# Applicability of Honey on Silkworms (_Bombyx mori_) and Quality Improvement of Its Biomaterials
## 3 The Impact of Honey on Silk Fibroin-Based Biomaterials  
### Honey as a Medicine  
Antibacterial Activity  
Of the broad-spectrum of extraordinary therapeutic characteristics of honey, the most outstanding beneficial property, but also the most investigated one, is the antibacterial activity. Even though the revolutionary discovery of antibiotics decreased interest in honey in terms of medical use [44; 45], nowadays, due to the high resistance of countless bacterial strains to antibiotics, this remarkable natural product has gained much more attention in the scientific community [46]. In the literature, there are mentioned several factors that are relevant to honey's strong bactericidal activity [47]. An important characteristic of honey is that it possesses a low water content [48]. This aspect exhibits great importance due to the fact that in order to grow, microorganisms require water. However, there are several strains of bacteria that are able to grow despite the reduced quantity of water. For instance, _Staphylococcus aureus_ (_S. aureus_) possesses this capacity, but it has been also shown that by using honey, the bacteria's growth is inhibited [49]. In addition, [PERSON] et al. successfully demonstrated the bacteriostatic and bactericidal effect of honey on _S. aureus_ methicillin-resistant strains. This finding suggests that not only the low water content is responsible for honey's inhibitory activity [46]. Being the majority constituents in honey, the high amounts of sugars have a key role in fulfilling the antibacterial activity by dehydrating bacterial cells through the process of osmosis. However, by using honey in order to combat wound infections, the antibacterial activity is reduced due to the fact that when it comes to the human body, there are body fluids that dilute the honey [50; 51]. There are small quantities of organic acids in honey's composition, and these elements are important players for honey's acidic pH [52]. Having a pH between 3.2 and 4.5 [53], honey is not an appropriate medium for bacterial growth since most strains need, for optimal growth, a pH between 6.5 and 7.5 [50]. The main organic acid that is responsible for honey's acidity is gluconic acid. By analyzing different types of honey, [PERSON] et al. observed that the highest concentration of gluconic acid is found in raspberry honey. The concentration of gluconic acid, thus the pH of the honey, is influenced by its botanical source [54]. One of the major elements that exhibits inhibitory activity against bacterial growth and proliferation is hydrogen peroxide (H\({}_{2}\)O\({}_{2}\)). In order for H\({}_{2}\)O\({}_{2}\) to be produced, the presence of glucose oxidase (GOx) is required [55; 56; 57; 58], but in view of honey's low pH range, the enzyme is inactive until the honey is diluted. There are several scenarios that could negatively influence the level of H\({}_{2}\)O\({}_{2}\) in honey. For instance, by exposing to heat, the GOx could be inactivated, but also, a catalase enzyme present in the pollen could deteriorate the H\({}_{2}\)O\({}_{2}\). Additionally, as it was expected, the level of GOx influences the H\({}_{2}\)O\({}_{2}\)[59]. Another study also highlighted the strong connection between the presence of H\({}_{2}\)O\({}_{2}\) and the strong antibacterial activity of honey, evidencing at the same time that there are some exceptions that exhibit strong bactericidal activity but have low levels of H\({}_{2}\)O\({}_{2}\)[60]. It was shown that honeydew honey possesses a very high level of H\({}_{2}\)O\({}_{2}\) in addition to a great amount of polyphenols [61; 62]. [PERSON] et al. illustrated that the polyphenols that are found in honey interact with the H\({}_{2}\)O\({}_{2}\). They showed not only that these interactions lead to a high antibacterial activity, but that they are the key elements responsible for the bacteriatic and bactericidal properties of honeydew honey [63].