Effects of diabetic pharmacotherapy on prolactin hormone in patients with type 2 diabetes mellitus: Bane or Boon

Dysregulation of proBDNF/p75NTR and BDNF/TrkB Signaling in Acute Ischemic Stroke: Different Sides of the Same Coins

Acute ischemic stroke (AIS) is a focal neurological deficit due to sudden occlusion of cerebral vessels in the brain. AIS-induced neuronal injury and associated excite-toxicity and neurodegeneration affect the synthesis and the release of different neurotrophic factors such as brain-derived neurotropic factor (BDNF) and its precursor proBDNF. Both BDNF and proBDNF act on the specific receptors with different neurological effects. BDNF activates tropomyosin receptor kinase B (TrkB) receptor results in promoting neuronal survival, synaptic plasticity, and neuronal growth. However, the proBDNF activates p75 neurotrophin receptor (p75NTR) and sortilin which attenuates synaptic plasticity and promotes neuronal apoptosis. Dysregulation of central and peripheral expression of proBDNF/BDNF is linked with the severity and clinical outcomes of AIS. Therefore, this review aims to discuss the alterations of proBDNF/BDNF signaling in AIS. Findings from the present review illustrated that proBDNF/p75NTR/sortilin signaling pathway is exaggerated whereas; BDNF-TrkB signaling is reduced in AIS leading to neuronal apoptosis. Therefore, activation of BDNF-TrkB signaling, and inhibition of proBDNF/p75NTR/sortilin signaling pathway could be a promising therapeutic strategy in the management of AIS.

The Possible Role of Metformin and Fibroblast Growth Factor-21 in Multiple Sclerosis Neuropathology: Birds of a Feather Flock Together

Multiple sclerosis (MS) is a progressive demyelinating disease of the CNS, characterized by inflammation, the formation of CNS plaques, and damage to the neuronal myelin sheath (Graphical abstract). Fibroblast growth factor 21 (FGF21) is involved in various metabolic disorders and neurodegenerative diseases. FGF21 and its co-receptor β-Kloth are essential in the remyelination process of MS. Metformin, an insulin-sensitizing drug that is the first-line treatment for type 2 diabetes mellitus (T2DM), may have a potential neuroprotective impact by up-regulating the production of FGF21, which may prevent the onset of neurodegenerative diseases including MS. The purpose of this review is to clarify how metformin affects MS neuropathology mechanistically via modifying FGF21. Metformin increases the expression of FGF21. Metformin also increases the expression of β-Klotho, modulates oxidative stress, reduces glutamate-induced excitotoxicity, and regulates platelet function and coagulation cascades. In conclusion, metformin can enhance the functional activity of FGF21 in counteracting the development and progression of MS. Preclinical and clinical studies are warranted in this regard.

Evaluating the efficacy of metformin in reducing hyperprolactinemia among patients with schizophrenia: A meta-analysis of randomized controlled trials

BACKGROUND

Antipsychotic treatment is commonly associated with hyperprolactinemia, leading to menstrual disturbances, sexual dysfunction, and decreased bone mineral density. Nearly all antipsychotic drugs can elevate prolactin levels, affecting up to 70% of patients with schizophrenia. We aim to evaluate the potential therapeutic role of metformin in reducing hyperprolactinemia among these patients.

METHODS

We systematically searched PubMed, CNKI, Embase, Cochrane, and Web of Science through January 31, 2024, for randomized controlled trials (RCTs) evaluating metformin's effect on prolactin levels in patients with schizophrenia. Data were extracted and synthesized using random-effects meta-analysis.

RESULTS

This meta-analysis included 10 RCTs with 1046 participants (584 received metformin and 462 received placebo or no treatment). Metformin significantly reduced prolactin levels compared to control groups (SMD = -0.98, 95% CI: -1.62, -0.35, p = 0.002; transformed MD = -34.88 ng/mL, 95% CI: -57.65, -12.46). Subgroup analyses indicated that higher doses (1500 mg), shorter treatment durations (<24 weeks), higher BMI (>25 kg/m²), and longer illness duration (>1 year) were associated with more significant prolactin reductions. Metformin was well tolerated with no significant increase in adverse events or all-cause discontinuation rates compared to the control group.

CONCLUSION

This meta-analysis suggests that metformin shows potential as a treatment for antipsychotic-induced hyperprolactinemia, with a favorable tolerability profile in patients with schizophrenia, particularly at higher doses, shorter treatment durations, higher BMI, and longer illness duration. Despite the robustness of the findings, high heterogeneity necessitates cautious interpretation. Future research should explore demographic and clinical factors influencing the response to metformin for optimizing treatment.

Decrypting the Possible Mechanistic Role of Fenofibrate in Alzheimer's Disease and Type 2 Diabetes: The Truth and Mystery

Alzheimer's disease (AD) is a neurodegenerative disease caused by the progressive deposition of extracellular amyloid beta (Aβ) and intracellular neurofibrillary tangles (NFTs). Of note, metabolic disorders such as insulin resistance (IR) and type 2 diabetes (T2D) are associated with the development of brain IR and associated neurodegeneration. In addition, AD neuropathology and linked cognitive impairment accelerate the development of peripheral IR and the progression of T2D. Therefore, there is a bidirectional relationship between T2D and AD. It has been demonstrated that AD and T2D induce dysregulation of peroxisome proliferator-activated receptor alpha (PPAR-α) leading to the central and peripheral metabolic disturbances. Hence, dysregulated PPAR-α could be a shared mechanism in both AD and T2D, and restoration of PPAR-α signalling by PPAR-α agonist fenofibrate (FN) may alleviate T2D and AD. Therefore, this review aims to shed light on the potential involvement of PPAR-α in T2D and AD, and how FN could be effective in the management of AD. FN seems to be effective in both AD and T2D by dual neuroprotective and antidiabetic effects that can mitigate AD neuropathology and T2D-related complications by modulating various cellular processes and inflammatory signalling pathways. In conclusion, FN could be a possible candidate in the management of AD and T2D by modulating different signalling pathways involved in the pathogenesis of these conditions.

The potential therapeutic role of berberine in treating epilepsy focusing on temporal lobe epilepsy: State of art and ongoing perspective

Epilepsy is a neurological disease characterized by unprovoked recurrent epileptic seizures. Temporal lobe epilepsy (TLE) is the commonest type of focal epilepsy in adults that resist to the conventional anti-seizure medications (ASMs). Interestingly, ASMs do not affect the epileptogenesis and progression of disease. Therefore, repurposing of natural products with anti-inflammatory, anti-oxidant and anti-seizure effects such as berberine (BRB) may be logical in treating refractory epilepsy and TLE. However, the molecular mechanism of BRB against the development of epilepsy and progression of epileptic seizure mainly in TLE was not fully elucidated. Therefore, we attempt in this review to discuss the potential underlying molecular mechanism of BRB against the development and progression of epilepsy mainly the TLE.

Autophagy modulators in type 2 diabetes: A new perspective

Type 2 diabetes (T2D) is a chronic metabolic disorder caused by defective insulin signaling, insulin resistance, and impairment of insulin secretion. Autophagy is a conserved lysosomal-dependent catabolic cellular pathway involved in the pathogenesis of T2D and its complications. Basal autophagy regulates pancreatic β-cell function by enhancing insulin release and peripheral insulin sensitivity. Therefore, defective autophagy is associated with impairment of pancreatic β-cell function and the development of insulin rersistance (IR). However, over-activated autophagy increases apoptosis of pancreatic β-cells leading to pancreatic β-cell dysfunction. Hence, autophagy plays a double-edged sword role in T2D. Therefore, the use of autophagy modulators including inhibitors and activators may affect the pathogenesis of T2D. Hence, this review aims to clarify the potential role of autophagy inhibitors and activators in T2D.

Prolactin effects on the pathogenesis of diabetes mellitus

BACKGROUND

Prolactin (PRL) is a pituitary hormone promoting lactation in response to the suckling reflex. Beyond its well-known effects, novel tissue-specific and metabolic functions of PRL are emerging.

AIMS

To dissect PRL as a critical mediator of whole-body gluco-insulinemic sensitivity.

METHODS

PubMed-based search with the following terms 'prolactin', 'glucose metabolism', 'type 2 diabetes mellitus', 'type 1 diabetes mellitus', 'gestational diabetes mellitus' was performed.

DISCUSSION

The identification of the PRL-glucose metabolism network poses the basis for unprecedented avenues of research in the pathogenesis of diabetes mellitus type 1 or 2, as well as of gestational diabetes. In this regard, it is of timely relevance to define properly the homeostatic PRL serum levels since glucose metabolism could be influenced by the circulating amount of the hormone.

RESULTS

This review underscores the basic mechanisms of regulation of pancreatic β-cell functions by PRL and provides a revision of articles which have investigated the connection between PRL unbalancing and diabetes mellitus. Future studies are needed to elucidate the burden and the role of PRL in the regulation of glucose metabolism and determine the specific PRL threshold that may impact the management of diabetes.

CONCLUSION

A careful evaluation and context-driven interpretation of PRL levels (e.g., pregnancy, PRL-secreting pituitary adenomas, drug-related hyper- and hypoprolactinemia) could be critical for the correct screening and management of glucometabolic disorders, such as type 1 or 2 as well as gestational diabetes mellitus.

Role of ketogenic diet in neurodegenerative diseases focusing on Alzheimer diseases: The guardian angle

The ketogenic diet (KD) is a low-carbohydrate, adequate protein and high-fat diet. KD is primarily used to treat refractory epilepsy. KD was shown to be effective in treating different neurodegenerative diseases. Alzheimer disease (AD) is the first common neurodegenerative disease in the world characterized by memory and cognitive impairment. However, the underlying mechanism of KD in controlling of AD and other neurodegenerative diseases are not discussed widely. Therefore, this review aims to revise the fundamental mechanism of KD in different neurodegenerative diseases focusing on the AD. KD induces a fasting-like which modulates the central and peripheral metabolism by regulating mitochondrial dysfunction, oxidative stress, inflammation, gut-flora, and autophagy in different neurodegenerative diseases. Different studies highlighted that KD improves AD neuropathology by regulating synaptic neurotransmission and inhibiting of neuroinflammation and oxidative stress. In conclusion, KD improves cognitive function and attenuates the progression of AD neuropathology by reducing oxidative stress, mitochondrial dysfunction, and enhancing neuronal autophagy and brain BDNF.

New insight on the possible role of statins in Vascular Parkinsonism: A need for presumptive therapy

Vascular Parkinsonism (VP) is clinical term represents a progressive ischemic changes and subcortical lacunar infarct leading to Parkinsonism mainly in the lower limbs so called lower body Parkinsonism. The VP neuropathology is differed from that of PD neuropathology which rarely associated with basal ganglion lesions. Dopamine transporters are normal in VP but are highly reduced in PD, and dopaminergic agonists had no effective role on VP. The neuropathological mechanisms of VP are related to vascular injury which induces the interruption of the neural connection between basal ganglion and cerebral cortex. Hyperlipidemia and other cardiometabolic risk factors augment VP risk and the related neuropathology. Targeting of these cardiometabolic disorders by lipid-lowering statins may be effective in the management of VP. Therefore, this mini-review aims to clarify the possible role of statins in the management of VP. Statins have neuroprotective effects against different neurodegenerative diseases by anti-inflammatory, antioxidant and antithrombotic effects with enhancement of endothelial function. In conclusion, statins can prevent and treat VP by inhibiting inflammatory and oxidative stress disorders, mitigating of white matter hyperintensities and improving of neuronal signaling pathways. Additional preclinical, clinical trials and prospective studies are warranted in this regard.

Role of fenofibrate in multiple sclerosis

Multiple sclerosis (MS) is the most frequent inflammatory and demyelinating disease of the central nervous system (CNS). The underlying pathophysiology of MS is the destruction of myelin sheath by immune cells. The formation of myelin plaques, inflammation, and injury of neuronal myelin sheath characterizes its neuropathology. MS plaques are multiple focal regions of demyelination disseminated in the brain's white matter, spinal cords, deep grey matter, and cerebral cortex. Fenofibrate is a peroxisome proliferative activated receptor alpha (PPAR-α) that attenuates the inflammatory reactions in MS. Fenofibrate inhibits differentiation of Th17 by inhibiting the expression of pro-inflammatory signaling. According to these findings, this review intended to illuminate the mechanistic immunoinflammatory role of fenofibrate in mitigating MS neuropathology. In conclusion, fenofibrate can attenuate MS neuropathology by modulating different pathways, including oxidative stress, autophagy, mitochondrial dysfunction, inflammatory-signaling pathways, and neuroinflammation.

Current Insights in Prolactin Signaling and Ovulatory Function

Prolactin (PRL) is a pleiotropic hormone released from lactotrophic cells of the anterior pituitary gland that also originates from extrapituitary sources and plays an important role in regulating lactation in mammals, as well as other actions. Acting in an endocrine and paracrine/autocrine manner, PRL regulates the hypothalamic-pituitary-ovarian axis, thus influencing the maturation of ovarian follicles and ovulation. This review provides a detailed discussion of the current knowledge on the role of PRL in the context of ovulation and ovulatory disorders, particularly with regard to hyperprolactinemia, which is one of the most common causes of infertility in women. Much attention has been given to the PRL structure and the PRL receptor (PRLR), as well as the diverse functions of PRLR signaling under normal and pathological conditions. The hormonal regulation of the menstrual cycle in connection with folliculogenesis and ovulation, as well as the current classifications of ovulation disorders, are also described. Finally, the state of knowledge regarding the importance of TIDA (tuberoinfundibular dopamine), KNDγ (kisspeptin/neurokinin B/dynorphin), and GnRH (gonadotropin-releasing hormone) neurons in PRL- and kisspeptin (KP)-dependent regulation of the hypothalamic-pituitary-gonadal (HPG) axis in women is reviewed. Based on this review, a rationale for influencing PRL signaling pathways in therapeutic activities accompanying ovulation disorders is presented.

The possible role of nuclear factor erythroid-2-related factor 2 activators in the management of Covid-19

COVID-19 is caused by a novel SARS-CoV-2 leading to pulmonary and extra-pulmonary manifestations due to oxidative stress (OS) development and hyperinflammation. COVID-19 is primarily asymptomatic though it may cause acute lung injury (ALI), acute respiratory distress syndrome (ARDS), systemic inflammation, and thrombotic events in severe cases. SARS-CoV-2-induced OS triggers the activation of different signaling pathways, which counterbalances this complication. One of these pathways is nuclear factor erythroid 2-related factor 2 (Nrf2), which induces a series of cellular interactions to mitigate SARS-CoV-2-mediated viral toxicity and OS-induced cellular injury. Nrf2 pathway inhibits the expression of pro-inflammatory cytokines and the development of cytokine storm in COVID-19. Therefore, Nrf2 activators may play an essential role in reducing SARS-CoV-2 infection-induced inflammation by suppressing NLRP3 inflammasome in COVID-19. Furthermore, Nrf2 activators can attenuate endothelial dysfunction (ED), renin-angiotensin system (RAS) dysregulation, immune thrombosis, and coagulopathy. Thus this mini-review tries to clarify the possible role of the Nrf2 activators in the management of COVID-19. Nrf2 activators could be an effective therapeutic strategy in the management of Covid-19. Preclinical and clinical studies are recommended in this regard.

The possible role furin and furin inhibitors in endometrial adenocarcinoma: A narrative review

BACKGROUND

Endometrial adenocarcinoma (EAC) is a malignant tumor of the endometrium. EAC is the most common female malignancy following the menopause period. About 40% of patients with EAC are linked with obesity and interrelated with hypertension, diabetes mellitus, and high circulating estrogen levels. Proprotein convertase (PC) furin was involved in the progression of EAC.

RECENT FINDINGS

Furin is a protease enzyme belonging to the subtilisin PC family called PC subtilisin/kexin type 3 that converts precursor proteins to biologically active forms and products. Aberrant activation of furin promotes abnormal cell proliferation and the development of cancer. Furin promotes angiogenesis, malignant cell proliferation, and tissue invasion by malignant cells through its pro-metastatic and oncogenic activities. Furin activity is correlated with the malignant proliferation of EAC. Higher expression of furin may increase the development of EAC through overexpression of pro-renin receptors and disintegrin and metalloprotease 17 (ADAM17). As well, inflammatory signaling in EAC promotes the expression of furin with further propagation of malignant transformation.

CONCLUSION

Furin is associated with the development and progression of EAC through the induction of proliferation, invasion, and metastasis of malignant cells of EAC. Furin induces ontogenesis in EAC through activation expression of ADAM17, pro-renin receptor, CD109, and TGF-β. As well, EAC-mediated inflammation promotes the expression of furin with further propagation of neoplastic growth and invasion.

Neprilysin inhibitors and risk of Alzheimer's disease: A future perspective

Alzheimer's disease (AD) is a heterogeneous neurodegenerative disease with multifaceted neuropathological disorders. AD is characterized by intracellular accumulation of phosphorylated tau proteins and extracellular deposition of amyloid beta (Aβ). Various protease enzymes, including neprilysin (NEP), are concerned with the degradation and clearance of Aβ. Indeed, a defective neuronal clearance pathway due to the dysfunction of degradation enzymes might be a possible mechanism for the accumulation of Aβ and subsequent progression of AD neuropathology. NEP is one of the most imperative metalloproteinase enzymes involved in the clearance of Aβ. This review aimed to highlight the possible role of NEP inhibitors in AD. The combination of sacubitril and valsartan which is called angiotensin receptor blocker and NEP inhibitor (ARNI) may produce beneficial and deleterious effects on AD neuropathology. NEP inhibitors might increase the risk of AD by the inhibition of Aβ clearance, and increase brain bradykinin (BK) and natriuretic peptides (NPs), which augment the pathogenesis of AD. These verdicts come from animal model studies, though they may not be applied to humans. However, clinical studies revealed promising safety findings regarding the use of ARNI. Moreover, NEP inhibition increases various neuroprotective peptides involved in inflammation, glucose homeostasis and nerve conduction. Also, NEP inhibitors may inhibit dipeptidyl peptidase 4 (DPP4) expression, ameliorating insulin and glucagon-like peptide 1 (GLP-1) levels. These findings proposed that NEP inhibitors may have a protective effect against AD development by increasing GLP-1, neuropeptide Y (NPY) and substance P, and deleterious effects by increasing brain BK. Preclinical and clinical studies are recommended in this regard.

The conceivable role of prolactin hormone in Parkinson disease: The same goal but with different ways

Parkinson disease (PD) is a progressive neurodegenerative disease (NDD) of the brain. It has been reported that prolactin (PRL) hormone plays a differential effect in PD, may be increasing, reduced or unaffected. PRL level is dysregulated in different neurodegenerative disorders including PD. Preclinical and clinical studies pointed out that PRL may has a neuroprotective against PD neuropathology . Though, the mechanistic role of PRL in PD is not fully elucidated. Therefore, the objective of the present review was to clarify the potential role and mechanistic pathway of PRL in PD neuropathology. The present review highlighted that PRL appears to have a neuroprotective effect against PD neuropathology by inhibiting the expression of pro-inflammatory signaling pathways, antioxidant effects and by inhibiting neuroinflammation. Thus, preclinical and clinical studies are warranted in this regard.

New insights on the potential effect of progesterone in Covid-19: Anti-inflammatory and immunosuppressive effects

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a pandemic disease caused by severe acute respiratory syndrome CoV type 2 (SARS-CoV-2). COVID-19 is higher in men than women and sex hormones have immune-modulator effects during different viral infections, including SARS-CoV-2 infection. One of the essential sex hormones is progesterone (P4).

AIMS

This review aimed to reveal the association between P4 and Covid-19.

RESULTS AND DISCUSSION

The possible role of P4 in COVID-19 could be beneficial through the modulation of inflammatory signaling pathways, induction of the release of anti-inflammatory cytokines, and inhibition release of pro-inflammatory cytokines. P4 stimulates skew of naïve T cells from inflammatory Th1 toward anti-inflammatory Th2 with activation release of anti-inflammatory cytokines, and activation of regulatory T cells (Treg) with decreased interferon-gamma production that increased during SARS-CoV-2 infection. In addition, P4 is regarded as a potent antagonist of mineralocorticoid receptor (MR), it could reduce MRs that were activated by stimulated aldosterone from high AngII during SARS-CoV-2. P4 active metabolite allopregnanolone is regarded as a neurosteroid that acts as a positive modulator of γ-aminobutyric acid (GABAA ) so it may reduce neuropsychiatric manifestations and dysautonomia in COVID-19 patients.

CONCLUSION

Taken together, the anti-inflammatory and immunomodulatory properties of P4 may improve central and peripheral complications in COVID-19.

SARS-CoV-2 infection and dysregulation of nuclear factor erythroid-2-related factor 2 (Nrf2) pathway

Coronavirus disease 2019 (COVID-19) is a recent pandemic caused by a novel severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) leading to pulmonary and extra-pulmonary manifestations due to the development of oxidative stress (OS) and hyperinflammation. The underlying cause for OS and hyperinflammation in COVID-19 may be related to the inhibition of nuclear factor erythroid 2-related factor 2 (Nrf2), a master regulator of antioxidative responses and cellular homeostasis. The Nrf2 pathway inhibits the expression of pro-inflammatory cytokines and the development of cytokine storm and OS in COVID-19. Nrf2 activators can attenuate endothelial dysfunction (ED), renin-angiotensin system (RAS) dysregulation, immune thrombosis, and coagulopathy. Hence, this review aimed to reveal the potential role of the Nrf2 pathway and its activators in the management of COVID-19. As well, we tried to revise the mechanistic role of the Nrf2 pathway in COVID-19.

Antidepressants and type 2 diabetes: highways to knowns and unknowns

Type 2 diabetes (T2D) is a metabolic disease caused by the development of insulin resistance (IR), relative insulin deficiency, and hyperglycemia. Hyperglycemia-induced neurochemical dysregulation activates the progression of depression in T2D patients. Therefore, management of depression by antidepressant agents improves glucose homeostasis and insulin sensitivity. However, prolong use of antidepressant drugs may increase the risk for the development of T2D. However, there is strong controversy concerning the use of antidepressant drugs in T2D. Therefore, this review try to elucidate the potential effects of antidepressant drugs in T2D regarding their detrimental and beneficial effects.

The potential effect of metformin on fibroblast growth factor 21 in type 2 diabetes mellitus (T2DM)

Fibroblast growth factor 21 (FGF21) is a peptide hormone mainly synthesized and released from the liver. FGF21 acts on FGF21 receptors (FGFRs) and β-Klotho, which is a transmembrane co-receptor. In type 2 diabetes mellitus (T2DM), inflammatory disorders stimulate the release of FGF21 to overcome insulin resistance (IR). FGF21 improves insulin sensitivity and glucose homeostasis. Metformin which is used in the management of T2DM may increase FGF21 expression. Accordingly, the objective of this review was to clarify the metformin effect on FGF21 in T2DM. FGF21 level and expression of FGF2Rs are dysregulated in T2DM due to the development of FGF21 resistance. Metformin stimulates the hepatic expression of FGF21/FGF2Rs by different signaling pathways. Besides, metformin improves the expression of β-Klotho which improves FGF21 sensitivity. In conclusion, metformin advances FGF21 signaling and decreases FGF21 resistance in T2DM, and this might be an innovative mechanism for metformin in the enhancement of glucose homeostasis and metabolic disorders in T2DM patients.

The potential role of human islet amyloid polypeptide in type 2 diabetes mellitus and Alzheimer's diseases

Human Islet amyloid polypeptide (hIAPP) from pancreatic β cells in the islet of Langerhans has different physiological functions including inhibiting the release of insulin and glucagon. Type 2 diabetes mellitus (T2DM) is an endocrine disorder due to relative insulin insufficiency and insulin resistance (IR) is associated with increased circulating hIAPP. Remarkably, hIAPP has structural similarity with amyloid beta (Aβ) and can engage in the pathogenesis of T2DM and Alzheimer's disease (AD). Therefore, the present review aimed to elucidate how hIAPP acts as a link between T2DM and AD. IR, aging and low β cell mass increase expression of hIAPP which binds cell membrane leading to the aberrant release of Ca2+ and activation of the proteolytic enzymes leading to a series of events causing loss of β cells. Peripheral hIAPP plays a major role in the pathogenesis of AD, and high circulating hIAPP level increase AD risk in T2DM patients. However, there is no hard evidence for the role of brain-derived hIAPP in the pathogenesis of AD. Nevertheless, oxidative stress, mitochondrial dysfunction, chaperon-mediated autophagy, heparan sulfate proteoglycan (HSPG), immune response, and zinc homeostasis in T2DM could be the possible mechanisms for the induction of the aggregation of hIAPP which increase AD risk. In conclusion, increasing hIAPP circulating levels in T2DM patients predispose them to the development and progression of AD. Dipeptidyl peptidase 4 (DPP4) inhibitors and glucagon-like peptide-1 (GLP-1) agonists attenuate AD in T2DM by inhibiting expression and deposition of hIAP.

A Potential Link Between Visceral Obesity and Risk of Alzheimer's Disease

Alzheimer's disease (AD) is the most common type of dementia characterized by the deposition of amyloid beta (Aβ) plaques and tau-neurofibrillary tangles in the brain. Visceral obesity (VO) is usually associated with low-grade inflammation due to higher expression of pro-inflammatory cytokines by adipose tissue. The objective of the present review was to evaluate the potential link between VO and the development of AD. Tissue hypoxia in obesity promotes tissue injury, production of adipocytokines, and release of pro-inflammatory cytokines leading to an oxidative-inflammatory loop with induction of insulin resistance. Importantly, brain insulin signaling is involved in the pathogenesis of AD and lower cognitive function. Obesity and enlargement of visceral adipose tissue are associated with the deposition of Aβ. All of this is consonant with VO increasing the risk of AD through the dysregulation of adipocytokines which affect the development of AD. The activated nuclear factor kappa B (NF-κB) pathway in VO might be a potential link in the development of AD. Likewise, the higher concentration of advanced glycation end-products in VO could be implicated in the pathogenesis of AD. Taken together, different inflammatory signaling pathways are activated in VO that all have a negative impact on the cognitive function and progression of AD except hypoxia-inducible factor 1 which has beneficial and neuroprotective effects in mitigating the progression of AD. In addition, VO-mediated hypoadiponectinemia and leptin resistance may promote the progression of Aβ formation and tau phosphorylation with the development of AD. In conclusion, VO-induced AD is mainly mediated through the induction of oxidative stress, inflammatory changes, leptin resistance, and hypoadiponectinemia that collectively trigger Aβ formation and neuroinflammation. Thus, early recognition of VO by visceral adiposity index with appropriate management could be a preventive measure against the development of AD in patients with VO.

Metformin and growth differentiation factor 15 (GDF15) in type 2 diabetes mellitus: A hidden treasure

Type 2 diabetes mellitus (T2DM) is a chronic endocrine disorder due to the reduction of insulin sensitivity and relative deficiency of insulin secretion. Growth differentiation factor 15 (GDF15) belongs to the transforming growth factor beta (TGF-β) superfamily and was initially identified as macrophage inhibitory cytokine-1 (MIC-1). GDF15 is considered a cytokine with an anti-inflammatory effect and increases insulin sensitivity, reduces body weight, and improves clinical outcomes in diabetic patients. GDF15 acts through stimulation of glial-derived neurotrophic factor (GDNF) family receptor α-like (GFRAL), which is highly expressed in the brain stem to induce taste aversion. Metformin belongs to the group of biguanides that are derived from the plant Galega officinalis. It is interesting to note that metformin is an insulin-sensitizing agent used as a first-line therapy for T2DM that has been shown to increase the circulating level of GDF15. Thus, the present review aims to determine the critical association of the GDF15 biomarker in T2DM and how metformin agents affect it. This review illustrates that metformin activates GDF15 expression, which reduces appetite and leads to weight loss in both diabetic and nondiabetic patients. However, the present review cannot give a conclusion in this regard. Therefore, experimental, preclinical, and clinical studies are warranted to confirm the potential role of GDF15 in T2DM patients.

Novel hit of DPP-4Is as promising antihyperglycemic agents with dual antioxidant/anti-inflammatory effects for type 2 diabetes with/without COVID-19

DPP-4Is are well recognized therapy for type 2 diabetes. In spite of sharing a common mode of action, the chemical diversity among members of DPP-4Is raised the question whether structural differences may result in distinguished activities. DPP-4Is were recently explored as drug repurposing means for treatment of SARS-CoV-2 due to the urgent need for small molecule drugs for controlling infections. The use of DPP-4Is was not correlated with adverse COVID-19-related consequences among patients with type 2 diabetes. Inspired by these reasons and the importance of pyrimidinone ring as DPP-4I with both antioxidant and anti-inflammatory activities, we succeeded to prepare some novel pyrimidinone and thio-pyrimidinone derivatives, which were then screened for their antidiabetic activity and DPP-4 inhibition. In addition, their anti-inflammatory effect on LPS-stimulated RAW 264.7 cells were evaluated. Furthermore, their antioxidant activities were also tested.

Plasminogen activator inhibitor 1 and gestational diabetes: the causal relationship

Plasminogen activator inhibitor 1 (PAI-1) also known as serpin E1 or endothelial plasminogen activator inhibitor, is produced from endothelial cells and adipose tissue. PAI-1 inhibits tissue plasminogen activator (tPA) and urokinase (uPA) preventing activation of plasminogen and fibrinolysis. Gestational diabetes mellitus (GDM) is defined as glucose intolerance and hyperglycemia during pregnancy. The underlying mechanism of GDM is due to the reduction of insulin secretion or the development of insulin resistance (IR). Normal PAI-1 is a crucial mediator for maintaining pregnancy, though aberrantly high PAI-1 promotes inflammation and thrombosis with increased risk of pregnancy loss. Increasing PAI-1 level had been shown to be an early feature of cardio-metabolic derangement in women with GDM. As well, GDM is regarded as an independent predictor for increasing PAI-1 levels compared to normal pregnancy. Taken together, GDM seems to be the causal factor in the increase of PAI-1 via induction of IR, hyperglycemia and hypertriglyceridemia. In conclusion, GDM triggers expression and release of PAI-1 which linked with GDM severity due to exaggerated pro-inflammatory and inflammatory cytokines with the development of IR. High PAI-1 levels in GDM may induce hypofibrinolysis and thrombotic complications.

The Potential Use of Carnosine in Diabetes and Other Afflictions Reported in Long COVID Patients

Carnosine is a dipeptide expressed in both the central nervous system and periphery. Several biological functions have been attributed to carnosine, including as an anti-inflammatory and antioxidant agent, and as a modulator of mitochondrial metabolism. Some of these mechanisms have been implicated in the pathophysiology of coronavirus disease-2019 (COVID-19). COVID-19 is caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). The clinical manifestation and recovery time for COVID-19 are variable. Some patients are severely affected by SARS-CoV-2 infection and may experience respiratory failure, thromboembolic disease, neurological symptoms, kidney damage, acute pancreatitis, and even death. COVID-19 patients with comorbidities, including diabetes, are at higher risk of death. Mechanisms underlying the dysfunction of the afflicted organs in COVID-19 patients have been discussed, the most common being the so-called cytokine storm. Given the biological effects attributed to carnosine, adjuvant therapy with this dipeptide could be considered as supportive treatment in patients with either COVID-19 or long COVID.

The crucial role of prolactin-lactogenic hormone in Covid-19

Prolactin (PRL) is a peptide hormone secreted from anterior pituitary involved in milk production in the females and regulation of sex drive in both sexes. PRL has pro-inflammatory and anti-inflammatory functions. High PRL serum level or hyperprolactinemia is associated with different viral infections. In coronavirus disease 2019 (Covid-19), which caused by positive-sense single-strand RNA virus known as severe acute respiratory distress syndrome coronavirus type 2 (SARS-CoV-2), PRL serum level is increased. PRL in Covid-19 may exacerbate the underlying inflammatory status by induction release of pro-inflammatory cytokines. However, PRL through its anti-inflammatory effects may reduce the hyperinflammatory status in Covid-19. The underlying mechanism of increasing PRL in Covid-19 is poorly understood. Therefore, in this review we try to find the potential anti-inflammatory or pro-inflammatory role of PRL in Covid-19. As well, this review was aimed to discuss the underlying causes and mechanisms for Covid-19-induced hyperprolactinemia.

Association of Serum Prolactin With Type 2 Diabetes Mellitus: A Comparative Cross-Sectional Study From South India

BACKGROUND

 The association of serum prolactin (PRL) with diabetes is still uncertain, with a paucity of data in the south Indian population. This study aims to compare the serum PRL levels between type 2 diabetes mellitus (T2DM) patients and normoglycaemic volunteers and correlate the serum PRL level with fasting plasma glucose (FPG), postprandial plasma glucose (PPG), glycated haemoglobin (HbA1c) levels, and the lipid profile in the study population.

METHODS

 This was a comparative cross-sectional study among 112 T2DM participants and 112 healthy volunteers in a tertiary care centre in India. All participants were tested for FPG, PPG, HbA1c, fasting serum lipid profile, and serum PRL, which were compared between T2DM patients and healthy volunteers.

RESULTS

 The serum PRL in T2DM patients was significantly lower compared to healthy volunteers (8.67 ± 4.37 vs. 13.76 ± 6.55 ng/ml, P < 0.001). FPG, PPG, and HbA1c correlated inversely with serum PRL in our study population. On multivariable logistic regression adjusted for age and sex, a higher serum PRL level within the physiological range was protective for T2DM (adjusted odds ratio: 0.83, 95% CI: 0.77-0.90, P < 0.001). Serum PRL levels were inversely correlated with serum total cholesterol, low-density lipoprotein cholesterol, and triglycerides, but not with high-density lipoprotein cholesterol.

CONCLUSIONS

A high serum PRL within the physiological range was inversely associated with the prevalence of T2DM in the south Indian population. Serum PRL also correlated inversely with glycaemic and blood lipid parameters. Larger longitudinal studies are required to further validate the association of serum PRL with various components of metabolic syndrome in the south Indian population.

Associations between Prolactin, Diabetes, and Cognitive Impairment: A Literature Review

BACKGROUND

Converging evidence indicates prolactin (PRL) and diabetes play an important role in the pathophysiology of cognitive impairment. However, little is known about the mechanisms responsible for the effects of PRL and diabetes on cognitive impairment.

SUMMARY

We summarize and review the available literature and current knowledge of the association between PRL and diabetes on aspects of cognitive impairment.

KEY MESSAGES

The phosphatidylinositol 3-kinase/protein kinase B pathway is central to the molecular mechanisms underlying how PRL and diabetes interact in cognitive impairment. Further work is needed to identify the interaction between PRL and diabetes, especially in the molecular aspects of cognitive impairment, which can suggest novel strategies for cognitive dysfunction treatment.

Statin therapy associated with decreased neuronal injury measured by serum S100β levels in patients with acute ischemic stroke

Background

Acute ischemic strokes (AIS) are a common cause of morbidity, mortality, and disability. The serum biomarker S100β correlates with poor neurological outcomes in the setting of AIS. This study describes the impact of statin treatment on S100β levels following AIS.

Methods

This was a prospective case-control study of AIS patients compared to healthy controls. Patients were stratified into three groups: (1) AIS patients on statin therapy, (2) AIS patients not on statin therapy, and (3) healthy controls. Demographics, clinical parameters, stroke risk scores (SRS), and S100β levels were recorded for all patients.

Results

Blood pressure, lipids, and SRS scores were higher in stroke versus control patients (all P < 0.05), and lower in Group I versus II (all P < 0.05). S100β levels were higher in stroke versus nonstroke patients (P = 0.001), and lower in Group I versus II (P = 0.001). Furthermore, patients on atorvastatin showed greater S100β reductions than those on rosuvastatin therapy (P = 0.01).

Conclusion

In acute stroke patients, statins therapy correlated with reductions in the neuronal injury biomarker S100β, with greater reductions observed for atorvastatin than rosuvastatin therapy.

Impact of Sitagliptin in Non-Diabetic Covid-19 Patients

OBJECTIVE

In Coronavirus disease 2019 (Covid-19), SARS-CoV-2 may use dipeptidyl peptidase 4 (DPP4) as an entry-point in different tissues expressing these receptors. DPP4 inhibitors (DPP4Is), also named gliptins like sitagliptin, have anti-inflammatory and antioxidant effects; thereby lessen inflammatory and oxidative stress in diabetic Covid-19 patients. Therefore, the present study aimed to illustrate the potential beneficial effect of sitagliptin in managing Covid-19 in non-diabetic patients.

METHODS

A total number of 89 patients with Covid-19 were recruited from a single-center at the time of diagnosis. The recruited patients were assigned according to the standard therapy for Covid-19 and our interventional therapy into two groups; Group A: Covid-19 patients on the standard therapy (n=40) and Group B: Covid-19 patients on the standard therapy plus sitagliptin (n=49). The duration of this interventional study was 28 days according to the guideline in management patients with Covid-19. Routine laboratory investigations, serological tests, complete blood count (CBC), C-reactive protein (CRP), D-dimer, lactate dehydrogenase (LDH), and serum ferritin were measured to observed Covid-19 severity and complications. Lung computed tomography (CT) and clinical scores were evaluated.

RESULTS

The present study illustrated that sitagliptin add-on standard therapy improved clinical outcomes, radiological scores, and inflammatory biomarkers than standard therapy alone in non-diabetic patients with Covid-19 (P<0.01).

CONCLUSIONS

Sitagliptin add-on standard therapy in managing non-diabetic Covid-19 patients may have a robust beneficial effect by modulating inflammatory cytokines with subsequent good clinical outcomes.

Factors Behind the Higher COVID-19 Risk in Diabetes: A Critical Review

Diabetes mellitus (DM) and coronavirus disease 2019 (COVID-19) are public health issues worldwide, and their comorbidities trigger the progress to severe disease and even death in such patients. Globally, DM has affected an estimated 9.3% adults, and as of April 18, 2021, the World Health Organization (WHO) has confirmed 141,727,940 COVID-19 confirmed cases. The virus is spread via droplets, aerosols, and direct touch with others. Numerous predictive factors have been linked to COVID-19 severity, including impaired immune response and increased inflammatory response, among others. Angiotensin receptor blockers and angiotensin converting enzyme 2 have also been identified as playing a boosting role in both susceptibility and severity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Specifically, in DM patients, both their control and management during this pandemic is herculean as the restriction periods have markedly hampered the maintenance of means to control glycemia, hypertension, and neuroendocrine and kidney diseases. In addition, as a result of the underlyin cardio-metabolic and immunological disorders, DM patients are at a higher risk of developing the severe form of COVID-19 despite other comorbidities, such as hypertension, also potentially boosting the development of higher COVID-19 severity. However, even in non-DM patients, SARS-CoV-2 may also cause transient hyperglycemia through induction of insulin resistance and/or pancreatic β-cell injury. Therefore, a strict glucose monitoring of DM patients with COVID-19 is mandatory to prevent life-threatening complications.

COVID-19 in Relation to Hyperglycemia and Diabetes Mellitus

Coronavirus disease 2019 (COVID-19), triggered by the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), may lead to extrapulmonary manifestations like diabetes mellitus (DM) and hyperglycemia, both predicting a poor prognosis and an increased risk of death. SARS-CoV-2 infects the pancreas through angiotensin-converting enzyme 2 (ACE2), where it is highly expressed compared to other organs, leading to pancreatic damage with subsequent impairment of insulin secretion and development of hyperglycemia even in non-DM patients. Thus, this review aims to provide an overview of the potential link between COVID-19 and hyperglycemia as a risk factor for DM development in relation to DM pharmacotherapy. For that, a systematic search was done in the database of MEDLINE through Scopus, Web of Science, PubMed, Embase, China National Knowledge Infrastructure (CNKI), China Biology Medicine (CBM), and Wanfang Data. Data obtained underline that SARS-CoV-2 infection in DM patients is more severe and associated with poor clinical outcomes due to preexistence of comorbidities and inflammation disorders. SARS-CoV-2 infection impairs glucose homeostasis and metabolism in DM and non-DM patients due to cytokine storm (CS) development, downregulation of ACE2, and direct injury of pancreatic β-cells. Therefore, the potent anti-inflammatory effect of diabetic pharmacotherapies such as metformin, pioglitazone, sodium-glucose co-transporter-2 inhibitors (SGLT2Is), and dipeptidyl peptidase-4 (DPP4) inhibitors may mitigate COVID-19 severity. In addition, some antidiabetic agents and also insulin may reduce SARS-CoV-2 infectivity and severity through the modulation of the ACE2 receptor expression. The findings presented here illustrate that insulin therapy might seem as more appropriate than other anti-DM pharmacotherapies in the management of COVID-19 patients with DM due to low risk of uncontrolled hyperglycemia and diabetic ketoacidosis (DKA). From these findings, we could not give the final conclusion about the efficacy of diabetic pharmacotherapy in COVID-19; thus, clinical trial and prospective studies are warranted to confirm this finding and concern.

Role of dyslipidemia in the development of early-onset preeclampsia

Preeclampsia (PE) is a gestational-related disease presented with hypertension, peripheral edema, and proteinuria after 20 weeks of gestation. In PE, there are various metabolic changes like dyslipidemia. In addition, both PE and dyslipidemia are associated with changes of platelet indices. Thus, objective of the current study was to illustrate the potential role of dyslipidemia and platelet changes in pregnant women with PE. This case–control study involved 37 preeclamptic pregnant women as compared to 24 healthy pregnant women as controls. Blood pressure profile, lipid profile, proteinuria, and platelet indices were measured. Blood pressure profile was higher in preeclamptic pregnant women as compared to the controls (P < 0.01). There was a significant dyslipidemic status in preeclamptic pregnant women compared with the controls (P < 0.01). Platetetcrit (PCT) and platelet count (PC) were lower in preeclamptic pregnant women compared with the controls (P = 0.001). On the other hand, platelet distribution width (PDW), mean platelet volume (MPV), and platelet-large cell ratio (P-LCR) were higher in the pregnant women with PE as compared with the controls (P = 0.001). PCT and PC were insignificantly linked, while P-LCR, MPV and PDW were significantly correlated with total cholesterol, triglyceride, low-density lipoprotein (LDL)/high-density lipoprotein (HDL) ratio, systolic blood pressure, DBP, and MAP in preeclamptic patients compared with women of normal pregnancy. Both dyslipidemia and alterations in the platelet indices are correlated with blood pressure profile in PE. High MPV and PDW in association with high LDL/HDL ratio in pregnant women herald risk of PE.

The potential role of neopterin in Covid-19: a new perspective

Neopterin (NPT) is a member of pteridines group, synthesized by macrophages when stimulated by interferon gamma (INF-γ). NPT is regarded as a macrophage stimulation indicator, marker of cellular immune activation and T helper 1 (Th1) type 1 immune response. Here, we aimed to provide a view point on the NPT features and role in Covid-19. Serum NPT level is regarded as an independent prognostic factor for Covid-19 severity, with levels starting to increase from the 3rd day of SARS-CoV-2 infection, being associated with severe dyspnea, longer hospitalization period and complications. Also, early raise of NPT reflects monocytes/macrophages activation before antibody immune response, despite the NPT level may also remain high in Covid-19 patients or at the end of incubation period before the onset of clinical symptoms. On the other hand, NPT attenuates the activity of macrophage foam cells and is linked to endothelial inflammation through inhibition of adhesion molecules and monocytes migration. However, NPT also exerts anti-inflammatory and antioxidant effects by suppressing NF-κB signaling and NLRP3 inflammasomes. NPT can be viewed as a protective compensatory mechanism to counterpoise hyper-inflammation, oxidative stress, and associated organ damage.

Impact of thioctic acid on glycemic indices and associated inflammatory-induced endothelial dysfunction in patients with type 2 diabetes mellitus: A case control study

Objective

To evaluate the effects of thioctic acid (TA) add-on metformin therapy on glycemic indices and associated inflammatory reactions induced-endothelial dysfunction (ED) in patients with type 2 diabetes mellitus (T2DM).

Methods

In this case-control clinical study, a total number of 70 patients with T2DM compared with 30 healthy controls were divided into three groups: Group A (n = 30), healthy controls; Group B (n = 36), T2DM patients on metformin and Group C (n = 34), T2DM patients on metformin plus TA 600 mg/day. Anthropometric measurements, lipid profile, and routine biochemical variables were estimated. Serum human vascular cell adhesion molecule-1 (VCAM-1) and E-selectin were measured before and after 10 consecutive week's therapy with metformin and/or TA.

Results

Metformin therapy led to significant reduction of fasting insulin and insulin resistance (IR) with an increment in the insulin sensitivity (P < 0.01). Metformin therapy improved lipid profile compared to the baseline (P < 0.01) with significant reduction of atherogenic index. Metformin plus TA therapy reduced fasting blood glucose, glycated hemoglobin, and IR and showed increment in the insulin sensitivity (P < 0.01) with insignificant effect on fasting insulin (P = 0.09) compared with metformin monotherapy. sVCAM-1 level was high in patients with T2DM (3.74 ± 1.34 ng/ml) at baseline, which decreased by metformin monotherapy to 2.32 ± 0.67 ng/ml or metformin plus TA to 1.98 ± 0.31 ng/ml (P < 0.01), but metformin plus TA illustrated insignificant difference compared to metformin alone (P = 0.29).

Conclusion

TA add on metformin therapy improves glycemic indices and associated inflammatory mediators in patients with T2DM through modulation of IR , IS , and direct direct anti-inflammatory effect.

Metformin and/or vildagliptin mitigate type II diabetes mellitus induced-oxidative stress: The intriguing effect

The aim of the present study was to investigate the probable effects of metformin plus vildagliptin on the oxidative stress index (OSI) in patients with type II diabetes mellitus (T2DM). In this case–control study, 44 patients with T2DM on either metformin monotherapy (n = 24) or metformin plus vildagliptin (n = 20) were compared with healthy controls (n = 20). Anthropometric and biochemical variables including body mass index, blood pressure profile, cardiac indices, lipid profile, fasting blood glucose, fasting serum insulin, and glycemic indices were assessed. Besides, total oxidant status (TOS), total antioxidant status (TAS), and OSI were determined. Patients with T2DM have higher risk of cardiometabolic changes compared with the control (P = 0.0001). TAS was lower while TOS and OSI were higher in patients with T2DM, as compared with the healthy controls (P < 0.001). TAS, TOS, and OSI were better in patients with T2DM on metformin plus vildagliptin therapy as compared with metformin monotherapy (P < 0.05). Therefore, this study concluded that metformin plus vildagliptin therapy is more effective than metformin monotherapy in attenuation of OSI in patients with T2DM.