The allopathic system of medicine that treats symptoms of diseases using drugs came into existence in the 19th century. Before that, traditional medicines were common in many Asian countries, including India. A common drawback of allopathic medications is their undesired side effects caused by the adverse reactions of specific drug compounds with parts of our body. This has now rekindled interests among scientists in many traditional forms of medicine which are known to have no side effects. In one such study, researchers from the Manipal Institute of Technology, Manipal, Karnataka, and Anna University, Chennai, have evaluated the anti-cancer properties of Pattu Karuppu, a traditional Siddha medicine.

The Siddha system of medicine has its origin in Tamil Nadu and is similar to Ayurveda where extracts of different plants are used to treat various diseases. Pattu Karuppu is a mercury-based Siddha medicine prepared by the combination of acidic and alkaline substances and is rich in mercuric sulphide (HgS). While mercury is well-known for its curative effects, sulphur neutralises the toxicity of the medicine and makes it more effective.

While Pattu Karuppu is used to treat pain during menstruation (dysmenorrhoea), the absence of menstrual cycle (amenorrhoea) and delirium, its anticancer properties have not yet been explored. In this study, for the first time, the researchers look into the physical and chemical properties of this formulation and evaluate its effects on healthy cells.

The researchers examined a sample of Pattu Karuppu under an electron microscope and found that it contains nanoparticles with an average size of 20-80 nanometers. These come together and form a ‘broccoli-like’ structure. A chemical analysis of the compound showed that it mainly contains carbon and oxygen, with traces of mercury, arsenic and sulphur. “The sample was found to have stable and spherical (porous) particles with size ranges between 20-80 nanometres. The negatively charged, nanosize and relatively high surface area of the particles were used to evaluate its biological action”, say the authors.

The researchers then tested different concentrations of the formulation on cell lines in labs. They observed that the formulation could inhibit the growth of cancerous cells. To determine the ‘safe’ concentrations of Pattu Karuppu,  they tested it on zebrafish. They observed that at high concentrations, the zebrafish developed problems with the rate of heartbeat (arrhythmias) and clotting of the blood cells in the heart. The results confirmed that a concentration of 100μg/ml was the safest, a finding that differentiates Pattu Karuppu from other toxic mercurials.

The study promises new hope for cancer patients whose life is bogged down by the side effects of radiation therapy and chemotherapy. As a next step, the authors plan to conduct similar studies on mouse models that could pave the way for effective anticancer drugs.