In India, seaweed resources are exclusively utilized for the production of commercially and industrially important phycocolloids (Reddy et al., 2014).Seaweeds are a diverse and large group of macro algae which are broadly classified into various types based on the presence of photosynthetic pigments as rhodophyta (red algae), chlorophyta (green algae), and phaeophyta (brown algae) (Hemasudha et al., 2019). Seaweed extracts contains major and minor nutrients, amino acids, vitamins, cytokinins, auxin and abscisic acid like growth promoting substances (Mooney and Staden, 1986). Agar, carrageenan and alginate are popular examples of seaweeds these have been used as food for human beings, fertilizers for plants and source of various chemicals (Shelar et al., 2012).
Antioxidant compounds play an important role against various diseases (e.g., chronic inflammation, atherosclerosis, cancer and cardiovascular disorders) and ageing processes (Kohen and Nyska, 2002). Some researchers have also worked and reported the same (Mhadhebi et al., 2014; Venkatesan et al., 2016; Keshari et al., 2018; Hemasudha et al., 2019). Nanoparticles extremely attractive for a large range of applications, including catalysis, gas and energy storage, photovoltaic, electrical and optical devices and biological and medical technologies (Goesmann et al., 2010; Lin et al., 2015, Kunjachan et al., 2015, Chinen et al., 2015; Pelaz et al., 2017; Wuttke et al., 2017; Peller et al., 2017; Li et al., 2017; Freund et al., 2018; Rosenblum et al., 2018). Several characterization methods have been devised to investigate size, distribution, shape, surface charge and porosity of nanoparticles in different environments (Modena et al., 2019). Silver nanoparticle (AgNPs) are known for their antimicrobial properties, being effective against pathogens, which explain their potential for several biotechnological application, in addition to their electrical, thermal, magnetic and catalytic characteristics (Vigeshwaran et al., 2008; Thakkar et al., 2010; Konwarh et al., 2011; MubarakAli et al., 2011; Mohanty et al., 2012; Chen et al., 2017). The AgNPs possess unique attributes which are breakthrough myriad applications such as antimicrobial, anticancer, larvicidal, catalytic, and wound healing activities (Jannathul and Lalitha, 2015). The biosynthesis of nanoparticles has been proposed as a cost-effective and environmental friendly alternative to chemical and physical methods (Anju et al., 2015). Biological synthesis of AgNPs has an outstanding numerous benefits without the use of toxic chemicals and possess advancement over both physical and chemical methods (Bhainsa and Souza, 2006; Song and Kim, 2009; Parashar et al., 2009; Saifuddin et al., 2009).
Many marine algae were screened for their antimicrobial activity by Reichelt and Borowitzka (1984) & Latha and Latha (2011).Silver nanoparticles attach with the microbial cell wall membrane by electrostatic attraction (Dibrov et al., 2002; Lara et al., 2010) and subsequently penetrate it, thereby changing the permeability of the cell membrane and causes cell death (Sondi and Salopek-Sondi, 2004). Extracted substances from seaweeds have antibacterial actions and other properties include antifungal activities and growth inhibition of plants (Burkholder and Sharma 1969; Su et al., 1973; Abdussalam, 1990; Scheuer, 1990; Rizvi and Shameel, 2003). Seaweeds are excellent source of bioactive compounds which demonstrated a broad range of biological activities such as: anti-inflammatory, antibiotics, antiviral, cytotoxic and antimitotic activities (Naqvi et al., 1980; Bhosale et al., 2002), anticoagulants, anti-ulcer (Fayaz et al., 2005). Enteromorpha sp have also been shown to contain certain bioactive substances (Dhawan 1992; Chauhan and Siddhanta 1992). Many investigations revealed that macroalgae have a broad range and potential use in pharmacology researches as antibacterial and antifungal( Karabay-Yavasoglu et al., 2007; Zbakh et al., 2012; Jeyaseelan et al., 2012; Alghazeer et al., 2013; Oumaskour et al., 2013; Abo-State et al., 2015). In this present study the seaweed E. Intestinalis was collected from the Pulicat estuary and the nanoparticles of the same were tested for various bioactivities to illustrate its potential utilizations.