The aim of the present study was to examine the antioxidant and antibacterial activity of 21 types of honey derived from Mount Olympus (Mt. Olympus), a region with great plant biodiversity. The antibacterial activity was examined against the growth of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) by the agar well diffusion assay and the determination of the minimum inhibitory concentration (MIC). The antioxidant activity was assessed by using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS•+) free radical scavenging assays. These activities were compared to Manuka honey which is used as an alternative medicine. The results revealed that all tested honey types exhibited antibacterial activity against S. aureus and P. aeruginosa. The MIC of the tested honey types against S. aureus ranged from 3.125 to 12.5% (v/v), while MIC of Manuka honey was determined to be 6.25% (v/v). The MIC values of the tested honey types against P. aeruginosa ranged from 6.25 to 12.5% (v/v) and the MIC of Manuka honey was determined at 12.5% (v/v). Moreover, the results suggested that the presence of hydrogen peroxide and proteinaceous compounds in the honey types accounted, at least in part, for the antibacterial activity. In addition, the total polyphenolic content (TPC) of the honey types seemed to contribute to the antibacterial activity against P. aeruginosa. Furthermore, some of the tested honey types exhibited potent free radical scavenging activity against DPPH and ABTS•+ radicals, which was greater than that of Manuka honey. The results indicated that not only the quantity, but also the quality of the polyphenols were responsible for the antioxidant activity. Moreover, four honey types exhibiting great antioxidant activity were converted to powder using a freeze drying method. The results indicated that following conversion to powder all honey types, apart from one, retained their antioxidant activity, although their TPC was reduced. On the whole, and at least to the best of our knowledge, the present study is the first that extensively examined the bioactivities of different types of honey derived from Mt. Olympus.
Grape pomace is a by-product of winemaking process and rich in bioactive compounds such as plant polyphenols having antioxidant and antimicrobial activities. As known, oxidative stress may cause a number of pathological conditions in farm animals and thus affecting animal welfare and production. Moreover, pathogenic bacteria affect animals' health status. Thus, the objective of this study was to investigate whether lambs' feed supplemented with grape pomace enhances the antioxidant mechanisms and reduces the growth of pathogenic bacteria. For this purpose, redox status was assessed in blood and tissues using oxidative stress markers in lambs fed with diet supplemented with grape pomace. Moreover, the effect on bacterial growth was assessed by examining microbial populations in lambs' faecal microflora. The following oxidative stress markers were assessed: reduced glutathione (GSH), catalase activity (CAT), total antioxidant capacity (TAC), thiobarbituric acid-reactive substances (TBARS) and protein carbonyls (CARB). Twenty-four lambs were assigned to two experimental groups receiving standard or experimental diet for 55 days. Blood and tissues (liver, quadriceps muscle, spleen, heart and brain) were collected at two different time-points, 42 and 70 days post-birth, after ration administration. The results showed that lambs fed with experimental diet had significantly increased antioxidants mechanisms in blood and tissues as shown by increases in CAT and GSH compared to control. Moreover, lambs fed with the experimental diet exhibited decreased oxidative stress-induced damage to lipids and proteins as shown by decreases in TBARS and CARB respectively. In addition, the experimental diet enhanced the growth of facultative probiotic bacteria and inhibited the growth of pathogen populations such as Enterobacteriacae and E. coli. This is the first study investigating the effect of diet supplemented with grape pomace on the redox status and microbiota of lambs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.