ORCID Profile
0000-0001-5322-9413
Current Organisation
University of Tasmania
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Baishideng Publishing Group Inc.
Date: 27-03-2022
Publisher: Frontiers Media SA
Date: 13-04-2021
DOI: 10.3389/FENDO.2021.615446
Abstract: Asperuloside is an iridoid glycoside found in many medicinal plants that has produced promising anti-obesity results in animal models. In previous studies, three months of asperuloside administration reduced food intake, body weight, and adipose masses in rats consuming a high fat diet (HFD). However, the mechanisms by which asperuloside exerts its anti-obesity properties were not clarified. Here, we investigated homeostatic and nutrient-sensing mechanisms regulating food intake in mice consuming HFD. We confirmed the anti-obesity properties of asperuloside and, importantly, we identified some mechanisms that could be responsible for its therapeutic effect. Asperuloside reduced body weight and food intake in mice consuming HFD by 10.5 and 12.8% respectively, with no effect on mice eating a standard chow diet. Fasting glucose and plasma insulin were also significantly reduced. Mechanistically, asperuloside significantly reduced hypothalamic mRNA ghrelin, leptin, and pro-opiomelanocortin in mice consuming HFD. The expression of fat lingual receptors (CD36, FFAR1-4), CB1R and sweet lingual receptors (TAS1R2-3) was increased almost 2-fold by the administration of asperuloside. Our findings suggest that asperuloside might exert its therapeutic effects by altering nutrient-sensing receptors in the oral cavity as well as hypothalamic receptors involved in food intake when mice are exposed to obesogenic diets. This signaling pathway is known to influence the subtle hypothalamic equilibrium between energy homeostasis and reward-induced overeating responses. The present pre-clinical study demonstrated that targeting the gustatory system through asperuloside administration could represent a promising and effective new anti-obesity strategy.
Publisher: MDPI AG
Date: 18-10-2022
DOI: 10.3390/ENDOCRINES3040055
Abstract: Obesity produces a systemic low-grade inflammation associated with many adverse health conditions and, as we recently learned, with complications of COVID-19. Functional studies in animal models have demonstrated that asperuloside, an iridoid glycoside found in many medicinal plants, has produced promising anti-obesity results. However, the safety profile and the anti-inflammatory properties of asperuloside remain unknown. Here, we confirmed the previously reported anti-obesity properties of asperuloside, and, importantly, we performed toxicity studies assessing cell viability providing a dose reference for future animal experiments. Asperuloside significantly reduced blood levels of leptin and the mRNA levels of orexigenic peptides, such as NPY and AgRP in mice consuming HFD, with no effect on mice eating a standard chow diet. In addition, our results indicate that ASP reduced both hypothalamic and hepatic mRNA levels of pro-inflammatory cytokines such as IL-1, IL-6 and TNF-α as well as the blood levels of plasminogen activator inhibitor-1 (PAI-1), which are known to play a major role in the development of insulin resistance and cardiovascular complications. Collectively, our findings suggest that asperuloside is a safe compound for long-term use in animal models and that it reduces the elevated levels of pro-inflammatory cytokines occurring in obesity.
Publisher: MDPI AG
Date: 04-04-2023
DOI: 10.3390/NU15071759
Abstract: Chemotherapy is still the first line of treatment for most cancer patients. Patients receiving chemotherapy are generally prone to infections, which result in complications, such as sepsis, mucositis, colitis, and diarrhoea. Several nutritional approaches have been trialled to counter the chemotherapy-associated side effects in cancer patients, but none have yet been approved for routine clinical use. One of the approaches to reduce or avoid chemotherapy-associated complications is to restore the gut microbiota. Gut microbiota is essential for the healthy functioning of the immune system, metabolism, and the regulation of other molecular responses in the body. Chemotherapy erodes the mucosal layer of the gastrointestinal tract and results in the loss of gut microbiota. One of the ways to restore the gut microbiota is through the use of probiotics. Probiotics are the ‘good’ bacteria that may provide health benefits if consumed in appropriate amounts. Some studies have highlighted that the consumption of probiotics in combination with prebiotics, known as synbiotics, may provide better health benefits when compared to probiotics alone. This review discusses the different nutritional approaches that have been studied in an attempt to combat chemotherapy-associated side effects in cancer patients with a particular focus on the use of pre-, pro- and synbiotics.
Publisher: Wiley
Date: 11-01-2017
Publisher: MDPI AG
Date: 24-05-2023
DOI: 10.3390/NUTRACEUTICALS3020021
Abstract: Comorbidities associated with obesity, including diabetes and kidney diseases, greatly increase mortality rates and healthcare costs in obese patients. Studies in animal models and clinical trials have demonstrated that L-serine supplementation is a safe and effective therapeutic approach that ameliorates the consequences of obesity. However, little is known about the effects of L-Serine supplementation following high-fat diet (HFD) consumption and its role in the mRNA expression of markers of kidney injury. We provide a descriptive action by which L-serine administration ameliorated the consequences of HFD consumption in relation to weight loss, glucose homeostasis as well as renal mRNA expression of markers of kidney injury. Our results indicated that L-Serine supplementation in drinking water (1%, ad libitum for 12 weeks) in male C57BL/6J mice promoted a significant reduction in body weight, visceral adipose mass (epididymal and retroperitoneal fat pads) as well as blood glucose levels in mice consuming a HFD. In addition, the amino acid significantly reduced the mRNA expression of the Kidney Injury Marker 1 (KIM-1), P2Y purinoceptor 1 (P2RY1), as well as pro-inflammatory cytokines (IL-6 and TNFα). L-serine administration had no effect on mice consuming a standard chow diet. Collectively, our findings suggest that L-serine is an effective compound for long-term use in animal models and that it ameliorates the metabolic consequences of HFD consumption and reduces the elevated levels of renal pro-inflammatory cytokines occurring in obesity.
Publisher: MDPI AG
Date: 11-12-2021
DOI: 10.3390/MD19120702
Abstract: Fucoidans are sulfated, complex, fucose-rich polymers found in brown seaweeds. Fucoidans have been shown to have multiple bioactivities, including anti-inflammatory effects, and are known to inhibit inflammatory processes via a number of pathways such as selectin blockade and enzyme inhibition, and have demonstrated inhibition of inflammatory pathologies in vivo. In this current investigation, fucoidan extracts from Undaria pinnatifida, Fucus vesiculosus, Macrocystis pyrifera, Ascophyllum nodosum, and Laminaria japonica were assessed for modulation of pro-inflammatory cytokine production (TNF-α, IL-1β, and IL-6) by human peripheral blood mononuclear cells (PBMCs) and in a human macrophage line (THP-1). Fucoidan extracts exhibited no signs of cytotoxicity in THP-1 cells after incubation of 48 h. Additionally, all fucoidan extracts reduced cytokine production in LPS stimulated PBMCs and human THP-1 cells in a dose-dependent fashion. Notably, the 5–30 kDa subfraction from Macrocystis pyrifera was a highly effective inhibitor at lower concentrations. Fucoidan extracts from all species had significant anti-inflammatory effects, but the lowest molecular weight subfractions had maximal effects at low concentrations. These observations on various fucoidan extracts offer insight into strategies that improve their efficacy against inflammation-related pathology. Further studies should be conducted to elucidate the mechanism of action of these extracts.
Publisher: Elsevier BV
Date: 12-2014
DOI: 10.1016/J.GENE.2014.09.042
Abstract: The Rhodopsin family is a class of integral membrane proteins belonging to G protein-coupled receptors (GPCRs). To date, several orphan GPCRs are still uncharacterized and in this study we present an anatomical characterization of the GPR162 protein and an attempt to describe its functional role. Our results show that GPR162 is widely expressed in GABAergic as well as other neurons within the mouse hippoc us, whereas extensive expression is observed in areas related to energy homeostasis and hedonic feeding such as hypothalamus, amygdala and ventral tegmental area, regions known to be involved in the regulation of palatable food consumption.
Publisher: Frontiers Media SA
Date: 24-09-2019
Publisher: Wiley
Date: 05-2022
Publisher: MDPI AG
Date: 04-11-2022
DOI: 10.3390/PHARMACEUTICS14112383
Abstract: Inflammatory bowel disease (IBD) is a complex and multifactorial disorder characterised by relapsing and remitting inflammation of the intestinal tract. Oxidative stress (OS) is the result of an imbalance between production and accumulation of reactive oxygen species (ROS), which has been associated with inflammatory responses and implicated in the exacerbation of IBD. Fucoidan, a sulfated polysaccharide from brown seaweed, is a well-known anti-inflammatory agent and emerging evidence indicates that fucoidan extracts from Macrocystis pyrifera (MPF and DP-MPF) may also modulate oxidative stress. This study investigated the impact of fucoidan extracts, MPF and DP-MPF in a dextran sodium sulphate (DSS)-induced mouse model of acute colitis. 3% DSS was administered in C57BL/6J male mice over a period of 7 days, and MPF and DP-MPF were co-administered orally at a dose of 400 mg/kg body weight. Our results indicated that MPF and DP-MPF significantly prevented body weight loss, improved the disease activity index (DAI), restored colon lengths, reduced the wet colon weight, reduced spleen enlargement, and improved the overall histopathological score. Consistent with the reported anti-inflammatory functions, fucoidan extracts, MPF and DP-MPF significantly reduced the colonic levels of myeloperoxidase (MPO), nitric oxide (NO), malondialdehyde (MDA) and increased the levels of antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT). In addition, MPF and DP-MPF significantly inhibited levels of pro-inflammatory cytokines in colon-derived tissues. Collectively, our results indicate that MPF and DP-MPF exhibited anti-inflammatory and antioxidant effects representing a promising therapeutic strategy for the cure of IBD.
No related grants have been discovered for Tauseef Ahmad.