Physicochemical and Antioxidant Potential of Raw Unprocessed Honey From Malaysian Stingless Bees

Antioxidant Activity, Physicochemical and Sensory Properties of Stingless Bee Honey from Australia

This study reports on the physicochemical and sensory attributes, total phenolic content, and antioxidant activity of 36 honey samples produced by two different stingless bee species (Tetragonula carbonaria and Tetragonula hockingsi) from Australia. The findings reveal moisture content across all samples ranges from 24.9% to 30.8% (w/w), electrical conductivity from 1.02 to 2.15 mS/cm, pH levels between 3.57 and 6.54, soluble solids from 69.2 to 75.1 °Brix, trehalulose concentrations from 6.20 to 38.2 g/100 g, fructose levels from 7.79 to 33.4 g/100 g, and glucose content from 3.36 to 26.8 g/100 g. Sucrose was undetectable in all investigated samples. In a sensory analysis involving 30 participants, Australian stingless bee honey was perceived as having a more pronounced sourness compared with New Zealand Manuka honey. The study reveals considerable variability in the composition of Australian stingless bee honey, influenced by factors such as floral availability, geographical origin, and time of harvest. It also demonstrates the presence of phenolic compounds and antioxidant activity in stingless bee honey, underlining their potential as a natural source of antioxidants. All investigated samples contain trehalulose, which supports the findings of other recent studies that propose this unusual disaccharide as a marker compound of stingless bee honey.

Stingless bee honey: Nutritional, physicochemical, phytochemical and antibacterial validation properties against wound bacterial isolates

With the rise of AMR the management of wound infections are becoming a big challenge. This has been attributed to the fact that most wound bacterial isolates have been found to possess various virulence factors like enzymes, toxins & biofilms production. Therefore, need for discovery of new lead compounds is paramount as such factors make these microbes to be resistant to already existing arsenal of antibiotics or even the immune system. This study aimed at documenting the nutritional, physicochemical, phytochemical and antibacterial properties of stingless bee honey. Isolation and characterization of bacterial isolates from 34 samples obtained from wounds of outpatients and surgical wards of Nakuru County Referral Hospital, Kenya was done. Various bacterial isolates (43) were isolated Staphylococcus aureus (34.8%) being predominant, followed by Pseudomonas aeruginosa (27.9%), Klebsiella pneumoniae (23.3%) and Escherichia coli (14.0%). A total of 36 out of the total isolates were genotypically characterized using molecular techniques detecting the prevalence of the following virulence genes; 16 srRNA (756 bp), hla (229 bp), cnf1 (426 bp), cnf2 (543 bp), hlyA (1011 bp), rmpA (461 bp), lasL (600 bp), gyrB (411 bp), khe (77 bp) and magA (128 bp). An assessment of the in vitro antibacterial activity of 26 stingless bee honey samples collected from their cerumen egg-shaped pots in Marigat sub-County, Baringo County, Kenya was done. Antibacterial properties of the stingless bee honey was done with varying susceptibility patterns being observed at different concentrations of honey impregnated discs (10x104, 20x104, 50x104 and 75x104 ml μg/ ml) giving mean inhibition diameters of 18.23 ± 0.4 mm (Staphylococcus aureus), 17.49 ± 0.3 mm (Pseudomonas aeruginosa), 16.05 ± 0.6 mm (Klebsiella pneumoniae) and 10.19 ± 0.5 mm (Escherichia coli) with a mean range of 14.54 ± 2.0 mm to 17.58 ± 3 mm. Higher susceptibility to honey was recorded across all the bacterial isolates compared to conventional antibiotics while the mean MIC and MBC of the honey were recorded at 62.5 ml μg/ ml and 250 ml μg/ ml respectively. Control bacterial isolates Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 27736 and Pseudomonas aeruginosa ATCC 27858 were used in the analysis. The stingless bee honey was found to be rich in various nutritive components like sugar (89.85 ± 5.07 g/100 g) and moisture (81.75 ± 10.35 mg/g) with a significant difference of P <0.05 as the main antibacterial components. Additionally, the stingless honey did possess water soluble vitamins, proteins and minerals of which potassium was the most dominant one. In regard to phytochemicals, on our preliminary analysis phenolic, flavonoid and carotenoid compounds were found to be present with phenolic compounds being the most dominant one. Stingless bee honey from Marigat, has antimicrobial properties which could be attributed to the rich phytochemicals it possesses and its physicochemical properties in addition to its high nutritive value.

Comparative analysis of the physicochemical, proximate, and antioxidant characteristics of stingless bee (Meliponula beccarii) honey from modern and wild beehives in Ethiopia

There is a dearth of information on the comparative studies of the physicochemical, proximate, and antioxidant properties as well as quality standards of stingless bee honey (SBH) in Ethiopia. Hence, this study was designed to assess and compare the physicochemical, proximate, and antioxidant properties of SBH, specifically sourced from Meliponula beccarii, and produced under both wild and modern apiary conditions at two distinct geographical locations. A total of forty-six honey samples were meticulously collected from domesticated stingless bee colonies and naturally occurring wild nests at Wolmera and Cheliya districts. Pollen analysis unveiled eleven distinct bee plant species distributed across six families, with Asteraceae being the most prevalent, primarily represented by Guizotia scabra and Vernonia amygdalina. Notably, the physicochemical, proximate, and antioxidant properties of SBH collected from modern pot hives exhibited significant variances (p < .05) when compared to SBH from wild nests. Principal component analysis (PCA) delineated the differentiation of SBH sources based on both geographical location and the type of beehive. One-way ANOVA corroborated these distinctions, underscoring significantly higher levels (p < .05) of ash, electrical conductivity, free acidity, hydroxymethylfurfural, sucrose, total phenolic content, total flavonoid content, and radical scavenging activities of SBH from modern pot hives in Wolmera. Whereas, Cheliya modern pot hives recorded higher values in pH, hydroxymethylfurfural and maltose contents compared to the wild nest SBH. Further analysis through Pearson correlation highlighted a strong positive association between total phenolic content and total flavonoid content with the antioxidant capacity of SBH. These findings underscore the significance of integrating modern pot hives to enhance the quality of SBH within Ethiopia's beekeeping sector.

The Importance of Testing the Quality and Authenticity of Food Products: The Example of Honey

The aim of this study was to review methods of honey testing in the assessment of its quality and authenticity. The quality of honey, like other food products, is multidimensional. This quality can be assessed not only on the basis of the characteristics evaluated by the consumer during purchase and consumption, but also on the basis of various physicochemical parameters. A number of research methods are used to verify the quality of honeys and to confirm their authenticity. Obligatory methods of assessing the quality of honey are usually described in legal acts. On the other hand, other, non-normative methods of honey quality assessment are used worldwide; they can be used to determine not only the elementary chemical composition of individual types of honey, but also the biological activity of honey and its components. However, so far, there has been no systematization of these methods together with a discussion of problems encountered when determining the authenticity of honeys. Therefore, the aim of our study was to collect information on the methods of assessing the quality and authenticity of honeys, and to identify the problems that occur during this assessment. As a result, a tabular summary of various research methods was created.

Differentiation of High-Fructose Corn Syrup Adulterated Kelulut Honey Using Physicochemical, Rheological, and Antibacterial Parameters

Kelulut (stingless bee) honey (KH) possesses a wide range of benefits for human consumption and can exhibit medical effects. Due to its high value, this premium honey is often adulterated with different types of cheaper sugars, causing low nutrients and potential food safety threats in the final product. This study aims to determine the physicochemical, rheological, and antibacterial properties of sugar-based adulterated KH from the stingless bee species Heterotrigona itama. Adulterated samples were prepared using pure honey mixed with different concentrations of high fructose corn syrup (HFCS), i.e., 10%, 20%, 30%, 40%, and 50%. Water activity, colour, total soluble solids, pH, turbidity, viscosity, and antimicrobial activity of KH were determined. In addition, the primary sugar composition (fructose, glucose, and trehalulose) was determined by high-performance liquid chromatography with evaporative light-scattering detection (HPLC-ELSD). This study shows that the increasing percentage of HFCS addition in the KH samples significantly increases (p < 0.05) the total soluble solids, colour, pH, turbidity, viscosity, glucose, and fructose content; meanwhile, the water activity and trehalulose were reduced significantly (p < 0.05). Antimicrobial activity against S. aureus was reduced significantly (p = 0.006) by an increased percentage of HFCS compared to Control. Antimicrobial activity against P. aeruginosa was also found to be reduced significantly but showed non-significant effect from an increased percentage of HFCS in honey (p = 0.413). The bacterium S. aureus was more vulnerable to treatment with honey from both Control and adulterated groups compared to P. aeruginosa. In conclusion, HFCS-adulterated KH and authentic KH can be differentiated using all the parameters investigated. These data are vital for the governing bodies to ensure that KH sold in the markets is free from HFCS adulteration.

The potential neuroprotective effects of stingless bee honey

Tropical Meliponini bees produce stingless bee honey (SBH). Studies have shown beneficial properties, including antibacterial, bacteriostatic, anti-inflammatory, neurotherapeutic, neuroprotective, wound, and sunburn healing capabilities. High phenolic acid and flavonoid concentrations offer SBH its benefits. SBH can include flavonoids, phenolic acids, ascorbic acid, tocopherol, organic acids, amino acids, and protein, depending on its botanical and geographic origins. Ursolic acid, p-coumaric acid, and gallic acid may diminish apoptotic signals in neuronal cells, such as nuclear morphological alterations and DNA fragmentation. Antioxidant activity minimizes reactive oxygen species (ROS) formation and lowers oxidative stress, inhibiting inflammation by decreasing enzymes generated during inflammation. Flavonoids in honey reduce neuroinflammation by decreasing proinflammatory cytokine and free radical production. Phytochemical components in honey, such as luteolin and phenylalanine, may aid neurological problems. A dietary amino acid, phenylalanine, may improve memory by functioning on brain-derived neurotrophic factor (BDNF) pathways. Neurotrophin BDNF binds to its major receptor, TrkB, and stimulates downstream signaling cascades, which are crucial for neurogenesis and synaptic plasticity. Through BDNF, SBH can stimulate synaptic plasticity and synaptogenesis, promoting learning and memory. Moreover, BDNF contributes to the adult brain's lasting structural and functional changes during limbic epileptogenesis by acting through the cognate receptor tyrosine receptor kinase B (TrkB). Given the higher antioxidants activity of SBH than the Apis sp. honey, it may be more therapeutically helpful. There is minimal research on SBH's neuroprotective effects, and the related pathways contribute to it is unclear. More research is needed to elucidate the underlying molecular process of SBH on BDNF/TrkB pathways in producing neuroprotective effects.

In vivo study of subacute oral toxicity of kelulut honey

Kelulut honey is favoured for its tremendous nutritional benefits. However, the lack of systematic safety studies leads to it having no quality control or safety guarantee for the consumers. Consequently, the present work was designed to assess the effect of daily kelulut honey consumption. Subacute oral toxicity study was conducted following the Organization for Economic Co-operation and Development (OECD) test guideline 407. Sprague Dawley rats were administered with kelulut honey at the concentrations of 500, 1,000, and 2,000 mg/kg for four weeks, and observed for any changes or toxicity signs following daily consumption. The rats were physically and biochemically analysed, and the serum of highest honey concentration (2,000 mg/kg) consumption underwent metabolite analysis. Histopathology observations on the kidney and liver were also performed. The highest concentration of kelulut honey did not show any mortality or toxicity. Overall, there were no significant differences in all parameters, physically and biochemically, as compared to the control (distilled water), thus indicating the absence of toxicity of kelulut honey daily consumption. It was found that kelulut honey consumption demonstrated generally good health effects, such as in controlling food intake, weight gain, and increasing immune function. The honey’s lethal medium dose surpassed 2,000 mg/kg, thus classified in category 5 according to the Globally Harmonized System of Classification and Labelling of Chemicals, which means that it is safe to consume at a high dose.

Physicochemical characteristics, antioxidant properties and bacterial profiling of three Malaysian honey varieties: a study using multivariate analysis

BACKGROUND

The physicochemical characteristics, antioxidant properties, and bacterial profiles of Heterotrigona itama, Apis dorsata, and Apis mellifera honey of Malaysian origin were studied and the results were assessed using Pearson correlation analysis and canonical correspondence analysis (CCA).

RESULTS

The analysis showed that the Mellifera honey was characterized by high total sugar content (717.5 g kg^-1 ); the Itama honey was characterized by high free acidity (347.5 meq kg^-1 ); and the Dorsata honey was characterized by high radical scavenging activity (RSA; 69.3%RSA), total phenolic content (TPC; 1284.5 mg GAE kg^-1 ) and hydroxymethylfurfural (HMF; 51.5 mg kg^-1 ). Pearson correlation analysis showed that the TPC was positively correlated with HMF as well as RSA. The bacterial profile of Mellifera honey was significantly less diverse than Itama and Dorsata honey. Mellifera and Itama honey seemed to harbour a significant abundance of lactic acid bacteria, with relative abundance of 0.339 and 0.195, which suggests that it possesses probiotic potential. The Dorsata honey, however, contained pathogenic Clostridium genus, constituting 5% of its bacterial profile.

CONCLUSION

The characteristic properties of the three investigated honey, Itama, Dorsata, and Mellifera were identified. The distinctive characteristics of the honey varieties informed the development of appropriate processing strategies for retaining the beneficial qualities of raw honey. It is hoped that the results of this study will shine light on Malaysian honey in a highly competitive global market. © 2022 Society of Chemical Industry.

Pathophysiology of Depression: Stingless Bee Honey Promising as an Antidepressant

Depression is a debilitating psychiatric disorder impacting an individual’s quality of life. It is the most prevalent mental illness across all age categories, incurring huge socio-economic impacts. Most depression treatments currently focus on the elevation of neurotransmitters according to the monoamine hypothesis. Conventional treatments include tricyclic antidepressants (TCAs), norepinephrine–dopamine reuptake inhibitors (NDRIs), monoamine oxidase inhibitors (MAOIs), and serotonin reuptake inhibitors (SSRIs). Despite numerous pharmacological strategies utilising conventional drugs, the discovery of alternative medicines from natural products is a must for safer and beneficial brain supplement. About 30% of patients have been reported to show resistance to drug treatments coupled with functional impairment, poor quality of life, and suicidal ideation with a high relapse rate. Hence, there is an urgency for novel discoveries of safer and highly effective depression treatments. Stingless bee honey (SBH) has been proven to contain a high level of antioxidants compared to other types of honey. This is a comprehensive review of the potential use of SBH as a new candidate for antidepressants from the perspective of the monoamine, inflammatory and neurotrophin hypotheses.

A Comprehensive Review of Stingless Bee Products: Phytochemical Composition and Beneficial Properties of Honey, Propolis, and Pollen

The stingless bee has been gaining more attention in recent years due to the uniqueness and benefits of its products. Similar to the common honeybee, stingless bees also produce honey, propolis, and pollen, which offer superior benefits for direct or indirect consumption. However, reports on the benefits of stingless bee products are scarce. This article summarises recent reports on stingless bee products. The function and application of the properties of the products such as phenolic compounds, antioxidant properties, and chemical content are elucidated. The antimicrobial properties and anticancer potential of the products are also highlighted. Future trends, potential, and uniqueness of stingless bee products are discussed. Stingless bee honey is highlighted as a superfood that exceptionally has the potential to be an active ingredient in treating cancer. Stingless bee propolis has been extensively studied for its rich beneficial chemical compounds that contribute to its antioxidant properties. Though studies on stingless bee pollen are scarce, it has been reported that it also has the potential of being a functional food.

A Review on Recent Progress of Stingless Bee Honey and Its Hydrogel-Based Compound for Wound Care Management

Stingless bee honey has a distinctive flavor and sour taste compared to Apis mellifera honey. Currently, interest in farming stingless bees is growing among rural residents to meet the high demand for raw honey and honey-based products. Several studies on stingless bee honey have revealed various therapeutic properties for wound healing applications. These include antioxidant, antibacterial, anti-inflammatory, and moisturizing properties related to wound healing. The development of stingless bee honey for wound healing applications, such as incorporation into hydrogels, has attracted researchers worldwide. As a result, the effectiveness of stingless bee honey against wound infections can be improved in the future to optimize healing rates. This paper reviewed the physicochemical and therapeutic properties of stingless bee honey and its efficacy in treating wound infection, as well as the incorporation of stingless bee honey into hydrogels for optimized wound dressing.

Addressing the unfulfilled codex standard for honey for stingless bee honey through lyophilization

Some studies have found that the nutritional values of stingless bee honey (SBH) may be similar if not more than normal honey, prompting the Malaysian government to promote it as a superfood. However, SBH does not fulfil the Codex Standard for Honey (CODEX STAN 12-19811) in terms of moisture content and the lack of protein to be analysed with Internal Standard Carbon Isotope Ratio Analysis (ISCIRA). Hence, a lyophilization process was introduced prior to stable carbon isotope analysis of SBH to address both of these issues. It was found that once moisture content was decreased to a level below 20 % for 19 SBH samples, the percentage increment of protein extracted from the samples varied between 6 and 385 % relative to protein extracted from SBH before lyophilization with nine samples found to be adulterated. Caution is necessary when lyophilizing the SBH as significant isotope shifts were seen for SCIRA and ISCIRA values. Nevertheless, the carbon isotope shifts did not change the final outcome of the 'pass' or 'fail' of the adulteration result. Overall, the removal of water from SBH is required but caution is necessary as carbon isotope shifts were observed as SBHs underwent the lyophilization process.

Unique physicochemical properties and rare reducing sugar trehalulose mandate new international regulation for stingless bee honey

Stingless bee honey (SBH) of four stingless bee species (Heterotrigona itama, Geniotrigona thoracica, Tetragonula carbonaria, and Tetragonula hockingsi) from two geographic regions (Malaysia and Australia, n = 36) were studied for their physicochemical parameters, including total phenolic and multi-elemental contents. Sugar analysis confirmed the prominent presence of trehalulose in all samples. All SBH failed to meet the CODEX Standard for honey moisture, free acidity, and total fructose plus glucose levels. One-way ANOVA, principal component analysis (PCA) and hierarchical component analysis (HCA) confirm distinctive differences between Australian and Malaysian SBH with Australian SBH having significantly (P < 0.05) higher pH, total phenolic, total mineral, and electrical conductivity attributes. Toxic elements in all SBH were much lower than standard CODEX limit. The species G. thoracica produced honey with significantly (P < 0.05) higher trehalulose than both Australian bee species. This research will add value to SBH and hasten new international standards ensuring commercial viability, safety, quality, and marketability of SBH.

Antioxidant Properties and Characterization of Heterotrigona itama Honey from Various Botanical Origins according to Their Polyphenol Compounds

Stingless bee honey is a good source of antioxidants, which is attributed to the phenolic compounds. The type and concentration of phenolic compounds in honey can be affected by botanical origin. Therefore, in this study, Heterotrigona itama honey from three botanical origins (gelam, acacia, and starfruit) was evaluated for its antioxidant activity and profile of phenolic compounds. Apis mellifera honey was used as a comparison. Antioxidant activity and profile of phenolic compounds in honey were determined using spectrophotometric and chromatographic methods, respectively. The total phenolic content (TPC), total flavonoids content (TFC), free radical scavenging activity (IC50), and ferric reducing antioxidant power (FRAP) of H. itama were ranged between 52.64 and 74.72 mg GAE/100 g honey, 10.70–25.71 mg QE/100 g honey, 11.27–24.09 mg/mL, and 77.88–164.88 µmol FeSO4.7H2O/100 g honey, respectively. The findings showed that the antioxidant activity and phenolic and flavonoid contents in H. itama honey were significantly higher than Apis honey. Benzoic acid and taxifolin were found as the predominant phenolic acid and flavonoid in all samples. However, chrysin was significantly highest in Apis honey than stingless bee honey. This result suggested that chrysin can be used as a chemical marker to distinguish Apis honey from stingless bee honey. Gallic acid and ellagic acid were found as the chemical marker for gelam honey, salicylic acid, benzoic acid, and 4-hydroxybenzoic acid for starfruit honey while ferulic acid for acacia honey.

Application of Heating on the Antioxidant and Antibacterial Properties of Malaysian and Australian Stingless Bee Honey

In the honey industry, heat treatments are usually applied to maintain honey’s quality and shelf life. Heat treatment is used to avoid crystallisation and allow the easy use of honey, but treatment with heat might affect the antioxidant and antibacterial activities, which are the immediate health effects of honey. This study will determine the effect of heat treatment on Malaysian and Australian stingless bee honey (SBH) produced by the common bee species in both countries. Eighteen honey samples were subjected to heat at 45 °C, 55 °C and 65 °C for one hour and subsequently analysed for their total phenolic content (TPC), total flavonoid content (TFC), DPPH radical scavenging activity, ferric reducing antioxidant power (FRAP) and minimum inhibitory concentration (MIC). The results show that all samples had high TPC, TFC and antioxidant activities before the treatment. The heat treatments did not affect (p < 0.05) the TPC, TFC and antioxidant activities in most samples, but did inhibit the antibacterial activities consistently in most of the samples, regardless of the bee species and country of origin. This study also confirms a strong correlation between TPC and TFC with FRAP activities for the non-heated and heated honey samples (p < 0.05). Other heat-sensitive bioactive compounds in SBH should be measured to control the antibacterial properties present.

Optimisation of Stingless Bee Honey Nanoemulsions Using Response Surface Methodology

Nanoemulsions (NEs) have been used in a wide range of products, such as those produced by the food, cosmetics, and pharmaceutical industries, due to their stability and long shelf life. In the present study, stingless bee honey (SBH) NEs were formulated using SBH, oleic acid, tween 80, glycerol, and double-distilled water. SBH NEs were prepared using a high-pressure homogeniser and were characterised by observing their stability and droplet size. Fourier Transform-Infrared (FTIR) analysis was used to observe the functional groups of the SBH NEs after being subjected to high-pressure homogenisation. Transmission Electron Microscopy (TEM) images were then used to confirm the particle size of the SBH NEs and to investigate their morphology. The effects of the independent variables (percentage of oleic acid, storage time, and storage temperature) on the response variables (particle size and polydispersity index) were investigated using the response surface methodology, along with a three-level factorial design. The results showed that the models developed via the response surface methodology were reliable, with a coefficient of determination (R²) of more than 0.90. The experimental validation indicated an error of less than 10% in the actual results compared to the predicted results. The FTIR analysis showed that SBH NEs have the same functional group as SBH. Observation through TEM indicated that the SBH NEs had a similar particle size, which was between 10 and 100 nm. Thus, this study shows that SBH NEs can be developed using a high-pressure homogeniser, which indicates a new direction for SBH by-products.

Stingless bee honey: An overview of health benefits and main market challenges

This review aimed to evaluate the nutraceutical and medicinal effects of stingless bee honey (SBH) by bringing a discussion focused on the main known in vitro/in vivo health-promoting effects. SBH has a high-water content, slight sweetness, acidic flavor, fluid texture, and slow crystallization. The type and concentration of phenolic compounds and consequent antioxidant activity were mainly associated with the floral sources, geographical location, bee species, and processing steps. SBH has anti-inflammatory, antimicrobial (against spoilage and pathogenic microorganisms), anti-diabetic, and skin aging delay activities in in vitro tests. It has also shown antioxidant and hypolipidemic effects, can protect from injuries caused by dyslipidemia, possess anti-inflammatory activity against chronic subclinical systemic inflammation and anti-diabetic properties, and can control and prevent Staphylococcus aureus infection on infected wound healings in in vivo tests (rats). However, clinical trials are crucial for the probation of the medicinal and nutraceutical properties of SBH. Despite this, there are still no general norms and/or quality standards for this type of honey. The information summarized in this review is important to add value to this little-consumed food, providing helpful information to spread knowledge about its benefits, assisting future studies, and raising perspectives for its recognition as a functional food. Furthermore, it may encourage the creation of standard quality for the production and marketing of SBH. PRACTICAL APPLICATIONS: Previous studies have already summarized the chemical profile and physicochemical properties of stingless bee honey (SBH) and its potential health properties. However, no study has performed an overview of the potential nutraceutical and medicinal effects of SBH, presenting results from in vitro and in vivo investigations. Therefore, this review is the first study to overview the potential nutraceutical and medicinal effects of SBH, showing results of in vitro/in vivo health-promoting effects. The bioactivity of SBH is related to bee species and floral sources. The SBH has anti-inflammatory, antimicrobial, anti-diabetic, and antioxidant in vitro activity. It has also shown hypolipidemic effects and protection from injuries caused by dyslipidemia in rats.

Phenolic composition and biological activities of stingless bee honey: An overview based on its aglycone and glycoside compounds

Stingless bees are native to tropical and subtropical countries, such as Brazil. The wide variety of species, the sources of food collection (nectar and pollen), and the climate conditions strongly affect the chemical composition of the honey, making this a unique product with peculiar characteristics. Stingless bee honey presents higher water content, higher acidity, and a lower sugar concentration when compared to Apis mellifera honey. Moreover, there is a wide variety of microorganisms in stingless bees' environment, which leads their honey to go through a natural fermentative process during its production in the hive. Besides, fermentation and hydrolysis are effective ways to convert glycosides into aglycones, thus increasing the bioavailability of compounds. In this sense, stingless bee honey may possess a greater concentration of phenolic compounds aglycones than glycosides, which would increase its potential benefits. Therefore, this review aims to compile the most recent studies of stingless bee honey phenolic profile and its biological potential (antioxidant, antimicrobial, and anti-inflammatory activities) and a possible connection to its natural fermentation process.

Stingless Bee Honey: Evaluating Its Antibacterial Activity and Bacterial Diversity

Stingless bee honey (SBH) is an astounding 'miracle liquid' with countless medicinal properties for various diseases such as gastroenteritis, cataracts, as well as for wound-healing. However, knowledge regarding it is still rather scarce. Henceforth, it is intriguing for us to contemplate on the less-studied stingless bee and its honey in particular. First and foremost, the antimicrobial ability of honey from eight different stingless bee species was tested to further proven its health benefit. Homotrigona fimbriata honey showed the highest antimicrobial activity with inhibition against five bacteria; Serratia marcescens, Escherichia coli, Bacillus subtilis, Alcaligenes faecalis and Staphylococcus aureus. The next aim of our study is to characterize their honey bacterial community via the use of 16S rRNA amplicon sequencing technology. A total of eight bacterial phyla, 71 families, 155 genera and 70 species were identified from our study and two of the stingless bee species honey were determined to have the highest bacterial diversity compared to other six stingless bee species, namely Heterotrigona erythrogastra and Tetrigona melanoleuca. Furthermost, Lactobacillus malefermentans was thought to be the native dominant bacteria of SBH due to its predominant presence throughout all studied species. The aforementioned SBH's antimicrobial results and characterization study of its bacterial diversity are hoped to carve the pathway towards extending its probiotic ability into our everyday lives.

Melissopalynological Study, Phenolic Compounds, and Antioxidant Properties of Heterotrigona itama Honey from Johor, Malaysia

Six honey samples produced by the stingless bee Heterotrigona itama were analyzed for their plant sources, phenolic compositions, and antioxidant activities. The honey samples were acetolyzed and identified microscopically, and the phenolic compounds were identified by using HPLC-DAD. The antioxidant activities were evaluated using three different assays (FRAP, DPPH, and ABTS) by spectrophotometry. The melissopalynological analysis showed that 26 pollen types from 14 plant families were identified in the honey. Cocos nucifera and Rhizophora mucronata presented as predominant pollen. A total of 6 phenolic acids such as catechin, chlorogenic acid, epicatechin, protocatechuic acid, p-coumaric acid, and rutin were identified. Rhizophora mucronata honey possessed the highest antioxidant activity in all assays. The result showed the influence of plant sources on the phenolic compounds and the antioxidant properties of stingless bee honey. These findings could be significant contributions for the sustainability of stingless bee industry as well as to promote Malaysian stingless bee honey worldwide.

In vitro modulation of extracellular matrix genes by stingless bee honey in cellular aging of human dermal fibroblast cells

This study determined the antiaging effect of stingless bee honey on the expression of extracellular matrix genes. MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) assay was performed for determination of optimum concentration and incubation time of stingless bee honey. Gene expression of matrix metalloproteinase-1 (MMP-1) and collagen type Ⅰ (COL1A1) were analyzed using real time reverse transcriptase polymerase chain reaction technique. Incubation with stingless bee honey at concentration of 0.02% for 72 hr showed significant increase in the viability of human fibroblast cells. Stingless bee honey significantly downregulates metalloproteinase-1 gene expression in both pre-senescence and senescence fibroblast cells and upregulates collagen type Ⅰ gene expression in senescence fibroblast cells. In conclusion, stingless bee honey potentially delayed skin aging through modulation of extracellular matrix genes. PRACTICAL APPLICATIONS: Changes of the extracellular matrix regulation promote skin aging. Stingless bee honey is a good source of natural antioxidant which potentially delays skin aging. This study demonstrated that stingless bee honey beneficially increases collagen type Ⅰ expression and decreases MMP-1 expression during cellular aging of human dermal fibroblast cells.

The Effect of Kelulut Honey on Fasting Blood Glucose and Metabolic Parameters in Patients with Impaired Fasting Glucose

Background

Impaired fasting glucose (IFG) poses a higher risk of diabetes. Honey has been reported to improve metabolic abnormalities including lowering hyperglycemia. This study is sought at determining the effect of Malaysian Kelulut honey (KH) on fasting glucose levels and metabolic parameters in IFG patients.

Methods

This quasi-experimental intervention study of 30-day duration was conducted among 60 adult patients with IFG. They were allocated into taking 30 g/day KH group (experimental group, n=30) and not taking KH group (control group, n=30). Body mass index (BMI), waist circumference, blood pressure (BP), fasting glucose, and lipid profile levels (total cholesterol, triglyceride, high-density lipoprotein, and low-density lipoprotein) were measured before and after treatment.

Results

There was no significant difference in all measured variables at day 30 compared to day 1 within both groups. Similarly, all measured variables neither at day 1 nor at day 30 had shown a statistically significant difference between the groups.

Conclusions

Daily intake of 30 g KH for 30 days resulted in insignificant effect on fasting glucose, fasting lipid profiles, and other metabolic parameters in patients with IFG. Further studies that employ longer study duration are needed to ascertain the finding.

Supplementation of Stingless Bee Honey from Heterotrigona itama Improves Antiobesity Parameters in High-Fat Diet Induced Obese Rat Model

Heterotrigona itama is a common stingless bee species found in Southeast Asia. Studies on the health benefits of its honey are limited in comparison with other stingless bee species. This study examines the antiobesity benefits found in stingless bee honey (SBH) from H. itama. The parameters used to measure the benefits were weight change, morphological structures, and biochemical characteristics. The research was conducted by using rats that were given a high-fat diet (HFD). In total 48 male Sprague Dawley (SD) rats were given a formulated HFD to increase the levels of obesity, the HFD was administered with a value of 0.68 g/cm2. The duration of the treatment was six weeks, and the results show that the induction obesity using the HFD was successful. Following this, the rats were then treated with SBH (at dosages of 1000 mg/kg, 750 mg/kg or 500 mg/kg), with orlistat or with a placebo. Compared with typical obesity treatment methods, the one that used the three dosages of SBH showed a higher reduction in body mass index (BMI), percentage of body weight gain, adiposity index, and relative organ weight (ROW). The levels of liver enzymes (ALT, AST, and ALP) were also significantly lower in SBH-treated groups. The levels of triglycerides and LDL-cholesterol were significantly lower, while the level of HDL-cholesterol was significantly higher in comparison with the control obese group. In terms of morphological structures, the number of adipocyte cells was reduced, and the hepatocytes found in the liver were less prone to rupturing when treated with SBH. In conclusion, the administration of SBH led to an improvement in indicators associated with obesity reduction. SBH also possesses a hepatoprotective potential which can reduce the health risks related to obesity.