Low-molar-mass oat beta-glucan impacts autophagy and apoptosis in early stages of induced colorectal carcinogenesis in rats

Int J Biol Macromol. 2024 Jan;254(Pt 2):127832. doi: 10.1016/j.ijbiomac.2023.127832. Epub 2023 Nov 2.

Abstract

Oat beta-glucan is one of the soluble dietary fibre fractions with a wide spectrum of biological activities such as anti-inflammatory and anti-tumour properties. In the present study, the effect of low-molar-mass oat beta-glucan isolate (OβGl) on the level of autophagy and apoptosis in the colorectum of rats with induced early stages of colorectal cancer was investigated. Forty-five male Sprague-Dawley rats were divided into two main groups: control and azoxymethane-induced early-stage colorectal carcinogenesis (CRC). Both groups were divided into three dietary subgroups fed standard feed without OβGl (OβGl-), with 1 % of OβGl (OβGl+1 %) or with 3 % of OβGl (OβGl+3 %). The expression of autophagy (LC3B, beclin-1) and apoptosis (caspase-3, cleaved caspase-3, BAX, BCL-2 and PARP-1) markers was determined by immunohistochemistry, Western blot and PCR analysis. The obtained results showed that the expression of LC3B, caspase-3 and cleaved caspase-3 in the CRC mucosa, and LC3B-II expression in the CRC wall were higher in the OβGl+3 % compared to the OβGl- rats. A higher BAX/BCL-2 ratio was also observed in the CRC OβGl+1 % rats compared to the other CRC animals. In summary, OβGl+3 % has a modulatory effect, stimulating autophagy and the extrinsic apoptosis pathway, while OβGl+1 % has a stimulatory effect on the intrinsic apoptosis pathway.

Keywords: Apoptosis; Colorectal cancer; Oat beta-glucan.

MeSH terms

  • Animals
  • Apoptosis
  • Autophagy*
  • Carcinogenesis
  • Caspase 3 / metabolism
  • Colorectal Neoplasms* / chemically induced
  • Colorectal Neoplasms* / drug therapy
  • Colorectal Neoplasms* / metabolism
  • Male
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • bcl-2-Associated X Protein / metabolism

Substances

  • Caspase 3
  • beta-glucan, (1-3)(1-4)-
  • bcl-2-Associated X Protein
  • Proto-Oncogene Proteins c-bcl-2