Phytochemicals From Mangroves and Their Anti-Viral Applications

Introduction

Plant-derived compounds are being used as an important natural source of drug molecules and have gained importance in the medicinal chemistry. The parent molecules of most of the currently used medications have been derived from the plant. Also, due to their less toxic, and minimum side effects properties, the phytochemical is being preferred in therapeutic applications in comparison to synthetic drug molecules (Heywood, 2002; Sofowora et al., 2013; Inoue et al., 2019; Ghildiyal et al., 2020). So, the researchers are currently emphasizing deriving new knowledge based on natural plant-based compounds for their potential use in the healing process of infectious diseases. The plants also contain several types of secondary metabolites with diversity in their molecular structure and functional properties. Many of the plant's secondary metabolites are effective in treating several metabolic diseases as well as infectious diseases. An experimental basis of the study of these secondary metabolites of the plants and their efficacy on the human disease treatment process has been performed. Several scientific studies have revealed the promising use of phytochemicals for the treatment of viral infections (Inoue & Craker, 2014; Satpathy, 2020; Kaur & Ahmed, 2021; Satpathy, 2021). The development of antiviral drug molecules is an important task to combat the life-threatening disease caused by the deadliest virus (Figure 31.1). Also, many of the viruses do not have established anti-viral treatment methods. Hence, due to the urgency is concern, suitable phytochemicals are to be explored scientifically as effective and inexpensive anti-viral inhibitor molecules (Ghorbanpour et al., 2017). To date, several viral diseases have been reported and the mutant form of the deadly viruses are also occurring frequently. Among the emerging viral diseases, most of them are caused by pathogenic viruses like Human Immunodeficiency Virus (HIV), Influenza, Herpes simplex virus (HSV), Dengue, Chikungunya, Zika, Hepatitis B (HSB), Hepatitis C (HCV), Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and so on. Viral infections are associated with great health risks to human health. Also, the infection is difficult to control as the origin of new mutant forms of the viral strains. In the past, deadly viruses caused pandemics in the world thereby increasing the risk of spreading viral diseases between continents.

Very few drugs have been developed to date to effectively treat viral diseases. The majority of the approved antiviral drugs possess adverse drug reactions and have also developed viral resistance in long-term therapy. The infectious virus is a major cause of mortality in the recent few years. For instance, the infection by SARS–CoV-2 and influenza virus are responsible for over a million deaths throughout the globe (Gasparini et al., 2012; Nováková et al., 2018; Ben-Shabat et al., 2020; Hafeez et al., 2020). However, the repurposing method for the already reported phytochemical as an inhibitor for virus target is possible to study the antiviral property of the molecule. Although most of the antiviral drugs approved for the management of the viral disease are effective some of them have adverse reactions leading to raise the need for the development of plant-based drug development (Bahadur et al., 2020; Anand et al., 2021). Recently, the creation of SARS-CoV-2 virus-based pandemic situations and enhanced mortality rate in human beings have raised a serious global concern. Moreover, antiviral drugs also exhibit adverse side effects, which directly and indirectly affect human health. This provides opportunities for the development of plant-based drugs and herbal treatments with minimal side effects (Kapoor et al., 2017; Irwin et al., 2016; Biswas et al., 2020).