Evaluation of the pharmacokinetics of metformin and acarbose in the common marmoset

Age-related changes in hematological biomarkers in common marmosets

Researchers and veterinarians often use hematology and clinical chemistry to evaluate animal health. These biomarkers are relatively easy to obtain, and understanding how they change across healthy aging is critical to clinical care and diagnostics for these animals. We aimed to evaluate how clinical biomarkers from a chemistry profile and complete blood count (CBC) change with age in common marmosets (Callithrix jacchus). We assessed blood samples collected during routine physical exams at the Southwest National Primate Research Center and the University of Texas Health San Antonio marmoset colonies from November 2020-November 2021. We found that chemistry and CBC profiles varied based on facility, sex, and age. Significant changes in albumin, phosphorus/creatinine ratio, albumin/globulin ratio, amylase, creatinine, lymphocyte percent, hematocrit, granulocytes percent, lymphocytes, hemoglobin, red cell distribution width, and platelet distribution width were all reported with advancing age. Aged individuals also demonstrated evidence for changes in liver, kidney, and immune system function compared with younger individuals. Our results suggest there may be regular changes associated with healthy aging in marmosets that are outside of the range typically considered as normal values for healthy young individuals, indicating the potential need for redefined healthy ranges for clinical biomarkers in aged animals. Identifying animals that exhibit values outside of this defined healthy aging reference will allow more accurate diagnostics and treatments for aging colonies.

Review of Environmental and Health Factors Impacting Captive Common Marmoset Welfare in the Biomedical Research Setting

As a small-bodied neotropical nonhuman primate species, common marmosets have unique requirements for adequate husbandry and veterinary care to ensure proper maintenance and to promote good animal welfare in a biomedical research setting. Environmental conditions, as well as medical and research-related manipulations, can impact marmoset welfare. Research focus areas, including basic neuroscience, transgenics, and aging, involve additional implications for marmoset welfare. This manuscript provides a comprehensive review of factors that should be considered and mitigated as needed by clinical and research staff working with marmosets in biomedical research facilities to optimize the welfare of captive marmosets.

A Comprehensive Review on Weight Loss Associated with Anti-Diabetic Medications

Obesity is a complex metabolic condition that can have a negative impact on one's health and even result in mortality. The management of obesity has been addressed in a number of ways, including lifestyle changes, medication using appetite suppressants and thermogenics, and bariatric surgery for individuals who are severely obese. Liraglutide and semaglutide are two of the five Food and Drug Administration (FDA)-approved anti-obesity drugs that are FDA-approved agents for the treatment of type 2 diabetes mellitus (T2DM) patients. In order to highlight the positive effects of these drugs as anti-obesity treatments, we analyzed the weight loss effects of T2DM agents that have demonstrated weight loss effects in this study by evaluating clinical studies that were published for each agent. Many clinical studies have revealed that some antihyperglycemic medications can help people lose weight, while others either cause weight gain or neutral results. Acarbose has mild weight loss effects and metformin and sodium-dependent glucose cotransporter proteins-2 (SGLT-2) inhibitors have modest weight loss effects; however, some glucagon-like peptide-1 (GLP-1) receptor agonists had the greatest impact on weight loss. Dipeptidyl peptidase 4 (DPP-4) inhibitors showed a neutral or mild weight loss effect. To sum up, some of the GLP-1 agonist drugs show promise as weight-loss treatments.

Molecular dynamics simulations reveal the inhibitory mechanism of Withanolide A against α-glucosidase and α-amylase

Diabetes mellitus (DM) is a global chronic disease characterized by hyperglycemia and insulin resistance. The unsavory severe gastrointestinal side-effects of synthetic drugs to regulate hyperglycemia have warranted the search for alternative treatments to inhibit the carbohydrate digestive enzymes (e.g. α-amylase and α-glucosidase). Certain phytochemicals recently captured the scientific community's attention as carbohydrate digestive enzyme inhibitors due to their low toxicity and high efficacy, specifically the Withanolides-loaded extract of Withania somnifera. That said, the present study evaluated in silico the efficacy of Withanolide A in targeting both α-amylase and α-glucosidase in comparison to the synthetic drug Acarbose. Protein-ligand interactions, binding affinity, and stability were characterized using pharmacological profiling, high-end molecular docking, and molecular-dynamic simulation. Withanolide A inhibited the activity of α-glucosidase and α-amylase better, exhibiting good pharmacokinetic properties, absorption, and metabolism. Also, Withanolide A was minimally toxic, with higher bioavailability. Interestingly, Withanolide A bonded well to the active site of α-amylase and α-glucosidase, yielding the lowest binding free energy of -82.144 ± 10.671 kcal/mol and -102.1043 ± 11.231 kcal/mol compared to the Acarbose-enzyme complexes (-63.220 ± 13.283 kcal/mol and -82.148 ± 10.671 kcal/mol). Hence, the findings supported the therapeutic potential of Withanolide A as α-amylase and α-glucosidase inhibitor for DM treatment.Communicated by Ramaswamy H. Sarma.

In Vitro Evaluation of the Anti-Diabetic Potential of Aqueous Acetone Helichrysum petiolare Extract (AAHPE) with Molecular Docking Relevance in Diabetes Mellitus

Diabetes mellitus (DM) is a chronic metabolic condition that can lead to significant complications and a high fatality rate worldwide. Efforts are ramping up to find and develop novel α-glucosidase and α-amylase inhibitors that are both effective and potentially safe. Traditional methodologies are being replaced with new techniques that are less complicated and less time demanding; yet, both the experimental and computational strategies are viable and complementary in drug discovery and development. As a result, this study was conducted to investigate the in vitro anti-diabetic potential of aqueous acetone Helichrysum petiolare and B.L Burtt extract (AAHPE) using a 2-NBDG, 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl) amino)-2-deoxy-d-glucose uptake assay. In addition, we performed molecular docking of the flavonoid constituents identified and quantified by liquid chromatography-mass spectrometry (LC-MS) from AAHPE with the potential to serve as effective and safe α-amylase and α-glucosidase inhibitors, which are important in drug discovery and development. The results showed that AAHPE is a potential inhibitor of both α-amylase and α-glucosidase, with IC₅₀ values of 46.50 ± 6.17 (µg/mL) and 37.81 ± 5.15 (µg/mL), respectively. This is demonstrated by a significant increase in the glucose uptake activity percentage in a concentration-dependent manner compared to the control, with the highest AAHPE concentration of 75 µg/mL of glucose uptake activity being higher than metformin, a standard anti-diabetic drug, in the insulin-resistant HepG2 cell line. The molecular docking results displayed that the constituents strongly bind α-amylase and α-glucosidase while achieving better binding affinities that ranged from ΔG = -7.2 to -9.6 kcal/mol (compared with acarbose ΔG = -6.1 kcal/mol) for α-amylase, and ΔG = -7.3 to -9.0 kcal/mol (compared with acarbose ΔG = -6.3 kcal/mol) for α-glucosidase. This study revealed the potential use of the H. petiolare plant extract and its phytochemicals, which could be explored to develop potent and safe α-amylase and α-glucosidase inhibitors to treat postprandial glycemic levels in diabetic patients.

Rapamycin-induced hyperglycemia is associated with exacerbated age-related osteoarthritis

BACKGROUND

The objective of this study was to determine if mechanistic target of rapamycin (mTOR) inhibition with or without AMP-activated protein kinase (AMPK) activation can protect against primary, age-related OA.

DESIGN

Dunkin-Hartley guinea pigs develop mild primary OA pathology by 5 months of age that progresses to moderate OA by 8 months of age. At 5 months, guinea pigs served as young control (n = 3) or were fed either a control diet (n = 8), a diet enriched with the mTOR-inhibitor rapamycin (Rap, 14 ppm, n = 8), or Rap with the AMPK-activator metformin (Rap+Met, 1000 ppm, n = 8) for 12 weeks. Knee joints were evaluated by OARSI scoring, micro-computed tomography, and immunohistochemistry. Glenohumeral articular cartilage was collected for western blotting.

RESULTS

Rap- and Rap+Met-treated guinea pigs displayed lower body weight than control. Rap and Rap+Met inhibited articular cartilage mTORC1 but not mTORC2 signaling. Rap+Met, but not Rap alone, stimulated AMPK. Despite lower body weight and articular cartilage mTORC1 inhibition, Rap- and Rap+Met-treated guinea pigs had greater OA severity in the medial tibial plateau due to articular cartilage structural damage and/or proteoglycan loss. Rap and Rap+Met increased plasma glucose compared to control. Plasma glucose concentration was positively correlated with proteoglycan loss, suggesting hyperglycemic stress after Rap treatment was related to worsened OA.

CONCLUSIONS

This is the first study to show that Rap induced increase in plasma glucose was associated with greater OA severity. Further, articular cartilage mTORC1 inhibition and bodyweight reduction by dietary Rap and Rap+Met did not appear to protect against primary OA during the prevailing hyperglycemia.

San Antonio Nathan Shock Center: your one-stop shop for aging research

With evolving cores, enrichment and training programs, and supported research projects, the San Antonio (SA) Nathan Shock Center has for 26 years provided critical support to investigators locally, nationally, and abroad. With its existing and growing intellectual capital, the SA Nathan Shock Center provides to local and external investigators an enhanced platform to conduct horizontally integrated (lifespan, healthspan, pathology, pharmacology) transformative research in the biology of aging, and serves as a springboard for advanced educational and training activities in aging research. The SA Nathan Shock Center consists of six cores: Administrative/Program Enrichment Core, Research Development Core, Aging Animal Models and Longevity Assessment Core, Pathology Core, Analytical Pharmacology and Drug Evaluation Core, and Integrated Physiology of Aging Core. The overarching goal of the SA Nathan Shock Center is to advance knowledge in the basic biology of aging and to identify molecular and cellular mechanisms that will facilitate the development of pharmacologic interventions and other strategies to extend healthy lifespan. In pursuit of this goal, we provide an innovative "one-stop shop" venue to accelerate transformative research in the biology of aging through our integrated research cores. Moreover, we aim to foster and promote career development of early-stage investigators in aging biology through our research development programs, to serve as a resource and partner to investigators from other Shock Centers, and to disseminate scientific knowledge and enhanced awareness about aging research. Overall, the SA Nathan Shock Center aims to be a leader in research that advances our understanding of the biology of aging and development of approaches to improve longevity and healthy aging.

Comparison of Insulins Glargine and Degludec in Diabetic Rhesus Macaques (Macaca mulatta) with CGM Devices

Treating and monitoring type 2 diabetes mellitus (T2DM) in NHP can be challenging. Multiple insulin and hypoglycemic therapies and management tools exist, but few studies demonstrate their benefits in a NHP clinical setting. The insulins glargine and degludec are long-acting insulins; their duration of action in humans exceeds 24 and 42 h, respectively. In the first of this study's 2 components, we evaluated whether insulin degludec could be dosed daily at equivalent units to glargine to achieve comparable blood glucose (BG) reduction in diabetic rhesus macaques (Macaca mulatta) with continuous glucose monitoring (CGM) devices. The second component assessed the accuracy of CGM devices in rhesus macaques by comparing time-stamped CGM interstitial glucose values, glucometer BG readings, and BG levels measured by using an automated clinical chemistry analyzer from samples that were collected at the beginning and end of each CGM device placement. The CGM devices collected a total of 21,637 glucose data points from 6 diabetic rhesus macaques that received glargine followed by degludec every 24 h for 1 wk each. Ultimately, glucose values averaged 29 mg/dL higher with degludec than with glargine. Glucose values were comparable between the CGM device, glucometer, and chemistry analyzer, thus validating that CGM devices as reliable for measuring BG levels in rhesus macaques. Although glargine was superior to degludec when given at the same dose (units/day), both are safe and effective treatment options. Glucose values from CGM, glucometers, and chemistry analyzers provided results that were analogous to BG values in rhesus macaques. Our report further highlights critical clinical aspects of using glargine as compared with degludec in NHP and the benefits of using CGM devices in macaques.

Primary neuron and astrocyte cultures from postnatal Callithrix jacchus: a non-human primate in vitro model for research in neuroscience, nervous system aging, and neurological diseases of aging

The ability to generate in vitro cultures of neuronal cells has been instrumental in advancing our understanding of the nervous system. Rodent models have been the principal source of brain cells used in primary cultures for over a century, providing insights that are widely applicable to human diseases. However, therapeutic agents that showed benefit in rodent models, particularly those pertaining to aging and age-associated dementias, have frequently failed in clinical trials. This discrepancy established a potential "translational gap" between human and rodent studies that may at least partially be explained by the phylogenetic distance between rodent and primate species. Several non-human primate (NHP) species, including the common marmoset (Callithrix jacchus), have been used extensively in neuroscience research, but in contrast to rodent models, practical approaches to the generation of primary cell culture systems amenable to molecular studies that can inform in vivo studies are lacking. Marmosets are a powerful model in biomedical research and particularly in studies of aging and age-associated diseases because they exhibit an aging phenotype similar to humans. Here, we report a practical method to culture primary marmoset neurons and astrocytes from brains of medically euthanized postnatal day 0 (P0) marmoset newborns that yield highly pure primary neuron and astrocyte cultures. Primary marmoset neuron and astrocyte cultures can be generated reliably to provide a powerful NHP in vitro model in neuroscience research that may enable mechanistic studies of nervous system aging and of age-related neurodegenerative disorders. Because neuron and astrocyte cultures can be used in combination with in vivo approaches in marmosets, primary marmoset neuron and astrocyte cultures may help bridge the current translational gap between basic and clinical studies in nervous system aging and age-associated neurological diseases.

Advances in selecting appropriate non-rodent species for regulatory toxicology research: Policy, ethical, and experimental considerations

In vivo animal studies are required by regulatory agencies to investigate drug safety before clinical trials. In this review, we summarize the process of selecting a relevant non-rodent species for preclinical studies. The dog is the primary, default non-rodent used in toxicology studies with multiple scientific advantages, including adequate background data and availability. Rabbit has many regulatory advantages as the first non-rodent for the evaluation of reproductive and developmental as well as local toxicity. Recently, minipigs have increasingly replaced dogs and rabbits in toxicology studies due to ethical and scientific advantages including similarity to humans and breeding habits. When these species are not relevant, nonhuman primates (NHPs) can be used as the available animal models, especially in toxicology studies investigating biotherapeutics. Particularly, based on the phylogenetic relationships, the use of New-World marmosets can be considered before Old-World monkeys, especially cynomolgus with robust historical data. Importantly, the use of NHPs should be justified in terms of scientific benefits considering target affinity, expression pattern, and pharmacological cross-reactivity. Strict standards are required for the use of animals. Therefore, this review is helpful for the selection of appropriate non-rodent in regulatory toxicology studies by providing sufficient regulatory, ethical, and scientific data for each species.

Risk Factors for Poor Outcomes of Diabetes Patients With COVID-19: A Single-Center, Retrospective Study in Early Outbreak in China

Background: Diabetes has been found to increase severity and mortality under the current pandemic of coronavirus disease of 2019 (COVID-19). Up to date, the clinical characteristics of diabetes patients with COVID-19 and the risk factors for poor clinical outcomes are not clearly understood. Methods: The study was retrospectively carried out on enrolled diabetes patients with laboratory confirmed COVID-19 infection from a designated medical center for COVID-19 from January 25th, 2020 to February 14th, 2020 in Wuhan, China. The medical record was collected and reviewed. Univariate and multivariate analyses were performed to assess the risk factors associated with the severe events which were defined as a composite endpoint of admission to intensive care unit, the use of mechanical ventilation, or death. Results: A total of 52 diabetes patients with COVID-19 were finally included in the study. 21 (40.4%) patients had developed severe events in 27.50 (IQR 12.25-35.75) days follow-up, 15 (28.8%) patients experienced life-threatening complications and 8 patients died with a recorded mortality rate of 15.4%. Only 13 patients (41.9%) were in optimal glycemic control with HbA1c value of <7.0%. In addition to general clinical characteristics of COVID-19, the severe events diabetes patients showed higher counts of white blood cells and neutrophil, lower lymphocytes (40, 76.9%), high levels of hs-CRP, erythrocyte sedimentation rate (ESR) and procalcitonin (PCT) as compared to the non-severe diabetes patients. Mild higher level of cardiac troponin I (cTNI) (32.0 pg/ml; IQR 16.80-55.00) and D-dimer (1.70 μg/L, IQR 0.70-2.40) were found in diabetes patients with severe events as compared to the non-severe patients (cTNI:20.00 pg/ml, IQR5.38-30.00, p = 0.019; D-dimer: 0.70 μg/L, IQR 0.30-2.40, p = 0.037). After adjusting age and sex, increased level of cTNI was found to significantly associate with the incidence of severe events (HR: 1.007; 95% CI: 1.000-1.013; p = 0.048), Furthermore, using of α-glucosidase inhibitors was found to be the potential protectant for severe events (HR: 0.227; 95% CI: 0.057-0.904; p = 0.035). Conclusion: Diabetes patients with COVID-19 showed poor clinical outcomes. Vigorous monitoring of cTNI should be recommended for the diabetes patients with COVID-19. Usage of α-glucosidase inhibitors could be a potential protectant for the diabetes patients with COVID-19.