BackgroundDengue, 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 recognized as an unmet public health need.Methodology/Principal findingsUsing 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 inhibitory activity. Our results show 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 using the AG129 mouse model. A preliminary evaluation of the clinical relevance of Cipa extract showed that it had no adverse effects on platelet counts and RBC viability. In addition to inherent antipyretic activity in Wistar rats, it possessed the ability to down-regulate the production of TNF-α, a cytokine implicated in severe dengue disease. Importantly, it showed no evidence of toxicity in Wistar rats, when administered at doses as high as 2g/Kg body weight for up to 1 week.Conclusions/SignificanceOur findings above, taken in the context of the human safety of Cipa, based on its use in Indian traditional medicine, warrant further work to explore Cipa as a source for the development of an inexpensive herbal formulation for dengue therapy. This may be of practical relevance to a dengue-endemic resource-poor country such as India.
In the present study, resveratrol, a polyphenolic SIRT1 activator was evaluated for its SIRT1 activation in an in vitro fluorescent based assay (EC(50) : 7 μM). The efficacy of resveratrol was also evaluated in ob/ob mice for its antidiabetic and associated metabolic effects. Mice aged 5-8 weeks were included in four groups; control and resveratrol at 5, 15, 50 mg/kg, b.i.d. and were dosed orally. After 4 weeks of drug treatment, body weights were noted and random blood glucose and insulin was estimated for the antidiabetic effect. Animals were also subjected to the oral glucose tolerance test to observe any improvement in the glucose excursion. Triglycerides, total cholesterol, adiponectin and free fatty acid levels were also estimated. The results showed that resveratrol exhibited significant antihyperglycemic activity with an improvement in the insulin levels compared with the control mice. There was also a significant improvement observed in the glucose excursion in the oral glucose tolerance test performed for 120 min; although an insignificant improvement in the triglycerides, total cholesterol, adiponectin and free fatty acid levels was observed at different doses of resveratrol tested. The present findings suggest that resveratrol is an antihyperglycemic agent and drugs similar to resveratrol can be considered as an effective therapeutic adjuvant for the current treatment of diabetes mellitus.
Formyl peptide receptor (FPR) family members have been reported to play important role in the resolution of inflammation. A few FPR2/FPR1 dual agonists are reported in the public domain for their anti-inflammatory properties. None of these molecules, however, have been successful as a therapy yet. Recent reports bring forward the ambiguous role of FPR1 in inflammation. These include both positive and negative outcomes. We, therefore, aimed to develop selective FPR2 agonists and evaluated their potential in mitigating the non-resolving inflammation in mouse models of moderate to severe asthma. Extensive structure-activity-relationship (SAR) studies were conducted on the imidazole and benzimidazole chemotype series to identify potent and selective FPR2 agonists. A few molecules were shortlisted based on their in vitro profile and absorption, distribution, metabolism and excretion (ADME) properties and were further evaluated in mouse models of asthma. We report herewith identification of 3 RCI compounds with low nanomolar potency for FPR2 agonism and >10,000 fold selectivity over FPR1 in Ca2+ release assay. These molecules also showed potency in other in vitro assays and potent efficacy in three distinct animal models of asthma. Our data suggest that FPR2 agonism can be a potential therapeutic approach to treat asthma. Our findings also propose that FPR1 can be spared to achieve the desired pharmacological activity.
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