Anti-adenovirus activity, antioxidant potential, and phenolic content of black tea (Camellia sinensis Kuntze) extract

Abstract

BackgroundAdenovirus (ADV) causes a number of diseases in human, and to date, no specific antiviral therapy is approved against this virus. Thus, searching for effective anti-ADV agents seems to be an urgent requirement. Many studies have shown that components derived from medicinal plants have antiviral activity. Therefore, the present study was aimed to evaluate in vitro anti-ADV activity and also antioxidant potential and total phenolic compounds of black tea (Camellia sinensis) crude extract. MethodsIn this study, the hydroalchoholic extract of black tea was prepared and its anti-ADV activity was evaluated on HEp2 cell line using MTT [3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide] assay. The 50 % inhibitory concentration (IC50) and 50 % cytotoxicity concentration (CC50) of the extract were determined using regression analysis. Its inhibitory effect on adsorption and/or post-adsorption stages of the virus replication cycle was evaluated. To determine antioxidant activity, total phenol content, and flavonoids content of the extract, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, Folin-Ciocalteu method, and aluminum chloride colorimetric method were used, respectively. ResultsThe CC50 and the IC50 of the extract were 165.95±12.7 and 6.62±1.4 µg/mL, respectively, with the selectivity index (SI) of 25.06. This extract inhibited ADV replication in post-adsorption stage. The IC50 of DPPH radical was 8±1.41 μg/mL, compared with butylated hydroxytoluene, with IC50 of 25.41±1.89 μg/mL. The total phenol and flavonoid contents of the extract were 341.8±4.41 mg gallic acid equivalent per gram and 21.1±2.11 mg/g, respectively. ConclusionsHaving SI value of 25.06 with inhibitory effect on ADV replication, particularly during the post-adsorption period, black tea extract could be considered as a potential anti-ADV agent. The antiviral activity of this extract could be attributed to its phenolic compounds.

Distinct variation in taste quality of Congou black tea during a single spring season

“…Determination of TP was accomplished using ferrous tartrate spectrophotometry (Turkmen et al, ). Determination of total flavones used the aluminum trichloride colorimetric method (Karimi, Moradi, Alidadi, & Hashemi, ). Determination of tea soluble sugar (SS) used the fluorenone colorimetric method (Xu, Liu, et al, ).…”

Anti-adenovirus activity, antioxidant potential, and phenolic content of dried flower buds of Syzygium aromaticum extract in HEp2 cell line

“…Total phenolic and flavonoid amounts of S. aromaticum extract was 255.8±3.95 mg GAE/g and 63.9±2.35 mg RUT/g respectively. Phenolic compounds have been shown to have antibacterial and anti-viral activities [34,[37][38][39][40]. S. aromaticum is one of the richest sources of phenolic compounds such as gallic acid, eugenol and eugenol acetate [41].…”

“…Virus stock was prepared with infection of confluent monolayer HEp2 cells in 75 cm 2 culture flasks by DMEM medium with 1.5% FBS, under 37°C in 5% CO 2 . Virus titer was calculated by cytopathic effect (CPE) of adenovirus in HEp2 cell and expressed as the 50% tissue culture infective dose (TCID 50 ) per 1 mL [34].…”

“…Cell viability was determined by the cells' ability to cleave the tetrazolium salt MTT [3-(4,5-dimethylthiazol-2-ol)-2,5-diphenyltetrazolium bromide)] (Sigma, USA), by mitochondrial enzyme succinate dehydrogenase which develops a formazan blue color product. The protocol described earlier was followed [30,34]. Briefly, the supernatants were removed from the wells and 50μL of an MTT (Sigma, USA) solution (1 mg/mL in PBS) was added to each well.…”

In vitro anti influenza virus activity, antioxidant potential and total phenolic content of twelve Iranian medicinal plants

“…Therefore, in order to identify the probable sources of herbal medicines several plants are being gathered and examined [6][7][8][9][10][11]. Besides, different screening experiments have been performed on these plants to isolate the agents with antiviral activity [12][13][14][15]. In some cases of these herbal medicines there has been a development into therapeutic agents and they have had promising outcomes.…”