Table 4.

Studies evaluating cherries and anthocyanins on serum urate.

Author	Study	Treatment	Serum urate		Comments
			Control	Treated; p value
Cherries and anthocyanins versus control (or before and after) Animal studies
Haidari et al.77	Animal model examining the effect of tart cherry juice on SU, xanthine oxidoreductase activity, and markers of oxidative stress in rats	14 days of oral tart cherry juice (5 ml/kg)	Hyperuricemic control 214.36 ± 26.42 μmol/l (3.60 ± 0.44 mg/dl)	171.95 ± 25.78 μmol/l (2.89 ± 0.43 mg/dl); p ⩽ 0.05	XO inhibited by 20% SU after 14 days of allopurinol (5 mg/kg) was 72.38 ± 19.24 μmol/l (1.22 ± 0.32 mg/dl), with 58% XO inhibition
Hwa et al.79	Animal model examining the hypouricemic effects of anthocyanin extracts from purple sweet potato (APSP) extract on hyperuricemic mice	Single dose of 100 mg/kg of APSP	Hyperuricemic control 10.25 ± 0.63 mg/dl	4.1 ± 0.04 mg/d; p < 0.01	Reduction of 60% in SU One dose of allopurinol 10 mg/kg reduced SU to 1.84 ± 0.13 mg/dl (82%)
Tsai et al.80	Animal model exploring the antitumor effect of anthocyanin extract from Hibiscus sabdariffa in leukemic rats	Hibiscus anthocyanin extract at 0.2 g/kg/day for 220 days	Leukemic rat control 3.07 ± 0.89 mg/dl	0.87 ± 0.22 mg/dl; p < 0.005	Reduction of 72% in SU Significant SU reduction (p < 0.05) also seen in rats treated with 0.1 g/kg/d
Zhang et al.81	Animal model examining the effects of anthocyanin-rich purple sweet potato extract (APSPE) on XO activity in vitro/ in vivo, as well as SU in hyperuricemic mice	Single dose of 300 mg/kg of APSP (anthocyanin content of 3.53 × 10⁴ cyanidin 3-glucoside equivalent per 100 g APSPE)	Hyperuricemic control 134.67 μmol/l (2.26 mg/dl)	95.50 μmol/l (1.61 mg/dl); p < 0.001	Reduction of 29% in SU Positive control with allopurinol 5 mg/kg lowered SU to nearly undetectable level Significant inhibitory activity on XO
Human studies
Bell et al.26	Single-blind, two-phase, randomized, crossover study examining the effects of tart cherries on urate activity and inflammation in 12 healthy participants	Montmorency tart cherry juice concentrate at 30 or 60 ml (30 ml tart cherry juice ~90 cherries)	Baseline: ~494 µmol/l (8.3046 mg/dl)	8 hr postsupplementation: ~316 µmol/l (5.31 mg/dl); p < 0.0001	Reduction of 36% (178 µmol/l/ 2.99 mg/dl) in SU, 250% (178 μmol/mmol creatinine) increase in urinary urate at 2 h Change independent of dose
Jacob et al.78	Examining the effects of cherry consumption on plasma urate, antioxidant, and inflammatory markers in 10 healthy women	280 g of sweet Bing cherries (~45 cherries)	Baseline: 214 ± 13 μmol/l (3.60 ± 0.22 mg/dl)	5 h postcherry consumption: 183 ± 15 μmol/l (3.07± 0.25 mg/dl); p <0.05	Reduction of 14% in SU Urinary urate increased from 202 ± 13 to 350 ± 33 μmol/mmol creatinine (73%) after 3 h
Schlesinger et al.25	Randomized controlled trial of cherry versus pomegranate juice concentrate for gout prophylaxis in 14 patients with crystal-proven gout	1 Tbsp (~45–60 cherries) of cherry juice concentrate twice daily for 4 months	Pomegranate juice 7.45 ± 1.62 to 6.14 ± 1.07 mg/dl	Cherry juice 8.37 ± 0.82 to 8.17 ± 1.1 mg/dl; p value not provided	No significant change in serum urate
Schlesinger et al.25	Retrospective study evaluating cherry juice concentrate, taken for over 4 months, on gout flare prophylaxis in 24 crystal-proven gout patients	1 Tbsp (~45–60 cherries) of cherry juice concentrate twice daily for 4–6 months	Baseline: 9.0 ± 1.1 mg/dl	After cherry juice: 8.7 ± 1.4 mg/dl; p = 0.5943	Baseline SU in patients receiving allopurinol was 8.4 ± 0.6 mg/dl and decreased to 6.2 ± 0.4 mg/dl (p = 0.0052)

APSP, anthocyanin extracts from purple sweet potato; APSPE, anthocyanin-rich purple sweet potato extract; Tbsp, tablespoon; SU, serum urate; XO, xanthine oxidase.