The leaves, pods and extracts of the senna herb from the arid regions of Tuticorin and Virudhunagar in southern Tamil Nadu are sitting on shelves of stores in Hong Kong, Tokyo, California and Berlin. “Senna tea bags are a big hit abroad. And the market is set to grow further," says B S Sajwan, chief executive officer of the Union health ministry's national medicinal plants board. In 2007, over 20,000 metric tonnes of senna was exported from Tamil Nadu for $1 to $1.5 a kg. In the global market, it is sold for $3 per kg.
“The sennocide content in senna tea is believed to have potential to remove the toxins in the body and help complete the metabolic cycle resulting in weight control," says Ranjit Puranik, general secretary of the Ayurvedic drug manufacturers' association.
Tamil Nadu's connection with the world pharmaceutical industry began over a century ago, courtesy senna. It is also called 'avuri' or 'nilavagarai' locally. Senna is grown in the dry fields close to Tirunelveli, and came to be known as 'Tinneveli senna'. It is the second largest herb to be exported after Isabgol, largely grown in Gujarat.
With senna exports from Tamil Nadu soaring beyond Rs 50 crore, Rajasthan and Gujarat have also begun to grow the herb.