A compound found in green tea may help combat the joint pain, inflammation and tissue damage caused by rheumatoid arthritis, researchers, including those from India, have claimed.

Rheumatoid arthritis is a debilitating autoimmune disorder that mostly affects the small joints of the hands and feet. It causes painful swelling that progresses into cartilage damage, bone erosion and joint deformity.

"Existing drugs for rheumatoid arthritis are expensive, immunosuppressive and sometimes unsuitable for long-term use," said Salah-uddin Ahmed,lead researcher on the project from Washington State University (WSU) in Spokane.

His team evaluated a phytochemical called epigallocatechin-3-gallate (EGCG), which is a molecule with anti-inflammatory properties found in green tea.

The study suggests that EGCG has high potential as a treatment for rheumatoid arthritis because of how effectively the molecule blocks the effects of the disease without blocking other cellular functions.

"This study has opened the field of research into using EGCG for targeting TAK1 - an important signalling protein - through which proinflammatory cytokines transmit their signals to cause inflammation and tissue destruction in rheumatoid arthritis," said Ahmed.

The researchers, including Anil Singh and Sadiq Umar from WSU, confirmed their findings in a pre-clinical animal model of human rheumatoid arthritis, where they observed that ankle swelling in animals given EGCG in a 10-day treatment plan was markedly reduced.

The team joined researchers from the National Institute of Pharmaceutical Education and Research in Bihar for this project.

The research was published in the journal Arthritis and Rheumatology.