Antibacterial activity of watery and ethanolic extracts of Black Tea and peppermint (In vitrostudy)

Background:The most important medical challenge is the emergence of bacterial resistant to traditional antibiotics. So the need for new pharmaceutical compound derived from daily intake plant material. Mint and black tea used extensively in Arabic area as hot or cold drink Objective: investigate the bacterial activity of mint and black tea aqueous extract against many bacterial genera. Material and methods: from the local market of Baghdad Province, Iraq, dry black tea was obtained; while, peppermint (Mentha piperita L) was harvested from Iraqi plants during April 2020. Active ingredients extracted using either ethanol or water and their antibacterial activity evaluated against Staphylococcus aureus, S.epidermidis, Citrobacter sp and Klebsiella sp using well diffusion agar under invitro laboratory condition.  Results: Dried powder of each extract appeared with different color range from brown to black. Results recognized that S. aureus was susceptible to watery and ethanolic extract of both black tea and peppermint extracts. While, S. epidermidis showed resist to both plant extract and solvents used in extraction except minor inhibition with ethanolic extract of tea at 0.3% dose dose. Citrobacter spp gave susceptibility to watery extract of black tea as well as, watery and ethanolic of mint extract. Otherwise, Klebsiella spp. Growth inhibited by watery extract of black tea while, no bioactivity existed upon mint extract treatment. Conclusion: Dose dependent manner existed for watery and ethanolic extracts for both plant material in their antibacterial activity.