Agranulocytosis: an adverse effect of allopurinol treatment

A review of the Phyllanthus genus plants: Their phytochemistry, traditional uses, and potential inhibition of xanthine oxidase

Hyperuricemia is a risk factor for gout and other cardiovascular diseases. One of the therapies used is Allopurinol. Unfortunately, it has unwanted side effects. These conditions made researchers continue to seek and develop alternative treatments from natural products. One of which is from plants of the Phyllanthus genus. One of their contents was polyphenols, especially flavonoids. It is an alternative treatment for hyperuricemia because of its minimal side effects. The flavonoids in this genus were reported to have xanthine oxidase inhibitory: quercetin, kaempferol, rutin, apigenin, luteolin, myricetin, catechin, epicatechin, and epigallocatechin with IC50 values ​​from 0.44 M to > 100μM. The presence of π-π interactions between planar rings A and C on flavones with phe 1009 and phe 914 and the addition of hydroxyl groups on flavonoid compounds plays a crucial role in inhibiting xanthine oxidase.

Synthesis and biological evaluation of thiazolidine-2-thione derivatives as novel xanthine oxidase inhibitors

Xanthine oxidase (XO) is a key enzyme in the generation and development of hyperuricemia. Thiazolidine-2-thione, a typical heterocyclic compound, have been widely used in the field of drug synthesis. In this study, a series of novel thiazolidine-2-thione derivatives were synthesized as XO inhibitors, and the XO inhibitory potencies of obtained compounds were evaluated by in vitro enzyme catalysis. The result shown that compound 6k behaved the strongest XO inhibitory activity with an IC₅₀ value of 3.56 μmol/L, which was approximately 2.5-fold more potent than allopurinol. The structure-activity relationship revealed that the phenyl-sulfonamide group was indispensable for thiazolidine-2-thione derivatives to produce XO inhibitory activity. The enzyme inhibition kinetics analyses confirmed that compound 6k exerted a mixed-type XO inhibition. Additionally, the molecular docking results suggested that the 4-fluorophenyl-sulfonyl moiety could interact with Gly260 and Ile264 in the innermost part of the active pocket through 2 hydrogen bonds, while the thiazolidinethione moiety could form two hydrogen bonds with Glu263 and Ser347 in hydrophobic pockets. In summary, the results described above suggested that compound 6k could be a valuable lead compound for the treatment of hyperuricemia as a novel XO inhibitor.

Utilization of Thiopurine Metabolites and Allopurinol in Pediatric Acute Lymphoblastic Leukemia: Consideration for an Algorithmic Approach

Persistently elevated absolute neutrophil counts during maintenance for acute lymphoblastic leukemia is a risk factor for relapse and may be related to wild-type thiopurine methyltransferase activity and overly efficient shunting of 6-mercaptopurine to hepatotoxic metabolites (6-methylmercaptopurine nucleotides), leading to low 6-thioguanine nucleotides. 6-mercaptopurine is also metabolized by xanthine oxidase, and therefore allopurinol, an inhibitor of xanthine oxidase, allows for increased 6-thioguanine nucleotides and decreased 6-methylmercaptopurine nucleotide. Here, we report our experience with allopurinol for persistently elevated absolute neutrophil count or hepatotoxicity and suggest an algorithmic approach for checking thiopurine metabolites and initiating allopurinol in acute lymphoblastic leukemia maintenance.

In vitro and in vivo ameliorative effects of polyphenols from purple potato leaves on renal injury and associated inflammation induced by hyperuricemia

In the present study, the ameliorative effects of polyphenols from purple potato leaves (PSPLP) on hyperuricemia were investigated. HPLC-MS analysis showed that PSPLP was mainly composed of caffeoylquinic acid derivatives (84%). PSPLP inhibited the levels of cytokines (IL-1β, IL-6, and TNF-α) in monosodium urate-induced RAW264.7 cells. In vivo, PSPLP significantly inhibited the level of uric acid in hyperuricemia mice from 209.6 to 166.6 μM, and significantly interfered with the activities of xanthine oxidase (XOD) and adenosine deaminase in liver, the activity of XOD decreased from 13.5 to 11.6 U/gprot. PSPLP can decrease serum creatinine level from 105 to 59 μM, and urea nitrogen level from 21.9 to 14.1 mM, which can effectively protect kidney. These results provide a reference for future research and application of PSPLP as a functional food to intervene hyperuricemia and associated inflammation. PRACTICAL APPLICATIONS: This study evaluated the effect of polyphenols from purple potato leaves (PSPLP) on hyperuricemia. The results suggested that PSPLP has an important role in the intervention of hyperuricemia and hyperuricemic-related inflammation or renal injury, and can be used in the application of functional foods. These results provided a basis for further study on the biological activities of polyphenols from purple sweet potato leaves.

Effect of Lactobacillus acidophilus fermentation on the composition of chlorogenic acids and anti-hyperuricemia activity of Artemisia selengensis Turcz

FASTE can relieve hyperuricemia by inhibiting the production of uric acid, alleviating oxidative stress damage and inflammation, promoting uric acid excretion and improving the abundance of intestinal flora.

Leishmania mexicana in a central Texas cat: clinical presentation, molecular identification, sandfly vector collection and novel management

Case summary

This case report documents the clinical appearance, diagnosis and novel treatment of a central Texas cat with cutaneous leishmaniosis. The cat presented with a linear erosion on the right pinnal margin, an ulcerated exophytic nodule on the right hock and a swelling in the right nostril. Cytological and histopathological findings were consistent with leishmaniosis. PCR confirmed the presence of Leishmania mexicana, a species endemic to Texas. An epidemiological investigation was conducted by trapping sandflies from the cat’s environment. Sandflies collected were identified as Lutzomyia species, known vectors of Leishmania species. Given the lack of validated medical therapies for L mexicana in cats, treatments typically prescribed for canine leishmaniosis were administered. Allopurinol achieved clinical success but was discontinued due to suspected drug-related neutropenia. Topical imiquimod also improved lesional skin but was not sustainable due to application difficulty. Oral administration of artemisinin resulted in significant clinical improvement of cutaneous lesions without reported adverse events. Nearly 8 months after the initiation of artemisinin therapy, the cat remained systemically healthy with stable lesions.

Relevance and novel information

This case report demonstrates endemic feline leishmaniosis in central Texas and provides the clinician with alternative therapeutic options for medical management.

Therapeutic Efficacy of Urinile Against Gouty Arthritis

Gout is arthritis caused due to Monosodium urate (MSU) crystals deposition occurring particularly in patients with associated comorbidities limiting the use of conventional therapies. This study was planned to evaluate the therapeutic efficacy of urinile (a herbal drug) for the treatment of gouty arthritis. Allopurinol was used as standard drug (positive control). The study population of 250 volunteers (gouty arthritis patients) were divided into 2 groups as test and control group (n = 125 each). Gouty arthritis patients in test and control group were treated with 300 mg each of urinile and allopurinol, respectively. Clinical symptoms of all the study volunteers were recorded and serum uric acid was determined. Significant (p < 0.05) reduction in serum uric acid level toward normal was found in test group individuals. Clinical symptoms of gouty arthritis patients were also improved in test group compared to control group. Results showed that urinile has the potential to decrease serum uric acid level in gouty arthritis patients probably because of its antioxidant potential and xanthine oxidase inhibitory activity. It can be concluded that the tested herbal drug urinile is more potent in treating gouty arthritis patients and can be used as an effective alternative to the most commonly used allopathic drugs.

Anti-hyperuricemic and nephroprotective effects of extracts from Chaenomeles sinensis (Thouin) Koehne in hyperuricemic mice

CSF-E possesses potent anti-hyperuricemic through inhibiting XOD activity.

Anti-hyperuricemic and nephroprotective effects of Modified Simiao Decoction in hyperuricemic mice

ETHNOPHARMACOLOGICAL RELEVANCE

Modified Simiao Decoction (MSD), based on clinical experience, has been used for decades and famous for its efficiency in treating hyperuricemic and gouty diseases.

AIM OF THE STUDY

To investigate the effects of MSD on anti-hyperuricemic and nephroprotective effects are involved in potassium oxonate-induced hyperuricemic mice.

MATERIALS AND METHODS

The effects of MSD were investigated in hyperuricemic mice induced by potassium oxonate. MSD were fed to hyperuricemic mice daily at a dose of 0.45, 0.90, 1.80 g/kg for 10 days, and allopurinol (5mg/kg) was given as a positive control. Serum and urine levels of uric acid and creatinine, and fractional excretion of uric acid (FEUA) were determined by colorimetric method. Its nephroprotective effects were evaluated by determining a panel of oxidative stress markers after the intervention in hyperuricemic mice. Simultaneously, protein levels of urate transporter 1 (URAT1) and organic anion transporter 1 (OAT1) in the kidney were analyzed by Western blotting.

RESULTS

MSD could inhibit XOD activities in serum and liver, decrease levels of serum uric acid, serum creatinine and BUN, and increased levels of urine uric acid, urine creatinine, FEUA dose-dependently through down-regulation of URAT1 and up-regulation of OAT1 protein expressions in the renal tissue of hyperuricemic mice. It also effectively reversed oxonate-induced alterations on renal MDA levels and SOD activities in this model.

CONCLUSION

MSD processes uricosuric and nephroprotective actions by regulating renal urate transporters and enhancing antioxidant enzymes activities to improve renal dysfunction in hyperuricemic mice.