Anti-hyperuricemic and nephroprotective effects of Rhizoma Dioscoreae septemlobae extracts and its main component dioscin via regulation of mOAT1, mURAT1 and mOCT2 in hypertensive mice.

Rhizoma Dioscoreae septemlobae (RDSE) has been widely used for the treatment of hyperuricemia in China. However, the therapeutic mechanism has been unknown. This study investigated the antihyperuricemic mechanisms of the extracts obtained from RDSE and its main component dioscin (DIS) in hyperuricemic mice. Hyperuricemic mice were induced by potassium oxonate (250 mg/kg). RDSE or DIS was orally administered to hyperuricemic mice at dosages of 319.22, 638.43, 1276.86 mg/kg/day for 10 days, respectively. Uric acid or creatinine in serum and urine was determined by HPLC or HPLC-MS/MS, respectively. The xanthine oxidase (XO) activities in mice liver were examined in vitro. Protein levels of organic anion transporter 1 (mOAT1), urate transporter 1 (mURAT1) and organic cation transporter 2 (mOCT2) in the kidney were analyzed by western blotting. The results indicated that uric acid and creatinine in serum were significantly increased by potassium oxonate, as compared to that of control mice. Compared saline-treated group, after RDSE treatment in the high and middle dose, the expression of mOAT1 increased 47.98 and 54.48 %, respectively, which accompanied with the decreased expression of mURAT1 (47.63 %) in high dose. After DIS treatment in high, middle and low dose, the expression of mOAT1 increased 23.93, 32.80 and 25.28 % compared to saline-treated group, respectively, which accompanied with the decreased expression of mURAT1 (51.07, 51.42 and 51.35 %). However, RDSE and DIS displayed a weak XO inhibition activity compared with allopurinol. Therefore, RDSE and DIS processed uricosuric and nephroprotective actions by regulation of mOAT1, mURAT1 and mOCT2.

Clinical characteristics and surgical treatment of oesophageal gastrointestinal stromal tumours.

OBJECTIVE: Oesophageal gastrointestinal stromal tumours (GISTs) are extremely rare. The preoperative diagnosis is complicated by lack of specificity and the clinical features of patients with oesophageal GISTs need to be fully studied. METHODS: We have reviewed retrospectively the medical records of those patients who are treated surgically for oesophageal GISTs in our two hospitals. RESULTS: Eight oesophageal GISTs were identified among the 63 oesophageal mesenchymal tumours in our two hospitals in the past 30 years. Of the eight patients, the male:female ratio was 5:3; the median age of the patients was 57 years (range 49-71 years). Dysphagia was the most common symptom, and all cases were diagnosed postoperatively. The tumours were resected by enucleation or oesophagectomy. The median follow-up was 59 months, ranging from 14 to 202 months, with four of the patients succumbing to the disease, among them two with recurrence and another two with metastasis. CONCLUSIONS: Our study indicates that oesophageal GIST is rather rare, and it has relatively high recurrence and mortality rates, especially for patients with large tumours (larger than 9 cm). At present, surgical resection and postoperative diagnosis remain the mainstay for treatment of patients with oesophageal GISTs in China.