Antioxidant, Anticancer, Antibacterial, Antibiofilm Properties and Gas Chromatography and Mass Spectrometry Analysis of Manuka Honey: A Nature's Bioactive Honey  
[PERSON]  
1 Department of Medical Laboratory Science, College of Applied Medical Sciences, University of Ha'il,  
Hail 55476, Saudi Arabia 1,1 [EMAIL_ADDRESS]  
[PERSON]  
2 Department of Pharmacology and Toxicology, College of Pharmacy, University of Ha'il,  
Hail 55211, Saudi Arabia 2,2 [EMAIL_ADDRESS]  
[PERSON]  
3 Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, King Abdulalaziz University,  
Jeddah 22254, Saudi Arabia 3,4 ab  
antioxidant [7; 8], antibacterial [9] and antidiabetic [10] activities of honey. Honey has the properties of naturally sweetening food materials. This fluid of a chemically diverse nature is a by-product of ambrosia extracts from flowers. The existence of organic acids, phenolic acid enzymes, bioactive peptides and organic acids in honey contributes to a pronounced capacity in honey to cure and treat diseases of various etiologies [11]. Manuka honey (MH), compared to other honeys, constitutes a higher number of polyphenolic compounds and an even higher antioxidant capacity [12].  
MH is native of New Zealand or Australia, a work of pollinator bundle bees extracting the juices of Manuka myrtle (_Leptospermum scoparium_) [12]. It exerts strong bactericidal and bacteriostatic effects [13; 14] thanks to its composition of polyphenols, such as flavonoids and benzoic acids; of note here are cinnamic acid and methylglyoxal (MGO) [12]. MGO is found in other kinds of honey in very minute quantities. However, the concentration of MGO in MH may reach up to 800 mg/kg, whereas the level of MGO is comparatively low in other commercially available honeys, ranging from 100 to 550 mg/kg, giving the fact that the quantity of the MGO is a determinant of a honey's antibacterial properties. MGO potentially inhibits _Bacillus subtilis_ and _Staphylococcus aureus_. Even after neutralization of MGO, the bactericidal properties of MH remain effective as it contains other components that are not well elucidated yet, which would prevent the growth of pathogenic bacteria [15] that are associated with a wide range of infections, including _Pseudomonas aeruginosa_ and _Escherichia coli_[16; 17]. Therefore, the current understanding behind the key function of MH is directed toward possessing a high quantity of a mixture of compounds including fructose, glucose, sucrose, hydrogen peroxide, MGO, bee-defensin-1 peptide, as well as the acidity and certain other undiscovered substances [15; 18; 19]. A recently identified glycoside in MH known previously as methyl syringae (MSYR), and now named as Leptosin, is also found to contribute to the antimicrobial activity in a concentration-dependent manner and may serve as a specific marker of MH [20].  
Despite all previous efforts to define the chemical components associated with the biological activities of MH, there are limited reports describing its metabolites that are linked with its broad spectrum of antimicrobial activities. Consequently, current study aims to explore and validate the chemical composition along with different biological activities including antimicrobial, antibiofilm and anticancer of MH using an array of chemical and biological assays.