P.Siraj Basha

Bio: P.Siraj Basha is an academic researcher. The author has contributed to research in topics: Metallothionein & Superoxide dismutase. The author has an hindex of 1, co-authored 1 publications receiving 353 citations.

Antioxidant Defenses in Fish: Biotic and Abiotic Factors

Abstract: Oxygen in its molecular state O2, is essential for many metabolic processes that are vital to aerobic life. Aerobic organisms cannot exist without oxygen, which nevertheless is inherently dangerous to their lives. Like all aerobic organisms, fish are also susceptible to the effects of reactive oxygen and have inherent and effective antioxidant defenses that are well described in the literature. This review investigates the influence of different biotic and abiotic factors (age, phylogenetic position, feeding behavior, environmental factors, oxygen, temperature, presence of xenobiotics) on antioxidant defenses in fish. Studies of antioxidant activity in fish open a number of novel research lines providing greater knowledge of fish physiology, which will benefit various aspects of fish farming and artificial production.

Bioaccumulation of heavy metals in organs of fresh water fish Cyprinus carpio (Common carp)

Abstract: The objective of the present study is to determine the bioaccumulation of heavy metals in various organs of the fresh water fish exposed to heavy metal contaminated water system. The experimental fish was exposed to Cr, Ni, Cd and Pb at sublethal concentrations for periods of 32 days. The elements Cd, Pb, Ni and Cr were assayed using Shimadzu AA 6200 atomic absorption spectrophotometery and the results were given as μ/g dry wt. The accumulation of heavy metal gradually increases in liver during the heavy metal exposure period. All the results were statistically significant at p Pb > Ni > Cr and Pb > Cd > Ni > Cr. Similarly, in case of kidney and flesh tissues, the order was Pb > Cd > Cr > Ni and Pb > Cr > Cd > Ni. In all heavy metals, the bioaccumulation of lead and cadmium proportion was significantly increased in the tissues of Cyprinus carpio (Common carp).

Oxidative stress biomarkers in the freshwater characid fish, Brycon cephalus, exposed to organophosphorus insecticide Folisuper 600 (methyl parathion)

Abstract: Methyl parathion (MP) is an organophosphorus insecticide used worldwide in agriculture and aquaculture due to its high activity against a broad spectrum of insect pests. The effect of a single exposure to 2 mg L − 1 of a commercial formulation of MP (MPc: Folisuper 600®, MP 600 g L − 1 ) on catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathione S -transferase (GST), reduced glutathione (GSH) and lipid peroxidation (LPO) of the liver, white muscle and gills of Brycon cephalus was evaluated after 96 h of treatment. MPc exposure resulted in a significant induction of SOD, CAT and GST activity in all tissues. However, the GPx activity decreased significantly in white muscle and gills, whereas no alterations were observed in hepatic GPx activity. MPc also induced a significant increase in LPO values in the white muscle and gills, while hepatic LPO levels did not show any significant alteration. The current data suggest that MPc has oxidative-stress-inducing potential in fish, and that gills and white muscle are the most sensitive organs of B. cephalus , with poor antioxidant potentials. The various parameters studied in this investigation can also be used as biomarkers of exposure to MPc.

Use of Fish as Bio-indicator of the Effects of Heavy Metals Pollution

Abstract: The present review gives a brief account of the toxic effects of heavy metals on fish. In aquatic ecosystem, heavy metals are considered as the most important pollutants, since they are present throughout the ecosystem and are detectable in critical amounts. Heavy metals, such as mercury, cadmium, copper, lead and zinc are of the most important pollutants which effect aquatic environment and fish. They are extremely dangerous for the health of fish. Most of these metals are characterized by being accumulated in tissues, and lead to the poisoning of fish. These metals can effectively influence the vital operations and reproduction of fish; weaken the immune system, and induce pathological changes. As such, fish are used as bio-indictors, playing an important role in monitoring heavy metals pollution. Finally, some recommendations are given to treatment of different kinds of wastewaters, sewage and agricultural wastes before discharge into the aquatic systems. Also, enforcement of laws and legislations regarding the protection of aquatic environments must be taken into consideration.

Response of catalase activity to Ag+, Cd2+, Cr6+, Cu2+ and Zn2+ in five tissues of freshwater fish Oreochromis niloticus.

Abstract: Catalase (CAT, EC 1.11.1.6) is an important enzyme in antioxidant defense system protecting animals from oxidative stress. Freshwater fish Oreochromis niloticus were exposed for 96 h to different concentrations of Ag+, Cd2+, Cr6+, Cu2+ and Zn2+, known to cause oxidative stress, and subsequently CAT activities in liver, kidney, gill, intestine and brain were measured. In vivo, CAT was stimulated by all metals except Ag+ in the liver and the highest increase in CAT activity (183%) resulted from 1.0 mg Cd2+/L exposure, whereas 0.5 mg Ag+/L exposure resulted in a sharp decrease (44%). In tilapia kidney, cadmium and zinc had no significant effects on CAT activity, whereas 0.1 mg Cr6+/L exposure caused a decrease (44%). Cadmium and zinc did not significantly affect the CAT activity in gill; however, 0.5 mg Ag+/L exposure caused an increase (66%) and 1.5 mg Cr6+/L exposure caused a decrease (97%) in CAT activity. All metals, except Cu2+(41% increase), caused significant decreases in CAT activity in the intestine. In brain, 1.0 mg Zn2+/L resulted in an increase in CAT activity (126%), while 1.5 mg Ag+/L exposure caused a 54% decrease. In vitro, all metals — except Ag+ and Cu2+ in kidney — significantly inhibited the CAT activity in all tissues. Results emphasized that CAT may be considered as a sensitive bioindicator of the antioxidant defense system.