# A Comprehensive Review of Stingless Bee Products:
## 2 Stingless Bee Honey
### Antimicrobial  
It was reported that the stingless bees have been inhabiting Earth longer than European honeybees, since 65 million years ago, and their honey has higher antimicrobial activity [47]. Despite honey being produced globally, the composition and antimicrobial activity could still be variable due the difference in botanical origin and geographical and entomological sources [48] Some of the factors that have been reported to affect the antimicrobial activities of honey are phytochemicals, acidity, high osmolarity, and the presence of hydrogen peroxide [49]. Table 3 summarises the antimicrobial activity of various stingless bee honey samples from Malaysia, Thailand, the Western Amazon, Mexico, Trinidad and Tobago, Costa Rica, Brazil, and India. The antibacterial properties of honey have been acknowledged in traditional medicine for many years, with the healing properties attributed to the chemical composition, including the presence of hydrogen peroxide and other non-peroxide factors. Some of the non-peroxide elements that affect the antibacterial activities are phenolic compounds and flavonoids [30]. However, as for hydrogen peroxide, it is influenced by glucose oxide and catalase, which are enzymes in honey. The function of glucose oxide is to induce the production of hydrogen, whereas the catalase function is to destroy hydrogen peroxide. Thus, both of these enzymes preserve the nutritional content of honey [50]. On the other hand, a study by [PERSON] et al. [35] reported that besides osmotic properties and hydrogen peroxide, the antimicrobial activity of stingless bee honey might also be influenced by polyphenol content and low pH. This agrees with [PERSON] et al. [51] and [PERSON] et al. [52], who stated that it has been presumed that the antibacterial property of honey is affected by osmolarity, pH, phenolic compounds, and many other elements. Not all types of honey possess the same level of antibacterial activity, as it is mostly influenced by several factors such as botanical origin and the source of nectar [25]. It has been proven that stingless bee honey has the potential to inhibit bacteria [8; 18; 25; 53; 54; 55; 56; 57; 58]. Researchers [PERSON] et al. [58] stated that honey produced by _Heterotrigona itama_ showed greater inhibition of _P. aeruginosa_ compared to commercial antibiotics, indicating better antibacterial activity against pathogenic bacteria. A report showed that phenolic compounds such as coumaric acid, ferulic acid, salicylic acid, and gallic acid found in stingless bee honey could contribute to antifungal activity that prevents anthracose disease on papaya caused by _Colletotrichum brevisporum_[59]. Next, a study on three stingless bees, namely, _Geniotrigona thoracica_, _Heterotrigona itama_, and _Heterotrigona erythrogastra_, reported that all three stingless bee honeys had antifungal activity against _Alternaria brassicae_[30]. A study of the antifungal activity of stingless bee honey by [PERSON] et al. [60] reported that honey produced by _Melipona becheti_ was able to inhibit growth of _Candida albicans_. According to the author, flavonoids present in the honey helped inhibit the fungus and the origin of the nectar and pollen collected by the stingless bee, which when added to components in the digestive tract of the bees may boost antifungal activity. A study of the antifungal effect of three local Malaysian honey samples by [PERSON] et al. [61] demonstrated that stingless bee honey has the best antifungal activity compared to _Tualang_ and _Acacia_ honey against _Candida albicans_ and _Aspergillus niger_. The author stated that the stingless honey used for total growth inhibition of the fungus can be as low as 10% (\(v/v\)) concentration. [PERSON] et al. [62] investigated the biosynthesis of calcium oxide nanoparticles mixed with stingless bee honey, which was named CaO Nps. The study tested the antifungal activity of CaO Nps using in vivo and in vitro assays against _Colletotrichum brevisporum_.