Is there a role for cherries in the management of gout?

The alleviatory effects of koumine on MSU-induced gouty arthritis via the TLR4/NF-κB/NLRP3 pathway

The aim of this study was to validate the preventive effects of koumine (KM), a monoterpene indole alkaloid, on gouty arthritis (GA) and to explore its possible mechanisms. C57BL/6 mice were intraperitoneally administered KM (0.8, 2.4 or 7.2 mg/kg), colchicine (3.0 mg/kg) or sterile saline. One hour later, a monosodium urate (MSU) suspension was injected into the right hind paws of the mice to establish an acute gout model. Inflammation symptoms were evaluated at 0, 3, 6, 12 and 24 h, and the mechanical withdrawal threshold was evaluated at 0, 6 and 24 h. After 24 h, the mice were euthanized, and the joint tissue, kidney and blood were collected for subsequent experiments. Histological examination and antioxidant enzyme, kidney index and serum uric acid (UA) measurements were taken. The expression levels of the signalling pathway components were determined. KM effectively alleviated the symptoms of redness, swelling and pain; counteracted inflammatory cell infiltration; and increased antioxidant enzyme levels, reduced kidney index and serum UA levels through regulating UA excretion in MSU-induced mice. The expression of toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB)/nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) signalling pathway proteins and mRNA were reduced in the KM group. These results suggest that KM may be effective in alleviating GA through the TLR4/NF-κB/NLRP3 pathway.

Effect of Prunus cerasus (Sour Cherry) on Nephrolithiasis in Children: The First Noninferiority Two-Arm Randomized Clinical Trial

OBJECTIVE

 The present study evaluated the effect of Prunus cerasus (sour cherry) on children with nephrolithiasis.

METHOD

 We conducted a randomized noninferiority controlled trial to evaluate the therapeutic efficacy of P. cerasus among children with nephrolithiasis. Subjects in the intervention group received 1.25 mL/kg of cherry concentrate once daily for 2 months, while the control group received 1 mL/kg Polycitra-K, which consists of 220 g citrate potassium and 68 g citric acid in 1000 mL sterile water. The major outcome was sonographically determined number and sizes of kidney stones, which were assessed before and after the trial.

RESULTS

 Sixty-eight children completed the study. At trial onset, both groups were similar in baseline characteristics (P >.05). In within-group analysis, the number of stones significantly decreased in both groups (P <05). After 2 months, the number of nephrolithiasis was 1.55 ± 0.49 and 1.47 ± 0.67 in the control and intervention groups, respectively (P value=.56). The percentage of change in calculi number was 44.11 ± 11.12 and 38.14 ± 14.08 in the control and intervention groups, respectively (P value=.08). At the end of the study, the urine pH was 6.46 ± 0.99 and 6.14 ± 0.83 in the control and intervention groups, respectively (P value=.19). Urine calcium and uric acid concentrations were 32.00 ± 12.32 and 28.95 ± 10.96 mg/mm (P value=.68) and 24.11 ± 10.58 and 30.03 ± 11.39 mg/mm (P value=.012) in control and intervention groups, respectively.

CONCLUSION

 Our clinical data supported the efficacy of sour cherry in the treatment of nephrolithiasis compared to Polycitra-K. Future randomized controlled trials are needed to confirm the present observation.

A Review of Medicinal Plants and Phytochemicals for the Management of Gout

Gout, characterized by elevated uric acid levels, is a common inflammatory joint disease associated with pain, joint swelling, and bone erosion. Existing treatments for gout often result in undesirable side effects, highlighting the need for new, safe, and cost-effective anti-gout drugs. Natural products, including medicinal plants and phytochemicals, have gained attention as potential sources of anti-gout compounds. In this review, we examined articles from 2000 to 2020 using PubMed and Google Scholar, focusing on the effectiveness of medicinal plants and phyto-chemicals in managing gout. Our findings identified 14 plants and nine phytochemicals with anti-gout properties. Notably, Teucrium polium, Prunus avium, Smilax riparia, Rhus coriaria, Foenic-ulum vulgare, Allium cepa, Camellia japonica, and Helianthus annuus exhibited the highest xa-thine oxidase inhibitory activity, attributed to their unique natural bioactive compounds such as phenolics, tannins, coumarins, terpenoids, and alkaloids. Herbal plants and their phytochemicals have demonstrated promising effects in reducing serum urate and inhibiting xanthine. This review aims to report recent studies on plants/phytochemicals derived from herbs beneficial in gout and their different mechanisms.

Protective effects of corni fructus extract in mice with potassium oxonate-induced hyperuricemia

Corni fructus is consumed as food and herbal medicine in Chinese culture. Studies have revealed that corni fructus exhibits potent antioxidant activity; however, few studies have investigated the ability of corni fructus to lower uric acid concentrations. In this study, the xanthine oxidase (XO) inhibition and uric acid–lowering effect of corni fructus extract (CFE) were evaluated in mice with potassium oxonate–induced hyperuricemia. Hyperuricemia is a chronic disease prevalent worldwide and is associated with high recurrence rates. In addition, drugs used to treat hyperuricemia induce side effects that discourage patient compliance. Hyperuricemia induces metabolic imbalances resulting in accumulative uric acid deposition in the joints and soft tissues. Hyperuricemia not only induces gout but also interrupts hepatic and renal function, thereby trigging severe inflammation and various complications, including obesity, nonalcoholic fatty liver disease, diabetes, and metabolic diseases. In this study, the ethyl acetate fraction (EAF) of CFE resulted in yields of antioxidant photochemical components significantly higher than those of CFEs formed using other substances. The EAF of CFE exhibited high free radical scavenging activity and XO inhibition and effectively lowered uric acid concentrations in the animal model of chemically induced hyperuricemia. The results of this study can serve as a reference for the prevention of preclinical gout as well as for functional food research.

Hyperuricemia: Features of the Diet

The association of hyperuricemia (HU) with cardiovascular disease (CVD), diabetes, metabolic syndrome, and kidney disease has been demonstrated in numerous studies. НU is the main pathogenetic factor in the development of gout and is associated with an increase in overall and cardiovascular mortality. НU is included in the list of factors determining cardiovascular risk. According to epidemiological studies, there is a high prevalence of HU in the world and its increase in recent decades. A number of factors have been identified that contribute to the increased risk of НU. Non-modifiable factors include gender, age, genetic factors, and modifiable factors include diet and lifestyle. Nutritional unbalances, increased life expectancy, increased prevalence of obesity, and increased use of drugs (especially diuretics) are seen as contributing factors to the rise in НU. The review was carried out to summarize the available information on the effect of dietary habits, individual foods and nutrients on serum uric acid (SUA) levels and the risk of developing HU. The review presents the results of scientific studies demonstrating the relationship of НU with the consumption of foods rich in purines (offal, red meat, fish, seafood, legumes), alcohol consumption, drinks sweetened with fructose, coffee, dairy products, vegetables and fruits. Diet correction is an important and necessary step in the prevention and treatment of НU. The article reviews the basic principles of dietary management in HU and provides dietary recommendations for patients. For effective prevention and treatment of НU, a mandatory correction of the diet is required.

Role of diet in hyperuricemia and gout

BACKGROUND

Gout is the most common form of inflammatory arthritis, affecting 41 million adults worldwide. The global burden of gout has been increasing over the last three decades, yet its management remains suboptimal. The primary aim of this manuscript is to review the impact of various diets such as the DASH, Mediterranean, and low purine diets; weight loss; and individual foods, including alcohol, caffeine, cherry, dairy, high-fructose corn syrup, omega-3 fatty acids, and vitamin C on hyperuricemia and clinical gout outcomes such as flares and tophi.

CONCLUSION

Few studies to date have specifically evaluated the effect of various dietary approaches on hyperuricemia among people with gout and on gout-specific outcomes. Overall, the dietary factors appear to have a small effect on serum urate levels, and their impact on the long-term clinical course of gout is uncertain. Limited evidence suggests that avoidance of certain foods and beverages may decrease the frequency of gout flares. Weight loss may be beneficial for prevention as well as treatment of gout. Urate-lowering therapy remains the mainstay of therapy, with diet and dietary factors studied to date playing a limited role in the definitive management of gout.

The epigenome: key to understanding and predicting gout flares

Gout is a form of arthritis, resulting from an inflammatory reaction to the deposition of monosodium urate (MSU) crystals in the synovial fluid of the joint space. It is characterised by periods of acute inflammation in the affected joint, or joints (known as gout flares), separated by asymptomatic periods. There seems to be substantial overlap between environmental triggers of gout flares and common environmental modifiers (diet, pharmaceuticals, and stress) of epigenetic markers (DNA methylation, histone modifications, and ncRNA). Very few studies have looked at whether environment is influencing gout through epigenetic mechanisms. The pathogenesis of gouty inflammation is well understood but understanding the variation of response to hyperuricaemia in terms of gout flare initiation is less well known. In this review, we will examine the potential of epigenomics in understanding how gout flares may occur, both in terms of development of hyperuricaemia and the inflammatory response. Looking at the epigenome and its intersection with lifestyle could help identify new targets and strategies for effective management of gout flares.

Targets and mechanisms of dietary anthocyanins to combat hyperglycemia and hyperuricemia: a comprehensive review

Hyperglycemia and hyperuricemia are both metabolic disorders related to excessive amount of metabolites in blood, which are considered as high risk factors for the development of many chronic diseases. Enzymes, cells, tissues and organs, which are relevant to metabolism and excretion of glucose and UA, are usually regarded to be the targets in treatment of hyperglycemia and hyperuricemia. Several drugs have been commonly applied to combat hyperglycemia and hyperuricemia through various targets but with unignorable side effects. Anthocyanins have become promising alternatives against hyperglycemia and hyperuricemia because of their bio-activities with little side effects. Structurally different anthocyanins from berry fruits, cherries and purple sweet potato lead to the diverse functional activity and property. This review is aimed to illustrate the specific targets that are available for anthocyanins from berry fruits, cherries and purple sweet potato in hyperglycemia and hyperuricemia management, as well as discuss the structure-activity relationship, and the underlying mechanisms associated with intracellular signaling pathway, anti-oxidative stress and anti-inflammation. In addition, the relationship of hyperglycemia and hyperuricemia, and the possibly regulative role of anthocyanins against them, along with the effects of anthocyanins in clinical trial are mentioned.

Cherry extracts attenuate inflammation and oxidative stress triggered by monosodium urate crystals in THP-1 cells

The microwaves-assisted extraction (MAE) for concentration of cherry phytochemicals has seen explored. Polyphenols from cherries, Prunus avium (L.) L., were extracted using a microwave oven at 2,450 MHz, 453 W for a period of 60 s (T60), and was compared versus an unprocessed MAE extract (T0). The extracts were analyzed for total polyphenols, total anthocyanins, and antioxidant capacity. THP-1 cells were stimulated with monosodium urate (MSU) crystals at 150 µg/ml for 24 hr. Cherry extracts were added to cultures concurrently with MSU or 3 hr before MSU addition as pretreatments. Reactive oxygen species (ROS), IL-1β levels, and MSU crystal phagocytosis were evaluated. T60 extract showed a higher concentration of polyphenols, anthocyanins, and antioxidant activity than T0 extract. ROS were inhibited using the 1:800 and 1:1,600 (v:v) dilutions from both extracts, even used as pretreatments. IL-1β levels and MSU crystal phagocytosis were reduced. Cherry is a source of polyphenolic compounds with antioxidant and anti-inflammatory activity. PRACTICAL APPLICATIONS: The cherries and a cherry extract obtained via MAE has benefits as a possible coadjuvant to conventional gout therapy due to attenuate the inflammation and the oxidative stress triggered by monosodium urate crystals in THP-1 cells, which mimic an acute episode of gout.

Lack of effect of tart cherry concentrate dose on serum urate in people with gout

OBJECTIVES

Cherry concentrate has been suggested to reduce serum urate (SU) and gout flares. The aims of this study were to determine the magnitude of the effect of tart cherry concentrate on SU in people with gout, the most effective dose of tart cherry concentrate for lowering SU, and adverse effects.

METHODS

Fifty people with gout and SU > 0.36 mmol/l were recruited. Half were on allopurinol and half were on no urate-lowering therapy. Participants were randomized to receive tart cherry juice concentrate: placebo, 7.5 ml, 15 ml, 22.5 ml or 30 ml twice daily for 28 days. Blood samples were taken at baseline, then at 1, 3 and 5 h post cherry and then on days 1, 3, 7, 14, 21 and 28. The area under the curve for SU was calculated over the 28-day study period.

RESULTS

Cherry concentrate dose had no significant effect on reduction in SU area under the curve, urine urate excretion, change in urinary anthocyanin between day 0 and day 28, or frequency of gout flares over the 28-day study period (P = 0.76). There were 24 reported adverse events, with only one (hyperglycaemia) considered possibly to be related to cherry concentrate. Allopurinol use did not modify the effect of cherry on SU or urine urate excretion.

CONCLUSION

Tart cherry concentrate had no effect on SU or urine urate excretion. If there is an effect of cherry concentrate on gout flares over a longer time period, it is not likely to be mediated by reduction in SU.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR), https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=368887, ANZCTR 12615000741583).

Effects of Tart Cherry Powder on Serum Uric Acid in Hyperuricemia Rat Model

Hyperuricemia, as a critical risk factor for various adverse clinical outcomes, shows a trend of increasing prevalence among young-aged population. Dietary adjuvant therapy by function foods, such as tart cherry, is promising. Thus, effects of tart cherry powder specialized in hyperuricemia were explored via establishing a hyperuricemia model in Sprague Dawley rats by cotreatment with oteracil potassium and adenine. The results indicated that low dose of tart cherry powder (0.17 g/kg·bw) showed effects on hyperuricemia by slightly decreasing serum uric acid and improving kidney injury, whereas high dose of tart cherry powder (0.50 g/kg·bw) could merely alleviate kidney injury. Meanwhile, adenosine deaminase activity rather than xanthine oxidase activity was affected at low dose, which reveals low dose of tarty cherry powder may be beneficial to hyperuricemia through reduction of ADA activity, and its reported potentials on antioxidation or anti-inflammation provide clues for further study.

Effectiveness of Cherries in Reducing Uric Acid and Gout: A Systematic Review

BACKGROUND

Previous studies have reported the use of complementary therapies to reduce the risk of gout attacks. In this study, we assessed the effectiveness of cherries in reducing uric acid levels associated with gout.

METHODS

We searched for relevant studies on PubMed, Embase, and the Cochrane Library without restrictions on language from inception until August 15, 2019. The risk of bias was evaluated using the PRISMA statement and checklist, and the methodological quality was assessed using the Cochrane Collaboration tool.

RESULTS

The six studies included in this systematic review reported decreases in the incidence and severity of gout following the ingestion of cherries. Gout patients regularly ingesting cherry extract/juice reported fewer gout flare ups than those patients who did not supplement their diets with cherry products. Overall, we observed a positive correlation between the consumption of tart cherry juice and a decrease in serum uric acid concentration.

CONCLUSIONS

Current evidence supports an association between cherry intake and a reduced risk of gout attacks. Note however that we were unable to conduct effective meta-analysis due to a lack of relevant studies and a high degree of variation in the methodologies and metrics used in previous studies. Further comprehensive trials or long-term follow-up studies will be required to evaluate the efficacy of cherry intake in treating patients with gout or hyperuricemia.