Novel Research in Microbiology Journal (2019), 3(6): 485-492 (Print) (ISSN 2537-0286) Review Article (Online) (ISSN 2537-0294) www.nrmj.journals.ekb.eg DOI: 10.21608/nrmj.2019.66740 Antimicrobial and antioxidant activities of Tea plant Zakaria Ahmed1 1Microbiology Department, Technology Wing, Bangladesh Jute Research Institute, Dhaka 1207, Bangladesh *Corresponding author E-mail: [email protected] Received: 29 November, 2019; Accepted: 14 December, 2019; Published online: 28 December, 2019 Abstract Many complementary and alternative medicines have enjoyed increased popularity in recent decades. Efforts to validate their use have seen their putative therapeutic properties, which come under increasing scrutiny in vitro and in some cases in vivo. One of such products is tea and its tree oil (TTO); which is a secondary metabolite derived from tea plant (Melaleuca alternifolia). Both black and green tea has several polyphenolic compounds with possible antibacterial effects. It is employed largely due to its antimicrobial properties, and is incorporated as the active ingredient in many topical formulations used to treat cutaneous infections, in addition to being marketed as a remedy for various ailments. The essential oil of M. alternifolia exhibits broad-spectrum antimicrobial potential. The TTO may help to treat severe yeast infections. Results also suggested that TTO exerts a greater bactericidal potency against biofilm-grown methicillin-resistant Staphylococcus aureus (MRSA), and methicillin-sensitive Staph. aureus (MSSA) strains. Moreover, tea has inhibitory efficacy against the carcinogenic bacteria. Keywords: Tea, Tea tree oil, Antimicrobial, Antioxidant activity 1. Introduction Plant materials are widely used in developed consumed beverage in the world next to water. In a and developing countries as home remedies, over the recent study, Reygaert, (2017) reported that tea counter drug products and raw materials of the belongs to the family Theaceae, and is a product pharmaceutical industry. They represent a made by processing the leaves or buds. All tea substantial proportion of the global drug market varieties such as, green, oolong and black tea, are (Kunle et al., 2012). Many complementary and harvested from this species. Tea extracts work as alternative medicines have increased their popularity effective treatments for patients who suffer from in recent decades (Kyungseop, 2017). According to damaged skin following radiation treatment for previous studies of Martins, (2013); Napatt et al., cancer. Several previous studies of Priyanka et al., (2019), tea (Camellia sinensis) is the second most (2012); Ohishi et al., (2016); Arina et al., (2017) 485 Novel Research in Microbiology Journal, 2019 Ahmed, 2019 revealed that this might partly be due to the anti- Several years before, Chen et al., (2005) inflammatory properties of tea. Moreover, Arina et discovered that extracts of Puer and black teas were al., (2017) added that tea acts at the cellular level by effective inhibitors of the virus protein-destroying inhibiting the inflammatory pathways, and lowering enzyme (called 3CLPro), responsible for Severe the release of pro-inflammatory cytokines including; Acute Respiratory Syndrome (SARS). In addition, IL-1beta, IL-6, IL-8, TNF alpha, PGE2, and white they identified three compounds found in fully blood cells in human cell lines. Green tea extract had fermented teas mainly; tannic acid, theaflavin-3’- been shown to be potent in neuro-protectant (Orly et gallate and theaflavin-3,3’-digallate, acting as al., 2009). A study conducted by Qin et al., (2012) effective 3CLPro inhibitors. In another study, Kuo et suggested that the intracellular amyloid beta (iAβ)- al., (2005) reported that Puer and oolong induced toxicity was significantly inhibited by green significantly lowered the triglyceride levels, whereas tea polyphenols in cultured rat primary cortical green and black did not. Previously, Zhao et al., neurons. Previous studies of Li et al., (2007); Qin et (2002); Blanco et al., (2005) reported that the al., (2012) reported that the intracellular iAβ toxicity properties of green tea inhibit the bacterial growth, is related to the development of Alzheimer’s disease. which are mainly related to their polyphenolic In another study of Cong et al., (2016), it was components including; epicatechin, epicatechin explored that green tea polyphenols inhibit gallate, epigallocatechin, and epigallocatechin glutamate-induced neurotoxicity which is linked to gallate, against various Gram-positive and Gram- neurodegenerative diseases. negative bacteria. Moreover, Zhao et al., (2002); Hu et al., (2002); Stapleton et al., (2004); Cho et al., 2. The effects and mechanism of action of tea (2008) added that green tea have a synergistic effect with β-lactam antibiotics against Methicillin- Tea contains several naturally occurring dietary resistant Staphylococcus aureus (MRSA). In a polyphenols such as catechins, which possess anti- previous study, Zhao et al., (2001) revealed that the carcinogenic activity that act as effective chemo- main components of tea as polyphenols, preventive agents against the initiation, promotion epigallocatechin gallate, can reverse the methicillin and progression stages of multistage carcinogenesis. resistance of MRSA by inhibiting the synthesis of Usually, all the four types of tea could lower the Penicillin-binding Protein-2 (PBP2), and may also total cholesterol levels (Aleksandra et al., 2016). prevent adhesion to the mammalian epithelial cells Black tea has only about one-sixth of the antioxidant (HEp-2) without any probable alteration (Janecki power of green tea, owing mainly to the former’s and Kolodziej, 2010; Sharma et al., 2012). It has low levels of catechins (Anton and Sheila, 2003). On been proposed by Lee et al., (2009) that green tea the other hand, Duh et al., (2004) reported that leaves extract can prevent the attachment of although the polyphenolic compositions of all the pathogenic bacteria on the host cell membrane, four types of tea were dramatically different, they which in turn acts as a potential anti-adhesive agent. have nearly identical levels of antioxidant potential. Chung et al., (2003) previously documented that Agnieszka and Wilfried, (2014) suggested that the green tea extract may affect the activity of strong antioxidant catechins in green tea are dihydrofolate reductase, an enzyme that is needed by destroyed by the fermentation reactions, leading to the pathogenic bacteria to synthesize purine and oolong, black and Puer teas. Previously Jie et al., pyrimidine, as well as to increase the thickness of (2006) revealed that there is a compensatory gain in the epidermis. the antioxidant activity of tea due to the new compounds produced. 3. The tea tree oil (TTO) 486 Novel Research in Microbiology Journal, 2019 Ahmed, 2019 Recently, TTO has gained a good reputation as a removing bacteria from the surface of the hand. safe, natural and effective antiseptic, and is Aaron et al., (2006) studied the in vitro antibacterial employed significantly due to its antimicrobial activity of TTO against clinical skin isolates of properties. During the study of Carson et al., (2006), methicillin-resistant S. aureus (MRSA), methicillin it was reported that TTO is incorporated as the sensitive S. aureus (MSSA), and coagulase-negative active ingredient in many topical formulations used Staphylococci (CoNS) growing as biofilms, and to treat cutaneous infections. The chemical concluded that TTO exerted a greater bactericidal composition of TTO has been well defined, and it potential against the biofilm-growing MRSA and consists largely of cyclic monoterpenes of which MSSA isolates, than against some of the biofilm- about 50% are oxygenated, whereas the other 50% growing CoNS isolates. are hydrocarbons (Cox et al., 2000; Carson et al., 2006). TTO exhibits a broad-spectrum of 3.1. The antibacterial activity of TTO antimicrobial activity which can be primarily Banes-Marshall et al., (2001) reported that TTO attributed to the presence of terpinen-4-ol. is bactericidal in nature, although it may be Previously, Cox et al., (2000) observed that the bacteriostatic at lower concentrations. The activity essential oil of M. alternifolia exhibited broad- of TTO against antibiotic-resistant bacteria has spectrum antimicrobial activity, while TTO caused attracted considerable interest, especially with leakage of K ion in Escherichia coli, Staphylococcus methicillin-resistant S. aureus (MRSA) receiving the aureus and Candida albicans. Moreover, it has the most attention so far. In a previous study, Inouye et ability to disrupt the permeability barrier of the cell al., (2001) reported that vaporized TTO can inhibit membrane structures leading to the loss of several bacteria spp. including; Mycobacterium chemiosmotic control, which is the most likely cause avium ATCC 4676, E. coli, Haemophilus influenzae, of its lethal action at minimum inhibitory levels. Streptococcus pyogenes, and S. pneumoniae. Hammer et al., (2000) stated that germ tube Treatment of S. aureus with TTO resulted in the formation (GTF) by C. albicans is affected by the leakage of K ions (Cox et al., 2000; Hada et al., presence of and\ or the pre-exposure to sub- 2003), and inhibited its respiration (Cox et al., inhibitory concentrations of TTO. In addition, TTO 2000). Reichling et al., (2002) stated that treatment has been suggested by Hammer et al., (2000); (2003) with TTO sensitized S. aureus cells to sodium as a potential agent for MRSA decolonization.