Targeting of adipose tissue macrophages by bee venom phospholipase A2 attenuates high-fat diet-induced obesity

Metabolite-sensing GPCRs controlling interactions between adipose tissue and inflammation

Metabolic disorders including obesity, diabetes and non-alcoholic steatohepatitis are a group of conditions characterised by chronic low-grade inflammation of metabolic tissues. There is now a growing appreciation that various metabolites released from adipose tissue serve as key signalling mediators, influencing this interaction with inflammation. G protein-coupled receptors (GPCRs) are the largest family of signal transduction proteins and most historically successful drug targets. The signalling pathways for several key adipose metabolites are mediated through GPCRs expressed both on the adipocytes themselves and on infiltrating macrophages. These include three main groups of GPCRs: the FFA4 receptor, which is activated by long chain free fatty acids; the HCA₂ and HCA₃ receptors, activated by hydroxy carboxylic acids; and the succinate receptor. Understanding the roles these metabolites and their receptors play in metabolic-immune interactions is critical to establishing how these GPCRs may be exploited for the treatment of metabolic disorders.

Pharmacological effects and mechanisms of bee venom and its main components: Recent progress and perspective

Bee venom (BV), a type of defensive venom, has been confirmed to have favorable activities, such as anti-tumor, neuroprotective, anti-inflammatory, analgesic, anti-infectivity effects, etc. This study reviewed the recent progress on the pharmacological effects and mechanisms of BV and its main components against cancer, neurological disorders, inflammatory diseases, pain, microbial diseases, liver, kidney, lung and muscle injury, and other diseases in literature during the years 2018–2021. The related target proteins of BV and its main components against the diseases include Akt, mTOR, JNK, Wnt-5α, HIF-1α, NF-κB, JAK2, Nrf2, BDNF, Smad2/3, AMPK, and so on, which are referring to PI3K/Akt/mTOR, MAPK, Wnt/β-catenin, HIF-1α, NF-κB, JAK/STAT, Nrf2/HO-1, TrkB/CREB/BDNF, TGF-β/Smad2/3, and AMPK signaling pathways, etc. Further, with the reported targets, the potential effects and mechanisms on diseases were bioinformatically predicted via Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, disease ontology semantic and enrichment (DOSE) and protein-protein interaction (PPI) analyses. This review provides new insights into the therapeutic effects and mechanisms of BV and its main components on diseases.

Reviving the mutual impact of SARS-COV-2 and obesity on patients: From morbidity to mortality

Obesity-related metabolic dysfunction, endothelium imbalance, chronic inflammation, immune dysregulation, and its comorbidities may all have a role in systemic inflammation, leading to the pulmonary fibrosis and cytokine storm, which leads to failure of lung function, which is a hallmark of severe SARS-CoV-2 infection. Obesity may also disrupt the function of mucociliary escalators and cooperation of epithelial cell's motile cilia in the airway, limiting the clearance of the coronavirus that causes severe acute respiratory syndrome (SARS-CoV-2). Adipose tissues in obese patients have a greater number of proteases and receptors for SARS-CoV-2 admittance, proposing that they could serve as an accelerator and reservoir for this virus, boosting immunological response and systemic inflammation. Lastly, anti-inflammatory cytokines such as anti-IL-6 and the infusion of mesenchymal stem cells could be used as a modulation therapy of immunity to help COVID-19 patients. Obesity, on the other hand, is linked to the progress of COVID-19 through a variety of molecular pathways, and obese people are part of the SARS-CoV-2 susceptible individuals, necessitating more protective measures.

Serological and Histological Evaluation of the Effect of Honeybee Venom on Pancreas and Liver in Diabetic Mice

Natural toxins have been traditionally used to trigger several diseases among which bee venom (HBV) is of great importance. The present study aimed to investigate the therapeutic effects of honeybee venom (HBV) on alloxan and glucose fluid-induced Type 2 diabetes mellitus (T2DM). Therefore, a total of 20 adult laboratory male mice (Mus musculus) were selected, acclimated, and divided into four equal groups (n=5). Initially, 15 mice were fasted for 12 hrs and injected with alloxan at a single dose of 150 mg/kg of body weight. The animals were exposed to drinking glucose fluid in the morning for 4 days. Then, the blood glucose was measured. The studied animals having blood glucose of ≤200 mg/dl were considered non-diabetic and re-subjected to injecting alloxan (150 mg/kg body weight) and drinking glucose fluid for another 4 days. Four groups of mice population included, Group 1: non-diabetic and untreated with HBV, Group 2: diabetic and received no HBV as the potential therapeutic agent, Group 3: diabetic and received a low level of HBV at a dose of 0.5 mg/kg, Group 4: diabetic and received a high level of HBV at a dose of 1 mg/kg. At the end of the 35-day testing period, blood samples were tested to determine the levels of insulin, glucose, and lipid profiles [cholesterol, triglyceride (TG), high-density lipoprotein (HDL), and low-density lipoprotein (LDL)] using Sandwich ELISA kits. The results indicated a significant increase in blood glucose in the diabetic group compared to that of the control one, while both concentrations of HBV significantly reduced the level of blood glucose compared to that of the diabetic group. Furthermore, the level of insulin was significantly decreased in the diabetic group compared to that of the controls, while HBV significantly increased the level of insulin compared to that of the diabetic group. Moreover, the diabetic mice demonstrated a significant increase in the concentration of cholesterol and TG compared to that of control mice which were significantly reversed in response to HBV treatment. The level of HDL was significantly decreased in the diabetic group compared to that of the control group which was modulated by treatment, while no significant differences were seen between all the studied groups regarding the level of LDL. Histological examination of diabetic mice revealed a significant alteration in acinar cells and destruction of β-cells of pancreatic sections with marked lacerations in the liver extended to all structures of the organ. The present study concluded that HBV could be a potential therapeutic agent to prevent and manage diabetes and its complication.

Sweet Bee Venom Triggers Multiple Cell Death Pathways or Spurs Acute Cell Rupture According to Its Concentration in THP-1 Monocytic Leukemia Cells

Sweet bee venom (sBV) contains various pharmacologically active components of bee venom (BV), but it is modified via the removal of the harmful substances found in BV. Thus, sBV has been used for pain relief in Oriental medicine but has only recently been applied for the treatment of various diseases. In this study, we examined the pharmacological effects and immunomodulatory functions of sBV in THP-1 monocytic leukemia cells. Growth inhibition and cell death were observed according to the concentration of sBV. However, the rapid collapse of cell cycle distribution was shown at 20 μg/mL sBV treatment, indicating that sBV led to cell death or acute cell rupture according to concentration. sBV administration activated Caspase-9, PARP1, RIPK1, and RIPK3, suggesting that the pharmacological actions of sBV were associated with induction of apoptosis and necroptosis. On the other hand, sBV or LPS administration increased cytokine expression, including IL-1β, and showed synergistic cell death in combinatory treatment conditions. Moreover, combinatory administration of sBV and LPS induced severe damage or death during egg development. This result implies that sBV exhibits both pharmacological and toxic effects depending on its concentration. Therefore, sBV might be a promising therapeutic approach, but optimal concentration should be considered before treatment.

Protective Effects of Bee Venom-Derived Phospholipase A2 against Cholestatic Liver Disease in Mice

Hepatocyte apoptosis and inflammation play important roles in cholestatic liver diseases. Bee venom-derived secretory phospholipase A2 (bvPLA2) has been shown to ameliorate various inflammatory diseases. However, whether bvPLA2 has a therapeutic effect against cholestatic liver disease has not been evaluated. Therefore, we investigated the effects of bvPLA2 on cholestatic liver injury and fibrosis in a murine model of 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) diet feeding. The administration of bvPLA2 ameliorated liver damage, cholestasis, and fibrosis in DDC diet-fed mice, as assessed by serum biochemical tests and histological examinations. In addition, bvPLA2 reduced myofibroblast accumulation, concomitant with suppression of transforming growth factor-β signaling cascade. The administration of bvPLA2 inhibited hepatocyte apoptosis in DDC diet-fed mice as represented by a reduction in the number of cells stained with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and suppression of caspase-3 activation. Moreover, bvPLA2 reduced cytokine production along with the inhibition of the nuclear factor kappa-B pathway. The number of regulatory T-cells was increased by bvPLA2, while the number of other immune cells, including neutrophils, macrophages, and CD8⁺ T-cells, was decreased. Our data indicate that the administration of bvPLA2 ameliorates cholestatic liver injury and fibrosis by inhibiting hepatocyte apoptosis and inflammation.