Current Drug Discovery Technologies

Infectious diseases have plagued mankind since ancient times. Ancient civilizations relied largely on a variety of herbal and herbomineral formulations to combat infections. Later the twentieth century saw the dawn of antibiotic era. Antibiotics helped us greatly in combating pathogenic microbes, however, emergence of antimicrobial resistance (AMR) and its promiscuous exchange among pathogenic populations has brought us to a situation, where we are left with a limited number of effective antibiotics, and already quite a few pan-drug-resistant strains have started posing a formidable health challenge before us. Infections caused by resistant strains and microbial biofilms are causing a large number of deaths throughout the globe, and concerted efforts at a global scale are necessary [https://amr-review.org/]. Discovery of new antimicrobial agents is failing to keep pace with rapid emergence of AMR among pathogenic microorganisms, and there is a realistic threat of mankind losing this battle. Conventional bactericidal antibiotics exert strong selection pressure on target microbes, leading to rapid emergence of resistant phenotypes. Hence besides the continuous discovery of new bactericidal antibiotics, alternative non-antibiotic approaches also need to be pursued actively. Identifying new targets (e.g. quorum sensing, riboswitches, transcriptional regulators, metal homeostasis, etc.) in pathogenic microbial cells/ populations, and new leads for developing novel anti-infective/ anti-virulence agents is the need of the hour. This is about a paradigm shift from targeting pathogen to targeting pathogenicity. While researchers throughout the globe are focusing their antimicrobial research specifically on WHO (World Health Organization)/ CDC (Centers for Disease Control)- listed antibiotic-resistant bacteria [https://www.cdc.gov/drugresistance/ biggest- threats.html] [https://www.who.int/news-room/detail/27-02-2017-who-publishes-list-of-bacteria-for-which-new-antibiotics -are-urgently-needed], antibiotic-resistant fungal and protozoan pathogens remain equally grave challenges. Discovery of new effective antiviral agents is still more daunting task. Fulfilling the criteria of ‘selective toxicity’ becomes much more difficult while developing new antiviral/ antifungal/ anti-protozoal agents, as compared to antibacterials. We may never fully win the battle against microbial infections, but a lot needs to be done to ensure that we do not lose this battle. This thematic issue features review papers from researchers working on varied aspects of discovery and development of novel anti-infective agents. It will be an informative and useful read for all stakeholders. Besides the contributing authors and the publisher, I sincerely thank the reviewers who selflessly devoted their valued time in fulfilling their role as Sentinel of Scientific Literature.

Mother nature has blessed mankind with vast treasures of botanical wealth, endowed with infinite healing potential. For centuries, the recognition of the medicinal properties of plants had been limited to folklore and complementary medicine. The promulgation of herbal medicine has been largely propelled by the lacunae of synthetic drugs in addressing the medical needs of the people. Modern times have witnessed a dramatic increase in patients suffering from various lethal and debilitating disorders as well as infections. The adverse effects associated with the use of synthetic medicines and their limited antimicrobial potential, in view of emerging infections and microbial resistance, are matters of grave concern. The inquest of present day researchers towards safer and more effective treatment alternatives has revived their interest in herbal drugs and brought them into mainstream. Current Drug Discovery Technologies is dedicated to bringing forth the advancements that are taking place in the domain of drug discovery. The present issue entitled ‘Herbal Drugs: Expanding Horizons of Contemporary Therapeutics’ has been brought about with the objective of shedding light on the therapeutic properties of a various medicinal plants and their phytoconstituents, use of plant derived products in formulation development of biomedicals, technological advancements in the production of herbal drug products and the regulatory aspects concerning them. This thematic issue comprises of six articles by experts who have reviewed herbal drugs from the perspective of offering an enlarged field of solutions to satisfy current medical needs. Gallo and Bucalá have contributed a comprehensive article that discusses spray drying technology employed to produce dried medicinal plant extracts. The paper specifically focuses on the effect of different process parameters on the quality and yield of extracts, and will serve as a guide for researchers to reduce the time required for spray drying of extracts and economize the production process [1]. Sickle cell disease is a genetic condition characterized by a high degree of debility. It is endemic in Nigeria, and Alli and coworkers provided an insight into the herbal remedies used to ameliorate its symptoms. Also, they wrote an in-depth account on the limitations of these drugs, from the viewpoint of epigenetic interactions, to reactivate the gammaglobulin genes to strengthen the immune response in patients [2]. Essential oils are secondary plant metabolites obtained from aromatic flora, containing numerous phytoconstituents with many therapeutic probabilities. Sharma and colleagues wrote an elaborate review on the potential of citronella oil to circumvent as well as treat a myriad of diseases. The paper includes a section on novel drug delivery systems formulated with citronella oil and toxicity concerns pertaining to its use [3]. Panda and Kumari delved into the plant kingdom to present an overview of anti- ophidian properties of herbal medicinal agents. These agents are a safer alternative to treat snake bites, which are health concerns in many parts of the world. Phytochemicals with anti- ophidian properties can be explored to avoid the adverse effects of immunotherapy [4]. Plants have not only been a source of bioactives but also provided many compounds to aid formulation development. Chakraborty and co- authors came up with a detailed account on the physicochemical properties of native starch, due to which it has found application to serve as an excipient in design and development of advanced delivery systems, including nanoscale devices [5]. The expanding role of herbal drugs in contemporary medicine calls for robust regulatory framework. In light of the quality control difficulties and lack of data regarding their safety and efficacy, regulatory bodies around the globe must ensure strict legislative control on their marketing and utilization. The article by Bhat and colleagues makes an attempt to apprise the readers about the herbal drug regulations existing in some countries and the differences therein [6]. I hope that this thematic issue will enlighten the readers on some of the important aspects of herbal medicines and the realm of possibilities that these offer to the pharmaceutical scientists.