Validation of antioxidant, antiproliferative, and in vitro anti‐rheumatoid arthritis activities of epigallo‐catechin‐rich bioactive fraction from Camellia sinensis var. assamica , Assam variety white tea, and its comparative evaluation with green tea fraction

The epigallocatechin-rich polyphenolic fraction of Assam variety white tea, traditionally used for the management of diverse inflammatory ailments and health drink, was investigated through eco-friendly green aqueous extraction, TLC, and HPLC characterization, phytochemical screening, in vitro DPPH assay, anti-proteinase, MTT assay on synovial fibroblast and colon cancer cells, apoptotic FACS analysis, cytokine ELISA, p-STAT3 western blotting, and in silico docking analysis. HPLC-TLC standardized white tea fraction (WT-F) rendered higher extractive-yield (21%, w/w), than green tea fraction(GT-F) (12%, w/w). WT-F containing flavonoids and non-hydrolysable polyphenols showed better antioxidant activity, rather than equivalent GT-F. WT-F demonstrated remarkable anti-rheumatoid-arthritis activity via killing of synovial fibroblast cells (66.1%), downregulation of TNF-α (93.33%), IL-6 (87.97%), and p-STAT3 inhibition (77.75%). Furthermore, WT-F demonstrated better anti-proliferative activity against colon cancer cells (HCT-116). Collectively, our study revealed that the white tea fraction has boundless potential as anti-rheumatoid arthritis and anti-proliferative agent coupled with apoptotic, antioxidant anti-proteinase, and anti-inflammatory properties. PRACTICAL APPLICATIONS: Our eco-friendly extracted bioactive aqueous fraction of white tea, characterized by TLC-HPLC study and phytochemical screening have demonstrated remarkable anti-rheumatoid arthritis property and anti-proliferative action on colon cancer cells including potential anti-oxidant, anti-inflammatory, and anti-proteinase efficacy. The test WT-F sample has shown impressive safety on normal mammalian cells. WT-F has demonstrated better efficacy against rheumatoid arthritis and cancer model compared to equivalent green tea fraction. Traditionally, it is extensively used for boosting immunity, and energy, with cosmetic, and agricultural applications by the native inhabitants. So, the aqueous fraction of WT is suggested to be used as a prophylactic nutraceutical supplement and or therapeutic agent in commercial polyherbal formulation to attenuate and management of auto-inflammatory rheumatoid arthritis and carcinogenesis of colon. It is additionally suggested to establish in vivo rheumatoid arthritis animal and clinical study to validate their pharmacokinetic stability and dose optimization coupled with anti-inflammatory, cytotoxicity, and anti-oxidant property.