Plant that kills cancer cells – too good to be true?

An Indian plant, used for centuries to dampen inflammation and fever, has shown significant potential in killing cancer cells. This new study was performed at the Georgia Regents University Cancer Centre and published as the Journal of Biological Chemistry‘s Paper of the Week. The work has particular implications for hormone-dependent cancers affecting tissues such as breast, prostate and endometrium.

During the typical progression of cancer, cancerous cells evade normal apoptotic (cell death) mechanisms by ‘tricking’ chaperone proteins, which usually guide normal protein folding function. The chaperone heat shock protein 90 (Hsp90) plays a key role in aiding mutated proteins (present in cancer cells) to fold; this means that it is an attractive target for potential cancer drugs. However current experimental Hsp90 inhibitors yield disappointing clinical results.

A graduate student involved in the study, Chaitanya Patwardhan, was responsible for finding that a plant component called gedunin attacks a co-chaperone of Hsp90, called p23. The lead author of the paper, Dr Ahmed Chadli, explains as follows that “this compound (gedunin) binds directly to p23, leading to inactivation of the Hsp90 machine — without production of anti-apoptotic proteins — thus killing cancer cells.”

Gedunin is a plant compound derived from the Indian Neem tree, which has been used for many years due to its potent anti-malarial effects. In recent years the Neem tree has been dubbed ‘the wonder of the tropics’. Dr Samir Khleif is the director of the GRU Cancer Centre and states that  “this finding is an important piece of the puzzle, bringing us closer to our goal of helping patients with cancer.” The work is an elegant example of how scientists can harness old, naturally-derived remedies to work at the molecular level, with implications for patients worldwide.