New Delhi: In a breakthrough move that can help in the fight against dengue, a herbal medicine against it is claimed to have been developed by scientists in India, which accounts for 50 per cent of the global population estimated to be at risk from the disease.
Experts are now gearing up for the next step, which is to hold clinical trials and toxicity studies before seeking permission from the Ministry of Ayush and the Drug Controller of India (DCI) for commercial production.
The project was undertaken jointly by the Department of Biotechnology (DBT), under the Ministry of Science and Technology, the International Centre for Genetic Engineering and Biotechnology and Ranbaxy Research Laboratory (now owned by Sun Pharma), and employed Ayurveda in devising the drug.
"Using the knowledge of traditional Indian medicine – Ayurveda – we developed a systematic bioassay-guided screening approach to explore the indigenous herbal bio-resource to identify plants with pan-DENV (dengue virus) inhibitory activity.
"Results showed that the alcoholic extract of Cissampelos pariera Linn (Cipa extract) was a potent inhibitor of all four DENVs in cell-based assays, assessed in terms of viral NS1 antigen secretion using ELISA, as well as viral replication, based on plaque assays. Virus yield reduction assays showed that Cipa extract could decrease viral titers by an order of magnitude. The extract conferred statistically significant protection against DENV infection," said Navin Khanna, senior scientist at ICGEB and the group leader of the project.
He added that preliminary evaluation of the clinical relevance of Cipa extract showed it had no adverse impact on platelet count and RBC viability. It also showed no evidence of toxicity in Wistar rats, when administered doses as high as 2g/Kg body weight for up to a week.
"We have tested it on rats and have got positive results, but now it needs to be tested on bigger animals," Khanna said.
Mohammad Aslam, senior advisor to DBT, which funded the project, said since the drug has been made from plant extracts and not chemicals, it has sought permission from both the Ministry of Ayush and also the Drug Controller of India.
"The drug has proved to be resistant to four types of dengue virus.
"Sun Pharma has been tasked with launching the drug commercially after conducting the trials," Aslam said, adding that the company has patents in 17 countries where cases of dengue are high.
Dengue, a mosquito-borne viral disease, poses a significant global public health risk. In tropical countries such as India, where periodic dengue outbreaks can be correlated to the high prevalence of the mosquito vector circulation of all four dengue viruses (DENVs) and the high population density, a drug for dengue is being increasingly recognised as an unmet public health need.
India represents 50 per cent of the global population estimated to be at risk of dengue. Severe dengue, which is potentially fatal, correlates with very high virus load, reduction in platelet counts and haemorrhage.