ABSTRACT
@#Introduction: The increase of Type 2 diabetes mellitus has prompted numerous research toward finding an alternative to manage the disease through the oxidant-antioxidant balance, mainly through bioactive compounds in natural products. This study explored the antioxidant and antidiabetic properties of phenolic-rich extract (PRE) from Stingless bee honey (SBH) (Heterotrigona itama) as therapeutic agent to restore the redox balance. Methods: The total phenolic content (TPC), total flavonoid content (TFC) and antioxidant assays of PRE and SBH, were determined to provide preliminary insight into the sample’s antioxidant properties, followed by high-performance liquid chromatography analysis of PRE. The antidiabetic potential of PRE and SBH were determined based on their inhibition against α-amylase and α-glucosidase enzymes. The cytotoxicity analysis of PRE was conducted on 3T3-L1 adipocytes and L6 muscle cells before the glucose uptake and cellular antioxidant analyses were performed on both cell lines, respectively. Results: PRE yielded higher TPC, TFC and antioxidant activities than SBH. The phytochemical profile of PRE comprises gallic acid, myricetin, kaempferol, epicatechin, chlorogenic acid, quercetin, syringic acid, and cinnamic acid. The results from carbohydrate enzymatic inhibitory assays collectively suggested that PRE exhibited more robust antidiabetic activities than SBH. PRE showed good glucose uptake stimulating and reactive oxygen species scavenging effects in those cell lines. Conclusion: Overall, PRE from SBH showed higher carbohydrate enzymatic inhibition, glucose uptake, and protection against intracellular oxidative stress, primarily due to its high antioxidant content and may serve as an alternative therapeutic agent for managing T2DM.
ABSTRACT
@#Introduction: In Malaysia, Heterotrigona itama sp. (stingless bee) industries start to grow rapidly since 2015 but the study on its health benefit is still lacking. This study was aimed to analyse and compare the sugar content, minerals and antioxidant properties of stingless bee honey collected from forest and suburban area in Malaysia. Methods: Sugar content was determined by HPLC, minerals and heavy metals was determined by Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) and Atomic Absorption Spectrometer (AAS), total phenolic content (TPC) and total flavonoid content (TFC) by Folin-Ciocalteu and aluminium chloride colorimetry method, respectively. For determining the antioxidant activity of the samples, 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH), 2,2’-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and ferric reducing antioxidant power (FRAP) assay were used. Results: Fructose, glucose and sucrose are found in all samples in range of 16.03-33.13 g/100g, 8.63-20.72 g/100g and 2.68-34.04 g/100g, respectively. Potassium and sodium were major minerals in all stingless bee honey with an average of 622.36 and 496.01 mg/kg, respectively. Sample from the forest (Sibu, F2) has the highest TPC and TFC with value 520.663±8.119µg GAE/g and 443.25±18.194µg RE/g, respectively. The higher antioxidant activities (DPPH, ABTS, FRAP) also found in samples collected from the forest (F2) with 602.15±12.7 µg TE/g, 575.18±9.38 µg TE/g and 641.36±42.11µg TE/g, respectively. Conclusion: All stingless bee honey studied shown a significant amount of important minerals and antioxidant properties with samples from forest clearly shown significantly higher TPC and TFC as well as the antioxidant activity than samples collected from the suburban area.