Table 3.
Clinical trials analyzing the anti-inflammatory effects of certain polyphenols
| Polyphenol | Study design | Dose/duration | Population | Main finding | Reference |
|---|---|---|---|---|---|
| Anthocyanin | RCT | 40 mg/day (group 1); 80 mg/day (group 2); 320 mg/day (group 3); or placebo for 12 weeks |
Patients with dyslipidemia Group 1 (n = 44) Group 2 (n = 40) Group 3 (n = 42) Placebo (n = 43) |
↓ Blood TNF-α and IL-6 (group 2 vs. baseline) ↓ Blood TNF-α and IL-6, and MDA (group 3 vs. groups 1 and 2) |
[142] |
| Anthocyanin | OLCT | 320 mg/day for 4 weeks |
Patients with T2DM (n = 12) Patients at risk of T2DM (n = 14) Healthy individuals (n = 14) |
↓ Plasma TNF-α, IL-6, and IL-18 (patients with TD2M, pre vs. post intervention) NS effects on IL-1Rα, leptin, IL-8, and CRP in any group (pre vs. post intervention) |
[143] |
| Anthocyanin | RCT | 20 mg/day (group 1); 40 mg/day (group 2); 80 mg/day (group 3); 160 mg/day (group 4); 320 mg/day (group 5); or placebo for 14 days |
Healthy young adults Group 1 (n = 20) Group 2 (n = 19) Group 3 (n = 19) Group 4 (n = 19) Group 5 (n = 19) Placebo (n = 15) |
↓ Blood IL-10 (group 4 and 5 vs. placebo) ↓ IL-6 (groups 2 and 5 vs. placebo) NS effects on TNF-α in any group |
[144] |
| Anthocyanin | RCT | 640 mg/day or placebo for 4 weeks |
Pre-hypertensive men Experimental group (n = 16) Placebo group (n = 15) |
NS effects on serum CRP, IL-6, TNF-α, IL-4, MCP-1, P-selectin, ICAM, VCAM, and CD40L | [145] |
| Anthocyanin | RCT | 320 mg/day or placebo for 28 days |
Sedentary subjects Experimental group (n = 16) Placebo group (n = 16) |
NS effects on blood CRP | [146] |
| EGCG | RCT | 2 tablets 300 mg/day or placebo for 2 months |
Patients with T2DM Experimental group (n = 25) Placebo group (n = 25) |
NS changes in serum IL-6 | [147] |
| EGCG | RCT | 300 mg/day or placebo for 12 weeks |
Pre-menopausal women with obesity Experimental group (n = 43) Placebo group (n = 40) |
NS effects on blood CRP | [148] |
| Hesperidin | RCT | 500 mg or placebo twice daily for 12 weeks |
Patients with metabolic syndrome Experimental group (n = 25) Placebo group (n = 24) |
↓ Plasma TNF-α | [149] |
| Hesperidin | RCT | 600 mg/day or placebo for 4 weeks |
Patients with myocardial infarction Experimental group (n = 38) Placebo group (n = 37) |
NS effects on serum CRP, IL-6, and leptin | [150] |
| Hesperidin | RCT | 500 mg/day or placebo for 6 weeks |
Patients with T2DM Experimental group (n = 32) Placebo group (n = 32) |
↓ Blood TNF-α, CRP, and IL-6 | [151] |
| Hesperidin | RCT | 30 g/day flaxseed plus lifestyle (group 1); 1 g/day hesperidin plus lifestyle (group 2); 30 g/day flaxseed plus 1 g/day hesperidin plus lifestyle (group 3); or lifestyle alone (control) for 12 weeks |
Patients with NAFLD Group 1 (n = 24) Group 2 (n = 22) Group 3 (n = 25) Control (n = 21) |
↓ NF-κB (groups 1 and 2 vs. control) ↓ Plasma CRP (groups 2 and 3 vs. control) |
[152] |
| Hesperidin | RCT | 1 g/day plus lifestyle or placebo (only lifestyle) for 12 weeks |
Patients with NAFLD Experimental group (n = 25) Placebo group (n = 25) |
↓ Serum TNF-α, CRP, and NF-κB | [153] |
| Quercetin | RCT | 500 mg/day or placebo for 8 weeks |
Post-myocardial infarction patients Experimental group (n = 44) Placebo group (n = 44) |
NS changes in blood IL-6, CRP, and TNF-α | [154] |
| Quercetin | RCT | 500 mg/day of quercetin plus 250 mg/day vitamin C (group 1); 500 mg/day of quercetin alone (group 2); 250 mg/day of vitamin C alone (group 3); or placebo for 8 weeks |
Subjects with systematic and regular exercise Group 1 (n = 15) Group 2 (n = 15) Group 3 (n = 15) Placebo (n = 15) |
↓ Plasma IL-6 and F2-isoprostane (group 1 vs. placebo) | [155] |
| Quercetin | RCT |
100 mg/day (-)-epicatechin (group 1); 160 mg/day quercetin-3-glucoside (group 2); or placebo for 4 weeks |
Pre-hypertensive adults Group 1 (n = 37) Group 2 (n = 37) Placebo (n = 37) |
↓ Serum IL-1β (group 2 vs. placebo) | [156] |
| Quercetin | RCT | 500 mg/day or placebo for 8 weeks |
Women with rheumatoid arthritis Experimental group (n = 25) Placebo group (n = 25) |
↓ Blood TNF-α | [157] |
| Quercetin | RCT | 500 mg/day (group 1); 1000 mg/day (group 2); or placebo for 12 weeks |
Women Group 1 (n = 38) Group 2 (n = 40) Placebo (n = 42) |
NS effects on plasma IL-6, TNF-α, and blood leucocyte subsets (groups 1 and 2 vs. placebo) | [158] |
| Quercetin | RCT | 50 mg/day (group 1); 100 mg/day (group 2); or 150 mg/day (group 3) for 2 weeks |
Healthy volunteers Group 1 (n = 11) Group 2 (n = 12) Group 3 (n = 11) |
NS effects on serum TNF-α | [159] |
| Quercetin | RCT | 500 mg/day or placebo for 8 weeks |
Women with rheumatoid arthritis Experimental group (n = 20) Placebo group (n = 20) |
NS effects on blood CRP, MDA, and ox-LDL | [160] |
| Quercetin | RCT | 162 mg/day or placebo for 6 weeks |
Overweight-to-obese subjects with pre-hypertension Experimental group (n = 68) Placebo group (n = 68) |
NS effects on serum CRP and TNF-α | [161] |
| Resveratrol | RCT | 480 mg/day or placebo for 4 weeks |
Patients with T2DM and chronic periodontitis Experimental group (n = 21) Placebo group (n = 22) |
NS effects on blood IL-6 and TNF-α | [162] |
| Resveratrol | RCT | 500 mg/day or placebo for 12 weeks |
Patients with NAFLD Experimental group (n = 25) Placebo group (n = 25) |
↓ Plasma IL-6, CRP, cytokeratin-18, and NF-κB | [163] |
| Resveratrol | RCT | 500 mg/day or placebo for 6 weeks |
Patients with ulcerative colitis Experimental group (n = 25) Placebo group (n = 25) |
↓ Serum TNF-α, CRP, and NF-κB | [164] |
| Resveratrol | RCT | 500 mg/day or placebo for 30 days |
Adult smokers Experimental group (n = 25) Placebo group (n = 25) |
↓ CRP | [165] |
| Resveratrol | RCT | 800 mg/day or placebo for 8 weeks |
Patients with T2DM Experimental group (n = 25) Placebo group (n = 20) |
NS effects on blood TNF-α, IL-6, CRP, and IL-1β NS effects on expression of genes NF-κB, TLR2, and TLR4 |
[166] |
| Resveratrol | RCT | 500 mg/day or placebo for 4 weeks |
CKD patients Experimental group (n = 9) Placebo group (n = 11) |
NS changes in plasma TNF-α, CRP, IL-6, and NF-κB | [167] |
RCT randomized controlled trial, OLCT open-label clinical trial, NS no significant, CKD chronic kidney disease, NAFLD non-alcoholic fatty liver disease, T2DM type 2 diabetes mellitus, EGCG epigallocatechin-3-gallate, CRP C-reactive protein, IL-6 interleukin 6, TNF-α, tumor necrosis factor alpha, IL-4 interleukin 4, IL-8 interleukin 8, IL-18 interleukin 18, IL-1β interleukin-1β, NF-kB transcription nuclear factor kappa B, IL-1Rα interleukin-1R alpha, MCP-1 monocyte chemotactic protein, ICAM intercellular adhesion molecule, VCAM vascular cell adhesion molecule, CD40L CD40 ligand, MDA malondialdehyde, ox-LDL oxidized low density lipoprotein, TLR2 toll-like receptor 2, TLR4 toll-like receptor 4