Objectives Traditionally, mushrooms have been used to reduce hyperglycaemia. However, the mechanism underlying this effect has not yet been explored. AMP-activated protein kinase (AMPK) is known to reduce hyperglycaemia through an insulin-independent pathway. This study aimed to observe the effect of oyster mushroom powder (OMP) on phosphorylation of AMPK (p-AMPK) and expression of GLUT4 mRNA in diabetic model rats. Methods Long-Evans rats were used to develop type 2 diabetic model rats through intraperitoneal induction of streptozotocin (STZ). OMP was supplemented at 5% with the usual feed of rats for 8 consecutive weeks. Then, the rats were sacrificed. RNA was extracted by the TRIzol reagent, and proteins were extracted from different tissues with RIPA lysis buffer. Expression of GLUT4 mRNA was measured through cDNA-PCR techniques, and p-AMPK was detected using western blotting. The band intensities of the PCR products and proteins were measured using Image J software. Results Supplementation of OMP for 8 weeks resulted in a reduction of the serum glucose level in STZ-induced, type 2 diabetic model rats. The levels of p-AMPK, as a ratio relative to β-actin, increased in the muscle and adipose tissues of mushroom-treated type 2 diabetic model rats, compared to those in control diabetic model rats. Expression of GLUT4, as a ratio relative to GAPDH, increased significantly in both the muscle and adipose tissues of mushroom-treated diabetic rats. Conclusion Oyster mushroom may decrease hyperglycaemia through increased p-AMPK and also expression of GLUT4 in the muscle and adipose tissues.

Pulmonary fibrosis (PF) is a disease-refractive lung condition with an increased rate of mortality. The potential factors causing PF include viral infections, radiation exposure, and toxic airborne chemicals. Idiopathic PF (IPF) is related to pneumonia affecting the elderly and is characterized by recurring scar formation in the lungs. An impaired wound healing process, defined by the dysregulated aggregation of extracellular matrix components, triggers fibrotic scar formation in the lungs. The potential pathogenesis includes oxidative stress, altered cell signaling, inflammation, etc. Nintedanib and pirfenidone have been approved with a conditional endorsement for the management of IPF. In addition, natural product-based treatment strategies have shown promising results in treating PF. In this study, we reviewed the recently published literature and discussed the potential uses of natural products, classified into three types—isolated active compounds, crude extracts of plants, and traditional medicine, consisting of mixtures of different plant products—in treating PF. These natural products are promising in the treatment of PF via inhibiting inflammation, oxidative stress, and endothelial mesenchymal transition, as well as affecting TGF-β-mediated cell signaling, etc. Based on the current review, we have revealed the signaling mechanisms of PF pathogenesis and the potential opportunities offered by natural product-based medicine in treating PF.

Propolis which is a natural resinous product from the honeybees, is becoming increasingly popular for its diverse therapeutic and industrial applications. In this study, we report for the first time the antioxidant, cytotoxic, and antinociceptive activities of propolis from Bangladesh (BDP). The antioxidant activities were measured by biochemical analyses while cytotoxicity was evaluated by brine shrimp lethality bioassay. Analgesic activity was evaluated by tail immersion and acetic acid‐induced writhing models in mice. BDP contained higher concentrations of polyphenols, flavonoids, tannins, ascorbic acid, vitamin E, and reducing sugars, as compared to previous reports of propolis from several countries. BDP also exhibited higher free radical‐scavenging activities and a dose‐dependent reducing power activity indicating its superior antioxidant potential. Moreover, BDP extract was most toxic to brine shrimp nauplii, with 50% lethal concentration (LC50) of 57.99 µg/mL and exhibited considerable antinociceptive activities which may be mediated via central and peripheral inhibitory mechanisms. Practical applications BDP is a honeybee product, becoming increasingly popular due its potential contributions to human health. BDP is a rich source of natural antioxidants which has the potential to be used to ameliorate oxidative stress disorders and has useful antinociceptive activities. It may be useful as potential therapeutic agents against cancer, pesticidal agents, and for other cytotoxic uses.

AMP-activated protein kinase (AMPK) and c-AMP-response element binding protein (CREB) are found to be important proteins in metabolic system. AMPK has become the focus as a novel therapeutic target for the treatment of metabolic syndromes. Oyster mushroom is traditionally used as remedy of diabetes and hypertension. The present study aims to observe the stimulation of AMPK and CREB in streptozotocin-induced diabetic model rats through Oyster mushroom administration. Long Evan’s rats were used to create type 2 model diabetic rats through intraperitoneal injection of streptozotocin at 90mg/kg body weight of 48hr old pups. Rats were divided into three groups: diabetic control rats, glibenclamide treated diabetic rats (positive control) and mushroom treated diabetic rats (experimental group). Mushroom was administered orally at a dose of 1.25g/kg body weight in semisolid forms. After five weeks rats were sacrificed, serum and tissues were collected for future analysis. Glucose was measured using glucose-oxidase method, lipid profile by enzymaticcolorimetric method. Proteins from different tissues were extracted using RIPA cell lysis buffer, AMPK and CREB were identified using western blot and immuno-precipitation techniques. A significant decreased of fasting glucose was found after 35 days of experiment when it compared with control diabetic rats (M ± SD, mmol/l, Diabetic control group: 8.0±1.1; Mushroom treated diabetic group: 6.4±1.0; p=0.021). Glibenclamide treated diabetic rats have also shown decreased fasting glucose compared to control diabetic rats. In paired ‘t’ test analysis, it has been found that serum fasting glucose level was significantly decreased on 35th day compared the 0 day in both mushroom treated group (p=0.027) and in glibenclamide treated group (p=0.005). Serum TG level was decreased on 35th day compared to 0day in mushroom treated diabetic model rats only (M±SD, mg/dl, 0 day: 84±13; 35th day: 61±6, p=0.002). No significant changes of cholesterol, HDL and LDL were noticed in the experimental groups following treatment with mushroom. Western blot analyses have shown increased band intensity of AMPK and p-CREB in mushroom treated diabetic model rats. Therefore, it can be concluded that Anti-hyperglycemic property of Oyster mushroom could be explained through increased expression of AMPK and activation of CREB.Bangladesh Journal of Medical Science Vol.17(4) 2018 p.661-668