Caution may be required in using l-theanine in diabetes mellitus: A study on the rats

Biochem Biophys Res Commun. 2023 Jul 23:666:170-178. doi: 10.1016/j.bbrc.2023.04.095. Epub 2023 May 9.

Abstract

Background: The study aimed to identify the effects of l-theanine on kidney and heart tissues in diabetic rats. 24 male rats included in the study were divided into 4 groups (n = 6/group): SHAM, LTEA, DM and DM + LTEA. For 28 days, drinking water was given to SHAM and DM, and LTEA (200 mg/kg/day) to LTEA and DM + LTEA groups, intragastrically. DM was induced by 120 mg/kg nicotinamide (NA) + 60 mg/kg streptozotocin (STZ). The levels of cystatin C (CysC) and angiotensin-converting enzyme 2 (ACE2) were determined by ELISA kits, homocysteine, electrolytes and iron by an autoanalyzer, the ratio of oxidized/total reduced glutathione (GSSG/TGSH) by assay kits. The tissues were histopathologically analyzed.

Results: LTEA alleviated histopathological degenerations. However, it decreased significantly serum iron and homocysteine levels (p < 0.05).

Conclusion: LTEA did not exhibit significant protective effects on kidney and heart tissues; it may have affected the homocysteine and iron metabolisms in diabetics.

Keywords: ACE2; Cystatin C; Diabetes; Homocysteine; Iron; L-theanine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Diabetes Mellitus, Experimental* / metabolism
  • Glutamates / pharmacology
  • Glutathione Disulfide / metabolism
  • Kidney / pathology
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Streptozocin

Substances

  • theanine
  • Glutamates
  • Streptozocin
  • Glutathione Disulfide