Juvenile toxicity study of Gossence™ (galactooligosaccharides) in Sprague Dawley rats

Abstract

Gossence™ (galactooligosaccharide; GOS) is a prebiotics and used as one of the major constituents in infant milk formulas that act as a functional food. Gossence is manufactured by Tata Chemicals Ltd, India, through a patented process of biotransformation of lactose. A toxicology study in juvenile rats was carried out to assess the safety profile of Gossence intended for pediatric population. The objective of this study is to assess the potential systemic toxicity of Gossence when administered through gavage at dose levels of 1000, 2000, or 5000/3000 mg/kg/day (equivalent to 1347, 2694, and 6735/4041 mg/kg/day of GOS, respectively) to juvenile Sprague Dawley rats from postnatal day (PND) 4 to PND 52 (i.e. total 49 days of dosing period). A separate group of animals were treated with vehicle (purified Milli Q water) for a similar duration. The following parameters were evaluated during the study period: morbidity/mortality check, clinical signs, body weights, body weight changes, food consumption, functional observational battery, motor activity, postnatal developmental observations, hematology, clinical chemistry, urinalysis, organ weight, gross pathology, and histopathology. During dosing phase, the high-dose group, 5000 mg/kg/day, was reduced to 3000 mg/kg/day (equivalent to 4041 mg/kg/day dose of GOS) from day 16 (PND 19) onward, due to clinical signs of watery feces and yellow color stains at urogenital region and mortality in two animals on day 15 (PND 18) of the study. Time-weighted average dose for 5000 mg/kg/day was equivalent to 3600 mg/kg/day. No further deaths or clinical signs were noticed in animals at 3000 mg/kg/day from day 18 (PND 21) of dosing phase to until terminal euthanization. At the terminal euthanization, there were no test item-related gross changes observed in all surviving rats except for, an increased cecum size in some of the rats at 5000/3000 mg/kg/day, which correlated with the increased weights of cecum with contents during organ weight recording, but this had no correlating light microscopic changes during histological examination. The cecal enlargement was completely recovered following the 14-day recovery period. The no-observedadverse-effect level is 3000 mg/kg/day for Gossence, which is equivalent to 4041 mg/kg/day of GOS in both sexes.

Novel Galacto-oligosaccharides from Lactose: Chemical Synthesis, Structural Characterization, and in Vitro Assessment of Prebiotic Activity

“…All NMR spectra were processed using Topspin 4.0.8 (Bruker). Glycosidic linkage patterns (stereo-and regio-chemistry) in the synthesized GOS were elucidated from the signals ( 1 H, 13 C) of the structure−reporter groups of GOS reported in the literature. 35 To estimate the quantity of different glycosidic linkages in the GOS, the anomeric contours of α/β-1,1, α/β-1,2, α/β-1,3, α/β-1,4, and α/β-1,6 were integrated for relative comparison due to the similar chemical environment and distinguishable chemical shifts.…”

“…NMR spectroscopy ( 1 H, 1 H− 13 C HSQC) was recorded on a Bruker AVANCE III 500 MHz instrument with a DCH cryoprobe at 30 °C. 1 H− 13 C HSQC was conducted in 1 H-detected mode with proton decoupling in the 13 C domain. NMR parameters were 2k × 1k data points, zero-filled to 4k data points, 32 scans per t 1 value, spectral width in t 1 20 kHz and t 2 5 kHz, and a relaxation delay of 44 μs.…”

“…Reaction mechanism of acid-catalyzed glycosylation (Figure S1); HPAEC-PAD chromatograph of commercial β-GOS (Figure S2); acid-catalyzed side reactions (Figure S3); molar ratio of galactose to glucose in the synthesized GOS as a function of reaction time (Figure S4); MALDI-TOF MS spectra of the GOS synthesized from lactose versus from galactose (Figure S5); 2D 1 H− 13 C HSQC NMR spectra of lactose, melibiose (Figure S6), and the GOS synthesized from galactose (Figure S7); Growth curves (0−8 h) of L. rhamnosus ATCC 53103, L. casei BFLM 218, L. gasseri ATCC 33323 (Figure S8); effect of formic acid, levulinic acid, and HMF on the growth of lactobacilli (Table S1…”

“…GOS have generally been recognized as safe (GRAS) status in the United States and foods of specific health use (FOSHU) in Japan . Safety–toxicity evaluation studies showed that a daily dosage of up to 5 g of GOS/kg of body weight (90 days) did not induce any negative effects (e.g., osmotic diarrhea) in rats. , An important application of GOS is as a supplement in infant formula to mimic the function of HMO, which benefits infant gastrointestinal health mainly through the stimulation of indigenous bifidobacteria. , Moreover, GOS have gained great interest as supplements in a variety of novel functional foods due to their favorable physiochemical properties such as being pH and heat stable, mildly sweet, and low cariogenic. , …”