The Epidermal Mucus Extract Of Clarias Batrachus Inhibits Gram Negative Bacteria Growth / Jurnal Sains Kesihatan Malaysia

Recently, epidermal mucus of fish has been identified as a rich biological source of various bioactive substances,particularly antibacterial peptides. This study was conducted to identify the potential of epidermal mucosa of Clariasbatrachus as a source of antibacterial material. Mucosal samples were collected from C. batrachus epidermis and extractedusing an aqueous extraction method. Antibacterial activity of the crude epidermal mucus extract was determined byusing spectrophotometric method. As a result there was antibacterial activity by the mucus extract against Escherichiacoli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 27853). The results of this study supports the role of mucus asa part of body immune system with antibacterial peptide as a component of innate body immune system. Hence, thesefindings can be used as one of the first steps towards the development of new class antibiotics.

Clarias batrachus collagen extract increases fibroblast cell adhesion, migration and proliferation.

Collagen is an extracellular matrix protein with great importance in biomedical application. The search for collagen from various sources is intensified especially from marine source. This study was carried out to extract collagen from a Malaysian local fresh water fish, Clarias batrachus and characterized its biomedical potential In vitro. Collagen was extracted from C. batrachus skin using acetic acid method and identified using SDS-PAGE. MTT assay was performed to determine the effect of coated collagen on cell adhesion and proliferation of L929 skin fibroblast cells. Additionally, scratch assay was performed to examine the effect of collagen coating on fibroblast cell migration. Result showed that collagen extracted from C. batrachus was made up of collagen type I, which consists of two α chains (α-1 and α-2) and β chain. At 100 μg/cm2 density, collagen coating significantly increased fibroblast cell adhesion, proliferation and migration compared to negative control (p< 0.05). As a conclusion, collagen extracted from C. batrachus increased cell adhesion, proliferation and migration of fibroblast cells and has potential to be used as an alternative source of collagen.

Influence of environmental hypertonicity on the induction of ureogenesis and amino acid metabolism in air-breathing walking catfish (Clarias batrachus, Bloch).

Effect of environmental hypertonicity, due to exposure to 300 mM mannitol solution for 7 days, on the induction of ureogenesis and also on amino acid metabolism was studied in the air-breathing walking catfish, C. batrachus, which is already known to have the capacity to face the problem of osmolarity stress in addition to other environmental stresses in its natural habitats. Exposure to hypertonic mannitol solution led to reduction of ammonia excretion rate by about 2-fold with a concomitant increase of urea-N excretion rate by about 2-fold. This was accompanied by significant increase in the levels of both ammonia and urea in different tissues and also in plasma. Further, the environmental hypertonicity also led to significant accumulation of different non-essential free amino acids (FAAs) and to some extent the essential FAAs, thereby causing a total increase of non-essential FAA pool by 2-3-fold and essential FAA pool by 1.5-2.0-fold in most of the tissues studied including the plasma. The activities of three ornithine-urea cycle (OUC) enzymes such as carbamoyl phosphate synthetase, argininosuccinate synthetase and argininosuccinate lyase in liver and kidney tissues, and four key amino acid metabolism-related enzymes such as glutamine synthetase, glutamate dehydrogenase (reductive amination), alanine aminotransaminase and aspartate aminotransaminase were also significantly up-regulated in different tissues of the fish while exposing to hypertonic environment. Thus, more accumulation and excretion of urea-N observed during hypertonic exposure were probably associated with the induction of ureogenesis through the induced OUC, and the increase of amino acid pool was probably mainly associated with the up-regulation of amino acid synthesizing machineries in this catfish in hypertonic environment. These might have helped the walking catfish in defending the osmotic stress and to acclimatize better under hypertonic environment, which is very much uncommon among freshwater teleosts.

Hypoxia influences expression profile of Pleckstrin homology-like domain, family A, member 2 in Indian catfish, Clarias batrachus (Linnaeus, 1758): A new candidate gene for hypoxia tolerance in fish.

Several physiologically important genes were found to be regulated by hypoxia at the transcriptional level. The Pleckstrin homology-like domain, family A, member 2 (PHLDA2) gene was previously identified as an imprinted gene. The present study was aimed to determine the structure of complete cDNA and the deduced protein of PHLDA2 along with analysing the changes in its mRNA expression in Clarias batrachus tissues under hypoxic conditions. The complete cDNA of CbPHLDA2 gene consisted of 1009 nucleotides with an open reading frame of 417 nucleotides. The deduced CbPHLDA2 protein of 139 amino acids shared high homology with PHLD2A of other fishes as well as that of vertebrates. Importantly, a single amino acid (asparagine/lysine) insertion was identified in the PH domain of CbPHLDA2 and other fishes, which was absent in other vertebrates studied. Furthermore, under normoxic conditions, CbPHLDA2 was constitutively expressed with varying levels in analysed tissues. Short- and long-term hypoxia exposure resulted in significant changes in the expression of CbPHLDA2 in liver, spleen, head kidney, brain and muscle in a time-dependent manner. The results suggested that CbPHLDA2 might play an important role for adaptive significance under hypoxia.

Physiological responses to acute experimental hypoxia in the air-breathing Indian catfish, Clarias batrachus (Linnaeus, 1758).

With an aim to study the mechanism of adaptation to acute hypoxic periods by hypoxia-tolerant catfish, Clarias batrachus, the mass-specific metabolic rate (VO2) along with its hematological parameters, metabolic response and antioxidant enzyme activities were studied. During progressive hypoxia, C. batrachus was found to be an oxyconformer and showed a steady decline in its aquatic oxygen consumption rate. When C. batrachus was exposed for different periods at experimental hypoxia level (0.98±0.1 mg/L, DO), hemoglobin and hematocrit concentrations were increased, along with decrease in mean cellular hemoglobin concentration, which reflected a physiological adaptation to enhance oxygen transport capacity. Significant increase in serum glucose and lactate concentration as well as lactate dehydrogenase activity was observed. Antioxidant enzymes were found to operate independently of one another, while total glutathione concentration was unaffected in any of the tissues across treatments. These observations suggested that hypoxia resulted in the development of oxidative stress and C. batrachus was able to respond through increase in the oxygen carrying capacity, metabolic depression and efficient antioxidant defense system to survive periods of acute hypoxia.

Lambda cyhalothrin induced alterations in Clarias batrachus.

The present study was undertaken to find out the toxic effect of synthetic pyrethroid lambda cyhalothrin on the functioning of endocrine glands in freshwater catfish, Clarias batrachus.The fish were exposed to the pesticide for a period of 45 days at a sublethal concentration of 5.768 ppm. Analysis of hormone profile was carried out on the 15, 30 and 45 days of exposure to find out the alteration in hormone secretion and the response of the fish to the compound. The results obtained showed a significant decline(p<0.05) in levels of thyroid hormones and testosterone while a significant increase (p<0.05) was observed in cortisol levels during the different days of exposure of the fish to lambda cyhalothrin

Response of blood glucose, hepatic glycogen and pancreatic islets to treatment of sulphydryl inhibitors in Clarias batrachus L.

The correlative effects of the two sulphydryl inhibitors viz., the mono-and dithiol reagent, alloxan and cobalt chloride, were studied in the fresh water air breathing catfish, Clarias batrachus. Alloxan induced a typical mammalian-like triphasic response and necrobiotic changes in the islet β-cells. Cobalt chloride elicited a discontinuous hyperglycemia with cytopathological changes in β-cells following nearly the same sequence as those induced by alloxan. However, the α-cells of cobalt-treated fish showed, unlike those after alloxanization, specific degranulation, vacuolization and nuclear enlargement. The changes in the hepatic glycogen content of two experimental groups were observed to be equal. Both the drugs appeared to be detrimental to the normal islet function and were, thus, overtly or potentially diabetogenic agents to the fish.