Editorial [Hot Topic: Anti-Viral Agents and Emerging Diseases: Part - I (Guest Editor: Supa Hannongbua)]

The drug discovery research for new potent anti-viral drugs is one of the most interesting areas that may adopt a long process ranging from screening to marketing. Several attempts have been made in this direction because of the viral infection such as HIV, dengue and particular emerging diseases such as SARS and avian influenza. However, the severe problems are faced due to the mutation of DNA as well as RNA of the virus. For this reason, computer-aided drug design and virtual screening at the early stages of drug development are urgently needed.

Specific to this Hot Topic issue is the strong belief that knowledge and different disciplines of anti-viral drug researches can support to each other. The progress in one area is not known to scientists dealing with the same problem but belong to another discipline. For example, similar approaches of computer-aided drug design for two different anti-viral targets/enzymes have been applied to search for bioactive compounds as pharmaceutical drugs, with little mutual benefit. Thus in this issue, a special effort has been made to gather contributions from different viral targets, and to bridge the gap between various computational approaches and the knowledge-based anti-viral community.

The Hot Topic on Anti-viral agents and Emerging Diseases has been separated into two parts. In the first part, a mini-review by Beyer et al. focuses on a most important target for anti-AIDS therapy, HIV-1 Reverse Transcriptase (HIV-1 RT). Structural information as obtained by X-ray crystallographic studies on the enzyme and on enzyme complexes provide the protein-inhibitor interaction. By applying molecular simulations, the dynamic behavior of this biomolecular system can be obtained in order to get some insight into the molecular flexibilities and into the detailed inhibition mechanism. The paper emphasizes that the combination of various theoretical methods leads to faster and more accurate algorithms to perform QSAR studies and in silico screening. Weaknesses like the molecular alignment in 3D-QSAR or the ambiguities in docking procedures in virtual screening can be avoided by applying such combinatorial procedures.

The mini-review by Rahman et al. is related to the issue of the protein of the dengue virus. Much work has been done on dengue virus, and on searching for vaccine and therapeutic agents for DF and DHF/DSS. However, till date, there is still no suitable vaccine or therapeutic agents available for either type of fever. The discovery of potential candidates for vaccines is the result of a number of researches for many years by employing various strategies. One major difficulty faced by researchers in their efforts to develop a vaccine for dengue is due to the existence of 4 different serotypes of dengue virus, which has to be addressed in order to develop a successful vaccine. The review includes some of the work and strategies that have been carried out in the quest for finding vaccines and therapeutic drugs for dengue, particularly those employing computer-aided approaches.

To gain some knowledge for emerging diseases, such as avian influenza, a focus of the next mini-review by Sangma et al. is placed on avian influenza targeted on neuraminidase. Since there are only two approved drugs and the drug resistance strains seem to be severe, an urgent need is felt for the discovery of new anti-neuraminidase compounds. Current development of neuraminidase inhibitors is due to protein-based design. In this review, the basic concepts underlying the design of new drugs, and a number of drugs that are currently undergoing testing, are presented. Also various computational techniques that can be applied to enhance the drug activity and to extract basic knowledge, which we need to prepare ourselves for the pandemic, are discussed.

The second part of this Hot Topic issue (Anti-viral agents and Emerging Diseases (part II)), starts with a quite comprehensive review by Briggs et al. which presents an overview on the efforts undertaken to identify selective HIV-1 Integrase (HIV-1 IN) inhibitors with the goal of improving the outcome of AIDS therapy using highly active anti retroviral therapy (HAART). As computational technology has grown rapidly and is increasingly being used worldwide to accelerate the drug discovery processes, besides its application to HIV-1 IN and its inhibitors.........