P.G. Viswanathan Nair

Cholesterol content of Indian fish and shellfish

Abstract Ninety-seven samples of fish and 17 samples of shellfish from tropical waters were analysed for fat, nonsaponifiable matter (NSM) and cholesterol contents. Significant differences were noted in the cholesterol contents of the various families of fish analysed. However, the variation in the content of cholesterol was found to be not significant within the families. Higher contents of cholesterol were observed in shellfish than in fish. No correlation existed between the fat content of the fish/shellfish and the levels of cholesterol or NSM. ©

Anti-ulcerogenic effect of chitin and chitosan on mucosal antioxidant defence system in HCl-ethanol-induced ulcer in rats

The anti‐ulcerogenic effect of chitin and chitosan against ulcer induced by HCl‐ethanol in male Wistar rats was studied. Levels of acid output, pepsin, protein, lipid peroxides and reduced glutathione and the activity of glutathione peroxidase (GPx), glutathione‐S‐transferase (GST), catalase (CAT) and superoxide dismutase (SOD) were determined in the gastric mucosa of normal and experimental groups of rats. A significant increase in volume and acidity of the gastric juice was observed in the ulcer‐induced group of rats. Peptic activity was significantly decreased as compared with that of normal controls. In the rats pre‐treated with chitin and chitosan 2% along with feed, the volume and acid output and peptic activity of gastric mucosa were maintained at near normal levels. The level of lipid peroxidation was significantly higher in the ulcerated mucosa when compared with that of normal controls. This was paralleled by a decline in the level of reduced glutathione and in the activity of antioxidant enzymes like GPx, GST, CAT and SOD in the gastric mucosa of ulcer‐induced rats. Also, the levels of mucosal proteins and glycoprotein components were significantly depleted in ulcerated mucosa. The pre‐treatment with chitin and chitosan was found to exert a significant anti‐ulcer effect by preventing all the HCl‐ethanol‐induced ulcerogenic effects in experimental rats.

Effect of tetracycline on pancreas and liver function of adult male albino rats

The effect of tetracycline, at two doses of 50 and 200 mg kg−1 daily, was studied on pancreatic and liver tissue function for 14 and 21 days in adult male albino rats. For pancreatic function the parameters studied were content of amylase and lipase in pancreas, serum amylase and lipase, serum glucose and faecal fat excretion. For liver function, liver specific enzymes in serum, namely alanine amino transaminase, aspartate amino transaminase and lactate dehydrogenase were estimated. In addition, total lipid, antiperoxidative enzymes and lipid peroxidation were measured in pancreas and liver. The content of amylase and lipase in pancreas showed a small but significant decrease in the rats given 50 mg kg−1 for 21 days and the decrease was much more significant in those receiving the 200 mg kg−1 dose. In pancreas free radical levels show a significant increase and reduced glutathione shows a substantial decrease at the 50 mg kg−1 level and a significant change in these parameters was observed at the 200 mg kg−1 dose. Antioxidant enzymes, superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase, showed a small but significant decrease in the pancreas of the rats treated with 50 mg kg−1 tetracycline. A significant decrease in the antioxidant enzymes level was observed at the 200 mg kg−1 dose. In the liver, free radical levels and reduced glutathione were within the normal range at the 50 mg kg−1 level and significant changes were observed at 200 mg kg−1. The antioxidant status was unaffected in liver after treatment with tetracycline at the 50 mg kg−1 level and a significant decrease was observed at the higher dose. Our results reveal the safe nature of tetracycline with respect to the liver at the lower dose tested, whereas, both the higher and lower doses seem to have detrimental effect on the pancreas as revealed by the rise in free radical levels and decrease in the antioxidant enzyme levels.

SHELF LIFE OF DRIED ANCHOVIELLA IN FLEXIBLE PACKAGING MATERIALS

Packaging and storage studies of dried anchoviella have been conducted using two different types of flexible packaging materials, namely 250-gauge low density polyethylene (LDPE) and 12-micron plain polyester laminated with 200-gauge LDPE. Packing in the polyester polythene laminate gave a longer shelf life compared with the LDPE. In LDPE the shelf life was limited to 12 weeks. However the shelf life was extended up to 32 weeks in the plain polyester polythene laminate. The polyester/polythene laminate provides better resistance against penetration of insects than the LDPE film.