A vortex-assisted liquid-liquid-liquid microextraction method followed by high performance liquid chromatography-diode array detection for the determination of fourteen phenolic acids (cinnamic, m-coumaric, chlorogenic, syringic, ferulic, o-coumaric, p-coumaric, vanillic, p-hydroxybenzoic, caffeic, 2, 4-dihydroxybenzoic, sinapic, gentisic and gallic acids) in honey, iced tea and canned coffee drink samples has been developed. The separation was achieved using a Poroshell 120-EC-C18 column under a gradient elution at a flow rate of 0.6mLmin-1 and mobile phase composed of methanol and acetic acid (1%, v/v). Under the optimum chromatographic conditions, the fourteen phenolic acids were separated in less than 32min. The extraction was performed using a small volume (400µL) of ternary organic solvents (1-pentanol, propyl acetate and 1-hexanol) dispersed into the aqueous sample (10mL) and assisted by vortex agitation (2500rpm for 45s), the analytes were next back-extracted from the organic solvent using 0.02M KOH (40µL) with vortex speed and time of 2500rpm and 60s, respectively. Under these conditions, enrichment factors of 30-193-fold were achieved. The limits of detection (LODs) were 0.05-0.68µgL-1. Recoveries in honey, iced tea and canned coffee drinks were in the range 72.2-112%. The method was successfully applied for the determination of the phenolic acids in honey, iced tea and canned coffee drinks.
Honey is a good source of several important chemical compounds and antioxidants and is harvested throughout the year. However, no study has determined how their contents change over the years. The aim of the present research was to investigate the changes in the phenolics, flavonoids and antioxidant properties, as well as other physicochemical properties, of Malaysian acacia honey collected during different months during a two year period. The DPPH (1,1-diphenyl-2-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) methods were used to determine the total antioxidant activity of the honey samples. Generally, honey samples collected in the beginning and the middle of the year tended to have higher sugar content, which may be attributed to its high acidic nature and low moisture content. There was a gradual increase in the phenolic content of the acacia honey samples collected between September 2010 and December 2010. The honey sample collected at the beginning of the year (January) showed the highest color intensity and was dark amber in color. It also contained the highest concentration of phenolic compounds (341.67 ± 2.94 mg(gallic acid)/kg), the highest flavonoid content (113.06 ± 6.18 mg(catechin)/kg) and the highest percentage of DPPH inhibition and the highest FRAP value, confirming its high antioxidant potential. There was a positive correlation between DPPH and total phenolic content, suggesting that phenolic compounds are the strongest contributing factor to the radical scavenging activity of Malaysian acacia honeys. Overall, our results indicated that there were significant seasonal variations in the antioxidant potentials of honey over the two year period and the time of honey collection affects its physicochemical properties. Therefore, acacia honey from Malaysia should ideally be collected during the dry season, particularly in the months of January, May and June.
Stem cells with enhanced resistance to oxidative stress after in vitro expansion have been shown to have improved engraftment and regenerative capacities. Such cells can be generated by preconditioning them with exposure to an antioxidant. In this study we evaluated the effects of Tualang honey (TH), an antioxidant-containing honey, on human corneal epithelial progenitor (HCEP) cells in culture. Cytotoxicity, gene expression, migration, and cellular resistance to oxidative stress were evaluated. Immunofluorescence staining revealed that HCEP cells were holoclonal and expressed epithelial stem cell marker p63 without corneal cytokeratin 3. Cell viability remained unchanged after cells were cultured with 0.004, 0.04, and 0.4% TH in the medium, but it was significantly reduced when the concentration was increased to 3.33%. Cell migration, tested using scratch migration assay, was significantly enhanced when cells were cultured with TH at 0.04% and 0.4%. We also found that TH has hydrogen peroxide (H2O2) scavenging ability, although a trace level of H2O2 was detected in the honey in its native form. Preconditioning HCEP cells with 0.4% TH for 48 h showed better survival following H2O2-induced oxidative stress at 50 µM than untreated group, with a significantly lower number of dead cells (15.3 ± 0.4%) were observed compared to the untreated population (20.5 ± 0.9%, p<0.01). Both TH and ascorbic acid improved HCEP viability following induction of 100 µM H2O2, but the benefit was greater with TH treatment than with ascorbic acid. However, no significant advantage was demonstrated using 5-hydroxymethyl-2-furancarboxaldehyde, a compound that was found abundant in TH using GC/MS analysis. This suggests that the cellular anti-oxidative capacity in HCEP cells was augmented by native TH and was attributed to its antioxidant properties. In conclusion, TH possesses antioxidant properties and can improve cell migration and cellular resistance to oxidative stress in HCEP cells in vitro.
Many chronic diseases are associated with increased oxidative stress caused by an imbalance between free-radical production and the antioxidant level. Antioxidants, which are abundant in natural honey, are free-radical scavengers that either reduce the formation of or neutralize free radicals. The composition and source of honey greatly dictates its biochemical properties. We performed a comparative analysis of the total phenolic content and antioxidant potential of common commercially available honeys along with Malaysian tualang honey. In vitro biochemical analysis of the phenolic content by the Folin-Ciocalteau method revealed a significantly elevated phenolic content (83.96 ± 4.53 mg gallic acid equivalents per 100 g) in tualang honey. In addition, the antioxidant capacity (53.06 ± 0.41 mg ascorbic acid equivalents per gram) of tualang honey was greater, as assessed by the phosphomolybdenum method, 2,2-diphenyl-1-picryl-hydrazyl assay, and ferric reducing/antioxidant power assay. Peroxynitrite and superoxide radical scavenging activity was determined by spectrophotometric analysis in different honey types. Our data suggest that the elevated free-radical scavenging and antioxidant activity observed in tualang honey is due to the increased level of phenolic compounds. In addition to its antibacterial, anticarcinogenic, and anti-inflammatory properties, our study highlights the favorable antioxidant properties of tualang honey, which may be important to human nutrition and health.
Tualang honey has been shown to protect against neurodegeneration, leading to improved memory/learning as well as mood. In addition, studies have also demonstrated its anti-inflammatory and antioxidant properties. However, a substantial part of this research lacks systematization, and there seems to be a tendency to start anew with every study. This review presents a decade of research on Tualang honey with a particular interest in the underlying mechanisms related to its effects on the central nervous system. A total of 28 original articles published between 2011 and 2020 addressing the central nervous system (CNS) effects of Tualang honey were analysed. We identified five main categories, namely nootropic, antinociceptive, stress-relieving, antidepressant, and anxiolytic effects of Tualang honey, and proposed the underlying mechanisms. The findings from this review may potentially be beneficial towards developing new therapeutic roles for Tualang honey and help in determining how best to benefit from this brain supplement.
The effects of thermosonication on the quality of a stingless bee honey, the Kelulut, were studied using processing temperature from 45 to 90 ℃ and processing time from 30 to 120 minutes. Physicochemical properties including water activity, moisture content, color intensity, viscosity, hydroxymethylfurfural content, total phenolic content, and radical scavenging activity were determined. Thermosonication reduced the water activity and moisture content by 7.9% and 16.6%, respectively, compared to 3.5% and 6.9% for conventional heating. For thermosonicated honey, color intensity increased by 68.2%, viscosity increased by 275.0%, total phenolic content increased by 58.1%, and radical scavenging activity increased by 63.0% when compared to its raw form. The increase of hydroxymethylfurfural to 62.46 mg/kg was still within the limits of international standards. Optimized thermosonication conditions using response surface methodology were predicted at 90 ℃ for 111 minutes. Thermosonication was revealed as an effective alternative technique for honey processing.
Honey is rich in phenolic compounds, which act as natural antioxidants and are becoming increasingly popular because of their potential role in contributing to human health. A wide range of phenolic constituents is present in honey like quercetin, caffeic acid phenethyl ester (CAPE), acacetin, kaempferol, galangin which have promising effect in the treatment of cardiovascular diseases. Many epidemiological studies have shown that regular intake of phenolic compounds is associated with reduced risk of heart diseases. In coronary heart disease, the protective effects of phenolic compounds include mainly antithrombotic, anti-ischemic, anti-oxidant, and vasorelaxant. It is suggested that flavonoids decrease the risk of coronary heart disease by three major actions: improving coronary vasodilatation, decreasing the ability of platelets in the blood to clot, and preventing low-density lipoproteins (LDLs) from oxidizing. In this review paper, we discussed the preventive role of polyphenols of honey against cardiovascular diseases.
We investigated the effects of honey and its methanol and ethyl acetate extracts on inflammation in animal models. Rats' paws were induced with carrageenan in the non-immune inflammatory and nociceptive model, and lipopolysaccharide (LPS) in the immune inflammatory model. Honey and its extracts were able to inhibit edema and pain in inflammatory tissues as well as showing potent inhibitory activities against NO and PGE(2) in both models. The decrease in edema and pain correlates with the inhibition of NO and PGE(2). Phenolic compounds have been implicated in the inhibitory activities. Honey is potentially useful in the treatment of inflammatory conditions.
Gelam honey (GH) is a prized natural product synthesized from the nectar of flowers from Gelam trees (Melaleuca sp.). Gelam is an evergreen tree species that grows in tropical regions such as Malaysia. GH is a multifloral honey with proven antioxidant and anti-inflammatory properties. However, the beneficial effect of GH on female reproductive tissue has yet to be substantiated. Herein, we investigated the effects of GH administration on the uterine and vaginal epithelial thickness of sexually mature Sprague-Dawley rats. Epithelia thickness could be an indicator of an atrophy manifesting as a symptom of a cardio syndrome. Rats were given oral doses of GH in four groups for 14 days; the lowest dose was 0.2 g GH/kg body weight (bw) rat/day and the highest dose was 8 g GH/kg bw rat/day. The physicochemical characteristics of GH were assessed through hydroxymethylfurfural and moisture content determination and sugar identification. GH attenuated the atrophy of the uterine and vaginal epithelia and increased the thickness of the endometrial stroma and endometrial surface endothelial layer. However, the dissonance observed in the effect of GH administration on the vaginal epithelium requires further investigation. Nevertheless, GH may have a strong potential in attenuating uterine and vaginal atrophies.
Metabolic syndrome is a constellation of five risk factors comprising central obesity, hyperglycaemia, dyslipidaemia, and hypertension, which predispose a person to cardiometabolic diseases. Many studies reported the beneficial effects of honey in reversing metabolic syndrome through its antiobesity, hypoglycaemic, hypolipidaemic, and hypotensive actions. This review aims to provide an overview of the mechanism of honey in reversing metabolic syndrome. The therapeutic effects of honey largely depend on the antioxidant and anti-inflammatory properties of its polyphenol and flavonoid contents. Polyphenols, such as caffeic acid, p-coumaric acid, and gallic acid, are some of the phenolic acids known to have antiobesity and antihyperlipidaemic properties. They could inhibit the gene expression of sterol regulatory element-binding transcription factor 1 and its target lipogenic enzyme, fatty acid synthase (FAS). Meanwhile, caffeic acid and quercetin in honey are also known to reduce body weight and fat mass. In addition, fructooligosaccharides in honey are also known to alter lipid metabolism by reducing FAS activity. The fructose and phenolic acids might contribute to the hypoglycaemic properties of honey through the phosphatidylinositol 3-kinase/protein kinase B insulin signalling pathway. Honey can increase the expression of Akt and decrease the expression of nuclear factor-kappa B. Quercetin, a component of honey, can improve vasodilation by enhancing nitric oxide production via endothelial nitric oxide synthase and stimulate calcium-activated potassium channels. In conclusion, honey can be used as a functional food or adjuvant therapy to prevent and manage metabolic syndrome.
Stingless bee (Meliponini) honey has long been considered a high-value functional food, but the perceived therapeutic value has lacked attribution to specific bioactive components. Examination of honey from five different stingless bee species across Neotropical and Indo-Australian regions has enabled for the first time the identification of the unusual disaccharide trehalulose as a major component representing between 13 and 44 g per 100 g of each of these honeys. Trehalulose is an isomer of sucrose with an unusual α-(1 → 1) glucose-fructose glycosidic linkage and known acariogenic and low glycemic index properties. NMR and UPLC-MS/MS analysis unambiguously confirmed the identity of trehalulose isolated from stingless bee honeys sourced across three continents, from Tetragonula carbonaria and Tetragonula hockingsi species in Australia, from Geniotrigona thoracica and Heterotrigona itama in Malaysia and from Tetragonisca angustula in Brazil. The previously unrecognised abundance of trehalulose in stingless bee honeys is concrete evidence that supports some of the reported health attributes of this product. This is the first identification of trehalulose as a major component within a food commodity. This study allows the exploration of the expanded use of stingless bee honey in foods and identifies a bioactive marker for authentication of this honey in associated food standards.
Honey and other bee products were subjected to laboratory and clinical investigations during the past few decades and the most remarkable discovery was their antibacterial activity. Honey has been used since ancient times for the treatment of some diseases and for the healing of wounds but its use as an anti-infective agent was superseded by modern dressings and antibiotic therapy. However, the emergence of antibiotic resistant strains of bacteria has confounded the current use of antibiotic therapy leading to the re-examination of former remedies. Honey, propolis, royal jelly and bee venom have a strong antibacterial activity. Even antibiotic-resistant strains such as epidemic strains of methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycine resistant Enterococcus (VRE) have been found to be as sensitive to honey as the antibiotic-sensitive strains of the same species. Sensitivity of bacteria to bee products varies considerably within the product and the varieties of the same product. Botanical origin plays a major role in its antibacterial activity. Propolis has been found to have the strongest action against bacteria. This is probably due to its richness in flavonoids. The most challenging problems of using hive products for medical purposes are dosage and safety. Honey and royal jelly produced as a food often are not well filtered, and may contain various particles. Processed for use in wound care, they are passed through fine filters which remove most of the pollen and other impurities to prevent allergies. Also, although honey does not allow vegetative bacteria to survive, it does contain viable spores, including clostridia. With the increased availability of licensed medical stuffs containing bee products, clinical use is expected to increase and further evidence will become available. Their use in professional care centres should be limited to those which are safe and with certified antibacterial activities. The present article is a short review of recent patents on antibiotics of hives.
Large doses of ionizing radiation can damage human tissues. Therefore, there is a need to investigate the radiation effects as well as identify effective and non-toxic radioprotectors. This study evaluated the radioprotective effects of Kelulut honey (KH) from stingless bee (Trigona sp.) on zebrafish (Danio rerio) embryos. Viable zebrafish embryos at 24 hpf were dechorionated and divided into four groups, namely untreated and non-irradiated, untreated and irradiated, KH pre-treatment and amifostine pre-treatment. The embryos were first treated with KH (8 mg/mL) or amifostine (4 mM) before irradiation at doses of 11 Gy to 20 Gy using gamma ray source, caesium-137 (137Cs). Lethality and abnormality analysis were performed on all of the embryos in the study. Immunohistochemistry assay was also performed using selected proteins, namely γ-H2AX and caspase-3, to investigate DNA damages and incidences of apoptosis. KH was found to reduce coagulation effects at up to 20 Gy in the lethality analysis. The embryos developed combinations of abnormality, namely microphthalmia (M), body curvature and microphthalmia (BM), body curvature with microphthalmia and microcephaly (BMC), microphthalmia and pericardial oedema (MO), pericardial oedema (O), microphthalmia with microcephaly and pericardial oedema (MCO) and all of the abnormalities (AA). There were more abnormalities developed from 24 to 72 h (h) post-irradiation in all groups. At 96 h post-irradiation, KH was identified to reduce body curvature effect in the irradiated embryos (up to 16 Gy). γ-H2AX and caspase-3 intensities in the embryos pre-treated with KH were also found to be lower than the untreated group at gamma irradiation doses of 11 Gy to 20 Gy and 11 Gy to 19 Gy, respectively. KH was proven to increase the survival rate of zebrafish embryos and exhibited protection against organ-specific abnormality. KH was also found to possess cellular protective mechanism by reducing DNA damage and apoptosis proteins expression.
As consumption of stingless bee honey has been gaining popularity in many countries including Malaysia, ability to identify accurately its geographical origin proves pertinent for investigating fraudulent activities for consumer protection. Because a chemical signature can be location-specific, multi-element distribution patterns may prove useful for provenancing such product. Using the inductively coupled-plasma optical emission spectrometer as well as principal component analysis (PCA) and linear discriminant analysis (LDA), the distributions of multi-elements in stingless bee honey collected at four different geographical locations (North, West, East, and South) in Johor, Malaysia, were investigated. While cross-validation using PCA demonstrated 87.0% correct classification rate, the same was improved (96.2%) with the use of LDA, indicating that discrimination was possible for the different geographical regions. Therefore, utilization of multi-element analysis coupled with chemometrics techniques for assigning the provenance of stingless bee honeys for forensic applications is supported.
The aim of the present study was to evaluate the physicochemical and antioxidant properties of Malaysian monofloral honey samples-acacia, pineapple and borneo honey-and compare them with tualang honey. Acacia and pineapple honey are produced by Apis mellifera bees while borneo and tualang honey are produced by Apis cerana and Apis dorsata bees, respectively.
There is no available information on physicochemical and antioxidant properties on Bangladeshi honey. We investigated five different monofloral and three different multifloral honey samples collected from different parts of Bangladesh.
The aim of the present study was to characterize the physical, biochemical and antioxidant properties of Algerian honey samples (n = 4). Physical parameters, such as pH, moisture content, electrical conductivity (EC), total dissolved solids (TDS), color intensity, total sugar and sucrose content were measured. Several biochemical and antioxidant tests were performed to determine the antioxidant properties of the honey samples. The mean pH was 3.84 ± 0.01, and moisture the content was 13.21 ± 0.16%. The mean EC was 0.636 ± 0.001, and the mean TDS was 316.92 ± 0.92. The mean color was 120.58 ± 0.64 mm Pfund, and the mean 5-hydroxymethylfurfural (HMF) content was 21.49 mg/kg. The mean total sugar and reducing sugar contents were 67.03 ± 0.68 g/mL and 64.72 ± 0.52 g/g, respectively. The mean sucrose content was 2.29 ± 0.65%. High mean values of phenolic (459.83 ± 1.92 mg gallic acid/kg), flavonoid (54.23 ± 0.62 mg catechin/kg), ascorbic acid (159.70 ± 0.78 mg/kg), AEAC (278.15 ± 4.34 mg/kg), protein (3381.83 ± 6.19 mg/kg) and proline (2131.47 ± 0.90) contents, as well as DPPH (39.57% ± 4.18) and FRAP activities [337.77 ± 1.01 µM Fe (II)/100 g], were also detected, indicating that Algerian honey has a high antioxidant potential. Strong positive correlations were found between flavonoid, proline and ascorbic acid contents and color intensity with DPPH and FRAP values. Thus, the present study revealed that Algerian honey is a good source of antioxidants.
Tualang, Gelam and Kelulut honeys are tropical rainforest honeys reported to have various medicinal properties. Studies related to the medicinal properties and physicochemical characteristics of these honeys are growing extensively and receiving increased attention. This review incorporated and analysed the findings on the biological and physicochemical properties of these honeys. Tualang, Gelam and Kelulut honeys were found to possess a wide variety of biological effects attributed to their physicochemical characteristics. Findings revealed that these honeys have anti-diabetic, anti-obesity, anti-cancer, anti-oxidative, anti-microbial, anti-inflammatory and wound-healing properties and effects on the cardiovascular system, nervous system and reproductive system. The physicochemical properties of these honeys were compared and discussed and results showed that they have high-quality contents and excellent antioxidant sources.
The phenolic acid and flavonoid contents of Malaysian Tualang, Gelam, and Borneo tropical honeys were compared to those of Manuka honey. Ferric reducing/antioxidant power assay (FRAP) and the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical-scavenging activities were also quantified. All honey extracts exhibited high phenolic contents (15.21 ± 0.51- 42.23 ± 0.64 mg/kg), flavonoid contents (11.52 ± 0.27- 25.31 ± 0.37 mg/kg), FRAP values (892.15 ± 4.97- 363.38 ± 10.57 μM Fe[II]/kg), and high IC₅₀ of DPPH radical-scavenging activities (5.24 ± 0.40- 17.51 ± 0.51 mg/mL). Total of 6 phenolic acids (gallic, syringic, benzoic, trans-cinnamic, p-coumaric, and caffeic acids) and 5 flavonoids (catechin, kaempferol, naringenin, luteolin, and apigenin) were identified. Among the Malaysian honey samples, Tualang honey had the highest contents of phenolics, and flavonoids, and DPPH radical-scavenging activities. We conclude that among Malaysian honey samples, Tualang honey is the richest in phenolic acids, and flavonoid compounds, which have strong free radical-scavenging activities.
The elemental profiles of six honey samples from Malaysia had been constructed using the data obtained from both ICP-AES and ICP-MS. Potassium and sodium were the most abundant minerals covering from 69.3-78.6% and 14.1-28.7%, respectively. The ratio of potassium to sodium was more than one. Even though the minerals and trace elements composition varied dependent on the type of honey samples, there was no statistically significant difference between the analysed honey samples, namely tualang, gelam, acacia and a few forest honeys based on two-factor ANOVA and cluster analysis. The total element content of honey samples were strongly correlated with the electrical conductivity, but only have moderate correlation with the ash content and honey colour based on the regression analysis. PCA result on the available elemental data from worldwide honeys, including honey samples from Malaysia revealed that potassium and sodium were the mineral markers to distinguish honey origin. Both tualang and gelam honey samples from Malaysia have close mineral profile with sesame honeys from Egypt and multifloral honeys from India, whereas forest honeys Malaysia were near to avocado honeys from Spain and multifloral honeys from India.