Table 1.

Concentration of Tryptophan (Trp), kynurenine (KYN), Kynurenic acid (Kyn) and 3-hydroxykynurenine (3HKYN) in the retinas of different groups.

Group	TRP (µM)	KYN (µM)	KYNA (nM)	3HKYN (µM)
Group-I (Control)	40.56 ± 2.0	2.06 ± 0.13	0.17 ± 0.024	4.18 ± 0 0.05
Group-II (STZ-Treated)	44.03 ± 2.9	4.00 ± 0.12	0.38 ± 0.01	7.28 ± 0.18
Group-III (STZ + 1.5 mg/kg Andrographolide)	42.65 ± 9.4*	2.25 ± 0.43*	0.20 ± 0.024*	4.71 ± 0.27*
Group-IV (STZ + 4.5 mg/kg Andrographolide)	43.84 ± 3.1	2.96 ± 0.15	0.31 ± 0.02	6.47 ± 0.29