Two families of proteins, the bestrophins (Best) and the recently cloned TMEM16 proteins (anoctamin, Ano), recapitulate properties of Ca²⁺-activated Cl^- currents. Best1 is strongly expressed in the retinal pigment epithelium and could have a function as a Ca²⁺-activated Cl^- channel as well as a regulator of Ca²⁺ signaling. It is also present at much lower levels in other cell types including epithelial cells, where it regulates plasma membrane localized Cl^- channels by controlling intracellular Ca²⁺ levels. Best1 interacts with important Ca²⁺-signaling proteins such as STIM1 and can interact directly with other Ca²⁺-activated Cl^- channels such as TMEM16A. Best1 is detected in the endoplasmic reticulum (ER) where it shapes the dynamic ER structure and regulates cell proliferation, which could be important for renal cystogenesis. Ca²⁺-activated Cl^- channels of the anoctamin family (TMEM16A) show biophysical and pharmacological properties that are typical for endogenous Ca²⁺-dependent Cl^- channels. TMEM16 proteins are abundantly expressed and many reports demonstrate their physiological importance in epithelial as well as non-epithelial cells. These channels are also activated by cell swelling and can therefore control cell volume, proliferation and apoptosis. To fully understand the function and regulation of Ca²⁺-activated Cl^- currents, it is necessary to appreciate that Best1 and TMEM16A are embedded in a protein network and that they probably operate in functional microdomains.

Metabolic disease encompasses most contemporary non-communicable diseases, especially cardiovascular and fatty liver disease. Mulberry fruits of Morus alba L. are a favoured food and a traditional medicine. While they are anti-atherosclerotic and reduce hyperlipidemic risk factors, studies need wider scope that include ameliorating cardiovascular and liver pathologies if they are to become clinically effective treatments. Therefore, the present study sought to show that freshly dried mulberry fruits (dMF) might counteract the metabolic/cardiovascular pathologies in mice made hyperlipidemic by high-fat diet (HF). C57BL/6J mice were fed for 3 months with either: i) control diet, ii) HF, iii) HF+100 mg/kg dMF, or iv) HF+300 mg/kg dMF. Body weight gain, food intake, visceral fat accumulation, fasting blood glucose, plasma lipids, and aortic, heart, and liver histopathologies were evaluated. Adipocyte lipid accumulation, autophagy, and bile acid binding were also investigated. HF increased food intake, body weight, visceral fat, plasma total cholesterol (TC) and low-density lipoprotein (LDL), TC/HDL ratio, blood glucose, aortic collagen, arterial and cardiac wall thickness, and liver lipid. Both dMF doses prevented hyperphagia, body weight gain, and visceral fat accumulation, lowered blood glucose, plasma TG and unfavourable TC/HDL and elevated plasma HDL beyond baseline. Arterial and cardiac wall hypertrophy, aortic collagen fibre accumulation and liver lipid deposition ameliorated in dMF-fed mice. Clinical trials on dMF are worthwhile but outcomes should be holistic commensurate with the constellation of disease risks. Here, dMF should supplement the switch to nutrient-rich from current energy-dense diets that are progressively crippling national health systems.

B. monnieri extract (BME) is an abundant source of bioactive compounds, including saponins and flavonoids known to produce vasodilation. However, it is unclear which components are the more effective vasodilators. The aim of this research was to investigate the vasorelaxant effects and mechanisms of action of saponins and flavonoids on rat isolated mesenteric arteries using the organ bath technique. The vasorelaxant mechanisms, including endothelial nitric oxide synthase (eNOS) pathway and calcium flux were examined. Saponins (bacoside A and bacopaside I), and flavonoids (luteolin and apigenin) at 0.1–100 µM caused vasorelaxation in a concentration-dependent manner. Luteolin and apigenin produced vasorelaxation in endothelial intact vessels with more efficacy (E_max 99.4 ± 0.7 and 95.3 ± 2.6%) and potency (EC₅₀ 4.35 ± 1.31 and 8.93 ± 3.33 µM) than bacoside A and bacopaside I (E_max 83.6 ± 2.9 and 79.9 ± 8.2%; EC₅₀ 10.8 ± 5.9 and 14.6 ± 5.4 µM). Pretreatment of endothelial intact rings, with L-NAME (100 µM); an eNOS inhibitor, or removal of the endothelium reduced the relaxant effects of all compounds. In K⁺-depolarised vessels suspended in Ca²⁺-free solution, these active compounds inhibited CaCl₂-induced contraction in endothelial denuded arterial rings. Moreover, the active compounds attenuated transient contractions induced by 10 µM phenylephrine in Ca²⁺-free medium containing EGTA (1 mM). Thus, relaxant effects occurred in both endothelial intact and denuded vessels which signify actions through both endothelium and vascular smooth muscle cells. In conclusion, the flavonoids have about twice the potency of saponins as vasodilators. However, in the BME, there is ~20 × the amount of vaso-reactive saponins and thus are more effective.

The P2 receptors that mediate contraction of the rat isolated small (SPA, 200–500 μm i.d.) and large (LPA, 1–1.5 mM i.d.) intrapulmonary arteries were characterized. In endothelium‐denuded vessels the contractile order of potency was α,β‐methyleneATP (α,β‐meATP)>>UDP=UTP=ATP=2‐methylthioATP>ADP in the SPA and α,β‐meATP=UTPUDP>2‐methylthioATP, ATP>>ADP in the LPA. α,β‐meATP, 2‐methylthioATP and ATP had significantly greater effects in the SPA than the LPA (P<0.001), but there was no difference in the potency of UTP or UDP between the vessels. In the SPA, P2X₁ receptor desensitisation by α,β‐meATP (100 μM) inhibited contractions to α,β‐meATP (10 nM–300 μM), but not those to UTP or UDP (100 nM–300 μM). In the LPA, prolonged exposure to α,β‐meATP (100 μM) did not desensitize P2X receptors. Pyridoxalphosphate‐6‐azophenyl‐2′,4′‐disulphonic acid (PPADS), suramin and reactive blue 2 (RB2) (30–300 μM) inhibited contractions evoked by α,β‐meATP. UTP and UDP were potentiated by PPADS, unaffected by RB2 and inhibited, but not abolished by suramin. 1 and 3 mM suramin produced no further inhibition, indicating suramin‐resistant components in the responses to UTP and UDP. Thus, both P2X and P2Y receptors mediate contraction of rat large and small intrapulmonary arteries. P2Y agonist potency and sensitivity to antagonists were similar in small and large vessels, but P2X agonists were more potent in small arteries. This indicates differential expression of P2X, but not P2Y receptors along the pulmonary arterial tree. British Journal of Pharmacology (2002) 137, 637–646. doi:10.1038/sj.bjp.0704915