The Effect of Acute Oral Galactose Administration on the Redox System of the Rat Small Intestine

• Main Authors: Jan Homolak (Author), Ana Babic Perhoc (Author), Ana Knezovic (Author), Jelena Osmanovic Barilar (Author), Davor Virag (Author), Mihovil Joja (Author), Melita Salkovic-Petrisic (Author)
• Format: Book
• Published: MDPI AG, 2021-12-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.3390/antiox11010037; 2076-3921
• Keywords: galactose; oxidative stress; gastrointestinal tract; redox; redox homeostasis; Therapeutics. Pharmacology; RM1-950
• Source: Antioxidants, Vol 11, Iss 1, p 37 (2021)

Galactose is a ubiquitous monosaccharide with important yet incompletely understood nutritive and physiological roles. Chronic parenteral <span style="font-variant: small-caps;">d</span>-galactose administration is used for modeling aging-related pathophysiological processes in rodents due to its ability to induce oxidative stress (OS). Conversely, chronic oral <span style="font-variant: small-caps;">d</span>-galactose administration prevents and alleviates cognitive decline in a rat model of sporadic Alzheimer's disease, indicating that galactose may exert beneficial health effects by acting in the gut. The present aim was to explore the acute time-response of intestinal redox homeostasis following oral administration of <span style="font-variant: small-caps;">d</span>-galactose. Male Wistar rats were euthanized at baseline (<i>n</i> = 6), 30 (<i>n</i> = 6), 60 (<i>n</i> = 6), and 120 (<i>n</i> = 6) minutes following orogastric administration of <span style="font-variant: small-caps;">d</span>-galactose (200 mg/kg). The overall reductive capacity, lipid peroxidation, the concentration of low-molecular-weight thiols (LMWT) and protein sulfhydryls (SH), the activity of Mn and Cu/Zn superoxide dismutases (SOD), reduced and oxidized fractions of nicotinamide adenine dinucleotide phosphates (NADPH/NADP), and the hydrogen peroxide dissociation rate were analyzed in duodenum and ileum. Acute oral administration of <span style="font-variant: small-caps;">d</span>-galactose increased the activity of SODs and decreased intestinal lipid peroxidation and nucleophilic substrates (LMWT, SH, NADPH), indicating activation of peroxidative damage defense pathways. The redox system of the small intestine can acutely tolerate even high luminal concentrations of galactose (0.55 M), and oral galactose treatment is associated with a reduction rather than the increment of the intestinal OS. The ability of oral <span style="font-variant: small-caps;">d</span>-galactose to modulate intestinal OS should be further explored in the context of intestinal barrier maintenance, and beneficial cognitive effects associated with long-term administration of low doses of <span style="font-variant: small-caps;">d</span>-galactose.