Polyphenolic compounds and flavonoids found in Triphala are thought to be responsible for many of its effects. Gallic acid, a major polyphenol, has antioxidant and immunomodulatory properties ^(11) (33).

In preclinical studies, Terminalia chebula, one of the components of Triphala, was shown to be a potent hyaluronidase and collagenase inhibitor that prevented degradation of cartilage ⁽⁷⁾. In addition, bromobenzen-induced nephrotoxic effects were attenuated via increased antioxidant enzyme activity ⁽²³⁾. Antiarthritic and anti-flammatory effects of Triphala are thought to be via NF-kBp65 and COX-2 inhibition ^(25) (26), whereas the anti-colitic effects are likely due to its antioxidant effects ⁽²²⁾.

Triphala also appears to stimulate neutrophil function and to decrease corticosterone levels in immunized rats exposed to noise stress ⁽³⁴⁾. In a small study of healthy human volunteers, Triphala increased cytotoxic T cells and natural killer cells ⁽³¹⁾. It also exerted radioprotective effects ⁽²¹⁾ by inhibiting oxidative damage. Triphala also increased reactive oxygen species (ROS) in MCF-7 and T-47D breast cancer cells resulting in apoptosis ⁽⁸⁾; afforded protection against X-radiation and bleomycin, both of which generate DNA strand breaks, in HeLa cells ⁽⁴²⁾; and protected mice from radiation-induced mortality ^(2) (3).

Despite its antibacterial properties, compounds in Triphala may promote the formation of oral bacterial biofilm via activation of glucosyl transferases ⁽³⁰⁾.