. 2021 Aug 9;7(8):e07738. doi: 10.1016/j.heliyon.2021.e07738

Table 2.

Interventional and in vivo studies evaluating the antioxidant biological activity of cocoa and its derivatives.

Substances	Subjects	Study type	Dose	Outcome	Authors
Dark chocolate	20 healthy subjects	Interventional	40g/day for two weeks	↑ Epicatechin levels	[109]
Dark chocolate	20 healthy subjects	Interventional	40g/day for two weeks	↓ DNA damage	[109]
Dark chocolate	84 subjects with risk factors of metabolic syndrome	Interventional	2g/day for 6 months	↓ Genotoxicity in buccal epithelial cells	[110]
Cocoa powder	18 healthy subjects	Interventional	40g/day for 1 week cocoa powder in water	↓ NFκβ activation	[111]
Dark chocolate	20 healthy subjects	Interventional	40g/day	↑ Serum epicatechin level	[112]
	20 smokers			↓ ROS production
	20 smokers			↓ 8-iso-PGF2α and NADPH oxidase activation in smokers
Flavanol-rich cocoa	6 Healthy subjects	Interventional	1–4g/day for 4 weeks cocoa	↑ Plasma epicatechin and GSH levels	[113]
				↓ Reduction of F2 isoprostanes levels
				Modulation of PUFA metabolism
Cocoa extract	24 overweight/obese middle-aged subjects	Interventional	1.4g cocoa extract/daily for 4 weeks	↑ Cocoa-derived metabolites in plasma	[116]
Cocoa extract	24 overweight/obese middle-aged subjects	Interventional	1.4g cocoa extract/daily for 4 weeks	↓ Systolic blood pressure	[116]
Cocoa powder	42 high-risk volunteers	Interventional	40g/day for 4 weeks	↑ HDL	[52]
Cocoa powder	42 high-risk volunteers	Interventional	40g/day for 4 weeks	↓ Oxidized LDL	[52]
Cocoa powder	100 subjects with type 2 diabetes	Interventional	20g/day for 6 weeks	↓ Blood cholesterol, triglyceride, LDL	[115]
				↓ TNF-α, high sensitive C-reactive protein, IL-6
				Inhibition of lipid peroxidation
Cocoa product rich in fiber	24 healthy subjects	Interventional	30g/day cocoa product rich in fiber	↑ Serum HDL	[114]
Cocoa product rich in fiber	20 hypercholesterolaemic subjects	Interventional	30g/day cocoa product rich in fiber	↓ Glucose, IL-1β and IL-10	[114]
Cocoa product rich in fiber	21 volunteers with moderate hypercholesterolaemia	Interventional	30g/daily for 8 weeks	↓ Systolic and diastolic blood pressure	[114]
Cocoa product rich in fiber	21 volunteers with moderate hypercholesterolaemia	Interventional	30g/daily for 8 weeks	↓ MDA values	[114]
Dark chocolate	Sprague-dawley rats (40–60 g)	in vivo	10% of bodies weight for 3 weeks	↓ COX-2 expression levels	[120]
				Regulation of proliferation index
				↓ Lower ACF formation induced by AOM
Cocoa extract	BALB/c mice	in vivo	34.5 mg/kg for 2 weeks	Suppression of hepatotoxicity and inflammation	[119]
Cocoa extract	BALB/c mice	in vivo	34.5 mg/kg for 2 weeks	Early stage antifibrotic and anticarcinogenic effects	[119]
Cocoa liquor	Streptozotocin (STZ)-induced diabetic rats	in vivo	3.6 g/kg to 7.2 g/kg body weight by day for 40 days of cocoa liquor in water	↓ Plasma triacylglycerol levels	[45]
				↑ HDL and plasma antioxidant capacity
				↓ Lipid peroxidation in plasma and tissues
Cocoa-rich diet	Type 2 diabetic Zucker diabetic fatty rats	in vivo	All experimental groups were provided with food and water ad libitum	Improved glucose tolerance and insulin resistance
Cocoa-rich diet	Type 2 diabetic Zucker diabetic fatty rats	in vivo		↓ ROS levels and carbonyl content	[121]
Polyphenol enriched cocoa powder	Prediabetic model triggered by a sucrose rich diet	in vivo	200 mg/kg body weight by day for 3 weeks	↓ Insulin resistance	[122]
				↓ Hepatic carbohydrate and lipid dysmetabolism
				↓ Oxidative stress and inflammation
Cocoa fiber product	Spontaneously hypertensive rats	in vivo	200, 400, and 800 mg/kg/day by 10 weeks	↓ Systolic blood pressure	[123]
				↓ Glucose, cholesterol, and triglyceride levels
				↓ Liver and plasma MDA levels
Cocoa-rich diet	Spontaneously hypertensive rats	in vivo	300 mg/kg of cocoa-rich extract	↓ Systolic blood pressure	[124]
Phenolic-rich extract from Cocoa liquor	Wistar rats with high-fat diet	in vivo	2.1 g of liquor/kg to 7.2 g of liquor/kg body weight by day for 28 days	↓ Lipid peroxidation	[77]
Phenolic-rich extract from Cocoa liquor	Wistar rats with high-fat diet	in vivo		↑ Plasma and tissue antioxidant capacities	[77]
Cocoa powder	Sprague Dawley rats with high-fat diet	in vivo	52–108 days with 12.5% cocoa supplementation regimes	↓ NADPH oxidase protein levels	[125]
Cocoa powder	Sprague Dawley rats with high-fat diet	in vivo	52–108 days with 12.5% cocoa supplementation regimes	↓ Inflammation and fibrosis	[125]
Cocoa bean extracts	Wistar rats with high-fat diet	in vivo	2.25–2.45% of the total diet	Improvement of physiological parameters	[105]
Cocoa bean extracts	Wistar rats with high-fat diet	in vivo	2.25–2.45% of the total diet	Enhancement of antioxidant status	[105]

DNA: deoxyribonucleic acid; NFκβ: nuclear factor kappa β; ROS: reactive oxygen species; 8-iso-PGF2α: 8-iso-prostaglandin F2α; NADPH: nicotinamide adenine dinucleotide phosphate; GSH: glutathione; PUFA: polyunsaturated fatty acids; HDL: high-density lipoprotein; LDL: low-density lipoprotein; TNF-α: tumor necrosis factor alpha; IL-6: interleukin 6; IL-1β: interleukin 1β; IL-10: interleukin 10; MDA: malondialdehyde; COX-2: cyclooxygenase-2; ACF: aberrant crypt foci; AOM: azoxymethane.