 675) were used in the main analyses. Additional analyses were conducted in a subcohort, restricting the metformin cohort to children of mothers with GDM only (n=2361). Results were reported as inverse probability of treatment weighted OR (wOR), with the naïve cohort as reference. RESULTS  : No difference was found for the outcome of SGA between the cohorts in the main analyses (wOR 0.97, 95% CI 0.73 to 1.27) or in the additional analyses (wOR 1.01, 95% CI 0.75 to 1.37). No difference between the cohorts was found for the risk of LGA (wOR 0.91, 95% CI 0.75 to 1.11) in the main analyses but a decreased risk was observed in the additional analyses (wOR 0.72, 95% CI 0.56 to 0.92). CONCLUSIONS : This follow-up study found no increase in the risk of SGA or LGA after in utero exposure to metformin, compared with drug-naïve GDM. The decreased risk of LGA in mothers with GDM may suggest residual confounding. The lack of increased SGA risk aligns with findings from studies using metformin in non-diabetic pregnancies. In contrast, lower birth weight and increased SGA birth risk were observed in GDM pregnancies for metformin versus insulin. Metformin should be avoided with emerging growth restriction in utero. The interplay of intrauterine hyperglycemia and pharmacological treatments needs further assessment.

Gut microbiota is correlated with gastrointestinal adverse events of metformin in patients with type 2 diabetes

Aim

Gastrointestinal discomfort is the most common adverse event in metformin treatment for type 2 diabetes. The mechanism of action of metformin is associated with gut microbiota. However, the gut microbial community structure related to metformin-induced gastrointestinal adverse events remains unclear. This study aimed to investigate it.

Methods

50 patients with newly diagnosed diabetes were treated with metformin 1500mg/d for 12 weeks. The patients were divided into two groups according to whether gastrointestinal adverse events occurred (group B) or did not occur (group A) after treatment. The fecal bacterial communities and short-chain fatty acids (SCFAs) were sequenced and compared. 70 diabetes mice were randomly divided into 8 groups and treated with metformin (Met), clindamycin (Clin) and/or SCFA, which were the Met+/Clin+, Met+/Clin-, Met-/Clin+, Met-/Clin-, Met+/SCFA+, Met+/SCFA-, Met-/SCFA+ and Met-/SCFA- group. After 4 weeks of metformin treatment, blood glucose, food intake, fecal SCFAs, gut microbiota and gut hormones were measured.

Results

Metformin increased the abundance of Phascolarctobacterium, Intestinimonas and Clostridium III. Functional prediction analysis showed that the propanoate metabolism pathway was significantly up-regulated. The concentrations of acetic acid and propanoic acid in feces were significantly increased. The abundance of Clostridium sensu stricto, Streptococcus and Akkermansia induced by metformin in group B was higher than that in group A. The propanoate metabolism pathway and propanoic acid in feces were significantly up-regulated in group B. In the animal experiments, the food intake decreased and glucose control increased in metformin groups compared with those in the control groups. The total GLP-1 level in the Met+/Clin- group was significantly higher than that in the Met-/Clin- group, while there was no statistical difference between the Met-/Clin- and Met+/Clin+ group. The total GLP-1 level in the Met-/SCFA+ group was significantly higher than that in the Met-/SCFA-group, while the levels of total GLP-1 and active GLP-1 in the Met+/SCFA- group and the Met+/SCFA+ group were significantly higher than those in the Met-/SCFA-group.

Conclusions

Our data suggest that metformin promotes the secretion of intestinal hormones such as GLP-1 by increasing the abundance of SCFA-producing bacteria, which not only plays an anti-diabetic role, but also may causes gastrointestinal adverse events.

Shouldn't Stage 4 And 5 Chronic Kidney Disease Patients Use Metformin?

Metformin is the first place anti-diabetic agent recommended with life style changes in many guidelines for the treatment of patients with type 2 diabetes mellitus (DM). The mechanism of effect of the drug is to increase insulin sensitivity in peripheral tissue and reduce glucose secretion from the liver. Metformin is a low cost, effective and safe drug. Although its frequent side effects are gastrointestinal side effects and the most feared side effect is lactic acidosis. Due to this side effect, its use is limited in many guidelines in patients with chronic kidney disease (CKD). In this article, we examined the use of metformin in all stages of CKD. We investigated the incidence of metformin-associated lactic acidosis (MALA). Shouldn't stage 4 and 5 chronic kidney disease patients use metformin? We sought an answer to question. As a result, we decided that side effects like MALA are extremely rare. We observed that these side effects occur mostly in the presence of diseases in which tissue perfusion is impaired such as infections, serious cardiovascular events, and hypotension. We came to the conclusion that metformin should be used in patients with stage 4 and 5 CKD patients, without much fear, considering the profit and loss relationship.

Literature review of the clinical characteristics of metformin-induced hepatotoxicity

Background: Knowledge of metformin-induced hepatotoxicity is based on case reports. The aim of this study was to investigate the clinical features of metformin-induced hepatotoxicity. Methods: We collected relevant literature on metformin-induced hepatotoxicity published from January 1994 to February 2022 by searching Chinese and English databases. Results: Thirty patients (19 males and 11 females) from 29 articles were included, with a median age of 61 years (range 29-83). The median time to onset of liver injury was 4 weeks (range 0.3-648) after metformin administration. Clinical symptoms occurred in 28 patients, including gastrointestinal reactions (56.7%), jaundice (50.0%), fatigue (36.7%), anorexia (23.3%), pruritus (13.3%), dark urine (13.3%), and clay-colored stools (10.0%). Serum alanine transaminase, aspartate transaminase, γ-glutamyl transferase, total bilirubin and alkaline phosphatase were elevated to varying degrees. Liver imaging in 26 patients showed hepatic steatosis (6 cases, 23.1%) and gallbladder wall thickening (11.5%). Liver biopsies from 13 patients showed portal phlebitis (61.5%), cholestatic hepatitis (38.5%), and parenchymal inflammation (38.5%). After metformin discontinuation, liver function returned to normal levels at a median of 6 weeks (range 2-16). Conclusions: Metformin-induced hepatotoxicity is a rare adverse reaction. Physicians and patients should be alert to metformin-induced hepatotoxicity.

Thymus serpyllum Exhibits Anti-Diabetic Potential in Streptozotocin-Induced Diabetes Mellitus Type 2 Mice: A Combined Biochemical and In Vivo Study

Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder that is characterized by hyperglycemia, insulin resistance, and lack of insulin production. It has been previously reported that Thymus serpyllum has therapeutic potential against many diseases. To investigate the antidiabetic action of Thymus serpyllum, this study aimed to analyze its restorative impact in diabetic mice, in which it was administered in diet. Diabetes was induced in BALB/c mice fed with a high-fat diet and two intraperitoneal injections of streptozotocin. With the onset of diabetes, the mice were administered daily with aqueous extract of Thymus serpyllum (500 mg/kg/d and 800 mg/kg/d) for 4 weeks. Body weight and fasting blood glucose levels were measured after every 1 week of the treatment. Subsequently, intraperitoneal glucose tolerance and insulin tolerance tests were conducted. In addition, liver tissue was isolated for assessment in terms of levels of gene expression of the AMPK, IRS1, and GLUT2 gene. Treatment with the aqueous extract of Thymus serpyllum was found to be significantly effective in controlling hyperglycemia and improving glucose and insulin tolerance. Predictable with these impacts, the extract of Thymus serpyllum upregulated the AMPK expression at the mRNA level, as well as upregulating the expression of IRS1 and GLUT2 gene. Histopathological examination of the liver, kidney, and pancreas also revealed the restorative impact in terms of cellular morphology. The results hence demonstrated that oral administration of aqueous extract of Thymus serpyllum can potentially attenuate hyperglycemia in the liver muscle of streptozotocin (STZ)-induced diabetic mice via AMPK and IRS1 upregulation.

The effects of metformin in the treatment of osteoarthritis: Current perspectives

Osteoarthritis is a chronic and irreversible disease of the locomotor system which is closely associated with advancing age. Pain and limited mobility frequently affect the quality of life in middle-aged and older adults. With a global population of more than 350 million, osteoarthritis is becoming a health threat alongside cancer and cardiovascular disease. It is challenging to find effective treatments to promote cartilage repair and slow down disease progression. Metformin is the first-line drug for patients with type 2 diabetes, and current perspectives suggest that it cannot only lower glucose but also has anti-inflammatory and anti-aging properties. Experimental studies applying metformin for the treatment of osteoarthritis have received much attention in recent years. In our review, we first presented the history of metformin and the current status of osteoarthritis, followed by a brief review of the mechanism that metformin acts, involving AMPK-dependent and non-dependent pathways. Moreover, we concluded that metformin may be beneficial in the treatment of osteoarthritis by inhibiting inflammation, modulating autophagy, antagonizing oxidative stress, and reducing pain levels. Finally, we analyzed the relevant evidence from animal and human studies. The potential of metformin for the treatment of osteoarthritis deserves to be further explored.

The role of MicroRNA networks in tissue-specific direct and indirect effects of metformin and its application

Metformin is a first-line oral antidiabetic agent that results in clear benefits in relation to glucose metabolism and diabetes-related complications. The specific regulatory details and mechanisms underlying these benefits are still unclear and require further investigation. There is recent mounting evidence that metformin has pleiotropic effects on the target tissue development in metabolic organs, including adipose tissue, the gastrointestinal tract and the liver. The mechanism of actions of metformin are divided into direct effects on target tissues and indirect effects via non-targeted tissues. MicroRNAs (miRNAs) are a class of endogenous, noncoding, negative gene regulators that have emerged as important regulators of a number of diseases, including type 2 diabetes mellitus (T2DM). Metformin is involved in many aspects of miRNA regulation, and metformin treatment in T2DM should be associated with other miRNA targets. A large number of miRNAs regulation by metformin in target tissues with either direct or indirect effects has gradually been revealed in the context of numerous diseases and has gradually received increasing attention. This paper thoroughly reviews the current knowledge about the role of miRNA networks in the tissue-specific direct and indirect effects of metformin. Furthermore, this knowledge provides a novel theoretical basis and suggests therapeutic targets for the clinical treatment of metformin and miRNA regulators in the prevention and treatment of cancer, cardiovascular disorders, diabetes and its complications.

Long-term safety and efficacy of imeglimin as monotherapy or in combination with existing antidiabetic agents in Japanese patients with type 2 diabetes (TIMES 2): A 52-week, open-label, multicentre phase 3 trial

AIM

To evaluate the safety and efficacy of imeglimin for 52 weeks as monotherapy or combination therapy with existing antidiabetic agents in Japanese patients with type 2 diabetes.

MATERIALS AND METHODS

TIMES 2 was a phase 3, pivotal, open-label trial including patients with type 2 diabetes inadequately controlled despite diet/exercise or despite treatment with a single agent from one of several available classes of antidiabetic drugs along with diet/exercise. All patients received imeglimin 1000 mg twice-daily orally for 52 weeks as monotherapy or combination therapy. The primary endpoint was safety (adverse events, laboratory results, ECG). The secondary endpoints were changes from baseline in HbA1c and fasting plasma glucose at week 52.

RESULTS

A total of 714 patients received the following treatments: imeglimin monotherapy (n = 134), combination with an α-glucosidase inhibitor (n = 64), biguanide (n = 64), dipeptidyl peptidase-4 inhibitor (DPP4-I; n = 63), glinide (n = 64), glucagon-like peptide-1 receptor agonist (GLP1-RA; n = 70), sodium-glucose co-transporter-2 inhibitor (n = 63), sulphonylurea (n = 127), or thiazolidinedione (n = 65). The percentage of patients experiencing at least one treatment emergent adverse event (TEAE) was 75.5%. Most of these events were mild or moderate in intensity. Serious TEAEs, none of them related to the study drug, occurred in 5.6% of all patients. No clinically significant changes in ECG, vital signs, physical examination, or laboratory tests were noted in any groups. At week 52, HbA1c decreased by 0.46% with imeglimin monotherapy, by 0.56%-0.92% with imeglimin as oral combination therapy, and by 0.12% with injectable GLP1-RA combination therapy. The greatest net HbA1c reduction (0.92%) occurred in patients receiving a DPP4-I in combination with imeglimin.

CONCLUSIONS

Imeglimin provides well-tolerated, long-term safety and efficacy in both monotherapy and oral combination therapy in Japanese patients with type 2 diabetes.

Metformin: A Narrative Review of Its Potential Benefits for Cardiovascular Disease, Cancer and Dementia

The biguanide metformin has been used as first-line therapy in type 2 diabetes mellitus (T2DM) treatment for several decades. In addition to its glucose-lowering properties and its prevention of weight gain, the landmark UK Prospective Diabetes Study (UKPDS) demonstrated cardioprotective properties in obese T2DM patients. Coupled with a favorable side effect profile and low cost, metformin has become the cornerstone in the treatment of T2DM worldwide. In addition, metformin is increasingly being investigated for its potential anticancer and neuroprotective properties both in T2DM patients and non-diabetic individuals. In the meantime, new drugs with powerful cardioprotective properties have been introduced and compete with metformin for its place in the treatment of T2DM. In this review we will discuss actual insights in the various working mechanisms of metformin and the evidence for its beneficial effects on (the prevention of) cardiovascular disease, cancer and dementia. In addition to observational evidence, emphasis is placed on randomized trials and recent meta-analyses to obtain an up-to-date overview of the use of metformin in clinical practice.

Geographic variation in and contextual factors related to biguanide adherence amongst medicaid enrolees with type 2 Diabetes Mellitus

Much is known about the adverse impacts on diabetes outcomes of non-adherence to diabetes medication. Less is known about how adherence to diabetes medication varies geographically, and the correspondence of this variation to social and contextual factors. Using pharmacy claims data over a two-year period, this study analysed non-adherence to biguanide medication for N=24,387 adult Medicaid enrolees diagnosed with Type 2 Diabetes Mellitus (T2DM) and residing in Ohio. Spatial analysis was used to detect clusters of census tract level rates of non-adherence, defined as the proportion of patients below the Proportion Days Covered (PDC) threshold of 80%, the level at which patients have a reasonable likelihood of achieving most clinical benefit from their medication. Multilevel models were used to understand associations between medication non-adherence and contextual factors including social vulnerability, urbanicity and distance to utilised pharmacy, with adjustment for individual-level covariates. These findings indicate that contextual factors are associated with medication non-adherence in Medicaid clients with T2DM. They suggest a need for spatially specific, multifaceted intervention programmes that target and/or account for the features of residential settings beyond individual and health system-level factors alone. While “environmental” considerations are often acknowledged, few intervention initiatives are predicated on explicit knowledge of spatially variable influences that can be targeted to enable and support medication adherence.

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Medication adherence is a problem amongst Type 2 Diabetes patients on Medicaid.

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Social and contextual factors' influence on medication adherence is underexplored.

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Higher social vulnerability is associated with non-adherence to biguanides.

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Adopting spatial analysis techniques enables geographic targeting of health risk.

Mechanisms and Active Compounds Polysaccharides and Bibenzyls of Medicinal Dendrobiums for Diabetes Management

BACKGROUND

Medicinal dendrobiums are used popularly in traditional Chinese medicine for the treatment of diabetes, while their active compounds and mechanism remain unclear. This review aimed to evaluate the mechanism and active compounds of medicinal dendrobiums in diabetes management through a systematic approach.

METHODS

A systematic approach was conducted to search for the mechanism and active phytochemicals in Dendrobium responsible for anti-diabetic actions using databases PubMed, Embase, and SciFinder.

RESULTS

Current literature indicates polysaccharides, bibenzyls, phenanthrene, and alkaloids are commonly isolated in Dendrobium genusin which polysaccharides and bibenzyls are most aboundant. Many animal studies have shown that polysaccharides from the species of Dendrobium provide with antidiabetic effects by lowering glucose level and reversing chronic inflammation of T2DM taken orally at 200 mg/kg. Dendrobium polysaccharides protect pancreatic β-cell dysfunction and insulin resistance in liver. Dendrobium polysaccharides up-regulate the abundance of short-chain fatty acid to stimulate GLP-1 secretion through gut microbiota. Bibenzyls also have great potency to inhibit the progression of the chronic inflammation in cellular studies.

CONCLUSION

Polysaccharides and bibenzyls are the major active compounds in medicinal dendrobiums for diabetic management through the mechanisms of lowering glucose level and reversing chronic inflammation of T2DM by modulating pancreatic β-cell dysfunction and insulin resistance in liver as a result from gut microbita regulation.

Effects of Behavioral Weight Loss and Metformin on IGFs in Cancer Survivors: A Randomized Trial

CONTEXT

Higher levels of insulin-like growth factor-1 (IGF-1) are associated with increased risk of cancers and higher mortality. Therapies that reduce IGF-1 have considerable appeal as means to prevent recurrence.

DESIGN

Randomized, 3-parallel-arm controlled clinical trial.

INTERVENTIONS AND OUTCOMES

Cancer survivors with overweight or obesity were randomized to (1) self-directed weight loss (comparison), (2) coach-directed weight loss, or (3) metformin treatment. Main outcomes were changes in IGF-1 and IGF-1:IGFBP3 molar ratio at 6 months. The trial duration was 12 months.

RESULTS

Of the 121 randomized participants, 79% were women, 46% were African Americans, and the mean age was 60 years. At baseline, the average body mass index was 35 kg/m2; mean IGF-1 was 72.9 (SD, 21.7) ng/mL; and mean IGF1:IGFBP3 molar ratio was 0.17 (SD, 0.05). At 6 months, weight changes were -1.0% (P = 0.07), -4.2% (P < 0.0001), and -2.8% (P < 0.0001) in self-directed, coach-directed, and metformin groups, respectively. Compared with the self-directed group, participants in metformin had significant decreases on IGF-1 (mean difference in change: -5.50 ng/mL, P = 0.02) and IGF1:IGFBP3 molar ratio (mean difference in change: -0.0119, P = 0.011) at 3 months. The significant decrease of IGF-1 remained in participants with obesity at 6 months (mean difference in change: -7.2 ng/mL; 95% CI: -13.3 to -1.1), but not in participants with overweight (P for interaction = 0.045). There were no significant differences in changes between the coach-directed and self-directed groups. There were no differences in outcomes at 12 months.

CONCLUSIONS

In cancer survivors with obesity, metformin may have a short-term effect on IGF-1 reduction that wanes over time.

Combined Beneficial Effect of Genistein and Atorvastatin on Adipogenesis in 3T3-L1 Adipocytes

Genistein (4,5,7-trihydroxyisoflavone) is abundant in various dietary vegetables, especially soybeans, and is known to have not only an estrogenic effect but also an antiadipogenic effect. Atorvastatin (dihydroxy monocarboxylic acid) is a statin used to prevent heart disease. Although genistein and atorvastatin have been reported to possess antiadipogenic effects, their combined effects are still unclear. The aim of the current study was to explore whether the combination of genistein and atorvastatin at low concentrations significantly suppresses adipogenesis in a murine preadipocyte cell line (3T3-L1) compared to treatment with genistein or atorvastatin alone. Our results showed that cotreatment with 50 µM genistein and 50 nM atorvastatin significantly suppressed preadipocyte differentiation, whereas when each compound was used alone, there was no inhibitory effect. Additionally, cotreatment with genistein and atorvastatin significantly downregulated adipogenic marker proteins, including mitogen-activated protein kinases (MAPKs), peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein alpha (C/EBPα), glucocorticoid receptor (GR), and CCAAT/enhancer-binding protein β (C/EBPβ). This is the first evidence of the combined antiadipogenic effects of genistein and atorvastatin. Although additional experiments are required, combinational treatment with genistein and atorvastatin may be an alternative treatment for menopause-associated lipid metabolic disorders and obesity.

Metformin Affects Gut Microbiome Composition and Function and Circulating Short-Chain Fatty Acids: A Randomized Trial

OBJECTIVE

To determine the longer-term effects of metformin treatment and behavioral weight loss on gut microbiota and short-chain fatty acids (SCFAs).

RESEARCH DESIGN AND METHODS

We conducted a 3-parallel-arm, randomized trial. We enrolled overweight/obese adults who had been treated for solid tumors but had no ongoing cancer treatment and randomized them (n = 121) to either 1) metformin (up to 2,000 mg), 2) coach-directed behavioral weight loss, or 3) self-directed care (control) for 12 months. We collected stool and serum at baseline (n = 114), 6 months (n = 109), and 12 months (n = 105). From stool, we extracted microbial DNA and conducted amplicon and metagenomic sequencing. We measured SCFAs and other biochemical parameters from fasting serum.

RESULTS

Of the 121 participants, 79% were female and 46% were Black, and the mean age was 60 years. Only metformin treatment significantly altered microbiota composition. Compared with control, metformin treatment increased amplicon sequence variants for Escherichia (confirmed as Escherichia coli by metagenomic sequencing) and Ruminococcus torques and decreased Intestinibacter bartlettii at both 6 and 12 months and decreased the genus Roseburia, including R. faecis and R. intestinalis, at 12 months. Effects were similar in comparison of the metformin group with the behavioral weight loss group. Metformin versus control also increased butyrate, acetate, and valerate at 6 months (but not at 12 months). Behavioral weight loss versus control did not significantly alter microbiota composition but did increase acetate at 6 months (but not at 12 months). Increases in acetate were associated with decreases in fasting insulin. Additional whole-genome metagenomic sequencing of a subset of the metformin group showed that metformin altered 62 metagenomic functional pathways, including an acetate-producing pathway and three pathways in glucose metabolism.

CONCLUSIONS

Metformin, but not behavioral weight loss, impacted gut microbiota composition at 6 months and 12 months. Both metformin and behavioral weight loss altered circulating SCFAs at 6 months, including increasing acetate, which correlated with lower fasting insulin. Future research is needed to elucidate whether the gut microboime mediates or modifies metformin's health effects.

Compartmentally scavenging hepatic oxidants through AMPK/SIRT3-PGC1α axis improves mitochondrial biogenesis and glucose catabolism

Early treatment can prevent the occurrence of diabetes; however, there are few pharmacological treatment strategies to date. The liver is a major metabolic organ, and hepatic glucose homeostasis is dysregulated in type 1 and type 2 diabetes mellitus. However, the potential of specifically targeting the liver to prevent diabetes has not been fully exploited. In this study, we found that compartmentally inhibiting hepatic oxidants by nano-MitoPBN, a liver mitochondrial-targeting ROS scavenger, could effectively prevent diabetes. Our results demonstrated that nano-MitoPBN reversed the downregulation of PGC-1α and the enhanced gluconeogenesis in the livers of diabetic mice. PGC-1α, through an AMPK- and SIRT3-mediated mechanism, promoted mitochondrial biogenesis, increased the number of mitochondria, and enhanced the rate of aerobic oxidation, leading to decreased glucose levels in the blood by increasing glucose uptake and catabolism in the liver. Moreover, the increase in PGC-1α activity did not promote the activation of gluconeogenesis. Our study demonstrated that by regulating the redox balance of liver mitochondria in the early stage of diabetes, PGC-1α could selectively inhibit gluconeogenesis in the liver and promote hepatic mitochondrial function, which accelerated the catabolism of hepatic glucose and reduced blood glucose. Thus, glucose tolerance can be normalized through only three weeks of intervention. Our results showed that nano-MitoPBN could effectively prevent diabetes in a short period of time, highlighting the effectiveness and importance of early intervention for diabetes and suggesting the potential advantages of hepatic mitochondrial targeting oxidants nano-inhibitors in the prevention and early treatment of diabetes.

Impact of metformin treatment during pregnancy on maternal outcomes: a systematic review/meta-analysis

We systematically assessed the impact of metformin treatment on maternal pregnancy outcomes. PubMed, Ovid Embase, Medline, Web of Science, ClinicalTrials.gov and Cochrane databases were systematically searched (inception-1st February 2021). Randomised controlled trials reporting pregnancy outcomes in women randomised to metformin versus any other treatment for any indication were included. Outcomes included gestational weight gain (GWG), pre-eclampsia, gestational hypertension, preterm birth, gestational age at delivery, caesarean section, gestational diabetes, glycaemic control, and gastrointestinal side-effects. Two independent reviewers conducted screening, with a third available to evaluate disagreements. Risk-of-bias and GRADE assessments were conducted using Cochrane Risk-of-Bias and GRADE-pro software. Thirty-five studies (n = 8033 pregnancies) met eligibility criteria. GWG was lower in pregnancies randomised to metformin versus other treatments (1.57 kg ± 0.60 kg; I₂ = 86%, p < 0.0001), as was likelihood of pre-eclampsia (OR 0.69, 95% CI 0.50-0.95; I₂ = 55%, p = 0.02). The risk of gastrointestinal side-effects was greater in metformin-exposed versus other treatment groups (OR 2.43, 95% CI 1.53-3.84; I₂ = 76%, p = 0.0002). The risk of other maternal outcomes assessed was not significantly different between metformin-exposed versus other treatment groups. Metformin for any indication during pregnancy is associated with lower GWG and a modest reduced risk of pre-eclampsia, but increased gastrointestinal side-effects compared to other treatments.

A Bibliometrics Analysis of Metformin Development From 1980 to 2019

Metformin, the first-line oral blood glucose-lowering agent to manage type 2 diabetes, has gained growing popularity on both clinical application and basic research since early 1980s. A thorough and systematic knowledge map of metformin is pertinent to evaluate the research frontier and determine knowledge gaps. To this end, 20, 526 publications were analyzed by bibliometrics and data visualization to demonstrate the current global research status, potential hotspots, and perspectives on future research directions. In addition, the metformin development along the historical line was illustrated over the last 40 years. In sum, this study provides a comprehensive analysis that delineates the evolution of the historical milestones of metformin development, and we discuss the future research directions based on objective data analysis from a wide spectrum of metformin research areas.

Biguanides: Species with versatile therapeutic applications

Biguanides are compounds in which two guanidine moieties are fused to form a highly conjugated system. Biguanides are highly basic and hence they are available as salts mostly hydrochloride salts, these cationic species have been found to exhibit many therapeutic properties. This review covers the research and development carried out on biguanides and accounts the various therapeutic applications of drugs containing biguanide group-such as antimalarial, antidiabetic, antiviral, anticancer, antibacterial, antifungal, anti-tubercular, antifilarial, anti-HIV, as well as other biological activities. The aim of this review is to compile all the medicinal chemistry applications of this class of compounds so as to pave way for the accelerated efforts in finding the drug action mechanisms associated with this class of compounds. Importance has been given to the organic chemistry of these biguanide derivatives also.

A Review of Switching Strategies for Patients with Schizophrenia Comorbid with Metabolic Syndrome or Metabolic Abnormalities

Metabolic syndrome (MetS) in patients with schizophrenia occurs 2-3 times more frequently than in the general population. Antipsychotic medication is a primary risk factor for patients with MetS. In particular, the widely used second-generation antipsychotics can affect glucose and lipid metabolism and can induce insulin resistance and other metabolic abnormalities through various receptors. Notably, the metabolic risks of various antipsychotics may differ because of their different pharmacological affinity to MetS-related receptors. Several previous studies have shown that switching from high to low metabolic risk antipsychotics may improve patients' metabolic parameters. The current review aims to discuss the strategies for switching antipsychotic medications and the impact on metabolic abnormalities in patients with schizophrenia.

Evaluating the Evidence behind the Novel Strategy of Early Combination from Vision to Implementation

Type 2 diabetes mellitus (T2DM) is a complex and progressive chronic disease characterised by elevating hyperglycaemia and associated need to gradually intensify therapy in order to achieve and maintain glycaemic control. Treating hyperglycaemia with sequential therapy is proposed to allow holistic assessment of the efficacy and risk-to-benefit ratio of each added component. However, there is an array of evidence supporting the scientific rationale for using synergistic, earlier, modern drug combinations to achieve glycaemic goals, delay the deterioration of glycaemic control, and, therefore, potentially preserve or slow down the declining β-cell function. Additionally, implementation of early combination(s) may lead to opportunities to combat clinical inertia and other hurdles to optimised disease management outcomes. This review aims to discuss the latest empirical evidence for long-term clinical benefits of this novel strategy of early combination in people with newly diagnosed T2DM versus the current widely-implemented treatment paradigm, which focuses on control of hyperglycaemia using lifestyle interventions followed by sequentially intensified (mostly metformin-based) monotherapy. The recent reported Vildagliptin Efficacy in combination with metfoRmin For earlY treatment of T2DM (VERIFY) study results have provided significant new evidence confirming long-term glycaemic durability and tolerability of a specific early combination in the management of newly diagnosed, treatment-naïve patients worldwide. These results have also contributed to changes in clinical treatment guidelines and standards of care while clinical implementation and individualised treatment decisions based on VERIFY results might face barriers beyond the existing scientific evidence.

Protective Effects of Moderate Intensity Static Magnetic Fields on Diabetic Mice

The purpose of this study was to investigate the effects of moderate-intensity static magnetic field (SMF) on diabetic mice. We studied the effects of SMF on blood glucose of normal mice by starch tolerance and glucose tolerance tests. Then, we evaluated the effects of SMF on blood glucose of diabetic mice by establishing alloxan-induced type 1 diabetic mice and high-fat diet + streptozotocin (STZ)-induced type 2 diabetic mice. The results showed that different magnetic field intensities and blank control did not affect the blood glucose of normal mice. After starch and glucose administration, different magnetic fields could improve the glucose tolerance of normal mice, and this was obvious in the 600 mT group. In the experiment of type 1 diabetic mice induced by alloxan, the results showed that different magnetic field intensities could improve the starch tolerance of mice, and that in the 400 mT group was obvious. In the experiment of type 2 diabetic mice induced by a high-fat diet + STZ, the 400 mT group could reduce food intake and water consumption in the later period. The 600 mT group could improve the starch tolerance of mice. The 400 and 600 mT groups could reduce fasting blood glucose. At the same time, total cholesterol and triglyceride decreased in different magnetic field intensities, and the 600 mT group could significantly increase the serum insulin content of mice. In summary, the results of this study suggest that SMF has a protective role in diabetic mice. Bioelectromagnetics. © 2020 Bioelectromagnetics Society.

Combination of Scutellaria baicalensis and Metformin Ameliorates Diet-Induced Metabolic Dysregulation in Mice via the Gut-Liver-Brain Axis

Scutellaria baicalensis (SB), a herbal medicine, is commonly used to treat metabolic diseases, while Metformin (MF) is a widely used drug for type 2 diabetes. The purpose of this study was to investigate whether co-treatment of SB with MF could produce a potential therapeutic effect on high-fat and high-fructose diet (HFFD)-induced metabolic dysregulation. First, we optimized the dose of SB (100, 200, 400, and 800[Formula: see text]mg/kg) with MF (200[Formula: see text]mg/kg) in HFFD-induced C57BL6J mice. Next, the optimized dose of SB (400[Formula: see text]mg/kg) was co-administered with MF (50, 100, and 200[Formula: see text]mg/kg) in a similar animal model to find the effective combinations of SB and MF. Metabolic markers were determined in serum and tissues using different assays, histology, gene expression, and gut microbial population. The SB and MF co-treatment significantly decreased the body, liver, and VAT weights. The outcome of OGTT was improved, and the fasting insulin, HbA1c, TG, TC, LDL-c, AST, and ALT were decreased, while HDL-c was significantly increased. Histological analyses revealed maintained the integrity of liver, adipose tissue, and intestine prevented lipid accumulation in the liver and intestine and combated neuronal damage in the brain. Importantly, controlled the expression of PPAR[Formula: see text], and IL-6 genes in the liver, and expression of BDNF, Glut1, Glut3, and Glut4 genes in the brain. Treatment-specific gut microbial segregation was observed in the PCA chart. Our findings indicate that SB and MF co-treatment is an effective therapeutic approach for HFFD-induced metabolic dysregulation which is operated through the gut-liver-brain axis.

O impacto do uso da metformina para gestantes obesas na prevenção da pré-eclâmpsia

Objetivos: o artigo objetiva avaliar o uso de metformina em gestantes obesas na prevenção da pré-eclâmpsia.Métodos: trata-se de um ensaio clínico randomizado com mulheres grávidas obesas com índice de massa corporal superior ou igual a 30 kg/m2 divididos em dois grupos – um grupo de estudo, que utilizou metformina, e um grupo controle, que seguiu a rotina de pré-natal. As gestantes entraram no estudo com idade gestacional menor que 20 semanas e foram acompanhadas durante todo o período pré-natal. O diagnóstico de pré-eclâmpsia foi feito de acordo com os critérios da Organização Mundial de Saúde.Resultados: verificou-se a redução de risco absoluto e o número necessário para tratar em um intervalo de confiança de 95% para o resultado pré-eclâmpsia. Nos resultados, 272 gestantes foram avaliadas. No grupo de estudo (n = 127), oito (6,3%) desenvolveram pré-eclâmpsia. No grupo controle (n = 145), 31 (21,4%) tiveram a doença (p <0,01).Conclusão: o estudo apontou uma redução de risco absoluto de 15,1 vezes (IC95%: 7,1-22,9) e número necessário para tratar de sete (IC95%: 4,4-13,9). O uso de 1000 miligramas diárias de metformina indicou uma redução de 15,1 vezes no risco absoluto de pré-eclâmpsia na população estudada, com a necessidade de tratar sete gestantes para evitar um desfecho.

Comparison of gastrointestinal adverse events with different doses of metformin in the treatment of elderly people with type 2 diabetes

WHAT IS KNOWN AND OBJECTIVE

Gastrointestinal discomfort is the most common adverse event of metformin treatment for type 2 diabetes, especially in elderly patients. The aim of this study was to compare gastrointestinal adverse events resulting from different doses of metformin used for the treatment of elderly people with type 2 diabetes.

METHODS

A total of 361 elderly patients with newly diagnosed diabetes were randomly divided into three groups: metformin 1000 mg/d (N = 120), metformin 1500 mg/d (N = 121) and metformin 2000 mg/d (N = 120). Glycaemic control and gastrointestinal adverse events (abdominal pain, diarrhoea, nausea, vomiting, bloating and anorexia) were assessed and compared among the three groups after 12 weeks of treatment.

RESULTS AND DISCUSSION

At baseline, there was no significant difference in gastrointestinal symptoms among the three groups. After 12 weeks of treatment with metformin, the change in HbA1c level was -0.7%, -0.9% and -1.0% for the 1000 mg/d, 1500 mg/d and 2000 mg/d groups, respectively (P < .0001). There was no significant difference in gastrointestinal adverse events among the three groups after treatment with metformin. In total, 62 people (17.2%) could not tolerate the adverse effects of metformin, and most of them stopped treatment in the first 4 weeks. Logistic regression analysis shows that female sex (OR = 2.660, 95%CI 1.692-4.183, P < .0001) and the concurrent use of organic cation transporter 1-inhibiting drugs (OR = 1.874, 95%CI 1.076-3.265, P = .027) are independent risk factors for adverse events.

WHAT IS NEW AND CONCLUSIONS

Our data demonstrate that metformin doses of 1000 mg/d-2000 mg/d have similar adverse events but that 2000 mg/d of metformin yields the best glycaemic control in elderly people with diabetes. If elderly people can tolerate 1000 mg/d of metformin, we could gradually increase the dose to 2000 mg/d to achieve better glycaemic control.

Metformin for prevention of cesarean delivery and large-for-gestational-age newborns in non-diabetic obese pregnant women: a randomized clinical trial

OBJECTIVE

To evaluate the use of metformin for preventing cesarean deliveries and large-for-gestational-age (LGA) newborn (NB) outcomes in non-diabetic obese pregnant women.

SUBJECTS AND METHODS

This is a randomized clinical trial with obese pregnant women, divided into 2 groups: metformin group and control group, with followed-up prenatal routine. The gestational age of participants was less than or equal to 20 weeks and were monitored throughout entire prenatal period. For outcomes of delivery and LGA newborns, absolute risk reduction (ARR) and the number needed to treat (NNT) were calculated with a 95% confidence interval (CI).

RESULTS

357 pregnant women were evaluated. From the metformin group (n = 171), 68 (39.8%) subjects underwent cesarean delivery, and 117 (62.9%) subjects from the control group (n = 186) had intercurrence (p < 0.01). As for the mothers' general characteristics, there was significance for marital status (p < 0.01). Maternal-fetal results presented reduced preeclampsia (p < 0,01). Primary prophylactic results presented an ARR of 23.1 times (95% CI: 13.0-33.4) with NNT of 4 (95% CI: 3.0-7.7) and no significant values for LGA NB (p > 0.01). Secondary prophylactic outcomes presented decreased odds ratio for preeclampsia (OR = 0.17, 95% CI: 0.10-0.41).

CONCLUSION

The use of metformin reduced cesarean section rates, resulted in a small number of patients to be treated, but it did not reduce LGA NB. Administering a lower dosage of metformin from the early stages to the end of treatment may yield significant results with fewer side effects. Arch Endocrinol Metab. 2020;64(3):290-7.

GPD1 Enhances the Anticancer Effects of Metformin by Synergistically Increasing Total Cellular Glycerol-3-Phosphate

Metformin is an oral drug widely used for the treatment of type 2 diabetes mellitus. Numerous studies have demonstrated the value of metformin in cancer treatment. However, for metformin to elicit effects on cancer often requires a high dosage, and any underlying mechanism for how to improve its inhibitory effects remains unknown. Here, we found that low mRNA expression of glycerol-3-phosphate dehydrogenase 1 (GPD1) may predict a poor response to metformin treatment in 15 cancer cell lines. In vitro and in vivo, metformin treatment alone significantly suppressed cancer cell proliferation, a phenotype enhanced by GPD1 overexpression. Total cellular glycerol-3-phosphate concentration was significantly increased by the combination of GPD1 overexpression and metformin treatment, which suppressed cancer growth via inhibition of mitochondrial function. Eventually, increased reactive oxygen species and mitochondrial structural damage was observed in GPD1-overexpressing cell lines treated with metformin, which may contribute to cell death. In summary, this study demonstrates that GPD1 overexpression enhances the anticancer activity of metformin and that patients with increased GPD1 expression in tumor cells may respond better to metformin therapy. SIGNIFICANCE: GPD1 overexpression enhances the anticancer effect of metformin through synergistic inhibition of mitochondrial function, thereby providing new insight into metformin-mediated cancer therapy.

Mouse model of metformin-induced diarrhea

OBJECTIVE

Metformin, an oral medication used for type 2 diabetes mellitus, is the most commonly prescribed drug with less economic burden of patients. Although metformin's efficacy and safety have long been recognized, approximately 5% of the patients treated with this drug develop severe diarrhea as an adverse effect and have to abandon treatment. Because there is no animal model to study metformin-induced diarrhea, it is hard to develop methods to maintain quality of life of patients prescribed with metformin.

RESEARCH DESIGN AND METHODS

Using mouse models, we tried to develop an evaluation system for metformin-induced diarrhea to improve diarrheal symptoms in patients with diabetes. Healthy (C57BL/6J) and diabetic obese (db/db) mice were subjected to a stepwise dose escalation of metformin (250 mg/kg/day (125 mg/kg twice daily oral dose)-1000 mg/kg/day (500 mg/kg twice daily oral dose)), and fecal moisture contents and their score were monitored. To evaluate anti-diarrheal medications, wood creosote (a traditional medicine) was tested. Several groups of enterobacteria in fresh feces were examined by using PCR.

RESULTS

1000 mg/kg/day (four times maximal effective dose) of metformin significantly increased fecal moisture content. Although no symptoms of diarrhea were observed in healthy C57BL/6J mice, the same dose of metformin induced severe diarrhea in diabetic obese db/db mice. A reduction in PCR signals for the Firmicutes group was associated with metformin-induced diarrhea. Wood creosote reduced diarrhea (high water-content) without affecting metformin's efficacy or enterobacterial flora levels.

CONCLUSIONS

We have created the first animal model of metformin-induced diarrhea using db/db mice, which will provide better quality of life for patients suffering from diarrhea caused by metformin.