Table 2. The effects of curcumin on diabetes-related dementia.

Ref. No.	Study design	Treatment	Main findings
Maithilikarpagaselvi et al. [64]	Male Wistar rats (5 months old, 250–300 g), fructose (60% (w/w) feeding for 10 weeks (n = 10/group)	Curcumin (200 mg/kg), 10 weeks	• Attenuate insulin resistance by decreasing the activation of stress sensitive kinase (IRS-1) in skeletal muscle and inhibiting inflammatory cascades and oxidative stress
			• No direct evidence on cognitive function
Naijil et al. [65]	Male Wistar rats (90–110 g), multiple low-dose STZ (n = 6–8/group)	Curcumin pre-treatment (7.5 mg/kg), 60 days	• Decrease α2-adrenergic receptor (sympathetic inhibition of insulin release) and increase β-adrenergic receptor (neuronal stimulation of hyperglycemia-induced β-cell compensatory response) in pancreas
			• Up-regulate CREB, phospholipase C, insulin receptor, and glucose transporter 2 in pancreas
			• No direct evidence on cognitive function
Huang et al. [67]	Rat, single dose of 3.0 mg/kg ICV-STZ and subcutaneous D-galactose daily (125 mg/kg) for 7 weeks	Curcumin (10 mg/kg), 7 weeks	• Decrease oxidative stress
			• Improve the abilities of active avoidance and locomotor activity
			• Attenuate neurodegeneration

IRS-1, insulin receptor substrate-1; CREB, cyclic AMP response element-binding protein; ICV, intracerebroventricular; STZ, streptozotocin.