Cocculus hirsutus-derived phytopharmaceutical drug has potent anti-dengue activity
Authors: Poddar Ankur , Shukla Rahul , Beesetti Hemalatha , Arora Upasana , Rajpoot Ravi Kant , Shanmugam Rajgokul K , Palla Srinivas , Nayyar Kaushal , Singh Deepika , Singamaneni Venugopal , Gupta Prasoon , Gupta Ajai Prakash , Gairola Sumeet , Bedi Y. S. , Jain Tapesh , Vashishta Bhupendra , Patil Ravindra , Madan Harish , Madan Sumit , Kalra Rinku , Sood Ruchi , Vishwakarma Ram , Lal Altaf A , Khanna Navin 
Published: September 2020

Background

Dengue is a serious public health concern worldwide, with ~3 billion people at risk of contracting dengue virus (DENV) infections. Currently, no effective vaccine or drug is available for the prevention or treatment of dengue, which leaves only anti-mosquito strategies to combat this disease. The present study was initiated to determine thein-vitroandin vivoprotective effects of a plant-derived phytopharmaceutical drug for the treatment of dengue.

Methodology/Principal Findings

In our previous report, we had identified methanolic extract of the aerial parts ofCissampelos pareirato exhibitin vitroandin vivoanti-dengue activity against all the four DENV serotypes. In the current study, we have identified another Indian medicinal plant,Cocculus hirsutus, which has a more potent anti-dengue activity thanC. pareira.The activity has been evaluated through flow-cytometry-based virus inhibition assay. Interestingly, the stem ofC. hirsutuswas found to be more potent than the aerial part irrespective of the extraction solvent used viz., denatured spirit, hydro-alcohol (50:50) and water. Hence, the aqueous extract of stem ofC. hirsutus(AQCH) was further advanced for investigations because of greater regulatory acceptance. The AQCH exhibited dose-dependent inhibition of release of DENV and its secretory antigen, NS1. Five chemical markers viz. Sinococuline, 20-Hydroxyecdysone, Makisterone-A, Magnoflorine and Coniferyl alcohol were identified as the major chemical ingredients of the AQCH extract. These chemicals were subsequently used for extract standardisation. Importantly, AQCH completely protected AG129 mice at 25 mg/kg/dose body weight when fed 4 times a day post-infection with a lethal dose of DENV-2 S221 strain. Because of its potential as an effective phytopharmaceutical drug against dengue, AQCH, has been formulated into tablets for further pre-clinical and clinical developments.

Conclusions/Significance

We provide evidence of the pan anti-dengue potential ofC. hirsutus-based phytopharmaceutical drug as determined throughin vitroandin vivoexperiments. We have also characterized five chemical entities in the drug substance, which provides means for standardization of drug substance and drug product. Based on these findings, a program to develop a safe and effectiveC. hirsutus-derived phytopharmaceutical drug for the treatment of dengue has been initiated.

Author summary

There is an urgent need to develop a safe and effective drug against dengue, which is a rapidly expanding mosquito-borne viral disease. Half of the world’s population has been estimated to be at risk of contracting this disease and the situation remains grim due to lack of an approved drug. We aimed to develop an ethnopharmacological drug against dengue by exploring traditional Indian medicinal science, Ayurveda. This led us to identify a creeper,Cocculus hirsutus, as a more potent anti-dengue plant thanCissampelos pareira,reported in our earlier published study. The stem part ofC. hirsutuswas found to be more efficacious in inhibiting the propagation of dengue viruses (DENVs) in cell culture than its aerial part. Hence, we chose to advance aqueous extract of stem ofC. hirsutus(AQCH) for further studies. Importantly, AQCH also protected immune-compromised mice from lethal DENV infection, which is suggestive of its potential clinical relevance. We have identified five chemical marker compounds in AQCH to gauge the quality and consistency of extract preparation and its formulation into stable tablets. Based on the findings of this study, we have undertaken the development of a safe and effectiveC. hirsutus-derived phytopharmaceutical drug for the treatment of dengue.