Dapagliflozin added to metformin reduces perirenal fat layer in type 2 diabetic patients with obesity.

Sodium-glucose co-transporters type 2 inhibitors (SLGT2i) are highly effective in controlling type 2 diabetes, but reported beneficial cardiovascular effects suggest broader actions on insulin resistance. Weight loss may be initially explained by glycosuria-induced net caloric output and secondary volumetric reduction, but its maintenance could be due to loss of visceral fat mass. Structured ultrasound (US) imaging of abdominal adipose tissue ("eco-obesity") is a recently described methodology used to measure 5 consecutive layers of abdominal fat, not assessable by DEXA or CT scan: superficial subcutaneous (SS), deep subcutaneous (DS), preperitoneal (PP), omental (Om) and right perirenal (RK). PP, Om and RK are predictors of metabolic syndrome (MS) with defined cut-off points. To assess the effect of SLGT2i on every fat depot we enrolled 29 patients with type 2 Diabetes (HbA1c 6.5-9%) and Obesity (IMC > 30 kg/m2) in an open-label, randomized, phase IV trial (EudraCT: 2019-000979-16): the Omendapa trial. Diabetes was diagnosed < 12 months before randomization and all patients were treatment naïve. 14 patients were treated with metformin alone (cohort A) and 15 were treated with metformin + dapaglifozin (cohort B). Anthropometric measures and laboratory tests for glucose, lipid profile, insulin, HOMA, leptin, ultrasensitive-CRP and microalbuminuria (MAL) were done at baseline, 3rd and 6th months. At 6th month, weight loss was -5.5 ± 5.2 kg (5.7% from initial weight) in cohort A and -8.4 ± 4.4 kg (8.6%) in cohort B. Abdominal circumference showed a -2.7 ± 3.1 cm and -5.4 ± 2.5 cm reduction, respectively (p = 0.011). Both Metformin alone (-19.4 ± 20.1 mm; -21.7%) or combined with Dapaglifozin (-20.5 ± 19.4 mm; -21.8%) induced significant Om fat reduction. 13.3% of cohort A patients and 21.4% of cohort's B reached Om thickness below the cut-off for MS criteria. RK fat loss was significantly greater in cohort B group compared to cohort A, at both kidneys. Only in the Met + Dapa group, we observed correlations between Om fat with leptin/CRP/MAL and RK fat with HOMA-IR. US is a useful clinical tool to assess ectopic fat depots. Both Metformin and Dapaglifozin induce fat loss in layers involved with MS but combined treatment is particularly effective in perirenal fat layer reduction. Perirenal fat should be considered as a potential target for cardiovascular dapaglifozin beneficial effects.

The impact of empagliflozin and metformin on cardiac parameters in patients with mid-range ejection fraction heart failure without diabetes.

Heart failure (HF) remains a significant problem for healthcare systems, requiring the use of intervention and multimodal management strategies. We aimed to assess the short-term effect of empagliflozin (EMPA) and metformin on cardiac function parameters, including ventricular dimension-hypertrophy, septal thickness, ejection fraction (EF), and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in patients with HF and mildly reduced EF. A case-control study included 60 newly diagnosed patients with HF. Patients were divided into two groups: Group E received standard HF treatment (carvedilol, bumetanide, sacubitril-valsartan, spironolactone) plus EMPA 10 mg daily, and Group M received standard HF treatment plus metformin 500 mg daily. After three months of treatment, Group E had a significantly higher EF than Group M compared to initial measurements (a change of 9.2% versus 6.1%, respectively). We found similar results in the left ventricular end-systolic dimension (LVESD), with mean reductions of 0.72 mm for Group E and 0.23 mm for Group M. Regarding cardiac indicators, the level of NT-proBNP was considerably decreased in both groups. However, the reduction was significantly greater in group E than in group M compared to the initial level (mean reduction: 719.9 vs. 973.6, respectively). When combined with quadruple anti-heart failure therapy, metformin enhanced several echocardiographic parameters, showing effects similar to those of EMPA when used in the same treatment regimen. However, the benefits of EMPA were more pronounced, particularly regarding improvements in EF and LVESD.

The effects of green tea tablets and metformin on ovulation and menstrual cycle regularity in women with polycystic ovary syndrome.

Polycystic ovary syndrome is the most common cause of oligo-ovulation and anovulation among women of reproductive age, contributing to infertility. This study aimed to compare the effects of green tea tablets and metformin on ovulation, menstrual cycle regularity, and antioxidant biomarkers in women with polycystic ovary syndrome (PCOS). In this clinical trial study, 94 women with PCOS were randomly assigned to three groups: green tea (n = 33), metformin (n = 29), and control (n = 32). Menstrual status and oxidative stress parameters, including total antioxidant capacity, thiol, and lipid peroxidation, were compared before and 3 months after the intervention among all three groups. Data analysis was conducted using SPSS software version 22 and employing the analysis of variance and paired t-tests. Following the intervention, the mean menstrual cycle duration in the green tea, metformin, and control groups was 32.22 ± 12.78, 48.72 ± 37.06, and 48.53 ± 31.04 days, respectively (P = 0.040). There was no statistically significant difference between the three groups in terms of biochemical, hormonal, and antioxidant indices before and after the intervention (P > 0.05). The intake of green tea tablets was associated with better outcomes in regulating the menstrual cycle in women with PCOS.

Molecular interactions between metformin and D-limonene inhibit proliferation and promote apoptosis in breast and liver cancer cells.

BACKGROUND: Cancer is a fatal disease that severely affects humans. Designing new anticancer strategies and understanding the mechanism of action of anticancer agents is imperative. HYPOTHESIS/PURPOSE: In this study, we evaluated the utility of metformin and D-limonene, alone or in combination, as potential anticancer therapeutics using the human liver and breast cancer cell lines HepG2 and MCF-7. STUDY DESIGN: An integrated systems pharmacology approach is presented for illustrating the molecular interactions between metformin and D-limonene. METHODS: We applied a systems-based analysis to introduce a drug-target-pathway network that clarifies different mechanisms of treatment. The combination treatment of metformin and D-limonene induced apoptosis in both cell lines compared with single drug treatments, as indicated by flow cytometric and gene expression analysis. RESULTS: The mRNA expression of Bax and P53 genes were significantly upregulated while Bcl-2, iNOS, and Cox-2 were significantly downregulated in all treatment groups compared with normal cells. The percentages of late apoptotic HepG2 and MCF-7 cells were higher in all treatment groups, particularly in the combination treatment group. Calculations for the combination index (CI) revealed a synergistic effect between both drugs for HepG2 cells (CI = 0.14) and MCF-7 cells (CI = 0.22). CONCLUSION: Our data show that metformin, D-limonene, and their combinations exerted significant antitumor effects on the cancer cell lines by inducing apoptosis and modulating the expression of apoptotic genes.

Metformin induction of heat shock factor 1 activation and the mitochondrial unfolded protein response alleviate cardiac remodeling in spontaneously hypertensive rats.

Heart failure and cardiac remodeling are both characterized by mitochondrial dysfunction. Healthy mitochondria are required for adequate contractile activity and appropriate regulation of cell survival. In the mammalian heart, enhancement of the mitochondrial unfolded protein response (UPRmt) is cardioprotective under pressure overload conditions. We explored the UPRmt and the underlying regulatory mechanism in terms of hypertension-induced cardiac remodeling and the cardioprotective effect of metformin. Male spontaneously hypertensive rats and angiotensin II-treated neonatal rat cardiomyocytes were used to induce cardiac hypertrophy. The results showed that hypertension induced the formation of aberrant mitochondria, characterized by a reduced mtDNA/nDNA ratio and swelling, as well as lower levels of mitochondrial complexes I to V and inhibition of the expression of one protein subunit of each of complexes I to IV. Such changes eventually enlarged cardiomyocytes and increased cardiac fibrosis. Metformin treatment increased the mtDNA/nDNA ratio and regulated the UPRmt, as indicated by increased expression of activating transcription factor 5, Lon protease 1, and heat shock protein 60, and decreased expression of C/EBP homologous protein. Thus, metformin improved mitochondrial ultrastructure and function in spontaneously hypertensive rats. In vitro analyses revealed that metformin reduced the high levels of angiotensin II-induced mitochondrial reactive oxygen species in such animals and stimulated nuclear translocation of heat shock factor 1 (HSF1). Moreover, HSF1 small-interfering RNA reduced the metformin-mediated improvements in mitochondrial morphology and the UPRmt by suppressing hypertrophic signals and cardiomyocyte apoptosis. These results suggest that HSF1/UPRmt signaling contributes to the beneficial effects of metformin. Metformin-mediated targeting of mitochondrial protein homeostasis and modulation of HSF1 levels have potential therapeutic implications in terms of cardiac remodeling.

Cinnamaldehyde ameliorates STZ-induced diabetes through modulation of autophagic process in adipocyte and hepatic tissues on rats.

Type 2 diabetes mellitus is a worldwide public health issue. In the globe, Egypt has the ninth-highest incidence of diabetes. Due to its crucial role in preserving cellular homeostasis, the autophagy process has drawn a lot of attention in recent years, Therefore, the purpose of this study was to evaluate the traditional medication metformin with the novel therapeutic effects of cinnamondehyde on adipocyte and hepatic autophagy in a model of high-fat diet/streptozotocin-diabetic rats. The study was conducted on 40 male albino rats, classified into 2 main groups, the control group and the diabetic group, which was subdivided into 4 subgroups (8 rats each): untreated diabetic rats, diabetic rats received oral cinnamaldehyde 40 mg/kg/day, diabetic rats received oral metformin 200 mg/kg/day and diabetic rats received a combination of both cinnamaldehyde and metformin daily for 4 weeks. The outcomes demonstrated that cinnamaldehyde enhanced the lipid profile and glucose homeostasis. Moreover, Cinnamaldehyde had the opposite effects on autophagy in both tissues; by altering the expression of genes that control autophagy, such as miRNA 30a and mammalian target of rapamycin (mTOR), it reduced autophagy in adipocytes and stimulated it in hepatic tissues. It may be inferred that by increasing the treatment efficacy of metformin and lowering its side effects, cinnamaldehyde could be utilized as an adjuvant therapy with metformin for the treatment of type 2 diabetes.

Effects of metformin, saxagliptin and repaglinide on gut microbiota in high-fat diet/streptozocin-induced type 2 diabetic mice.

INTRODUCTION: There has been increasing evidence that the gut microbiota is closely related to type 2 diabetes (T2D). Metformin (Met) is often used in combination with saxagliptin (Sax) and repaglinide (Rep) for the treatment of T2D. However, little is known about the effects of these combination agents on gut microbiota in T2D. RESEARCH DESIGN AND METHODS: A T2D mouse model induced by a high-fat diet (HFD) and streptozotocin (STZ) was employed. The T2D mice were randomly divided into six groups, including sham, Met, Sax, Rep, Met+Sax and Met+Rep, for 4 weeks. Fasting blood glucose level, serum biochemical index, H&E staining of liver, Oil red O staining of liver and microbiota analysis by 16s sequencing were used to access the microbiota in the fecal samples. RESULTS: These antidiabetics effectively prevented the development of HFD/STZ-induced high blood glucose, and the combination treatment had a better effect in inhibiting lipid accumulation. All these dosing regimens restored the decreasing ratio of the phylum Bacteroidetes: Firmicutes, and increasing abundance of phylum Desulfobacterota, expect for Met. At the genus level, the antidiabetics restored the decreasing abundance of Muribaculaceae in T2D mice, but when Met was combined with Rep or Sax, the abundance of Muribaculaceae was decreased. The combined treatment could restore the reduced abundance of Prevotellaceae_UCG-001, while Met monotherapy had no such effect. In addition, the reduced Lachnospiraceae_NK4A136_group was well restored in the combination treatment groups, and the effect was much greater than that in the corresponding monotherapy group. Therefore, these dosing regimens exerted different effects on the composition of gut microbiota, which might be associated with the effect on T2D. CONCLUSIONS: Supplementation with specific probiotics may further improve the hypoglycemic effects of antidiabetics and be helpful for the development of new therapeutic drugs for T2D.

Modulatory effects of rutin and vitamin A on hyperglycemia induced glycation, oxidative stress and inflammation in high-fat-fructose diet animal model.

In the current study we investigated the impact of combination of rutin and vitamin A on glycated products, the glyoxalase system, oxidative markers, and inflammation in animals fed a high-fat high-fructose (HFFD) diet. Thirty rats were randomly divided into six groups (n = 5). The treatments, metformin (120 mg/kg), rutin (100 mg/kg), vitamin A (43 IU/kg), and a combination of rutin (100 mg/kg) and vitamin A (43 IU/kg) were given to relevant groups of rats along with high-fructose high-fat diet for 42 days. HbA1c, D-lactate, Glyoxylase-1, Hexokinase 2, malondialdehyde (MDA), glutathione peroxidase (GPx), catalase (CAT), nuclear transcription factor-B (NF-κB), interleukin-6 (IL-6), interleukin-8 (IL-8) and histological examinations were performed after 42 days. The docking simulations were conducted using Auto Dock package. The combined effects of rutin and vitamin A in treated rats significantly (p < 0.001) reduced HbA1c, hexokinase 2, and D-lactate levels while preventing cellular damage. The combination dramatically (p < 0.001) decreased MDA, CAT, and GPx in treated rats and decreased the expression of inflammatory cytokines such as IL-6 andIL-8, as well as the transcription factor NF-κB. The molecular docking investigations revealed that rutin had a strong affinity for several important biomolecules, including as NF-κB, Catalase, MDA, IL-6, hexokinase 2, and GPx. The results propose beneficial impact of rutin and vitamin A as a convincing treatment strategy to treat AGE-related disorders, such as diabetes, autism, alzheimer's, atherosclerosis.

Metformin attenuates lung ischemia-reperfusion injury and necroptosis through AMPK pathway in type 2 diabetic recipient rats.

BACKGROUND: Diabetes mellitus (DM) can aggravate lung ischemia-reperfusion (I/R) injury and is a significant risk factor for recipient mortality after lung transplantation. Metformin protects against I/R injury in a variety of organs. However, the effect of metformin on diabetic lung I/R injury remains unclear. Therefore, this study aimed to observe the effect and mechanism of metformin on lung I/R injury following lung transplantation in type 2 diabetic rats. METHODS: Sprague-Dawley rats were randomly divided into the following six groups: the control + sham group (CS group), the control + I/R group (CIR group), the DM + sham group (DS group), the DM + I/R group (DIR group), the DM + I/R + metformin group (DIRM group) and the DM + I/R + metformin + Compound C group (DIRMC group). Control and diabetic rats underwent the sham operation or left lung transplantation operation. Lung function, alveolar capillary permeability, inflammatory response, oxidative stress, necroptosis and the p-AMPK/AMPK ratio were determined after 24 h of reperfusion. RESULTS: Compared with the CIR group, the DIR group exhibited decreased lung function, increased alveolar capillary permeability, inflammatory responses, oxidative stress and necroptosis, but decreased the p-AMPK/AMPK ratio. Metformin improved the function of lung grafts, decreased alveolar capillary permeability, inflammatory responses, oxidative stress and necroptosis, and increased the p-AMPK/AMPK ratio. In contrast, the protective effects of metformin were abrogated by Compound C. CONCLUSIONS: Metformin attenuates lung I/R injury and necroptosis through AMPK pathway in type 2 diabetic lung transplant recipient rats.

Data-dependent and -independent acquisition lipidomics analysis reveals the tissue-dependent effect of metformin on lipid metabolism.

INTRODUCTION: Despite the well-recognized health benefits, the mechanisms and site of action of metformin remains elusive. Metformin-induced global lipidomic changes in plasma of animal models and human subjects have been reported. However, there is a lack of systemic evaluation of metformin-induced lipidomic changes in different tissues. Metformin uptake requires active transporters such as organic cation transporters (OCTs), and hence, it is anticipated that metformin actions are tissue-dependent. In this study, we aim to characterize metformin effects in non-diabetic male mice with a special focus on lipidomics analysis. The findings from this study will help us to better understand the cell-autonomous (direct actions in target cells) or non-cell-autonomous (indirect actions in target cells) mechanisms of metformin and provide insights into the development of more potent yet safe drugs targeting a particular organ instead of systemic metabolism for metabolic regulations without major side effects. OBJECTIVES: To characterize metformin-induced lipidomic alterations in different tissues of non-diabetic male mice and further identify lipids affected by metformin through cell-autonomous or systemic mechanisms based on the correlation between lipid alterations in tissues and the corresponding in-tissue metformin concentrations. METHODS: A dual extraction method involving 80% methanol followed by MTBE (methyl tert-butyl ether) extraction enables the analysis of free fatty acids, polar metabolites, and lipids. Extracts from tissues and plasma of male mice treated with or without metformin in drinking water for 12 days were analyzed using HILIC chromatography coupled to Q Exactive Plus mass spectrometer or reversed-phase liquid chromatography coupled to MS/MS scan workflow (hybrid mode) on LC-Orbitrap Exploris 480 mass spectrometer using biologically relevant lipids-containing inclusion list for data-independent acquisition (DIA), named as BRI-DIA workflow followed by data-dependent acquisition (DDA), to maximum the coverage of lipids and minimize the negative effect of stochasticity of precursor selection on experimental consistency and reproducibility. RESULTS: Lipidomics analysis of 6 mouse tissues and plasma allowed a systemic evaluation of lipidomic changes induced by metformin in different tissues. We observed that (1) the degrees of lipidomic changes induced by metformin treatment overly correlated with tissue concentrations of metformin; (2) the impact on lysophosphatidylcholine (lysoPC) and cardiolipins was positively correlated with tissue concentrations of metformin, while neutral lipids such as triglycerides did not correlate with the corresponding tissue metformin concentrations; (3) increase of intestinal tricarboxylic acid (TCA) cycle intermediates after metformin treatment. CONCLUSION: The data collected in this study from non-diabetic mice with 12-day metformin treatment suggest that the overall metabolic effect of metformin is positively correlated with tissue concentrations and the effect on individual lipid subclass is via both cell-autonomous mechanisms (cardiolipins and lysoPC) and non-cell-autonomous mechanisms (triglycerides).

Beneficial effects of metformin treatment on memory impairment.

Memory issues are a prevalent symptom in different neurodegenerative diseases and can also manifest in certain psychiatric conditions. Despite limited medications approved for treating memory problems, research suggests a lack of sufficient options in the market. Studies indicate that a significant percentage of elderly individuals experience various forms of memory disorders. Metformin, commonly prescribed for type 2 diabetes, has shown neuroprotective properties through diverse mechanisms. This study explores the potential of metformin in addressing memory impairments. The current research gathered its data by conducting an extensive search across electronic databases including PubMed, Web of Science, Scopus, and Google Scholar. Previous research suggests that metformin enhances brain cell survival and memory function in both animal and clinical models by reducing oxidative stress, inflammation, and cell death while increasing beneficial neurotrophic factors. The findings of the research revealed that metformin is an effective medication for enhancing various types of memory problems in numerous studies. Given the rising incidence of memory disorders, it is plausible to utilize metformin, which is an affordable and accessible drug. It is often recommended as a treatment to boost memory.

Development of chitosan lipid nanoparticles to alleviate the pharmacological activity of piperine in the management of cognitive deficit in diabetic rats.

The aim of the present study was to prepare and evaluate Piperine (PP) loaded chitosan lipid nanoparticles (PP-CLNPs) to evaluate its biological activity alone or in combination with the antidiabetic drug Metformin (MET) in the management of cognitive deficit in diabetic rats. Piperine was successfully loaded on CLNPs prepared using chitosan, stearic acid, Tween 80 and Tripolyphosphate (TPP) at different concentrations. The developed CLNPs exhibited high entrapment efficiency that ranged from 85.12 to 97.41%, a particle size in the range of 59.56-414 nm and a negatively charged zeta potential values (- 20.1 to - 43.9 mV). In vitro release study revealed enhanced PP release from CLNPs compared to that from free PP suspensions for up to 24 h. In vivo studies revealed that treatment with the optimized PP-CLNPs formulation (F2) exerted a cognitive enhancing effect and ameliorated the oxidative stress associated with diabetes. PP-CLNPs acted as an effective bio-enhancer which increased the potency of metformin in protecting brain tissue from diabetes-induced neuroinflammation and memory deterioration. These results suggested that CLNPs could be a promising drug delivery system for encapsulating PP and thus can be used as an adjuvant therapy in the management of high-risk diabetic cognitive impairment conditions.

Metformin normalizes mitochondrial function to delay astrocyte senescence in a mouse model of Parkinson's disease through Mfn2-cGAS signaling.

BACKGROUND: Senescent astrocytes play crucial roles in age-associated neurodegenerative diseases, including Parkinson's disease (PD). Metformin, a drug widely used for treating diabetes, exerts longevity effects and neuroprotective activities. However, its effect on astrocyte senescence in PD remains to be defined. METHODS: Long culture-induced replicative senescence model and 1-methyl-4-phenylpyridinium/α-synuclein aggregate-induced premature senescence model, and a mouse model of PD were used to investigate the effect of metformin on astrocyte senescence in vivo and in vitro. Immunofluorescence staining and flow cytometric analyses were performed to evaluate the mitochondrial function. We stereotactically injected AAV carrying GFAP-promoter-cGAS-shRNA to mouse substantia nigra pars compacta regions to specifically reduce astrocytic cGAS expression to clarify the potential molecular mechanism by which metformin inhibited the astrocyte senescence in PD. RESULTS: We showed that metformin inhibited the astrocyte senescence in vitro and in PD mice. Mechanistically, metformin normalized mitochondrial function to reduce mitochondrial DNA release through mitofusin 2 (Mfn2), leading to inactivation of cGAS-STING, which delayed astrocyte senescence and prevented neurodegeneration. Mfn2 overexpression in astrocytes reversed the inhibitory role of metformin in cGAS-STING activation and astrocyte senescence. More importantly, metformin ameliorated dopamine neuron injury and behavioral deficits in mice by reducing the accumulation of senescent astrocytes via inhibition of astrocytic cGAS activation. Deletion of astrocytic cGAS abolished the suppressive effects of metformin on astrocyte senescence and neurodegeneration. CONCLUSIONS: This work reveals that metformin delays astrocyte senescence via inhibiting astrocytic Mfn2-cGAS activation and suggest that metformin is a promising therapeutic agent for age-associated neurodegenerative diseases.

Metformin suppresses NFE2L1 pathway activation to inhibit gap junction beta protein expression in NSCLC.

OBJECTIVE: Non-small-cell lung cancer (NSCLC) is a deadly form of cancer that exhibits extensive intercellular communication which contributed to chemoradiotherapy resistance. Recent evidence suggests that arrange of key proteins are involved in lung cancer progression, including gap junction proteins (GJPs). METHODS AND RESULTS: In this study, we examined the expression patterns of GJPs in NSCLC, uncovering that both gap junction protein, beta 2 (GJB2) and gap junction protein, beta 2 (GJB3) are increased in LUAD and LUSC. We observed a correlation between the upregulation of GJB2, GJB3 in clinical samples and a worse prognosis in patients with NSCLC. By examining the mechanics, we additionally discovered that nuclear factor erythroid-2-related factor 1 (NFE2L1) had the capability to enhance the expression of connexin26 and connexin 31 in the NSCLC cell line A549. In addition, the use of metformin was discovered to cause significant downregulation of gap junction protein, betas (GJBs) by limiting the presence of NFE2L1 in the cytoplasm. CONCLUSION: This emphasizes the potential of targeting GJBs as a viable treatment approach for NSCLC patients receiving metformin.

Metformin Loaded Zein Polymeric Nanoparticles to Augment Antitumor Activity against Ehrlich Carcinoma via Activation of AMPK Pathway: D-Optimal Design Optimization, In Vitro Characterization, and In Vivo Study.

Metformin (MET), an antidiabetic drug, is emerging as a promising anticancer agent. This study was initiated to investigate the antitumor effects and potential molecular targets of MET in mice bearing solid Ehrlich carcinoma (SEC) as a model of breast cancer (BC) and to explore the potential of zein nanoparticles (ZNs) as a carrier for improving the anticancer effect of MET. ZNs were fabricated through ethanol injection followed by probe sonication method. The optimum ZN formulation (ZN8) was spherical and contained 5 mg zein and 30 mg sodium deoxycholate with a small particle size and high entrapment efficiency percentage and zeta potential. A stability study showed that ZN8 was stable for up to three months. In vitro release profiles proved the sustained effect of ZN8 compared to the MET solution. Treatment of SEC-bearing mice with ZN8 produced a more pronounced anticancer effect which was mediated by upregulation of P53 and miRNA-543 as well as downregulation of NF-κB and miRNA-191-5p gene expression. Furthermore, ZN8 produced a marked elevation in pAMPK and caspase-3 levels as well as a significant decrease in cyclin D1, COX-2, and PGE2 levels. The acquired findings verified the potency of MET-loaded ZNs as a treatment approach for BC.

Metformin: A Dual-Role Player in Cancer Treatment and Prevention.

Cancer continues to pose a significant global health challenge, as evidenced by the increasing incidence rates and high mortality rates, despite the advancements made in chemotherapy. The emergence of chemoresistance further complicates the effectiveness of treatment. However, there is growing interest in the potential of metformin, a commonly prescribed drug for type 2 diabetes mellitus (T2DM), as an adjuvant chemotherapy agent in cancer treatment. Although the precise mechanism of action of metformin in cancer therapy is not fully understood, it has been found to have pleiotropic effects, including the modulation of metabolic pathways, reduction in inflammation, and the regulation of cellular proliferation. This comprehensive review examines the anticancer properties of metformin, drawing insights from various studies conducted in vitro and in vivo, as well as from clinical trials and observational research. This review discusses the mechanisms of action involving both insulin-dependent and independent pathways, shedding light on the potential of metformin as a therapeutic agent for different types of cancer. Despite promising findings, there are challenges that need to be addressed, such as conflicting outcomes in clinical trials, considerations regarding dosing, and the development of resistance. These challenges highlight the importance of further research to fully harness the therapeutic potential of metformin in cancer treatment. The aims of this review are to provide a contemporary understanding of the role of metformin in cancer therapy and identify areas for future exploration in the pursuit of effective anticancer strategies.

[Metformin suppresses hypoxia-inducible factor-1α expression in cancer-associated fibroblasts to block tumor-stromal cross-talk in breast cancer].

OBJECTIVE: To investigate the mechanism of metformin for regulating tumor-stromal cell cross-talk in breast cancer. METHODS: Tumor associated fibroblasts (CAFs) co-cultured with breast cancer cells were treated with metformin, and the changes in expressions of hypoxia-inducible factor-1α (HIF-1α), p-AMPK, stroma-derived factor-1 (SDF-1) and interleukin-8 (IL-8) in the CAFs were detected using ELISA, RT-qPCR or Western blotting; Transwell assay was used to evaluate the invasiveness of the tumor cells and its changes following treatment with exogenous SDF-1, IL-8 and TGF-ß1. The effects of HIF-1α shRNA or overexpression plasmid, AMPK shRNA, and treatment with OG (a proline hydroxylase inhibitor) or 2-OXO (a proline hydroxylase activator) were examined on p-AMPK, HIF-1α, SDF-1 and IL-8 expressions and invasiveness of the CAFs. RESULTS: Metformin treatment significantly increased the expression levels of p-AMPK, SDF-1 and IL-8 (P<0.05) and decreased HIF-1α expression (P<0.05) without affecting AMPK expression level (P>0.05) in the CAFs. The invasion ability of metformintreated breast cancer cells was significantly decreased (P<0.05). Exogenous SDF-1 and IL-8, HIF-1α overexpression, and OGinduced upregulation of HIF-1α all significantly attenuated the inhibitory effects of metformin on breast cancer cell invasion (P<0.05) and HIF-1α, SDF-1 and IL-8 expressions in CAFs (P<0.05). Transfection with HIF-1α shRNA or treatment with 2-OXO significantly decreased the invasiveness of breast cancer cells (P<0.05). P-AMPK knockdown significantly suppressed the inhibitory effect of metformin on HIF-1α expression in CAFs and on invasion of breast cancer cells (P<0.05). Treatment with TGF-ß1 partially decreased the inhibitory effect of metformin on HIF-1α expression in CAFs and invasiveness of the breast cancer cells (P<0.05). CONCLUSION: Metformin suppresses HIF-1α expression in CAFs to block tumor-stromal cross talk in breast cancer.

[Metformin ameliorates PM2.5-induced functional impairment of placental trophoblasts by inhibiting ferroptosis].

OBJECTIVE: To investigate the protective effect of metformin against PM2.5-induced functional impairment of placental trophoblasts and explore the underlying mechanism. METHODS: Sixteen pregnant Kunming mice were randomly assigned into two groups (n=8) for intratracheal instillation of PBS or PM2.5 suspension at 1.5, 7.5, and 12.5 days of gestation. The pregnancy outcome of the mice was observed, and placental zonal structure and vascular density of the labyrinth area were examined with HE staining, followed by detection of ferroptosis-related indexes in the placenta. In cultured human trophoblasts (HTR8/SVneo cells), the effects of PM2.5 exposure and treatment with metformin on cell viability, proliferation, migration, invasion, and tube formation ability were evaluated using CCK8 assay, EDU staining, wound healing assay, Transwell experiment, and tube formation experiment; the cellular expressions of ferroptosis-related proteins were analyzed using ELISA and Western blotting. RESULTS: M2.5 exposure of the mice during pregnancy resulted in significantly decreased weight and number of the fetuses and increased fetal mortality with a reduced placental weight (all P<0.001). PM2.5 exposure also caused obvious impairment of the placental structure and trophoblast ferroptosis. In cultured HTR8/SVneo cells, PM2.5 significantly inhibited proliferation, migration, invasion, and angiogenesis of the cells by causing ferroptosis. Metformin treatment obviously attenuated PM2.5-induced inhibition of proliferation, migration, invasion, and angiogenesis of the cells, and effectively reversed PM2.5-induced ferroptosis in the trophoblasts as shown by significantly increased intracellular GSH level and SOD activity, reduced MDA and Fe2+ levels, and upregulated GPX4 and SLC7A11 protein expression (P<0.05 or 0.01). CONCLUSION: PM2.5 exposure during pregnancy causes adverse pregnancy outcomes and ferroptosis and functional impairment of placental trophoblasts in mice, and metformin can effectively alleviate PM2.5-induced trophoblast impairment.

Respiratory complex I regulates dendritic cell maturation in explant model of human tumor immune microenvironment.

BACKGROUND: Combining cytotoxic chemotherapy or novel anticancer drugs with T-cell modulators holds great promise in treating advanced cancers. However, the response varies depending on the tumor immune microenvironment (TIME). Therefore, there is a clear need for pharmacologically tractable models of the TIME to dissect its influence on mono- and combination treatment response at the individual level. METHODS: Here we establish a patient-derived explant culture (PDEC) model of breast cancer, which retains the immune contexture of the primary tumor, recapitulating cytokine profiles and CD8+T cell cytotoxic activity. RESULTS: We explored the immunomodulatory action of a synthetic lethal BCL2 inhibitor venetoclax+metformin drug combination ex vivo, discovering metformin cannot overcome the lymphocyte-depleting action of venetoclax. Instead, metformin promotes dendritic cell maturation through inhibition of mitochondrial complex I, increasing their capacity to co-stimulate CD4+T cells and thus facilitating antitumor immunity. CONCLUSIONS: Our results establish PDECs as a feasible model to identify immunomodulatory functions of anticancer drugs in the context of patient-specific TIME.

Metformin Inhibits Zika Virus Infection in Trophoblast Cell Line.

Zika virus (ZIKV) infections have been associated with severe clinical outcomes, which may include neurological manifestations, especially in newborns with intrauterine infection. However, licensed vaccines and specific antiviral agents are not yet available. Therefore, a safe and low-cost therapy is required, especially for pregnant women. In this regard, metformin, an FDA-approved drug used to treat gestational diabetes, has previously exhibited an anti-ZIKA effect in vitro in HUVEC cells by activating AMPK. In this study, we evaluated metformin treatment during ZIKV infection in vitro in a JEG3-permissive trophoblast cell line. Our results demonstrate that metformin affects viral replication and protein synthesis and reverses cytoskeletal changes promoted by ZIKV infection. In addition, it reduces lipid droplet formation, which is associated with lipogenic activation of infection. Taken together, our results indicate that metformin has potential as an antiviral agent against ZIKV infection in vitro in trophoblast cells.