Isolation, characterisation and complement fixation activity of acidic polysaccharides from Argemone mexicana used as antimalarials in Mali.

CONTEXT: Global studies on Argemone mexicana L. (Papaveraceae) traditionally used against malaria in Mali are limited to its low-mass compounds activities, and little information on its bioactive polysaccharides is available. OBJECTIVE: This study determines the structure and the immunomodulatory activity of polysaccharides from aerial parts of A. mexicana. MATERIALS AND METHODS: Acidic polysaccharides from this plant material named HMAmA1 and HMAmA2 were isolated from water extracts. Their monosaccharide composition was determined by gas chromatography. Glycosidic linkages were determined using GC-MS. NMR was also applied. The polymers were tested for effects on the human complement system in vitro at different doses. RESULTS: The monosaccharide composition showed that the two polysaccharides contained in different amounts the following monomers: arabinose, rhamnose, galactose, and galacturonic acid. Overall structural analysis showed the presence of a low ratio of 1,2-linked rhamnose compared to 1,4-linked galacturonic acid with arabinogalactans substituted on position 4 of rhamnose. NMR data showed the presence of galacturonans alternated by rhamnogalacturonans bearing arabinose and galactose units. α-Linkages were found for l-arabinose, l-rhamnose and d-galacturonic acid, while ß-linkages were found for d-galactose. The two polysaccharides exhibited strong complement fixation activities, with HMAmA1 being the highest potent fraction. ICH50 value of HMAmA1 was 5 µg/mL, compared to the control BPII being 15.9 µg/mL. DISCUSSION AND CONCLUSIONS: Polysaccharides form A. mexicana presented a complement fixation effect. The complement system is an important part of the immune defense, and compounds acting on the cascade are of interest. Therefore, these polymers may be useful as immunodulatory agents.

Serum uric acid levels and non-alcoholic fatty liver disease in Uyghur and Han ethnic groups in northwestern China.

OBJECTIVE: The aim of this study was to compare serum uric acid values in two ethnically distinct Chinese populations: Uyghur, with a high prevalence of nonalcoholic fatty liver disease, and Han, with a lower prevalence. SUBJECTS AND METHODS: Serum uric acid and several clinical features and laboratory tests relevant to the metabolic syndrome were measured in 4,157 Uyghur and 6,448 Han subjects in a health examination program. The diagnosis of hepatic steatosis was established by abdominal ultrasound examination. RESULTS: The prevalence of nonalcoholic fatty liver disease was 42.3% and 33.3% among Uyghur and Han subjects, respectively. The corresponding prevalence of hyperuricemia was 8.8% and 14.7%. The mean concentration of serum uric acid in Uyghurs also was lower than in Hans (282.75 vs. 310.79 µmol/L; p < 0.01). However, in both populations, the prevalence of nonalcoholic fatty liver disease was increased in association with increasing serum uric acid concentrations, a trend that was more pronounced in Uyghur than in Han subjects (OR 3.279 and 3.230, respectively). Several components of the metabolic syndrome were more pronounced in Uyghurs than in Hans. CONCLUSIONS: Serum uric acid is an independent risk factor in nonalcoholic fatty liver disease in both Uyghurs and Hans, but other risk factors may be more important in the differences in prevalence of the disease between the two ethnic groups.

Serum uric acid levels and non-alcoholic fatty liver disease in Uyghur and Han ethnic groups in northwestern China / Concentração sérica de ácido úrico e doença hepática gordurosa não alcoólica em grupos étnicos Uyghur e Han no nordeste da China

OBJECTIVE: The aim of this study was to compare serum uric acid values in two ethnically distinct Chinese populations: Uyghur, with a high prevalence of nonalcoholic fatty liver disease, and Han, with a lower prevalence. SUBJECTS AND METHODS: Serum uric acid and several clinical features and laboratory tests relevant to the metabolic syndrome were measured in 4,157 Uyghur and 6,448 Han subjects in a health examination program. The diagnosis of hepatic steatosis was established by abdominal ultrasound examination. RESULTS: The prevalence of nonalcoholic fatty liver disease was 42.3% and 33.3% among Uyghur and Han subjects, respectively. The corresponding prevalence of hyperuricemia was 8.8% and 14.7%. The mean concentration of serum uric acid in Uyghurs also was lower than in Hans (282.75 vs. 310.79 µmol/L; p < 0.01). However, in both populations, the prevalence of nonalcoholic fatty liver disease was increased in association with increasing serum uric acid concentrations, a trend that was more pronounced in Uyghur than in Han subjects (OR 3.279 and 3.230, respectively). Several components of the metabolic syndrome were more pronounced in Uyghurs than in Hans. CONCLUSIONS: Serum uric acid is an independent risk factor in nonalcoholic fatty liver disease in both Uyghurs and Hans, but other risk factors may be more important in the differences in prevalence of the disease between the two ethnic groups.

OBJETIVO: O objetivo deste estudo foi comparar os valores de ácido úrico em duas populações chinesas etnicamente diferentes: Uyghur, com alta prevalência de doença hepática gordurosa não alcoólica, e Han, com prevalência mais baixa. SUJEITOS E MÉTODOS: A concentração sérica de ácido úrico e várias características clínicas e testes laboratoriais relevantes para a síndrome metabólica foram determinados em 4.157 indivíduos Uyghur e 6.448 indivíduos Han submetidos a um programa de checkups. O diagnóstico de esteatose hepática foi estabelecido por ultrassom abdominal. RESULTADOS: A prevalência de doença hepática gordurosa não alcoólica foi de 42,3% e 33,3% entre os indivíduos Uyghur e Han, respectivamente. A prevalência correspondente de hiperuricemia foi de 8,8% e 14,7%. A concentração sérica média de ácido úrico em Uyghurs também foi mais baixa do que em Hans (282,75 contra 310,79 µmol/L; p < 0,01). Entretanto, em ambas as populações, a prevalência de doença hepática gordurosa não alcoólica aumentou com a elevação da concentração sérica de ácido úrico, uma tendência mais pronunciada em Uyghurs do que em Hans (OR 3,279 e 3,230, respectivamente). Vários componentes da síndrome metabólica são mais pronunciados em Uyghurs do que em Hans. CONCLUSÕES: A concentração sérica de ácido úrico é um fator de risco independente para a doença hepática gordurosa não alcoólica tanto em Uyghurs quando em Hans, mas outros fatores de risco podem ser mais importantes nas diferenças na prevalência da doença entre esses dois grupos étnicos.