Table 2.

Summary of the effects of curcumin on PCOS in animals.

Type of Model	Treatment and Treatment Duration	Findings	References
Adult female Wistar rats treated with oestradiol valerate to induce PCOS	1. 100 mg/kg curcumin 2. 300 mg/kg curcumin Method of administration not specified 14 days	-Reduced number of insulin resistance index (HOMA-IR decreased, QUICKI increased) -Reduced interleukin-6 and C-reactive protein -Reduced necrotic liver cells	[45]
Prepuberal BALB/c female mice treated with DHEA to induce PCOS	5.4 mg/100 g curcumin in the form of curcumin-loaded super-paramagnetic iron oxide (Fe3O4) nanoparticles Intraperitoneally 20 days	-Reduced ovarian volume and total number of primary, secondary, antral and primordial follicles compared to the PCOS and vehicle groups -Significantly decreased Bcl-2-associated X protein (BAX) and levels of expression of Caspase3 (CASP3) protein; increased levels of B-cell lymphoma 2 (Bcl2) expression and moderated apoptosis in granulosa cells compared with PCOS group	[46]
Adult female Wistar rats treated with letrozole to induce PCOS	1. Nanocurcumin (50, 100 and 200 mg/kg) 2. Clomiphene citrate (1 mg/kg) Orally 15 days	-Nanocurcumin (50 mg/kg) and clomiphene citrate attenuated the PCOS-induced reduction in oestradiol and progesterone levels -Nanocurcumin (50 and 100 mg/kg) and clomiphene citrate attenuated the PCOS-induced testosterone increment -Nanocurcumin (50 mg/kg) and clomiphene citrate improved triglyceride, total cholesterol, and LDL and HDL cholesterol levels -All doses of curcumin and clomiphene citrate reduced the PCOS-induced increment of fasting blood glucose and insulin -Clomiphene citrate and curcumin alleviated insulin resistance -Clomiphene citrate and curcumin decreased the MDA level and increase GSH and SOD activity -Clomiphene citrate and curcumin decreased TNF-α levels -Clomiphene citrate and curcumin increased the protein expression of PI3K/AKT/mTOR levels -Treatment with nanocurcumin showed thickened granulosa cells and the appearance of oocytes in a dose-dependent manner -Nano curcumin treatment and clomiphene retained the pancreatic tissue integrity and caused a gradual increase in the area of the islet and count of β-cells	[47]
Adult female Wistar rats treated with oestradiol valerate to induce PCOS	Curcumin (100, 200, 300 and 400 mg/kg) Intraperitoneally 14 days	-Significant reduction in thickness of theca layer and increased corpus luteum diameter in the curcumin-treated group compared with the PCOS group -Curcumin decreased the IL-6 and CRP levels -Curcumin decreased TNF-α in the granulosa layer and follicular fluid	[48]
Adult female Wistar rats treated with letrozole to induce PCOS	1. Curcumin (100 and 200 mg/kg) 2. 1 mg/kg clomiphene citrate Orally 15 days	-Curcumin significantly inhibited the decrease in uterine weight -Clomiphene citrate and 100 and 200 mg/kg curcumin reversed the disturbance in testosterone and progesterone levels in PCOS-induced rats, whereas only clomiphene and 200 mg/kg curcumin effectively normalised the oestrogen level -Both doses of curcumin reduced fasting blood glucose and HbA1c levels -Clomiphene and 100 and 200 mg/kg curcumin decreased triglyceride, total cholesterol and LDL levels, whereas only 200 mg/kg curcumin increased HDL level -100 and 200 mg/kg curcumin increased SOD and CAT activity, and only 200 mg/kg curcumin decreased the TBARS level and increased GSH level -Clomiphene increased catalase activity, reduced TBARS and showed no effect on GSH and SOD -Clomiphene citrate and both curcumin doses resulted in the disappearance of cysts and the appearance of healthy follicles and corpora lutea	[49]

Abbreviations: HOMA-IR: homeostatic model assessment of insulin resistance; QUICKI: quantitative insulin sensitivity check index; LDL cholesterol: low-density lipoprotein cholesterol; HDL cholesterol: high-density lipoprotein cholesterol; BAX: Bcl-2-associated X protein; CASP3: caspase3; Bcl2: B-cell lymphoma 2; MDA: malondialdehyde; TBARS: thiobarbituric acid reactive substances; GSH: glutathione peroxidase; SOD: superoxide dismutase; CAT: catalase; TNF-α: tumor necrosis factor alpha; PI3K: phosphoinositide 3-kinase; AKT: protein kinase B; mTOR: mammalian target of rapamycin; IL-6: interleukin-6; CRP: C-reactive protein; HbA1c: hemoglobin A1C.