Retinoic acid receptor γ (RARγ), a unique member of the nuclear receptor superfamily, plays an important role in the progression of several cancers such as hepatocellular carcinoma, esophageal cancer, and cholangiocarcinoma. However, little is known about the regulatory mechanism of the RARγ expression in colorectal cancer (CRC) progression. In the present study, we found that RARγ was frequently overexpressed in human CRC specimens and CRC cell lines, and it mainly resided in the cytoplasm in CRC specimens. Tissue microarrays showed that RARγ indicated vital clinical significance in CRC. RARγ knockdown neither affected CRC cell proliferation nor blocked the cell cycle of CRC cells. However, RARγ knockdown increased the sensitivity of CRC cells to chemotherapeutics through downregulation of multi-drug resistance 1(MDR1). Further studies suggested that RARγ knockdown resulted in downregulation of MDR1, in parallel with suppression of the Wnt/β-catenin pathway. Moreover, a significantly positive association between RARγ and MDR1 was demonstrated in CRC tissue microarrays. Collectively, these results suggested that overexpression of RARγ contributed to the multidrug chemoresistance of CRC cells, at least in part due to upregulation of MDR1 via activation of the Wnt/β-catenin pathway, indicating that RARγ might serve as a potential therapeutic target for chemoresistant CRC patients.

Ursodeoxycholic acid (UDCA) is a type of hydrophilic bile acid extracted from animal bile with a wide range of biological functions. The present results demonstrated that UDCA could effectively inhibit the proliferation of two human melanoma cell line (M14 and A375) with time- and concentration-dependence. Following exposure to various concentrations of UDCA, M14 cells exhibited typical morphological changes and weaker ability of colony forming. Flow cytometry analysis demonstrated that UDCA could induce a decrease of mitochondrial membrane potential and an increase in reactive oxygen species (ROS) levels in M14 cells. The cell cycle was arrested in the G2/M phase, which was confirmed by the decrease of cyclin-dependent kinase 1 and cyclinB1 at the protein level. However, when M14 cells were treated with UDCA and Z-VAD-FMK (caspase inhibitor) synchronously, the apoptosis rate of the cells was reduced significantly. In addition, it was demonstrated that UDCA induced apoptosis of human melanoma M14 cells through the ROS-triggered mitochondrial-associated pathway, which was indicated by the increased expression of cleaved-caspase-3, cleaved-caspase-9, apoptotic protease activating factor-1, cleaved-poly (ADP-ribose) polymerase 1 and the elevation of B cell lymphoma-2 (Bcl-2) associated X protein/Bcl-2 ratio associated with apoptosis. Therefore, UDCA may be a potential drug for the treatment of human melanoma.

The total phenolic content and the concentration of extractable and bound condensed tannins of Ficus altissima leaves were determined. The antioxidant activity of crude extracts and condensed tannins of F. altissima leaves was evaluated using 2,2-diphenyl-1-pichydrazyl (DPPH), 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric-reducing antioxidant power (FRAP) methods. The results showed that condensed tannins possessed higher free radical scavenging power. The structure of condensed tannins was characterized using high-performance liquid chromatography electrospray ionization mass spectrometry coupled with thiolysis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The findings showed that condensed tannins from F. altissima leaves were mixtures of procyanidins, prodelphinidins, and propelargonidins with a degree of polymerization up to 30-mer. In addition, condensed tannins effectively protected plasmid DNA against free radical damage and alleviated t-butylhydroperoxide-induced cytotoxicity on human hepatocyte LO2 cells. Condensed tannins exhibited remarkable inhibitory effects on both monophenolase and diphenolase activities of tyrosinase. The IC 50 values were estimated to be 256.7 ± 0.3 and 41.3 ± 0.2 µg/mL, respectively. For the diphenolase activity, inhibition by condensed tannins was reversible and of mixed-type. Condensed tannins from leaves of F. altissima were indicated to possess significant antioxidant and antityrosinase activities, suggesting that F. altissima might be a good source of proanthocyanidins with biological activity.

Background: Crocodile oil and its products are used as ointments for burns and scalds in traditional medicines. A new ointment formulation -crocodile oil burn ointment (COBO) was developed to provide more efficient wound healing activity. The purpose of the study was to evaluate the burn healing efficacy of this new formulation by employing deep second-degree burns in a Wistar rat model. The analgesic and anti-inflammatory activities of COBO were also studied to provide some evidences for its further use. Materials and methods:The wound healing potential of this formulation was evaluated by employing a deep second-degree burn rat model and the efficiency was comparatively assessed against a reference ointment -(1% wt ⁄ wt) silver sulfadiazine (SSD). After 28 days, the animals were euthanized and the wounds were removed for transversal and longitudinal histological studies. Acetic acid-induced writhing in mice was used to evaluate the analgesic activity and its anti-inflammatory activity was observed in xylene -induced edema in mice. Results: COBO enhanced the burn wound healing (20.5±1.3 d) as indicated by significant decrease in wound closure time compared with the burn control (25.0±2.16 d) (P<0.01). Hair follicles played an importance role in the physiological functions of the skin, and their growth in the wound could be revealed for the skin regeneration situation. Histological results showed that the hair follicles were well-distributed in the post-burn skin of COBO treatment group, and the amounts of total, active, primary and secondary hair follicles in post-burn 28-day skin of COBO treatment groups were more than those in burn control and SSD groups. On the other hand, the analgesic and anti-inflammatory activity of COBO were much better than those of control group, while they were very close to those of moist exposed burn ointment (MEBO). Conclusions: COBO accelerated wound closure, reduced inflammation, and had analgesic effects compared with SSD in deep second degree rat burn model. These findings suggest that COBO would be a potential therapy for treating human burns.

Crocodile choline, an active compound isolated from Crocodylus siamensis, was found to exert potent anti-cancer activities against human gastric cancer cells in vitro and in vivo. Our study revealed that crocodile choline led to cell cycle arrest at the G2/M phase through attenuating the expressions of cyclins, Cyclin B1, and CDK-1. Furthermore, crocodile choline accelerated apoptosis through the mitochondrial apoptotic pathway with the decrease in mitochondrial membrane potential, the increase in reactive oxygen species production and Bax/Bcl-2 ratio, and the activation of caspase-3 along with the release of cytochrome c. In addition, this study, for the first time, shows that Notch pathway is remarkably deregulated by crocodile choline. The combination of crocodile choline and Notch1 short interfering RNA led to dramatically increased cytotoxicity than observed with either agent alone. Notch1 short interfering RNA sensitized and potentiated the capability of crocodile choline to suppress the cell progression and invasion of gastric cancer. Taken together, these data suggested that crocodile choline was a potent progression inhibitor of gastric cancer cells, which was correlated with mitochondrial apoptotic pathway and Notch pathway. Combining Notch1 inhibitors with crocodile choline might represent a novel approach for gastric cancer.