Antioxidant and antimicrobial studies on white mulberry (morus alba) and black mulberry (Morus nigra) leaves

In recent years, antioxidants attracted great interests due to their role about food and human metabolism. In 1954 use of 3,5-di-tert-4-butyl hydroxytoluene (BHT) and tert-butyl hydroquinone (TBHQ) was started to extend foods? expiry date. But use of these synthetic antioxidants causes great concern because of their potantial cancerogenic effects. Therefore there is an increase for the use of natural antioxidants instead of these synthetic variants.In this work antioxidant and antimicrobial activities of extracts obtained from White Mulberry (Morus alba) and Black Mulberry (Morus nigra) leaves extracted by using different various solvents studied. n-hexane, etil acetate, methanol and water were used in the given sequence and continuous extraction procedure was applied. The antioxidant activity was determined by four differrent test systems: ß-Carotene-linoleic acid, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, reducing power and metal chelation capacity). Total fenolic and flavonoid compounds amount was also determined.A maximum antioxidant was determined activity in water extracts of both species. The antioxidant activity of Morus alba and Morus nigra leaves are given respectively: ß-Carotene/linoleic acid %94,77-93,38 DPPH radical scavenging activity %74,34-78,25 reducing power 0,422-0,482 (?max 700nm) metal chelation capacity %89,90-92,7311 species bacteria and 1 microfungi were used in this work. They are: Escherichia coli, Staphylococcus aureus, Proteus vulgaris, Bacillus subtilis, Bacillus cereus, Enterobacter aerogenes, Sarcina lutea, Salmonella typhimurium, Enterococcus faecalis, Enterobacter cloacae, Staphylococcus epidermidis and micro fungi Candida albicans. Only methanol extracts showed antimicrobial activity. These extracts were also used to determine Minimum Inhibition Concentration (MIC). According to MIC results methanol extract of Morus alba has showed maximum inhibition against Staphylococcus epidermidis bacteria (0,625 mg/mL).