Table 1.

Skin changes induced by D-galactose.

	Strain	Gender	D-gal doses	Period of exposure	Age	Aging effects	Ref.
Mice
1	C57BL/6J	Female	50 mg/kg daily subcutaneous injection	8 weeks	5 months	Skin HYP ↑	[66]
2	C57BL/6J	Female	1000 mg/kg daily subcutaneous injection	8 weeks	6 weeks	Dermal thickness ↓ Type I collagen fibers ↓ Type III collagen ↓	[67]
3	C57BL/6J	Male	1000 mg/kg daily subcutaneous injection	8 weeks	8 weeks	Dermal thickness, density ↓ p16 ↑ MDA ↑ SOD ↓ CAT ↓ GSH-Px ↓	[83]
4	Kunming mice	Not reported	1000 mg/kg daily subcutaneous injection	6 weeks	22 months	Collagen ↓ Dermal thickness ↓ Collagen fibers are shorter, less compact, and more disordered Type I collagen fibers ↓ Type III collagen fibers ↑	[68]
5	Kunming mice	Male	400 mg/kg intraperitoneally	30 days	8 weeks	Destruction of hair follicles in skin Skin HYP ↓	[69]
6	Kunming mice	Male and female	1000 mg/kg daily subcutaneous injection	42 days	6 weeks	SOD ↓ MDA ↑ Skin HYP ↓ Elastin ↓ Skin moisture ↓ Dermal thickness ↓ Collagen ↓ HYP ↓	[70]
7	Kunming mice	Male	150 mg/kg daily intraperitoneally	6 weeks	Unknown	Dermal thickness ↓ HYP ↓	[71]
8	Kunming mice	Female	1000 mg/kg daily subcutaneous injection	42 days	3 months	MDA ↑ and GSH-Px ↑ HYP ↓	[72]
9	Kunming mice	Female	1000 mg/kg daily subcutaneous injection	30 days	8 weeks	CAT ↓ SOD ↓ GPH-Px ↓ HYP ↓ MDA ↑	[73]
10	Kunming mice	Male	200 mg/kg daily subcutaneous injection	8 weeks	6 weeks	H2O2 ↑ MDA ↑ CAT ↓ GSH ↓ GSH-Px ↓ Dermal thickness ↓ Skin integrity and hair follicles were also impaired Collagen ↓ Skin collagen fiber content is reticular, more loose, and irregular	[84]
11	Kunming mice	Male	500 mg/kg daily intraperitoneally	8 weeks	Unknown	Skin moisture ↓ HYP ↓ Dermal thickness ↓ Collagen ↓ SOD ↓ MDA ↑ CAT ↑ and GSH-Px ↑ p16 ↑ and p21 ↑ Sirtuin1 ↓ and cyclin D1 ↓	[74]
12	Kunming mice	Male	200 mg/kg daily intraperitoneally	30 days	Unknown	HYP ↓	[75]
13	Nude mice	Not reported	1000 mg/kg daily subcutaneous injection	8 weeks	6 weeks	Skin elasticity ↓ Dermal thickness ↓ SOD ↓ MDA ↑ AGEs ↑ CD31 expression ↓.	[76]
14	Nude mice	Male	1000 mg/kg daily subcutaneous injection	3 weeks	6 weeks	Collagen ↓ Dermal thickness ↓	[77]
15	Nude mice	Not reported	1000 mg/kg daily subcutaneous injection	8 weeks	6 weeks	AGE ↑ SOD ↓ MDA ↑ Dermal thickness ↓ Collagen ↓	[78]
16	BALB/c	Male	500 mg/kg daily per oral administration	6 weeks	12 weeks	Fibroblast count ↓ Collagen ↓	[86]
Rats
17	Wistar	Male	125 mg/kg daily subcutaneous injection	6 weeks	Unknown	Dermal thickness ↓ Skin moisture-no difference HYP ↓ Collagen type I expression ↓	[79]
18	Wistar	Female	150 mg/kg daily intraperitoneally	12 weeks	170-180 days	Skin moisture ↓ HYP ↓	[80]
19	Wistar	Male	200 mg/kg daily intraperitoneally	6 weeks	Unknown	Rats had brittle and less elastic hair Thin, inelastic, and sagged skin is reported	[85]
20	Sprague-Dawley	Male	1000 mg/kg daily subcutaneous injection	8 weeks	4-6 weeks	Skin elasticity ↓	[81]
21	Sprague-Dawley	Male and female	100 mg/kg daily hypodermically injected	8 weeks	Unknown	CAT ↓ and GSH-Px ↓ MDA ↑ Dermal thickness ↓.	[82]

HYP: skin hydroxyproline; SOD: skin superoxide dismutase; MDA: malondialdehyde; GSH-Px: glutathione peroxidase; CAT: catalase; GSH: glutathione S-transferase.