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Malus toringoides (Rehd.) Hughes (Rosaceae) is used as a traditional folk medicine in the Tibet autonomous region of China to treat hypertension, hyperglycemia, and hyperlipidemia. However, few modern pharmacological data on the use of this plant against diabetic syndrome are available. In this study, we examined the vascular protection provided by a 70% ethanol extract of M. toringoides (EMT) in human umbilical vein endothelial cells (HUVECs) grown in high-glucose medium and in a high-fat diet/streptozotocin-induced rat diabetes model. EMT significantly suppressed the expression of cell adhesion molecules in both HUVECs and diabetic rats. EMT also inhibited activation of the CX3CL1/CX3CR1 axis and the nuclear factor kappa B (NF-κB) signaling pathway in vivo and in vitro. The results provide a significant information on the vasoprotective properties of M. toringoides that may contribute to the development and application of related herbal medicines. [ABSTRACT FROM AUTHOR]

Chemotherapeutic multidrug resistance (MDR) is a significant challenge to overcome in clinic practice. Several mechanisms contribute to MDR, one of which is the augmented drug efflux induced by the upregulation of ABCB1 in cancer cells. Regorafenib, a multikinase inhibitor targeting the RAS/RAF/MEK/ERK pathway, was approved by the FDA to treat metastatic colorectal cancer and gastrointestinal stromal tumors. We investigated whether and how regorafenib overcame MDR mediated by ABCB1. The results showed that regorafenib reversed the ABCB1-mediated MDR and increased the accumulation of [3H]-paclitaxel in ABCB1-overexpressing cells by suppressing efflux activity of ABCB1, but not altering expression level and localization of ABCB1. Regorafenib inhibited ATPase activity of ABCB1. In mice bearing resistant colorectal tumors, regorafenib raised the intratumoral concentration of paclitaxel and suppressed the growth of resistant colorectal tumors. But regorafenib did not induce cardiotoxicity/myelosuppression of paclitaxel in mice. Strategy to reposition one FDA-approved anticancer drug regorafenib to overcome the resistance of another FDA-approved, widely used chemotherapeutic paclitaxel, may be a promising direction for the field of adjuvant chemotherapy. This study provides clinical rationale for combination of conventional chemotherapy and targeted anticancer agents. [ABSTRACT FROM AUTHOR]