Drug Repurposing Approaches: Existing Leads For Novel Threats And Drug Targets.

Drug Repurposing (DR) is an alternative to the traditional drug discovery process. It is cost and time effective, with high returns and low risk process that can tackle the increasing need for interventions for varied diseases and new outbreaks. Repurposing of old drugs for other diseases has gained a wider attention, as there have been several old drugs approved by FDA for new diseases. In the global emergency of COVID19 pandemic, this is one of the strategies implemented in repurposing of old anti-infective, anti-rheumatic and anti-thrombotic drugs. The goal of the current review is to elaborate the process of DR, its advantages, repurposed drugs for a plethora of disorders, and the evolution of related academic publications. Further, detailed are the computational approaches: literature mining and semantic inference, network-based drug repositioning, signature matching, retrospective clinical analysis, molecular docking and experimental phenotypic screening. We discuss the legal and economical potential barriers in DR, existent collaborative models and recommendations for overcoming these hurdles and leveraging the complete potential of DR in finding new indications.

Evaluation of phytochemical constituents and antioxidant activity of selected actinorhizal fruits growing in the forests of Northeast India.

Hippophae salicifolia, Elaeagnus pyriformis, Myrica esculenta and M. nagi are actinorhizal plants growing in the sacred forests of Northeast India with multipurpose uses. The present investigation was undertaken to determine the phenol, flavonoid and flavonol contents of the fresh fruit juice of these plant species including the antioxidant potential by means of DPPH, H2O2 and NO scavenging activity and FRP. The total phenolic, flavonoid and flavonol contents of fruit juice ranged from 321.68+/-0.06 to 76.67+/-0.01 mg/g GAE, 272.92+/-0.07 to 20.12+/-0.02 mg/g QE and 258.92+/-0.08 to 18.72+/-0.02 mg/g QE, respectively. At 2.0 mg/mL concentration, DPPH scavenging activity was found to be the highest in M. esculenta (89.62 percent) and the lowest in E. pyriformis (17.58 percent). The reducing power activity was found significantly higher in H. salicifolia juice, which increased with increase in concentration. The H2O2 scavenging activity of H. salicifolia juice was found to be as high as 98.78 percent, while Elaeagnus juice was found to be less effective with just 48.90 percent. Juice of H. salicifolia showed the greatest NO scavenging effect of 75.24 percent as compared to juice of E. pyriformis, where only 37.54 percent scavenging was observed at the same concentration. Taking into account all the experimental data, it can be said that the fruits of H. salicifolia and both M. nagi and M. esculenta have good antioxidant activity compared to fruits of E. pyriformis.

Antioxidant profiling of Hippophae salicifolia growing in sacred forests of Sikkim, India.

Hippophae commonly known as sea-buckthorn, is a versatile plant with multipurpose uses including the control of soil erosion, biological nitrogen fixation and medicinal properties. In India, two species of sea-buckthorn; namely, Hippophae salicifolia D. Don and Hippophae rhamnoides L., are very common. H. salicifolia has a shrub-to-tree habit and is restricted to the Himalayan region, whereas H. rhamnoides is bushy, growing at higher altitude in India, and widely distributed in Europe and Asia. In this study, aqueous, methanol and acetone extracts of various parts of female and male plants of H. salicifolia were evaluated for total antioxidant activity, phenolic and flavonoid contents, and correlations were made. The total phenolic and flavonoid content in all the samples ranged from 99±32 to 1459±53mg gallic acid equivalent g-1, 135±12 to 707±62mg quercetin equivalent g-1 of dry extract, respectively. The highest free radical (DPPH) scavenging activity was found in methanol extracts of female bark and male leaf. Methanol extracts of male bark and male leaf showed maximum H2O2 activity at a concentration of 1mgmL-1. Antioxidant activity (FRAP method) ranged from 0.021 to 1.041 at concentrations ranging from 20 to 200µgmL-1 with a reducing capacity of extracts as water>methanol>acetone. Strong correlation (P<0.05) was observed between DPPH scavenging activity and total phenolic content from all the extracts under study.