Theaflavin 3,3'-digallate (8-Gingerol) , a major polyphenol found in black tea, is an inducer of oxidative stress which has anti-inflammatory and cancer chemopreventive actions, it reduces tumor angiogenesis by downregulating HIF-1αand VEGF.

8-Gingerol has antioxidant activity, inhibiting the formation of superoxide radicals, singlet oxygen, hydrogen peroxide, and hydroxyl radicals in vitro (IC50s = 26.7, 0.83, 0.39, and 25.07 μmol/L, respectively) [1].

In vivo, 8-Gingerol reduces serum levels of TNF-α, IL-1β, and IL-6 and decreases pulmonary edema, pulmonary congestion, and thickening of the alveolar wall in a mouse model of LPS-induced acute lung injury. It also inhibits osteoclast formation, polarization, and osteoclastic bone resorption in vitro and reduces titanium particle-induced bone erosion and the number of mature osteoclasts in mice in a dose-dependent manner [3].