Background Currently, no vaccines or modern drugs are available for dengue and chikungunya and only symptomatic relief is provided to the patients. Siddha medicine, a traditional form of indigenous medical system uses specific polyherbal formulations for the treatment of such infections with considerable success. One such polyherbal formulation for the treatment of chikungunya and dengue is Nilavembu kudineer (NVK). The mechanistic details of this drug as an antiviral for chikungunya virus (CHIKV) and dengue virus (DENV) is poorly understood. Objectives The current study was undertaken to study the efficacy of NVK as an antiviral formulation against CHIKV and DENV. Materials and methods Cytotoxicity assays (MTT) were performed to determine the role of NVK as an antiviral during chikungunya and dengue infections in the following conditions-i). post infection, ii). during active infections and iii) protective, not allowing virus infection. Results It was observed that NVK provides protection against CHIKV and DENV-2 during active infection as well can help to prevent virus infection in the cells and it mainly depends on the cellular availability of drugs for maximum protection against both the infections. Conclusion Our study establishes that extraction protocols are important to ensure maximum efficacy of NVK along with the time of addition of the drug during CHIKV and DENV infections in the cells. This study provides insights to the possible mode of action of NVK in in vitro condition during CHIKV and DENV infection.

Background and aim Globally, the ongoing pursuit in exploring an effective drug to combat severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus has not met with significant success to date. Indian traditional medicines, especially polyherbal formulations like Nilavembu Kudineer (NVK) and Kaba Sura Kudineer (KSK) of the Siddha system of medicine, have been used as public health interventions for controlling viral epidemics like dengue and Chikungunya. These traditional therapies have been found safe, effective, and widely accepted. The current study evaluates the comparative efficacy of NVK and KSK as opposed to the placebo, in the management of mild to moderate COVID-19 disease. Methods The study was a double-blind, placebo-controlled comparative clinical trial, with the primary objective of determining the efficacy of KSK and NVK. Patients (n=125) diagnosed with mild to moderate COVID-19 symptoms were enrolled in the study over a period of 4 months (Aug 2020—Dec 2020). Participants were randomized into 3 arms; placebo-decaffeinated tea in Arm I, NVK in Arm II, and KSK in Arm III. Each arm received 60 ml of the respective treatment twice a day, post morning and evening meals, along with standard allopathy treatment for a maximum of 10 days. The main outcome measures of the study were the reduction in SARS-CoV-2 viral load, hospital stay, and time taken by the patients to become asymptomatic from symptomatic. Efficacy assessments included clinical symptoms (fever, cough, and breathlessness) each day and real-time reverse transcription-polymerase chain reaction (RT-PCR), liver function test (LFT), renal function test (RFT), and electrolytes and electrocardiogram (ECG) at baseline (day 0) and days 3, 6, and 10. Post-treatment, participants were followed up for 30 days via phone for adverse effects if any. Effects of drugs on inflammatory markers (IL6) at the end of treatment were also recorded. Adverse events (AE) were monitored throughout the study. Results The results revealed that when compared to patients in the placebo arm, those in NVK and KSK arms showed a statistically significant reduction in hospital stay time, reduction in viral load of SARS-CoV-2, and the time taken to become symptomatic from asymptomatic. Out of 125 COVID-19 patients recruited, 120 completed the study; two from the placebo group developed severe symptoms and were shifted to the intensive care unit (ICU) and three patients from Arms II and III withdrew from the study. The mean age of females (n=60) and males (n=60) enrolled was between 40.2 and 44.3 years, respectively. Results were more promising for all the patients in NVK and KSK arms as all enrolled participants (100%) under this group got discharged by day 6 as compared to only 42.5% (n=17) from the placebo group on that day. The hospital stay time for patients in Arm I was significantly longer (mean [SD]=8.4 [2.0] days) as compared to the Arms II and III (mean [SD]=4.7 [1.5] and 4.2 [1.5] days, respectively (Kruskal-Wallis test, P=0.0001). Patients in the three groups took a significantly different number of days to become asymptomatic. While Arm II and III patients took mean of 2.5 and 1.7 days, respectively, Arm I, patients took a mean of 4.2 days (Kruskal-Wallis test, P=0.0001). In all, two adverse events were recorded, one for vomiting and one for diarrhea lasting a day in Arm I and Arm II, respectively. The mean value of interleukin-6 (IL6) was significantly different in comparison to the placebo-decaffeinated tea arm (NVK=2.6 and KSK=2.2, placebo=4.0, P=0.02). The other blood biochemical parameters like C-reactive protein (CRP), lactate dehydrogenase (LDH), ferritin, and D-dimer that were analyzed at the baseline and at the time of discharge from the hospital, were not significantly different in the three arms. Conclusion NVK and KSK arms showed a statistically significant reduction in hospital stay time, reduction in viral load of SARS-CoV-2, and time taken for patients to become asymptomatic from symptomatic, when compared to the placebo (decaffeinated tea). The primary outcome measures of the KSK arm were significantly better than those in the NVK arm.

Chikungunya fever (CHIKF) is a major public health concern and is caused by chikungunya virus (CHIKV). In 2005, the virus was reintroduced into India, resulting in massive outbreaks in several parts of the country. During 2010 and 2016 outbreaks, we recruited 588 patients from a tertiary care hospital in New Delhi, India, during the acute phase of CHIKF; collected their blood and clinical data; and determined their arthralgic status 12 weeks post-onset of fever. We evaluated IgM/IgG CHIKV-binding antibodies and their neutralizing capacity, sequenced complete genomes of 21 CHIKV strains, and correlated mutations with patient sequelae status. We also performed infections in murine models using representative strains from each outbreak to evaluate differences in pathogenesis. Our screening and analysis revealed that patients of the 2016 outbreak developed earlier IgM and neutralizing antibody responses that were negatively correlated with sequelae, compared with 2010 patients. Mutations that correlated with human disease progression were also correlated with enhanced murine virulence and pathogenesis. Overall, our study suggests that the development of early neutralizing antibodies and sequence variation in clinical isolates are predictors of human sequelae.

Chikungunya viral fever results in extreme morbidity and arthralgia in affected individuals. Currently, modern medicines providing symptomatic relief for the acute febrile phase and the chronic arthritic phase are only options available. Traditional Indian medical system, however, uses specific formulations for treatment of this infection; one such polyherbal formulation used to treat the postpyretic phase of chikungunya is amukkara choornam. The current study was undertaken to study the efficacy of amukkara choornam in the treatment of chikungunya in C57BL/6J mice. The formulation when administered to chikungunya-infected mice relieved morbidity and joint swelling. Analysis of virus clearance in brain and joint tissues on formulation treatment revealed a direct correlation of viral load in brain to morbidity during infection; likewise, joint swelling receded prior to complete viral clearance explaining possible immunomodulatory effect of amukkara choornam. This study provides insight into the possible mode of action of amukkara choornam during chikungunya.

Chikungunya (CHIK) is a febrile arboviral illness caused by chikungunya virus (CHIKV) and has been identified in more than 60 countries across the globe. A major public health concern, the infection occurs as an acute febrile phase and a chronic arthralgic phase. The disease manifests differently in different age groups that can range from asymptomatic infection in the younger age group to a prolonged chronic phase in the elderly population. The present study was undertaken to evaluate strain-specific pathogenesis of ECSA genotype of CHIKV strains derived from clinical isolates in adult C57BL/6J mice model. The strain that was pathogenic and developed distinct acute and post–acute phase of CHIK infection was further evaluated for dose-dependent pathogenesis. Upon arriving on the optimal dose to induce clinical symptoms in the mice, the disease progression was evaluated across the acute and the post–acute phase of infection for a period of 15 days post–infection in two age groups of mice, namely eight weeks old and 20 weeks old mice groups. Biochemical, hematological, and virology attributes were measured and correlated to morbidity and linked neurotropism and limb thickness in the two age groups. Our results show that CHIKV exhibit strain-specific pathogenesis in C57BL/6J mice. Distinct dissimilarities were observed between the two age groups in terms of pathogenesis, viral clearance and host response to CHIKV infection.