Tetragonula Biroi Research Articles

Physicochemical analysis of trigona honey produced by Tetragonula biroi in Soppeng Regency, Indonesia

Indonesia is a country with a tropical climate that is rich in biodiversity. Various types of bees are discovered in the country, including the trigona bees, whose honey offers numerous health benefits. This study aimed to analyze the nutritional and phytochemical content of trigona honey produced by Tetragonula biroi in Soppeng Regency, South Sulawesi, Indonesia. The honey samples are extracted directly from the hives, filtered and examined through laboratory tests. The results of this study showed that trigona honey from Soppeng has a low pH (4.5) and a high vitamin C content compared to other vitamins. The calcium content is higher than magnesium and zinc, while its high polyphenols contain flavonoids and antioxidants. The water content of 26.67% is indicated in trigona honey, which is within the acceptable range of the Indonesian National Standard (SNI). The sugar content of trigone honey indicates 6.99% w/w glucose, 12.96% w/w fructose and a fructose/glucose ratio of 1.85.

ANALYSIS OF PROPOLIS STINGLESS BEE BIOACTIVE COMPOUNDS FROM SEVERAL REGIONS IN INDONESIA

Objective: Propolis is a bee product collected by honeybees from a resinous substance of various plant sources. Its antioxidant activities are different from various geographic origins. This study aimed to analyze bioactive compounds by lC-MS/MS, compare antioxidant activity total phenolic and flavonoid contents in stingless bee propolis samples from several regions in Indonesia. Methods: The propolis samples were taken from stingless bee hives of Tetragonula clypearis from Sumbawa, Tetragonula laeviceps from Magelang, Tetragonula biroi from Bogor, and Geniotrigona thoracica from South Kalimantan). Analysis of bioactive compounds was identified by lC-MS/MS. The quantification of the chemical compound determined its total phenolics and flavonoid (TPC and TFC) contents. The antioxidant activity was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay. Results: The results of this study obtained 10 compounds from G. thoracica, 8 compounds each from T. laeviceps and T. biroi, and 7 compounds from T. clypearis. The results of TPC was ranging from 57.24±5.35 to 139.39±15.79 mg GAE/g. The TFC was ranging from 22.13±0.79 to 37.20±3.63 mg QE/g. With the highest TPC and TFC was propolis of G. thoracica. The IC50 of antioxidant activity was ranging from 11.12 to 162.72 ppm. Conclusion: The compounds contained in propolis T. clypearis, T. laeviceps, G. thoracica and T. biroi have a potential as a new herbal candidate as antioxidant agents.

Morphology and morphometric of Tetragonula biroi bees at three different altitudes in South Sulawesi, Indonesia

Abstract. Prastiyo A, Nuraeni S, Budiaman. 2024. Morphology and morphometric of Tetragonula biroi bees at three different altitudes in South Sulawesi, Indonesia. Biodiversitas 25: 1993-2002. Tetragonula biroi Friese 1898 is a stingless bee species that plays an essential role in pollination and environmental conservation. This research is important because bees play a crucial role as pollinators for the sustainability of plants, and morphometric measurements can reveal patterns of adaptation and the potential production of products generated by these bees. This research aims to analyze the morphological and morphometric variations of T. biroi at three different altitudes in South Sulawesi. The study was conducted from November 2023 to January 2024, with sampling points in lowland (158 meters above sea level or masl), midland (417 masl), and highland (709 masl), using Principal Component Analysis (PCA) test using XLSTAT and one-way analysis of variance (ANOVA) test using program SPSS. Observations of T. biroi morphology at the three locations were generally similar, with a black body color tinged with brown and characteristic hamuli numbering five. The morphometric analysis involved measuring body dimensions of T. biroi across 35 characters/sections of the external body, and the one-way ANOVA test results showed that the dominant characters significantly influencing were body length (BL) and length of fore wing, including tegula (WL1). T. biroi bees at lowlands tend to have smaller bodies, measuring 3.73±0.09 mm, while those at higher altitudes tend to have larger bodies, measuring 4.09±0.14 mm. This indicates adaptation to environmental conditions such as temperature (26.75C), humidity (81%), and dominant vegetation (Cocos nucifera L.) in lowland, which influence bee adaptation, as well as in midland and highland areas. This research provides a better understanding of morphological and morphometric variations in T. biroi bees at various altitudes in South Sulawesi. The morphology and morphometrics description of bees is crucial in determining the growth and production of a species.

Botanical Originand Extraction Methods of Philippine Stingless Bee (Tetragonula biroiFriese) Pollen and its Food Functionality: Phenolic and Flavonoid Content and Antioxidant Activity

With its high nutritional and bioactive content, bee pollen is recognized as a functional food. However, its composition is highly dependent on a range of factors, such as geographical location. In this research, we used DPPH to determine the antioxidant activity of several stingless bee (Tetragonula biroi) pollen samples sourced from five different areas in the Philippines and compare their phenolic and flavonoid content. Additionally, we compared two extraction methods: maceration (or soaking of samples) for three days and sonication for 30 minutes. Interestingly, our findings show that the phenolic content of bee pollen is weakly associated with antioxidant activity, indicating that other bioactive chemicals may play a more significant part in the antioxidant characteristics of bee pollen. Antioxidant properties based on the DPPH assay of pollen harvested from Calamba are higher compared to other samples from different geographic areas, i.e., Quezon Province, Sorsogon, Laguna, and Albay. When compared to the maceration approach, extracts generated from the sonication process had lower antioxidant activity. These findings suggest that Philippine stingless bee pollen is a potential source of bioactive compounds, and the choice of extraction method and geographic source are significant factors affecting its antioxidant activity.

Ethanolic extract of propolis from Indonesian stingless bee (Tetragonula biroi) is ineffective against ESBL-producing Klebsiella pneumoniae: An in vitro study and a brief review of propolis antibacterial and anti-inflammatory activity.

The number of antimicrobial resistance which is increasing every year is a big problem that attracts attention. The prevalence of infections due to bacterial resistance is quite high, especially from nosocomial infections. This encourages the search for new materials that have the potential to fight resistant bacteria. Propolis is a product of bees that is not only used for structural support for their hives but also as an antiseptic to protect their hives from microorganisms. This study aims to determine whether the ethanolic extract of propolis (EEP) from the stingless bee Tetragonula biroi has an antibacterial effect against extended spectrum beta-lactamase (ESBL) producing Klebsiella pneumoniae. This study used the broth dilution test and agar-well diffusion test to test for antibacterial activity. EEP is generally inactive against ESBL-producing K. pneumoniae. It could not produce an inhibition zone in the agar-well diffusion test. The results of the dilution test for the minimum inhibitory concentration (MIC) are difficult to determine. Phytochemical qualitative test found EEP of T. biroi contains alkaloids, flavonoids, and phenols.

Cytotoxicity evaluation of phytochemicals from stingless bee (Tetragonula biroi) propolis

Three prenylated flavonoids (1–3) were isolated from Tetragonula biroi propolis. The structures of the isolated compounds were characterized by NMR, IR, and UV spectroscopic and mass spectrometric analyses. The cytotoxicity activity of the crude extracts, fractions and the isolated compounds were established against four cell lines such as Caco-2, HeLa, MCF-7, and OVK-18. Among the tested compounds, compound 1 showed cytotoxicity activity against MCF-7 cell lines, whereas compound 2 showed good activity against Caco-2 and OVK-18 cell lines with IC50 values of 14.73 and 14.44, respectively. Moreover, compound 3 exhibited strong activity against OVK-18 cell lines. These findings contribute to the phytochemical understanding of the T. biroi propolis, and their cytotoxicity effects for future pharmaceutical purposes.

Foraging Activities, Environmental Factors, and Increment Weight of Tetragonula biroi Colonies in Beekeeping with Different Hive Materials

Tetragonula biroi is one of the stingless bee species that has many benefits for human life besides producing honey, propolis, and 13 derivative products. Another important service provided by this bee is as a plant pollinator. This research aims to determine the relationship between the foraging activity of T. biroi bees, environmental factors, and colony development in hives made of different materials. The study was conducted in Rompegading Village, Maros Regency. This research method used a completely randomized design consisting of four different hive materials, namely glass, triplex, cement, and tree hollows, and each treatment was repeated three times. Parameters observed were the number of worker bees leaving and entering the hive throughout the day, colony weight gain, and environmental factors (temperature, humidity, and light intensity). The results showed that the highest foraging activity of worker bees and colony weight gain occurred in natural hives (tree hollows) in the fourth week of observation and in artificial hives made from cement materials. The peak of bee activity entering and leaving the hive occurred in the morning from 07:00–10:00 and in the late afternoon from 13:00–16:00. In the morning, more bees leave the hive, while more enter in the afternoon. Factors such as temperature, humidity, and light affect the foraging activity of worker bees.

Effect of Storage Time on the Quality of Stingless Bee (Tetragonula biroi Friese) Honey

Stingless bee honey (SBH) has a unique sour taste and distinct flavor compared to honey from Apis species. The demand for SBH has increased in the Philippines because of its known therapeutic properties. Even if it is sold immediately after harvest, it is crucial to know its shelf-life in anticipation of large-volume production shortly. Thus, this study was conducted to determine if storage for 5 mo at room temperature will alter its physicochemical characteristics. The average values for the pH level, moisture content, HMF content, reducing sugar content, and total sugar content during the 5-mo storage period were 3.30 ± 0.02, 26.95 ± 0.07%, 2.40 ± 0.55 mg/kg, 46.08 ± 0.43%, and 46.78 ± 1.51%, respectively. The values for each parameter did not change significantly during the duration of the study. This indicates that SBH can remain stable for at least a 5-mo period.

Comparative analysis of the quantity of propolis Tetragonula biroi bees based on propolis type and colony origin

Propolis is one of the products produced by Tetragonula biroi bees which comes from resin collected by honey bees from various plants, which mixes with saliva and various enzymes to produce different new resins and bees collect other than resin to build nests with other materials. ingredients taken directly from nature. The purpose of this study was to determine the percentage of propolis propolis structure, the percentage of propolis waste and residue in nests of T. biroi in South Sulawesi. The data collected was then processed using descriptive methods. The results showed that the average percentage of propolis pillars was 30%, propolis batumen 26%, propolis involucrum 24%, propolis brood cells 6%, propolis pollen pots 4%, and contained in nests in the form of small wooden branches 6%, leaves 2.27 %. The percentage of waste in nests from Bone was 22.43% and a residue percentage of 77.56%, nests from Luwu had an average waste percentage of 19.19% and a percentage of propolis residue 80.8%, then nests from Soppeng had an average waste percentage of 18.92% and a residual percentage propolis 81.06 %.

Comparison of productivity from three stingless bees: Tetragonula sapiens, T. clypearis and T. biroi managed under same feed sources for meliponiculture

Abstract. Erwan, Habiburrohman, Wiryawan IKG, Muhsinin M, Supeno B, Agussalim. 2023. Comparison of productivity from three stingless bees: Tetragonula sapiens, T. clypearis and T. biroi managed under same feed sources for meliponiculture. Biodiversitas 24: 2988-2994. The productivity of stingless bee species is affected by the workers' population, especially the foragers' number, queen bee productivity, and the availability of plants as the nectar and pollen sources. The recent study aims to evaluate the productivity of three stingless bee species, Tetragonula sapiens (Cockerell, 1911), Tetragonula clypearis (Friese, 1908), and Tetragonula biroi (Friese, 1898), managed under the same feed sources for beekeeping in stingless bee (meliponiculture). Total of fifteen colonies and every five colonies per species of T. sapiens, T. clypearis, and T. biroi, respectively. The results showed that the different species of stingless bees highly affected the exit activities in the morning and afternoon and brood cell number (p<0.01). Furthermore, significant impacts on the honey pot number, production of honey and propolis (p<0.05) but not on the pollen pot number and the production of pot-pollen. Thus, productivity was characterized by honey pot number, brood cell number, and production of honey and propolis from the stingless bee of T. biroi was higher than T. sapiens and T. clypearis. However, the productivity of T. sapiens and T. clypearis was similar.

Honey Purity Analysis of Trigona sp. species in Royal Honey Sakah, Bali

Honey is a sweet liquid produced by bees and derived from the nectar of flowers. The increasing circulation of fake honey has alarmed the public. An analysis of the purity of honey still needs to be reported. This study aimed to analyze the purity of honey from Trigona sp. at Royal Honey Sakah. The qualitative design was used during the study in May 2022 at Royal Honey Sakah. Three honey samples from different bees were analyzed to determine how much water, sugar, and viscosity they had. Our findings show that the purity of honey depends on moisture content, sugar content, and viscosity and that these three parameters depend on the quality of nectar produced from flower plants around the place of cultivation. The purity level in sugar, water, and viscosity content in three types of honey, including Apis dorsata honey, wild forest honey (Tetragonula biroi), and tenganan local honey (Apis sp.), all meet the quality requirements of honey according to SNI 8664: 2018. Therefore, the higher the sugar concentration, the less water there is in the honey, and the higher the viscosity, the more pure or authentic the honey is. People who will consume honey are expected to be able to identify the quality of honey in terms of its viscous structure, no bubbles resembling heated sugar, and a dark brown or concentrated color. Honey is declared pure if there is no further processing other than filtering from the source.

Determination of productivity, yield and bioactivity of propolis extract produced by Tetragonula spp. Cultivated in Modular tetragonula hives

This study investigated the effects of microclimate conditions on the activity of Tetragonula laeviceps, Tetragonula biroi, and Tetragonula drescheri cultivated in Modular Tetragonula Hives for producing crude propolis. The hives were equipped with sensors that recorded microclimate data within the hive as well as the total activity of bees entering and leaving the hives. This study also investigated the effects of cultivating T. laeviceps, T. drescheri, and T. biroi with P. merkusii resin towards the productivity of crude propolis and the effects of different extraction methods on the yield, total phenolic content, total flavonoid content, and antibacterial activity of propolis extract produced by the Tetragonula spp. Based on the statistical analysis, there is a significant positive correlation between temperature and light intensity towards the activity Tetragonula spp. entering and leaving the beehives. The productivity of crude propolis lies in the range of 1.22–5.88 g/colony/week whereas the yield of propolis extract varies from 15.12 to 24.17%. The total phenolic and flavonoid content of the propolis extract lies in the range of 123.81–343.93 mg GAE/g and 5.48–35.77 mg QE/g, respectively. The highest propolis yield (32.45 ± 0.90%) was obtained from the crude propolis produced by T. drescheri followed by Soxhlet extraction method. Propolis extract with the highest phenolic content (343.93 ± 44.32 mg GAE/g) and flavonoid content (35.77 ± 9.94 mg QE/g) was obtained from the propolis produced by T. laeviceps followed by maceration method. All the propolis extracts inhibited the growth of Staphylococcus aureus with the inhibition diameter varies from 6.58 ± 0.04 mm to 9.70 ± 0.7 mm which be considered as moderate antimicrobial activity.

Morphology, Nest Characters, and Behavior: Taxonomic Aids in Facilitating Identification of Tetragonula biroi Friese (Hymenoptera: Apidae: Meliponini)

Tetragonula biroi Friese, the most popular stingless bee species in the Philippines, belongs to Tetragonula, a difficult genus to deal with due to the high character variability of workers. This paper provides a detailed description of the morphological characters, nest features, and behavioral characteristics of T. biroi to help facilitate its classification and identification. Proper identification of stingless bees is crucial in biodiversity conservation, genetic improvement, and pest management.

Morphology, Morphometry, and Nest Structure of Tetragonula biroi (Hymenoptera: Meliponini) In Central Sulawesi

Stingless bees are social bees that live in colonies. Indonesia has a variety of stingless bee species that can be identified based on morphological, morphometric and nest structure characters. This study aims to describe the morphological, morphometric and nest structure characteristics of Stingless bee Tetragonula biroi from Sigi Regency. This study used the roaming method to find samples in nature, with a purposive sampling technique. Obtained morphological, morphometry and nest structure data were analyzed using the Principal Component Analysis (PCA) method with PAST4 software. The morphological characters of the worker bee Tetragonula biroi have a dominant black body, blackish brown abdomen, antennae with 11 flagellomeres, black thorax, black hair standing on the mesoscutum and mesoscutellum, brownish black mandibles, with 5 hamuli. The most dominant character in the formation of seven groups of stingless bees in this study, namely Hamuli Number (HN), Fore Wing Length (FWL), and Length of Forewing Including Tegula (WL1). The nest entrance hole of T. biroi is elliptical in shape with a width of 7.1 cm and a height of 2.8 cm and is light brown in color. The internal structure of the nest of T. biroi consists of honey cells, pollen cells and stem cells. The existence of size differences in the same specimen and from different places, can be influenced by several environmental factors and is also a form of morphological adaptation.

Abrogation of Acute Inflammation in ICR Mice with Topical Administration of Philippine Stingless Bee (Tetragonula biroi Friese) Honey

Pharmacognosy Research,2023,15,2,258-266.DOI:10.5530/pres.15.2.028Published:February 2023Type:Original Article Authors:Mark Joseph Maranan Desamero, Mikaela Bernadette Andres Rabino, Maria Angelica Rimas Tayao, Mary Jasmin Cabillon Ang, Jussiaea Valente Bariuan, Roxanne Posilero Gapasin, Therese Marie Avena Collantes, Melissa Marie Risos Rondina, Cherry Pambid Fernandez-Colorado, Cleofas Rodriguez Cervancia, and Maria Amelita Celino Estacio Author(s) affiliations:Mark Joseph Maranan Desamero1,2,*, Mikaela Bernadette Andres Rabino1, Maria Angelica Rimas Tayao1, Mary Jasmin Cabillon Ang1, Jussiaea Valente Bariuan1,2, Roxanne Posilero Gapasin1,2, Therese Marie Avena Collantes3, Melissa Marie Risos Rondina4, Cherry Pambid Fernandez-Colorado3, Cleofas Rodriguez Cervancia2,5, Maria Amelita Celino Estacio1,2 1Department of Basic Veterinary Sciences, College of Veterinary Medicine, University of the Philippines Los Baños, Laguna, PHILIPPINES. 2UPLB Bee Program, University of the Philippines Los Baños, Laguna, PHILIPPINES. 3Department of Veterinary Paraclinical Sciences, College of Veterinary Medicine, University of the Philippines Los Baños, Laguna, PHILIPPINES. 4Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of the Philippines Los Baños, Laguna, PHILIPPINES. 5Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños, Laguna, PHILIPPINES Abstract:Background: Honey, a sweet sugar-rich bee-derived product, has been widely recognized in the realm of Ayurveda and Pharmacognosy for the treatment of various inflammatory conditions including inflammatory bowel disease, asthma, arthritis, and gastric ulcer. However, the anti-inflammatory effect of Philippine honey obtained from local stingless bees remains unexplored and poorly investigated. Hence, this study delved on the anti-inflammatory potential of topically applied Philippine stingless bee honey (PSH) using the λ-Carrageenan-induced mouse model of paw edema. Materials and Methods: A total of 30, male ICR mice of six weeks of age were randomly divided into the following groups (n=10 per group) as follows: Distilled water-, 1% Diclofenac sodium-, and Honey-treated group. All treatments were administered immediately after Carrageenan injection and then every 8 hr during the 24-hr test duration. Results: Repeated topical application of PSH significantly attenuated the gross hind paw swelling observed at the onset of the 6 hr post-induction (pi) until the 24 hr pi with Carrageenan in contrast to the Distilled water-treated group. This corresponded histologically to a marked reduction in dermal thickness, dermal edema, and leukocytic infiltration. Whereas, at the cytokine level, this correlated to significant suppression of the circulating blood levels of pro-inflammatory cytokines, TNF-α, IL-1β, and IL-6. Conclusion: Based on these results, honey from the Philippine stingless bees shows convincing anti-inflammatory activity which is partly mediated through the regulation of the expression of inflammation-associated cytokines. Keywords:Anti-inflammatory, Honey, IL-1β, IL-6, Philippine stingless bees, TNF-α.View:PDF (1.75 MB)

Diversity and spatial distribution of native bees in Mt. Banahaw de Lucban, Philippines

Abstract Native bees are pollinators and bioindicators of ecosystem health but only little is known about its abundance, species distribution, and habitat range, especially in the Philippines. This study assessed the diversity and spatial distribution of native bees in Mt. Banahaw de Lucban (MBDL). Belt transect coupled with opportunistic sampling were used in the inventory of bees and their nests. Nests occurrence and 7 environmental predictor variables including; 1) annual mean temperature; 2) precipitation of warmest quarter; 3) elevation; 4) slope; 5) Normalized Difference Vegetation Index (NDVI); 6) distance to agricultural areas (m); and 7) distance to forested areas (m) were used for modeling species distribution by MaxEnt. A total of 16 species of native bees including representatives from genus Apis, Tetragonula, Lasioglossum, Halictus, Hylaeus and Megachile were identified. A total of 96 bee nests from 5 species were also recorded yielding a nests density of 234 nests per km2. Results showed medium diversity of solitary native bees with H’ of 2.488. Most bee nests were found in lower elevations while the distance from agricultural areas and the distance from forest areas had the highest contributions to the nesting of Apis breviligula, A. cerana, and Tetragonula biroi. The mean distance from forest areas of all bee nests was 649.930 m and the mean extent of suitable area for these species was 5.340 km2. Hence, a landscape approach may be more appropriate to conserve native bees and sustain the ecosystem services they provide in MBDL.

Antioxidant, anti-inflammatory and anti-acne activities of stingless bee (Tetragonula biroi) propolis

We collected stingless bee propolis Tetragonula biroi in order to find materials for medicine and cosmetics applications from tropical rainforest resources. Even though this bee has some biological functions including a cancer cell line, hair growth promotion, asthma remedy, α-glucosidase enzyme inhibition, and antiviral action, the investigation on anti-acne has not been reported yet. This study was to focus on propolis Tetragonula biroi extracts and leads us to isolate active compounds for antioxidant, anti-inflammatory, and anti-acne. We used methanol to obtain the extract from this propolis and assayed it with antioxidants, anti-inflammation, and anti-acne. The extract showed strong activity in antioxidants by DPPH radical scavenging activity (82.31% in 6.25 μg/ml). Via a column chromatography and Reveleris PREP purification system, we isolated 3’–O–methyldiplacone, nymphaeol A, and 5,7,3′,4′–tetrahydroxy–6–geranyl flavonol. These compounds showed potential biological activity with IC50 for antioxidant 6.33, 15.49, 17.32 μM; and antiinflammatory 121.54, 121.20, 117.31 μM. The isolated compounds showed anti-acne properties with properties 0.00, 14.11, and 13.78 mm for the inhibition zone (at a concentration of 1 μg/well), respectively. The results indicated that the propolis extract of Tetragonula biroi has the potential to be developed as a cosmetic agent; however, further work needs to be done to clarify its application.

Floral Biology and Pollination of Red Hot F1 Hybrid Hot Pepper (Capsicum frutescens x C. annuum) in the Philippines

The floral biology and pollination of Red Hot F1 variety hot pepper, Capsicum frutescens x C. annuum, were studied in this paper. Its flowers are herkogamous and inodorous, and the pollen and nectar serve as rewards to visitors. Anthesis occurred during morning, from 0600 h to 1000 h and peaked on the second day. The pollen grains are simple and numerous with high viability, 96 ± 1.06%. Receptivity of stigma synchronized with pollen viability. This hot pepper variety is partially protogynous. The asynchronous flowering, dichogamy, and herkogamy in hot pepper are their adaptive strategies to promote outcrossing and for reproductive assurance. Four insect species visited the flowers but only the carpenter bee, Xylocopa sp., and the stingless bee, Tetragonula biroi (Friese), are the true pollinators. The foraging activity, which peaked at 0900 h, synchronized with anthesis. Fruit set in an open-pollinated (87 ± 13.12%) and hand-pollinated plants (84 ± 19.37%) were significantly higher than in the control (26 ± 14.30%). Open-pollinated plants produced fruits and seeds with significantly higher quantity and quality.

Inhibitory Activity of Propolis from Philippine Stingless Bees (Tetragonula biroi Friese) against Select Microorganisms

The antimicrobial activity of the ethanol extract of propolis (EEP) from the stingless bee, Tetragonula biroi Friese, was screened for activity against Escherichia coli, Pseudomonas aeruginosa,Bacillus cereus,Candida krusei, Staphylococcus aureus, and Penicillium chrysogenum using the disk diffusion method and agar-well assay. The highest inhibitory activities of EEP was observed at 30% (w/v) against Bacillus cereus (12.78 ± 1.92 mm), followed by Staphylococcus aureus (10.22 ± 0.83 mm), Penicillium chrysogenum (13.33 ± 2.40 mm), and Candida krusei (6.00 ± 0.00 mm) compared to the other concentrations – 10% (v/v) and 20% (v/v) of EEP. The antimicrobial activity of 30% w/v EEP against P. chrysogenum and C. krusei was comparable to mycostatin at 13.67 ± 0.58 and 6.33 ± 0.58 mm, respectively. The EEP was found to have no effect on Escherichia coli and Pseudomonas aeruginosa. Considered as a natural product, propolis has the potential to be a substitute for synthetic antimicrobial compounds commonly used in commercial products such as soaps.

Radiation sterilization of Honey and Honey-Alginate Wound Dressing from Stingless Bee (Tetragonula biroi) Collected from Sta. Maria, Laguna, Philippines

This study was conducted to determine the effect of radiation sterilization on alginate wound dressing containing honey from the Philippine stingless bee, Tetragonula biroi. Our results show that a radiation dose of 30 kGy did not affect the antibacterial property of honey against Staphylococcus aureus. Electron-beam irradiation did not produce significant alterations in the physicochemical properties (pH, total soluble solids, and flavonoids); however, the total phenolics was significantly increased in honey with higher irradiation doses. Demonstrating that irradiation can be applied to honey with negligible physicochemical effects, honey was incorporated in alginate and exposed to a sterilization dose of 25 kGy using an electron beam facility. Irradiation did not affect the physicochemical properties (pH, moisture content, gel fraction, moisture vapor transmission rate (MVTR), and fluid handling capacity) of the honey alginate wound dressing (HAWD). The perspectives for the potential use of irradiated HAWD as a natural product-based substitute for commercial wound care products may be considered.