In the present study, fish Labeo rohita were exposed to 20, 50 and 100 µg/L of both Cu NPs and copper sulphate (CuSO4, bulk copper) for 24 h and hematological profiles were estimated. A significant (P< 0.01) change in the hemoglobin (Hb), hematocrit (Hct), white blood cells (WBC) and Mean Corpuscular Volume (MCV) levels were observed in all the three concentrations of both bulk and Cu NPs treated fish when compared to control groups. However a non significant change in red blood cells (RBC) (20 and 50 µg/L Cu NPs) and mean corpuscular hemoglobin (MCH) (20 and 50 µg/L bulk Cu) were observed. The alteration in Mean Corpuscular Hemoglobin Concentration (MCHC) value was found to be non significant both in bulk and Cu NPs treated fish. The alterations of these parameters can be used as a potential indicator to examine the health of fish in aquatic ecosystem contaminated with metal and metal based nanoparticles.
TopIntroduction
Nanotechnology is a new branch of science, deals with synthesis of nano-sized particles that enhance the physical, chemical and biological properties of the metals. It is the fast growing and one of the prominent technologies in the 21st century (Chen et al., 2012; Lee et al., 2014; Abdel-Khalek et al., 2015). Nanoparticles (NPs) ranges between 1 and 100 nm, dimensions from quantum dots to one, two or three dimensional nanoparticles (Handy et al., 2008a; Lee et al., 2014) which in turn increase its surface to volume ratio of the NPs and provide large surface area for binding of biomolecules. Moreover, nanotechnology has wide applications in industries, biomedical sciences, electronics, cosmetics, pharmaceuticals and research fields (Zhao et al., 2011; Jovanovic and Palic, 2012). NPs have not only reached the markets, but also it is used for various domestic purposes and end up in the environment. In the environment these particles may pose a risk to the organisms.
In this juncture, the aquatic ecosystem is more susceptible to many kinds of pollutants including NPs (Scown et al., 2010; Jovanovi´c and Pali´c, 2012). NPs may enter the aquatic ecosystem from its manufacturing waste, nanoproducts and its byproducts (Moore, 2006; Navarro et al., 2008). Fate of nanoparticles in aquatic ecosystem is mainly governed by its solubility, dispersibility, and their interaction between biotic and abiotic factors (Brar et al., 2010). NPs are toxic to aquatic organisms when exposed to higher doses as these particles can cross biological cell membranes (Griffitt et al., 2007; Brar et al., 2010; Siddiqui et al., 2015). Recently the wide production of engineered nanoparticles (ENPs) due to their applications in many industrial processes finds their way in to the aquatic environment and cause adverse effects in aquatic organisms (Zhu et al., 2008; Binelli et al., 2009; Lu et al., 2011; Yokel and MacPhai, 2011; Sanchez et al., 2012; Qiuli et al., 2013; Baker et al., 2014). However, due to their unique physical and chemical properties, their fate in the aquatic organism is not clearly understood (Zhu et al., 2009; Scown et al., 2010; Remya et al., 2015).
Copper nanoparticles (Cu NPs) have distinctive characters and commonly used as a substitute for noble metal catalysts (Cava, 1990; Tranquada et al., 1995; Xu et al., 1999; Zhou et al., 2006; Chang et al., 2012) and cheaper than the other metal oxide NPs (Machado et al., 2008). Cu NPs find its application in textiles, skin products, ceramics, wood preservation, lubrication, nanofluids, bioactive coatings; electronic devices such as inkjet printing or integrated circuits; biocidal and antimicrobial activities (Yoon et al., 2007; Gomes et al., 2011; Santo et al., 2012; Wang et al., 2014; Nations et al., 2015; Siddiqui et al., 2015). Cu NPs are also used in medicine and as antifouling agents in paints used in boats (Kiaune and Singhasemanon, 2011; Perreault et al., 2012).