An Update on the Molecular and Cellular Basis of Pharmacotherapy in Type 2 Diabetes Mellitus.

Diabetes mellitus (DM) is a chronic illness with an increasing global prevalence. More than 537 million cases of diabetes were reported worldwide in 2021, and the number is steadily increasing. The worldwide number of people suffering from DM is projected to reach 783 million in 2045. In 2021 alone, more than USD 966 billion was spent on the management of DM. Reduced physical activity due to urbanization is believed to be the major cause of the increase in the incidence of the disease, as it is associated with higher rates of obesity. Diabetes poses a risk for chronic complications such as nephropathy, angiopathy, neuropathy and retinopathy. Hence, the successful management of blood glucose is the cornerstone of DM therapy. The effective management of the hyperglycemia associated with type 2 diabetes includes physical exercise, diet and therapeutic interventions (insulin, biguanides, second generation sulfonylureas, glucagon-like peptide 1 agonists, dipeptidyl-peptidase 4 inhibitors, thiazolidinediones, amylin mimetics, meglitinides, α-glucosidase inhibitors, sodium-glucose cotransporter-2 inhibitors and bile acid sequestrants). The optimal and timely treatment of DM improves the quality of life and reduces the severe burden of the disease for patients. Genetic testing, examining the roles of different genes involved in the pathogenesis of DM, may also help to achieve optimal DM management in the future by reducing the incidence of DM and by enhancing the use of individualized treatment regimens.

Nociceptin Increases Antioxidant Expression in the Kidney, Liver and Brain of Diabetic Rats.

Nociceptin (NC) consists of 17 amino acids (aa) and takes part in the processing of learning and memory. The role of NC in the induction of endogenous antioxidants in still unclear. We examined the effect of NC on the expression of endogenous antioxidants in kidney, liver, cerebral cortex (CC), and hippocampus after the onset of diabetes mellitus, using enzyme-linked immunosorbent assay and immunohistochemistry. Exogenous NC (aa chain 1-17; 10 µg/kg body weight) was given intraperitoneally to normal and diabetic rats for 5 days. Our results showed that catalase (CAT) is present in the proximal (PCT) and distal (DCT) convoluted tubules of kidney, hepatocytes, and neurons of CC and hippocampus. The expression of CAT was significantly (p < 0.05) reduced in the kidney of normal and diabetic rats after treatment with NC. However, NC markedly (p < 0.001) increased the expression CAT in the liver and neurons of CC of diabetic rats. Superoxide dismutase (SOD) is widely distributed in the PCT and DCT of kidney, hepatocytes, and neurons of CC and hippocampus. NC significantly (p < 0.001) increased the expression of SOD in hepatocytes and neurons of CC and the hippocampus but not in the kidney. Glutathione reductase (GRED) was observed in kidney tubules, hepatocytes and neurons of the brain. NC markedly increased (p < 0.001) the expression of GRED in PCT and DCT cells of the kidney and hepatocytes of liver and neurons of CC. In conclusion, NC is a strong inducer of CAT, SOD, and GRED expression in the kidney, liver and brain of diabetic rats.

Pharmacokinetics of Two Chlorine-Substituted Bis-Pyridinium Mono-Aldoximes with Regenerating Effect on Butyrylcholinesterase.

Our aim was to find chlorine-substituted antidotes against organophosphate poisoning and compare their pharmacokinetics to their parent compound, K-203. White male Wistar rats were intramuscularly injected with K-203, K-867 or K-870. Serum, brain, kidneys, liver, lung, eyes, and testes tissues were taken after 5, 15, 30, 60, and 120 min and analyzed using reversed-phase high-performance liquid chromatography. K-203, K-867, or K-870 was present in every tissue that was analyzed, including the serum, the eyes, testes, liver, kidneys, lungs, and the brain. The serum levels of K-867 and K-870 (chlorine-substituted derivatives of K-203) were nearly constant between 15 and 30 min, while their parent compound (K-203) showed peak level at 15 min after the administration of 30 µmol/rat. Neither K-203, nor K-867 or K-870 were toxic at a dose of 100 µmol/200 g in rats. Chlorine-substitution of K-867 and K-870 produced limited absorbance and distribution compared to their parent compound, K203.

An update of SGLT1 and SGLT2 inhibitors in early phase diabetes-type 2 clinical trials.

Introduction: More than 424 million adults have diabetes mellitus (DM). This number is expected to increase to 626 million by 2045. The majority (90-95%) of people with DM has type 2-diabetes (T2DM). The continued prevalence of DM and associated complications has prompted investigators to find new therapies. One of the most recent additions to the anti-diabetic armamentarium are inhibitors of sodium-glucose co-transporters 1 and 2 (SGLT1, SGLT2). Areas covered: The authors review the status of SGLT2 inhibitors for the treatment of T2DM and place an emphasis on those agents in early phase clinical trials. Data and information were retrieved from American Diabetes Association, Diabetes UK, ClinicalTrials.gov, PubMed, and Scopus websites. The keywords used in the search were T2DM, SGLT1, SGLT2, and clinical trials. Expert opinion: The benefits of SGLT inhibitors include reductions in serum glycated hemoglobin (HbA1c), body weight, blood pressure and cardiovascular and renal events. However, SGLT inhibitors increase the risk of genitourinary tract infections, diabetic ketoacidosis, and bone fractures. The development of SGLT inhibitors with fewer side effects and as combination therapies are the key to maximizing the therapeutic effects of this important class of anti-diabetic drug.

An update on therapies for the treatment of diabetes-induced osteoporosis.

Introduction: Currently, 424 million people aged between 20 and 79 years worldwide are diabetic. More than 25% of adults aged over 65 years in North America have Type 2 diabetes mellitus (DM). Diabetes-induced osteoporosis (DM-OS) is caused by chronic hyperglycemia, advanced glycated end products and oxidative stress. The increase in the prevalence of DM-OS has prompted researchers to develop new biological therapies for the management of DM-OS. Areas covered: This review covered the current and novel biological agents used in the management of DM-OS. Data were retrieved from PubMed, Scopus, American Diabetes Association and International Osteoporosis Foundation websites, and ClinicalTrials.gov. The keywords for the search included: DM, osteoporosis, and management. Expert opinion: Several biological molecules have been examined in order to find efficient drugs for the treatment of DM-OS. These biological agents include anti-osteoporosis drugs: net anabolics (parathyroid hormone/analogs, androgens, calcilytics, anti-sclerostin antibody), net anti-resorptive osteoporosis drugs (calcitonin, estrogen, selective estrogen receptor modulators, bisphosphonates, RANKL antibody) and anti-diabetic drugs (alpha glucosidase inhibitors, sulfonylureas, biguanides, meglitinides, thiazolidinediones, GLP-1 receptor agonists, dipeptidylpeptidase-4 inhibitors, sodium glucose co-transporter-2 inhibitors, insulin). Biological medications that effectively decrease hyperglycemia and, at the same time, maintain bone health would be an ideal drug/drug combination for the treatment of DM-OS.

Circulating nociceptin and CGRP in medication-overuse headache.

BACKGROUND: Previous studies found low serum levels of nociceptin in migraine patients but high serum levels of calcitonin gene-related peptide (CGRP). CGRP can elicit migraine-like headache. Medication-Overuse Headache (MOH) often has migraine features and can mimic chronic migraine. We therefore hypothesized that as in migraine, serum levels of nociceptin would be lower and CGRP serum levels higher in MOH patients compared with those in healthy volunteers. We hypothesized that the serum levels would normalize after detoxification. METHODS: Seventeen MOH patients, hereof 70.6% with chronic migraine and MOH, and 30 sex and age matched headache-free controls were included. MOH patients underwent a 2-month outpatient detoxification program and after 6 months, 10 patients and 19 controls were retested. Blood samples were analyzed blinded. RESULTS: We found no differences in the levels of nociceptin and CGRP between MOH patients and controls (P = 0.65 and P = 0.59). The mean headache frequency reduction was 43% and 70% of patients reverted to episodic headache after 6 months, but the levels of nociceptin and CGRP were unchanged (P = 0.71 and P = 0.82). CONCLUSION: In contrast to previous findings in migraine patients, we found normal serum levels of nociceptin and CGRP in MOH patients. Thus, we find no evidence that the increased headache frequency of MOH patients could be caused by altered nociceptin and CGRP levels. This underlines the importance of identifying medication overuse in chronic headache and treating the MOH.

Effect of nociceptin on insulin release in normal and diabetic rat pancreas.

Nociceptin (NC), also known as Orphanin FQ, is a brain peptide involved in the regulation of pain, but its role in the endocrine pancreas is poorly understood. The present study examines the pattern of distribution of NC and its effect on insulin and glucagon secretion after the onset of diabetes mellitus (DM). Male Wistar rats weighing 150-200 g were made diabetic with streptozotocin (60 mg/kg body weight, intraperitoneally). Four weeks after the induction of DM, pancreatic tissues were retrieved and processed for immunofluorescence, immunoelectron microscopy, and insulin and glucagon secretion. Isolated islets from non-diabetic and diabetic rats were used to determine the effect of NC on insulin release. NC was discerned in islet cells of non-diabetic control and diabetic rat pancreata. NC co-localized only with insulin in pancreatic beta cells. NC did not co-localize with either glucagon or somatostatin or pancreatic polypeptide. The number of NC-positive cells was markedly (p < 0.001) reduced after the onset of DM. Electron microscopy study showed that NC is located with insulin in the same secretory granules of the beta cells of both non-diabetic and diabetic rat pancreas. NC inhibits insulin release markedly (p < 0.05) from pancreatic tissue fragments of non-diabetic and diabetic rats. In contrast, NC at 10-12 M stimulates insulin release in isolated islets of DM rats. In conclusion, NC co-localizes with insulin only in the islet of Langerhans. The co-localization of NC with insulin suggests a role for NC in the regulation of pancreatic beta cell function.

Pharmacognostical Sources of Popular Medicine To Treat Alzheimer's Disease.

BACKGROUND: A large number of classical and recently discovered plants are indicated in preventing and/or treating Alzheimer's disease (AD). OBJECTIVE: Name of plants with their anti-AD effects are important for their further use and investigation. METHOD: A short overview of AD is given; anti-Alzheimer plants are given in a Table. RESULTS: Various medicinal plants are listed here as sources of popular medicines to be used in cases when patients are afraid of developing and/or suffer from AD. Some of these plants have been used for centuries. The major sources in the literature, over one hundred of references are given for plants that show beneficial effect on the progress of AD. CONCLUSION: Plant extracts are widely used addition to the synthetic drugs approved by various administrative authorities to stop/slow down the progress of symptoms of AD.

Monitoring the Level of 14C-Labelled Selegiline Following Oral Administration.

BACKGROUND: Selegiline [(-)-deprenyl] is widely used for the treatment of Parkinson's disease in humans. OBJECTIVE: Time-dependence of tissue distribution of selegiline following per os administration to rats. METHOD: Oral administration of radiolabeled selegiline to rats resulted in a pattern of tissue distribution similar to that following intraperitoneal injection. Analyses were done using both reversed-phase HPLC and also by counting radioactivity in various body compartments of rats. RESULTS: As a consequence of oral administration of 30 mg/kg of selegiline, its level in the stomach was extremely high (179.57 µg/g tissue through 54.67 µg/g at 15 min to 120 min), that is one magnitude higher than that in the serum level. High selegiline concentrations were also detected in the lacrimal glands (7.45 µg/g), kidneys (6.87 µg/g), livers (6.01 µg/g) and lungs (3.47 µg/g) after 30 minutes of application, which were higher than after intraperitoneal injections. CONCLUSION: The relatively high tissue levels remained for 120 min monitoring. Selegiline levels in the brain (1.69 µg/g) and in the testes (1.88 µg/g) were also considerably higher than following intraperitoneal administration during the entire period of observation (15 to 120 min).

Novel biological therapies for the treatment of diabetic foot ulcers.

INTRODUCTION: The number of people with diabetes mellitus (DM) is estimated to exceed 640 million by the year 2040. Diabetic foot ulcer (DFU) is a debilitating illness that affects more than 2% of DM patients. DFU is caused by DM-induced neural and vascular lesions leading to a reduced sensation and microcirculation. The increase in the prevalence of DFU has prompted researchers to find new therapies for the management of DFU. Areas covered: This review presents the current status of novel biological therapies used in the treatment of DFU. Literature information and data analysis were collected from PubMed, the website of the American Diabetes Association, and ClinicalTrials.gov. The keywords used in the search were: DM, DFU, complications of DM. Expert opinion: Many biological agents have been investigated in a bid to find an effective therapy for DFU. These include growth factors (platelet-derived growth factor, vascular endothelial growth factor etc), stem cells (epithelial progenitor-, adipose-derived stem cells etc), anti-diabetic drugs (insulin, exendin-4), herbs, urokinase, dalteparin, statins and bio-agents such as acid peptide matrix. Biological agents that can reduce hyperglycaemia, increase sensation, microcirculation and oxygenation and repair lost tissue are the most ideal for the treatment of DFU.

Effects on Sperms' Quality of Selegiline in Aged Rats.

BACKGROUND: Selegiline is used to treat Parkinsonian patients. Other indications of its use have recently been discovered. OBJECTIVE: Scouting special and beneficial side effects of selegiline treatment. METHOD: Two-year old male Wistar rats were daily treated with 0.25 mg/kg of selegiline s.c. (subcutaneous injection). The rats were sacrificed following a four-weeks' treatment. RESULTS: Mass of testes, number of sperms, progressive motility of sperms, and their viability definitely increased. CONCLUSION: Selegiline can successfully be used to stop/counterbalance certain symptoms of aging.

Diabetes-induced changes in the morphology and nociceptinergic innervation of the rat uterus.

The prevalence of diabetes mellitus (DM) is about 6% across the globe. This prevalence has been reported to increase in the near future. This means that the number of women with DM who would like to get pregnant and have children will also increase. The present study is aimed at investigating the morphological changes observed in the uterus after the onset of DM. The study also examined the pattern of distribution of nociceptin (NC), a neuropeptide involved in the regulation of pain, a major physiological factor during parturition. The study shows a severe atrophy of uteri as early as 15 days post DM and continued until the termination of the eight-week study. This atrophy was confirmed by light microscopy. Electron microscopy study showed atrophy of the columnar cells of the endometrium, reduced myofibril number and destruction of smooth muscle cells in the myometrium of diabetic rats compared to control. Immunofluorescence and immunoelectron microscopy studies clearly demonstrated the presence of NC in the endometrium, myometrium and on the myofibrils of the smooth muscles of both control and diabetic rat uteri. In addition, NC-positive neurons and varicose fibres were observed in the myometrium of both normal and diabetic rats. However, the expression of NC decreased after the onset of DM. Morphometric analysis showed that the number of NC-labeled cells was significantly (p < 0.05) lower in diabetic rat uteri compared to those of control. In conclusion, DM-induced uterine atrophy is associated with a decrease in the expression of NC in cells, neurons and myofibrils of the rat uterus.

Efficacy of N-Acetylcysteine, Glutathione, and Ascorbic Acid in Acute Toxicity of Paraoxon to Wistar Rats: Survival Study.

There are a great number of reports with assertions that oxidative stress is produced by organophosphorus compound (OPC) poisoning and is a cofactor of mortality and morbidity in OPC toxicity. In addition, antioxidants have been suggested as adjuncts to standard therapy. However, there is no substantial evidence for the benefit of the use of antioxidants in survival after acute intoxication of OPCs. The present study was conducted to assess the effectiveness of three non-enzymatic antioxidants (NEAOs), N-acetylcysteine (NAC), glutathione (GSH), and ascorbic acid (AA), in acute intoxication of adult male Wister rats with paraoxon. The efficacy of the antioxidants was estimated as both a pretreatment and a concurrent application along with the standard oxime, pralidoxime (2-PAM). Relative risk of death after 48 hours of application was estimated by Cox regression analysis. The results revealed no benefit of either tested NEAO to the improvement in survival of experimental rats. The application of these antioxidants was found to be deleterious when administered along with pralidoxime compared to the treatment with pralidoxime alone. It has been concluded that the tested non-enzymatic antioxidants are not useful in acute toxicity for improving survival rates. However, the individual toxic dynamics of diversified OPCs should not be overlooked and further studies with different OPCs are suggested.

Distribution of N-methyl-(14)C-labeled selegiline in the rat.

Tissue distribution of selegiline including N-methyl-(14)C-selegiline was studied with three different techniques. Whole body autoradiography of labeled selegiline in rats completed the former results obtained in mice. Counting radioactivity by liquid scintillation method in various body compartments gave an in-depth numerical estimation of distribution, while RP-HPLC determination of selegiline determined the fate of intact, non-metabolized parent compound. Whole body autoradiography following 15 and 60 min of intraperitoneal application of N-methyl-(14)C-selegiline verified definite and time-dependent blood-brain penetration of selegiline. Quantitative determination of tissue concentrations by liquid scintillation and RP-HPLC methods following 5, 15, 60 and 180 min of intraperitoneal administration of selegiline unanimously verified both blood-brain and blood-testis penetration of the compound through the barrier.

Distribution of nociceptin in pancreatic islet cells of normal and diabetic rats.

OBJECTIVES: Nociceptin has been reported to play an important role in the regulation of pancreatic exocrine secretion. Most of the studies performed on nociceptin are mainly physiological rather than morphological in nature. The present study investigated the pattern of distribution of nociceptin in the endocrine pancreas of normal and diabetic rats. METHODS: Immunohistochemistry, immunofluorescence, Western blot, and double-labeled immunoelectron microscopy were used in this study. Diabetes was induced using streptozotocin (60 mg/kg body weight). RESULTS: Nociceptin-immunoreactive cells were observed in the central and peripheral regions of the islets of both normal and diabetic rat pancreas. The number of nociceptin-positive cells was significantly (P < 0.05) lower in the islet of diabetic rats compared with the control. Immunofluorescence study showed that nociceptin colocalizes with insulin in pancreatic ß-cells. The degree of colocalization of nociceptin with insulin was severely deranged after the onset of diabetes. Moreover, immunogold particles conjugated with either nociceptin or insulin were observed on the granules of pancreatic ß-cell. The number of nociceptin-labeled colloidal gold particles was significantly lower after the onset of diabetes. CONCLUSIONS: Nociceptin is present in pancreatic islets cells and colocalizes with insulin. Nociceptin may have a physiological role in the metabolism of insulin.

Effects of nociceptin and nocistatin on uterine contraction.

The presence and effects of nociceptin (N/OFQ) and nocistatin (NST) in the central nervous system have been reasonably well described, but less data are available on their peripheral functions. Besides their presence in several peripheral organs (white blood cells, airway, liver, skin, vascular and intestinal smooth muscles, ovary, and testis), they have been found in the pregnant myometrium in both rat and human. The level of their precursor prepronociceptin is elevated in the preterm human myometrium as compared with full-term samples, whereas it gradually increases toward term in the pregnant rat uterus. Both N/OFQ and NST inhibit myometrial contractions, an effect which can be enhanced by naloxone and blocked by Ca²âº-dependent K⁺ channel (BK(Ca)) inhibitors. Both compounds increase the myometrial cAMP level which may be responsible for the activation of this channel and subsequent intracellular hyperpolarization. NST releases calcitonin gene-related peptide from the sensory nerve ends, which explains its cAMP-elevating effect. In contrast with the nervous system, where they behave as antagonists, N/OFQ and NST are able to potentiate the uterine-relaxing effect of each other in both rat and human tissues. Further studies are required to clarify the roles of N/OFQ and NST in the regulation of the myometrial contractions and the perception of pain during delivery.

HPLC analysis of blood-brain barrier penetration of 4-fluorodeprenyl.

Validated HPLC analysis was developed in order to monitor the level of 4-fluorodeprenyl in rats. Male Wistar rats were intraperitoneally treated with 30 mg/kg of (-)-4-fluorodeprenyl. The rats were sacrificed after 5, 15, 30 and 60 min of treatment, and various tissues were isolated, such as serum, brain, CSF, liver, testis and lacrimal gland. Perchloric acid was given to aliquots, which were then homogenized, centrifuged and the supernatants were taken. The 4-fluorodeprenyl content was determined using reversed-phase HPLC, based on the comparison of the calibration line of the spiked samples. The level of 4-fluorodeprenyl was between 0.5 and 24 µg/g, showing maximum concentration in the brain and the liver after 5 min following its administration and in serum, CSF, testis, eyes and lacrimal gland after 15 min following its administration, while a relatively high concentration was found in the liver and the lacrimal gland.

Basic aspects of the pharmacodynamics of tolperisone, a widely applicable centrally acting muscle relaxant.

Tolperisone (2-methyl-1-(4-methylphenyl)-3-piperidin-1-ylpropan-1-one hydro-chloride) was introduced in the clinical practice more than forty years ago and is still evaluated as a widely applicable compound in pathologically elevated skeletal muscle tone (spasticity) and related pains of different origin. In the present review, basic pharmacodynamic effects measured on whole animals, analyses of its actions on cell and tissue preparations and molecular mechanism of action on sodium and calcium channels are summarized as recently significantly new data were reported.

HPLC determination of brain biogenic amines following treatment with bispyridinium aldoxime K203.

Effect of a new acetylcholine-esterase reactivator, K203 as a new potential antidote in organophosphate intoxications was studied on dopamine (DA), homovanillic acid (HVA), serotonin (5-HT) and 5-hydroxyindolacetic acid (5-HIAA) levels in seven brain regions (cerebellum, spinal cord, hippocampus, hypothalamus, striatum, medulla oblongata and frontal cortex) of rats by an optimized and validated HPLC method. No significant change in brain level of these neurotransmitters was found either 15 or 60 min following treatment. However, when 5-HIAA/5-HT ratios were calculated as measure of turnover, significant decreases were found in the cerebellum, hippocampus, hypothalamus and the frontal cortex 15 min following K203 administration, but after 60 min only in the frontal cortex.