Table 1. Clinical studies on the activity of oxidant or antioxidant biomarkers in acne patients .

Year/ Authors	Sampling/ study population	Grouping	Evaluated biomarkers	Main Findings
2018, Awad et al (21)	60 patients, 40 control, Blood sampling	Mild (9), moderate (33), server (18), control (40)	MDA, TAC	Acne patients showed higher serum MDA and lower TAC compared with control subjects No significant difference was detected in MDA, and TAC level with respect to acne severity
2014, Al-Shobaili (10)	156 patients, 47 control, Blood sampling	Mild (46), moderate (83), severe (27), control (46)	CAT, SOD, TAC, MDA.	CAT, SOD, and TAC were significantly higher in the control group, MDA was significantly higher in the patients, No significant difference was reported in CAT activity between the mild, moderate, and severe acne patients, SOD was significantly lower and TAC and MDA were significantly higher in severe acne compared to mild and moderate groups.
2014, Yang et al (13)	50 patients, Skin biopsies from chin, cheek, and forehead	Nonsmoker (22), former smoker (7), Current smoker (21) (smokers n=28)	LPO	LPO level was significantly higher in the smokers, No significant difference was observed between the current and former smokers, No significant difference was observed in the LPO content of different facial area comedones and lesions in the acne patients.
2013, Al-Shobaili et al (11)	50 patients, 40 control, blood sampling	Mild (20), moderate (23), severe (7), control (40)	GSH, NO, SOD, MDA, Protein oxidation	NO, MDA, and protein oxidation were significantly elevated in patient group, GSH and SOD were markedly diminished in the patient group, Overall, SOD and GSH negatively, and MDA, NO and protein oxidation positively correlate with severity of acne vulgaris.
2012, Perihan et al (12)	50 patients, 40 control, Skin scraping from face	Mild (16), Moderate (18), Severe (16), control (40)	GSH, MDA, SOD, CAT	SOD, CAT, and GSH negatively, and MDA positively correlate with the severity of acne vulgaris.
2011, Ikeno et al(22)	40 patients, 19 control, biopsy from involved and uninvolved face and upper arm, female study population	Patient (40), Control (19)	GSH	GSH level was significantly lower in patients, GSH level of upper arm skin was significantly higher than face skin, No significant difference was observed between the diseased and healthy skin of the patients.
2010, Sarici et al (1)	32 patients, 34 control, blood sampling	Patient (32), Control (34)	MDA, SOD, CAT, NO, XO	MDA serum level and XO activity were significantly increased in the patients, SOD and CAT activity were significantly reduced in the patients, The serum level of NO was not markedly different between the control and patient groups.
2009, Abulnaja (23)	60 patients, blood sampling, female study population	Obese with acne (15), Obese without acne (15), Non-obese with acne (15), Non-obese without acne (15)	Vitamin A, Vitamin E, Vitamin C, MDA, β-carotene, MAO,	Vitamin A, E, C content was diminished in the acne patients, vitamin C was markedly decreased in obese patients compared with non-obese patients, MDA positively whereas MAO and β-carotene negatively correlate with obesity and acne severity.
2008, Fattah et al (24)	23 patients, 23 control, Blood sampling, skin biopsy	Mild (6), Moderate (10), Severe (7), Control (23)	SOD, MDA	SOD activity and MDA content were upregulated in the patients, SOD activity negatively and MDA content positively correlated with acne severity, SOD activity and MDA content of the skin biopsies were drastically higher compared to the blood sample.
2005, Kurutas et al (25)	43 patients, 24 control, Blood sampling,	Mild (7), Moderate (31), Severe (5), Control (24)	MPO, SOD	SOD activity was significantly lower in polymorphonuclear leukocytes of the patient group, no marked difference was reported between MPO activities of the patient and control group.
2005, Arican et al (26)	43 patients, 46 control, Blood sampling,	Patient (43), Control (46)	MDA, SOD, G6PD, CAT	MDA and SOD levels were significantly escalated in acne patients, G6PD and CAT levels were significantly lower in acne patients.
2005, Aybey et al (27)	79 patients, 17 control, Blood sampling,	Smokers (11), Nonsmokers (68), Control (17)	GSH-Px	GSH-Px level was significantly lower in the patients, no marked difference was observed in the GSH-Px level among smoker and non-smokers, No correlation was reported between the acne severity and GSH-Px level.
2001, Basak et al (28)	52 patients, 36 control, Blood sampling,	Mild (23%), Moderate (75%), Severe (2%), Control (n=36)	GSH-Px, SOD, CAT,	SOD and GSH-Px activity were significantly reduced and CAT activity and TBARS level were increased in acne patients,
1984, Michaelsson and edqvist (29)	89 patients,	severe male patients (n=47), moderate female patients (n=26), severe female patients (n=21).	GSH-Px	GSH-Px level was reported to be significantly diminished in the male patients comparing to the control, No significant difference was observed in GSH-Px level of female subjects comparing to the control group,