Abstract:
Tea is the second most consumed drink globally after water. Green tea is
the non-fermented form of tea prepared from the buds of Camellia senensis
plant. Green tea extract (GTE) and its isolated compounds epigallocatechin
gallate (EGCG), epicatechin gallate (ECG) and epigallocatechin (EGC) were
evaluated for their capacity to inhibit fowl adenovirus type 4 (FAdV-4) in-vitro
through plaque reduction assay, its virucidal effect and its cytotoxicity was
evaluated to normal cells through 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyl
tetrazoliumbromide (MTT) assay. In-vivo study was conducted in broiler chicks
to evaluate its protective efficacy against challenge of FAdV-4. Plaque reduction
assay GTE at dose rate of 100mg/ml was shown maximum inhibition of plaque
in-vitro followed by EGCG, EGC and ECG. In virus reduction assay, the test
compounds were added to infected cells and harvest the virus at 8, 24 and 36
hours of post infection. The harvested virus was subjected to plaque assay and
maximum inhibition in virus yield was observed at 100 mg/ml of GTE at 24
hours of post infection against FAdV-4 with (EC50) 34.80μg with a 50% CC50
109.23μg having SI 3.195 showed strong antiviral effects with minimum CC50
toward normal cells. Maximum cell inhibition was shown by EGCG, EGC, and
ECG at 120 μM and 180 μM and 200 μM respectively while GTE showed
minimum cell inhibition at different concentration.
In-vivo study, GTE was shown maximum protection in broiler chicks
against challenge which was shown survival rate of more than 90% at 100
mg/ml GTE. Gross and histopathological lesion score was minimum in GTE
treated group followed by EGCG, EGC and ECG. GTE was showed promising
antiviral activity against FAdV-4 in cell culture which was evaluated in in-vivo
and was a candidate agent to uaed in poultry for this virus infection.
