Effect of symbiotic bee fungus on survival of stingless bee Heterotrigona itama larvae

Aims@#Symbiotic bee fungus associated with the stingless bee larval food has been revealed to play a major role in performing a mutual relationship with the host. The fungus is believed capable to produce crucial nutrients that are required for larval pupation. However, detailed information on the fungus identification isolated from the larval food of our native Indo-Malaya stingless bee, Heterotrigona itama (Hymenoptera: Apidae), is poorly understood. Hence, this study was conducted to determine the effect of fungus isolated from the stingless bee larval food on the survival of H. itama larvae and identify the isolated fungus using both morphological and molecular analyses.@*Methodology and results@#Elisa plates designed with F-bottom type were used as artificial brood cells in a controlled condition. The eggs transferred to Elisa plates were kept in the incubator with 75%-100% humidity and 25 ± 2.5 °C of temperature. This study carried out in three different treatments: (1) microbes-free larval food, (2) fresh larval food and (3) microbes-free larval food with fungus supplement. Results showed that the survival of H. itama larvae depends on the presence of beneficial fungus with the highest survival rate (Treatment 2 = 85.71%). The absence of the beneficial fungus in the fluid food of H. itama showed the lowest survival rate (Treatment 1 = 37.14%). Microscopy analysis showed that the fungus had various forms, including unconjugated asci, round-shaped ascospore and pseudohyphae. The molecular characterisation of the isolated fungi was performed using 23S rRNA gene sequencing using universal primers ITS1 and ITS4. DNA barcoding of three isolated fungi confirmed all isolated fungi matched Panus lecomtei (Basidiomycetes; Poriales; Polyporaceae) with 99.70% of similarity.@*Conclusion, significance and impact of study@#This study provides information on the importance of whitish fungus in appearance that existed in the brood cell, which is proposed to be the crucial component of in-vitro stingless bee queen rearing protocol.

Introducing a Technique in Sustaining Adult Worker Bees of Heterotrigona itama (Cockerell, 1918) in Laboratory to Facilitate Future Health Research on Kelulut Honey

@#Introduction: The study is introducing a laboratory technique to sustain the longevity of Heterotrigona itama stingless bees collected from the farm in order to facilitate future health research on Kelulut honey. Methods: The worker bees were held in laboratory at 26 ± 2 oC, 57 ± 8 % relative humidity (RH) and 12:12 hours (light:dark period) in a cup covered with meshed cloth and installed with an inverted-wick system consists of a drinking straw with the bottom end loosely plugged with cotton wool. The artificial diet was pipetted into the straw to wet the cotton wool. The bees were divided into five diet groups, namely a) unfed - control, b) distilled water, c) purified tap water, d) non-carbonated isotonic drink or e) 5% honey solution. Feeding activity and survival of worker bees were observed daily. Results: The worker bees are seen to frequent and lick the cotton wool wetted with artificial diets. Comparison between the artificial diets, Kaplan-Meier statistical analysis showed that the 5% honey solution and non-carbonated isotonic drink have significantly (P < 0.05) extended the longevity of the worker bees with 50% survival probability at least 8 days. When the similar holding and feeding technique used for the bees from commercial farms, the 50% survival probability was extended to 14 days. Conclusion: The inverted-wick system with the use of 5% honey solution or isotonic drink as the artificial diet is capable to hold the H. itama worker bees at least for a week with survival above 50% for laboratory experiments.

Anti-Cancer Properties of Heterotrigona itama sp. Honey Via Induction of Apoptosis in Malignant Glioma Cells

@#Background: There has been increasing evidence showing that stingless bee honey exhibits anti-oxidant, anti-inflammatory and anti-cancer properties. Pharmacologically-active components in honey such as flavonoids and phenolic constituents are known to contribute to its medicinal benefits. To the best of our knowledge, this is the first study on evaluating anticancer effects of locally-produced Malaysian stingless bee honey from Heterotrigona itama sp. on malignant glioma cells. Methods: Proliferation and apoptosis studies of U-87 MG cells following stingless bee honey treatment were carried out using MTS assay and acridine orange/propidium iodide dual staining, respectively. Results: Results demonstrated time and dose-dependent cytotoxicity using 0.625%, 1.25% and 10% stingless bee honey (P < 0.05). IC50 values were calculated using cells treated with 10% stingless bee honey. It was also observed that 10% stingless bee honey induced nuclear shrinkage, chromatin condensation and nucleus fragmentation, indicating that cellular changes were consistent with the apoptotic characteristics of the cells. Conclusion: These data provide a good basis for further evaluation of the medicinal properties of stingless bee honey from Heterotrigona itama sp. This source of honey may serve as a potential therapy for malignant glioma.

Comparison of Sugar Content, Mineral Elements and Antioxidant Properties of Heterotrigona Itama Honey from Suburban and Forest in Malaysia

@#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.