A comparative study of white, black and green tea solutions as potential antiviral agents in rhesus monkey kidney cells induced with porcine rotavirus

Tea extract;porcine rotavirus;monkey kidney cells;scavengers;polyphenols;antioxidants

Bailey, Shorma ; Nguyen ; Thanh H.

关键词: Tea extract;    porcine rotavirus;    monkey kidney cells;    scavengers;    polyphenols;    antioxidants;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/49601/Shorma_Bailey.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Rotavirus, in humans or animals, is an important global health issue; porcine rotavirus not only affects developing countries, but developed countries as well; this may be a result of the transport of porcine rotavirus through the environment, in addition to the lack of sanitary resources. This study seeks to compare and determine, the inhibition of Group A porcine rotavirus survival in African green monkey kidney cells (MA-104), in an aqueous environment, when exposed to three different concentrations of aqueous teas: White, Black, and Green. Characterization of White, Black and Green Teas were conducted before virus inhibition experiments. Total polyphenol content, of each tea, was determined using Folin-Ciocalteu Method, with Gallic Acid (GA) as a standard in milligram equivalents to GA per milliliter. Total polyphenols were highest in Green Tea, 4.50 ± 0.58 mg GA equivalent/mL. Black and White teas were lower in total polyphenol content with values 3.80 ± 0.22 mg GA equivalent/mL, and 2.60 ± 0.23 mg GA equivalent/mL, respectively.Antioxidant capacities were determined using the oxygen radical absorbance capacity (ORAC) assay. The values of antioxidant capacity for all teas ranged from (31.6 ± 0.71 to 46.8 ± 0.14 mM Trolox equivalents/ml); Green Tea had the highest antioxidant capacity when compared to other teas.Analysis of aqueous tea extract, using LC-MS, suggested the presence of polyphenols, and their range concentrations in tea, including: gallic acid (GA) (1.9 - 7.6 μg/mg SE), (+)-catechin (CT) (1.0 - 4.8 μg/mg SE), (-) epicatechin (EC) (4.3 - 16.5 μg/mg SE), (-)-epigallocatechin (EGC) (9.6 - 76.9 μg/mg SE), gallocatechin gallate (GCG) (15.1 - 43.6 μg/mg SE), and (-)-epigallocatechin gallate (EGCG) (48.6 - 151.0 μg/mg SE). EGCG was found to have the highest concentration in White, Black, and Green Tea solutions.Prior to inactivation experiments, toxicity of tea samples on MA-104 monkey kidney cells were tested. None of the tea concentrations tested, were found to be toxic to the kidney cells.White, Black, and Green Tea solutions with concentrations of 50, 500, 1000 μg SE/mL in water, were allowed to react with porcine rotavirus, and the inhibition of tea extract was quantified using the Focus Forming Unit Assay (FFU), which measured virus particles in FFU/mL. The removal of virus (log) for all concentrations of teas ranged from 1.02 ± 0.49 to 3.16 ± 0.66. All previously mentioned teas were able to inactivate porcine rotavirus. Furthermore, results suggested a statistical difference (P<0.05) amongst the teas. Green Tea, at 1000 μg SE/mL, recorded the highest log removal of virus. In conclusion, White, Black and Green Teas inhibited porcine rotavirus in MA-104 monkey kidney cells. Green Tea showed the highest values for total polyphenol content, antioxidant capacity and removal of porcine rotavirus. The various types of polyphenols and their presence in White, Black, and Green Teas may play a role in their antiviral activity, against rotavirus survival in aqueous environments. Further studies are needed to understand the mechanisms between tea extract, polyphenols, and their anti-viral capacity to inhibit porcine rotavirus.