Bioreactor-grown exo- and endo-β-glucan from Malaysian Ganoderma lucidum: An in vitro and in vivo study for potential antidiabetic treatment

Abstract

This study aims to identify the roles of exo-β-glucan (EPS-BG) and endo-β-glucan (ENS-BG) extracted from Ganoderma lucidum (GL) in inhibiting the alpha-glucosidase enzyme, a target mechanism for postprandial hyperglycaemia regulation. Upscale production of GL was carried out using a 10 L bioreactor. The zebrafish embryo toxicity test (ZFET) was carried out based on OECD guidelines. The hatching rate, survival rate, heart rate, morphological malformation, and teratogenic defects were observed and determined every 24 h from 0–120 h of post-exposure (hpe). For diabetes induction, adult zebrafish (3–4 months of age) were overfed and induced with three doses of 350 mg/kg streptozotocin (STZ) by intraperitoneal injection (IP) on three different days (days 1, 3, and 5). The oral sucrose tolerance test (OSTT) and anti-diabetic activity of EPS-BG and ENS-BG were evaluated (day 7) using the developed model (n = 15). This study showed that EPS is the most potent compound with the highest inhibitory effect toward the alpha-glucosidase enzyme with an IC50 value of 0.1575 mg/ml compared to ENS extracts (IC50 = 0.3479 mg/ml). Both EPS-BG and ENS-BG demonstrated a strong inhibition of alpha-glucosidase activity similar to the clinically approved alpha-glucosidase inhibitor, acarbose (IC50 = 0.8107 mg/ml). ENS-BG is non-toxic toward zebrafish embryos with LC50 of 0.92 mg/ml and showed no significant changes in ZE hatching and normal heart rate as compared to untreated embryos (161 beats/min). Teratogenic effects of ENS-BG (<1.0 mg/ml) on zebrafish embryonic development were not observed. The DM model of zebrafish was acquired after the third dose of STZ with a fasting BGL of 8.98 ± 0.28 mmol/L compared to the normal healthy group (4.23 ± 0.62 mmol/L). The BGL of DM zebrafish after 30 min treated with EPS-BG and ENS-BG showed a significant reduction (p < 0.0001). Both EPS-BG and ENS-BG significantly reduced DM zebrafish’s peak blood glucose and the area under the curve (AUC) in OSTT. Hence, EPS-BG and ENS-BG extracted from GL showed promising inhibition of the alpha-glucosidase enzyme and are considered non-toxic in ZE. Moreover, EPS-BG and ENS-BG reduced blood glucose levels and inhibited hyperglycemia in DM zebrafish.

Editorial: “The value of microbial bioreactors to meet challenges in the circular bioeconomy”

“…In this report, Abdullah et al (2022 ) proved that both exo-β-glucan and endo-β-glucan can be extracted from the Malaysian mushroom Ganoderma lucidum using a 10-L industrial bioreactor crude-biomass. Both β-glucans showed a high inhibitory effect in the alpha-glucosidase enzyme test which mimics a clinically approved inhibitor (acarbose) for postprandial hyperglycemia regulation, which is an essential component in diabetic treatment.…”

Performance of Biomass and Exopolysaccharide Production from the Medicinal Mushroom Ganoderma lucidum in a New Fabricated Air-L-Shaped Bioreactor (ALSB)

“…The extracts have been tested to determine their potential to treat chronic diseases in humans, including cancer [2]. Numerous studies have been conducted on G. lucidum to determine its medicinal abilities, which also cover the bioactive products present in it, such as the exopolysaccharides (EPS) [3][4][5][6]. Fungal biomass from G. lucidum can also be used as a bioremediation material to remove pollutants from wastewater [7].…”