Response of gastrointestinal melatonin, antioxidants, and digestive enzymes to altered feeding conditions in carp (Catla catla)

Abstract

The purpose of present study was to ascertain whether the response of gastrointestinal (gut) melatonin to altered feeding conditions was related to the levels of different antioxidants and digestive enzymes in the same gut tissues of a sub-tropical carp (Catla catla). Accordingly, the fish were subjected to food deprivation for 4 or 8 days and separately to re-feeding for 4 or 8 or 12 days after deprivation of food for 8 days, and their gut tissue homogenates were used to measure the levels of melatonin, both enzymatic [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST)] and non-enzymatic [reduced glutathione (GSH)] antioxidants, as well as different digestive enzymes (α-amylase, cellulase, protease, and lipase). Notably, the gut levels of melatonin, SOD, CAT, GPx, and GST underwent gradual increase with the progress of food deprivation, but a sudden fall after restoration of food supply for 4 days and a rise thereafter. Conversely, the activity of all the digestive enzymes significantly decreased after deprivation of food, but started increasing when food supply was reinforced. Gut melatonin concentrations by showing a positive correlation with the titers of different antioxidants (in both food-deprived and re-fed fish groups) and a negative (in food-deprived fish) or a positive (in re-fed fish) correlation with the activity of each digestive enzyme underlined possible physiological interplay between them. Collectively, our findings lend support to the hypothesis that gut melatonin response to altered feeding conditions in carp might be associated with the oxidative status as well as the digestive functions of the gastrointestinal tissues itself.

Duration of stunting impacts compensatory growth and carcass quality of farmed milkfish, Chanos chanos (Forsskal, 1775) under field conditions

“…Colossoma macropomum , subjected to 7-weeks of feed starvation in the re-feeding stage showed a drastic increase in amylase activity 26 . The increased digestive enzyme activity in re-alimentation phase was due to the increased availability of feed, after a food restriction period 30 . In rainbow trout, significantly reduced lipase activity reported during starvation phase, however, the reduced activity was successfully restored in re-feeding phase 27 .…”

Adrenaline induced disruption of endogenous melatoninergic system, antioxidant and inflammatory responses in the gastrointestinal tissues of male Wistar rat: an in vitro study

“…Its production in GI tract is several hundred-folds higher than produced in the pineal gland (16,23,24,26). Its synthetic enzymes have been found in the GI tissues (19,24,23,25). The melatonin in GI tract is to regulate the physiological activities (14-16, 18-19, 21, 26) and locally protect GI tissue from the free radical damage (14-15, 18-19, 22).The mechanism study indicated that the gene expression of the melatonin synthetic enzyme, AANAT and its membrane receptor, MT1 was significantly down regulated by adrenaline.…”

“…The melatonin in GI tract is to regulate the physiological activities (14-16, 18-19, 21, 26) and locally protect GI tissue from the free radical damage (14-15, 18-19, 22).The mechanism study indicated that the gene expression of the melatonin synthetic enzyme, AANAT and its membrane receptor, MT1 was significantly down regulated by adrenaline. The decreased melatonin production is always associated with oxidative damage in tissues and organs (14,(19)(20). The pro-oxidation of adrenaline can cause DNA damage and impact the integrity of DNA (4, 52).…”

“…Among them melatonin (N-acetyl-5-methoxy tryptamine), a low molecular weight indolamine, seems to be the most potent free radical scavenger and antioxidant (14). It regulates numerous important physiological functions in a variety of tissues (15,16) including the GI tract (17)(18)(19). Melatonin, due to its lipophilic and hydrophilic natures, not only directly scavenges cytotoxic free radicals, but also stimulates the activities of different antioxidant enzymes (20), ultimately reducing the level of oxidative stress in cells and tissues (21,22).…”

Functional interplay of melatonin in the bile duct and gastrointestinal tract to mitigate disease development: An overview

“…These include use of some neuro-endocrine hormones, neurotransmitters, and growth factors which show promising effects in inhibiting the detrimental changes induced by the stressors (18)(19)(20). Among these, melatonin is considered as the most promising agent due to its lipophilic nature, paracrine actions, broad spectrum antioxidant and direct free radical scavenging properties (21)(22)(23)(24)(25)(26). High levels of melatonin presence in bile (27) and GI tract (25,28,29) of mammals including humans (30) provide a unique advantage to overcome many pathological conditions in these tissues.…”