Displaying 1 - 3 of 3
Zuota is regarded as the king of Tibetan medicine. However, due to the confidentiality of this precious medicine, the scientific characterization of Zuota is very scarce, which limits the pharmacology and biosafety studies of Zuota. Herein, we collected four different Zuota samples from Tibet, Qinghai, Gansu, and Sichuan and characterized them by multiple techniques. Our results showed that Zuota was mainly an inorganic mixture of HgS, sulfur, and graphite. Morphologically, Zuota samples were composed of nanoparticles, which further aggregated into microsized particles. Chemically, the majorities of Zuota were S and Hg (in the forms of HgS and pure sulfur). All samples contained pure sulfur with orthorhombic crystalline. Zuota from Qinghai province had different HgS crystalline, namely, hexagonal crystalline. The others were all face-centered cubic crystalline. Carbon in Zuota NPs was in the form of graphite. The implication to future studies of Zuota was discussed.
Erigeron multiradiatus (Lindl.) Benth is a traditional Tibetan medicine herb long used to treat various diseases related to inflammation. Our previous phytochemical studies on E. multiradiatus resulted in the isolation of scutellarin, which is a known flavone glucuronide with comprehensive pharmacological actions. In present study, we investigated the inhibition action of scutellarin on high glucose-induced vascular inflammation in human endothelial cells (ECV304 cells). Consistent with previous reports, exposure of ECV304 cells to high glucose for 24 h caused an increase of intercellular adhesion molecule-1 (ICAM-1) and monocyte chemoattractant protein 1 (MCP-1), and promoted cell adhesion between monocyte and ECV304 cells. However, pretreatment with scutellarin (0.1 and 1 microM) reversed these effects in a concentration-dependent manner. Scutellarin was able to inhibit the activation of NF-kappaB induced by high glucose in ECV304 cells. Furthermore, although oral administration of scutellarin (10 and 50 mg/kg) did not produce significant antihyperglycemic action, it lowered the serum MCP-1 levels significantly in alloxan-induced diabetic mice. Therefore, our results suggest that scutellarin has anti-inflammation effect that may afford some protection against hyperglycemia-induced vascular inflammatory both in vitro and in vivo.
Zuota is regarded as the king of Tibetan medicine. However, the major starting material of Zuota is mercury, which is one very toxic heavy metal. This has aroused serious doubts on the biosafety of Zuota containing drugs. In this study, we quantified the Hg contents in four Zuota samples, monitored the release of Hg in simulated gastric/intestinal juice and evaluated their cytotoxicity to Caco-2 cells. Our results showed that the Hg contents in Zuota samples were in the range of 566-676 mg/g. Fortunately, the release of Hg from Zuota samples was very low in simulated gastric juice, and much lower in simulated intestinal juice. Direct contact of Zuota with Caco-2 cells led to dose-dependent cytotoxicity, including activity loss and membrane leakage. The toxicity was closely related to apoptosis, because the caspase 3/7 levels of Caco-2 cells increased after the exposure to Zuota. Interestingly, Zuota samples inhibited the oxidative stress at low concentrations, but the toxicity could be relived by antioxidants. The possible toxicity should be attributed to the cellular uptake of Zuota particulates. Beyond the cytotoxicity, significant differences among Zuota samples from different institutions were observed, suggesting that the preparation process of Zuota had meaningful influence of its biosafety. The implications to the safety and clinical applications of Zuota are discussed.