Lutein attenuates oxidative stress markers and ameliorates glucose homeostasis through polyol pathway in heart and kidney of STZ‑induced hyperglycemic rat model.

Purpose Lutein’s role on chronic hyperglycemia-induced
oxidative stress and associated glucose homeostasis in heart
and kidney is limited. Purpose of the study is to investigate
the effect of lutein on cardiac and renal polyol pathway
enzymes and oxidative stress markers under hyperglycemia-
induced oxidative stress condition using streptozotocin
(STZ)-injected rat model.
Methods STZ-induced hyperglycemic (fasting blood glucose
≥11 mM) male Wistar rats were divided into two
groups (n = 11/group). Group 1 received micellar lutein
(39 nmol/day/rat) and group 2 (negative control) received
micelle without lutein for 8 weeks. A separate group (no
STZ injected) served as a positive control (n = 11/group).
Oral glucose tolerance test (OGTT), biweekly urine glucose
and activities of aldose reductase (AR) and sorbitol
dehydrogenase (SDH) enzymes were assessed. Activities
of antioxidant enzymes and antioxidant level were also
evaluated.
Results Lutein-administered hyperglycemic rats showed
better glucose tolerance as evidenced with OGTT and
biweekly urine glucose when compared to negative control.
Activities of AR and SDH were decreased in heart
and kidney of lutein-fed hyperglycemic rats. Also, they had
significantly (p < 0.05) decreased malondialdehyde levels
(66, 34, and 33 %) and increased reduced glutathione level (81, 18 and 92 %) in serum, heart and kidney, respectively.
Altered antioxidant enzyme activities such as superoxide
dismutase, catalase, glutathione peroxidase, glutathione
reductase and glutathione transferase were also affected in
serum, heart and kidney of lutein-fed diabetic group.
Conclusion Lutein prevented cardiac and renal injury in
STZ-induced hyperglycemic rats due to potential amelioration
of altered activities in polyol pathway and oxidative
stress markers.