ABSTRACT

Purpose

Hyaluronic acid-ceramide (HACE)-based nanoparticles (NPs) were developed for the targeted delivery of doxorubicin (DOX), and their antitumor efficacy for melanoma was evaluated.

Methods

DOX-loaded HACE-based self-assembled NPs were prepared and their physicochemical properties were characterized. The in vitro cytotoxicity of HACE was measured using an MTS-based assay. The cellular uptake efficiency of DOX into mouse melanoma B16F10 cells was assessed by confocal laser scanning microscopy and flow cytometry. Tumor growth and body weight were monitored after the intratumoral and intravenous injection of DOX-loaded NPs into a B16F10 tumor-bearing mouse model.

Results

DOX-loaded NPs, with a mean diameter of ~110 nm, a narrow size distribution, and high drug entrapment efficiency, were prepared. A sustained DOX release pattern was shown, and drug release was enhanced at pH 5.5 compared with pH 7.4. The cytotoxicity of HACE to B16F10 cells was negligible. It was assumed that DOX was taken up into the B16F10 cells through receptor-mediated endocytosis. A significant inhibitory effect was observed on tumor growth, without any serious changes in body weight, after the injection of DOX-loaded NPs into the B16F10 tumor-bearing mouse model.

Conclusions

DOX-loaded HACE-based NPs were successfully developed and their antitumor efficacy against B16F10 tumors was demonstrated.

Examination of the constituents of a marine sponge,Aplysina fistularis, indicated that brominated tyrosine metabolites were mainly responsible for antimicrobial and antineoplastic activities. Halogenated tyrosine metabolites, 2,6-dibromo-(2), 2-bromo-3-chloro-(3) and 2,6-dichloro-(4) 4-hydroxy-2, 5-cyclohexadienone-4-acetamides, as well as the lactam derivatives, 5-amino-2,6-dibromo-(5), 5-a mino-2-bromo-6-chloro-(6) and 5-amino-2,6-dichloro-(7) 4-hydroxy-2-cyclohexenone-4-acetic acid lactams were identified as the major antineoplastic and antimicrobial principles. Many other brominated tyrosine metabolites were also confirmed, but they did not show antimicrobial and antineoplastic activities.

G-protein-coupled receptor 119 (GPR119) represents a promising target for the treatment of type 2 diabetes as it can increase both GLP-1 secretion from intestinal L cells and glucose-stimulated insulin secretion (GSIS) from pancreatic β cells. Due to this dual mechanism of action, the development of small molecule GPR119 agonists has received much interest for the treatment of type 2 diabetes. Here, we identified a novel small-molecule GPR119 agonist, YH18421 and evaluated its therapeutic potential. YH18421 specifically activated human GPR119 with high potency and potentiated GLP-1 secretion and GSIS in vitro cell based systems. In normal mice, single oral administration of YH18421 improved glucose tolerance. Combined treatment of YH18421 and the DPP-4 inhibitor augmented both plasma active GLP-1 levels and glycemic control. In diet induced obese (DIO) mice model, glucose lowering effect of YH18421 was maintained after 4 weeks of repeat dosing and YH18421 acted additively with DPP-IV inhibitor. We also observed that YH18421 inhibited weight gain during 4 weeks of administration in DIO mice. These data demonstrate that YH18421 is capable of delivering sustained glucose control and preventing weight gain and combination with the DPP-IV inhibitor maybe an effective strategy for the treatment of type 2 diabetes.

A nabumetone tablet in development (Nabuton^R) was tested for its bioequivalence to the reference tablet (Uniton^R). Seventeen healthy Korean male subjects participated in this study. Each subject received a 1-g dose of nabumetone (2 tablets each) in an unbalanced, randomized, two-way crossover investigation. Serum concentrations of 6-methoxy-2-naphthylacetic acid (6-MNA), a major metabolite of nabumetone, were measured over 120 hr interval by a high-performance liquid chromatography. The maximum serum concentration (C_max) and time to reach the maximum concentration (T_max) were read directly, but area under the serum concentration time curve from time 0 to 120 hr (AUC) and mean residence time (MRT) of 6-MNA were calculated from the serum 6-MNA concentration-time curves. The serum curves showed multiple peaks of 6-MNA in most subjects, and the C_max and T_max were read from the highest serum peaks. Calculated bioavailability parameters for test and reference tablets were 1498.6∶1377.9 μg·hr/ml for AUC; 25.2∶23.1 μg/ml for C_max; 11.8∶16.4 hr for T_max and 42.6∶43.8 hr for MRT, respectively. The pairedt-test revealed no significant differences in all the parameters between the two tablets. Analysis of variance (ANOVA) revealed no significant differences between groups and formulations in all the parameters (C_max, T_max, AUC and MRT) indicating the crossover design of the experiment was properly performed. But significant differences (p<0.05) between subject/groups and periods were found for all the parameters indicating substantial intersubject and interperiodic variations for these parameters.

The hepatoprotective effect of DA-9601, a quality-controlled extract ofArtemisia asiatica, on liver damage induced by acetaminophen (APAP) and carbon tetrachloride (CCI₄) was investigated by means of serum-biochemical, hepatic-biochemical, and histopathological examinations. Doses of DA-9601 (10, 30, or 100mg/kg) were administered intragastrically to each rat on three consecutive days i.e. 48 h, 24 h and 2 h before a single administration of APAP (640 mg/kg, i.p.) or CCl₄ (2 ml/kg, p.o.). Four h and 24 h after hepatotoxin treatment, the animals were sacrificed for evaluation of liver damage. Pretreatment of DA-9601 reduced the elevation of serum ALT, AST, LDH and histopathological changes such as centrilobular necrosis, vacuolar degeneration and inflammatory cell infiltration dose-dependently. DA-9601 also prevented APAP- and CCl₄-induced hepatic glutathione (GSH) depletion and CCl₄-induced increase of hepatic malondialdehyde (MDA), a parameter of lipid peroxidation, in a dose-dependent manner. These findings suggest that pretreatment with DA-9601 may reduce chemically induced liver injury by complex mechanisms which involve prevention of lipid peroxidation and preservation of hepatic GSH.

To find pharmacologically active components ofAgrocybe cylindracea, its basidiocarps were extracted with water. The extracts were separated by DEAE cellulose column chromatography, Sepharose CL-4B gel filtration, and Concanavalin A-Sepharose 4B affinity chromatography. Among the obtained fractions fromA. cylindracea, fraction IN which was the neutral proteinbound-polysaccharide fraction exhibited a marked antitumor activity and it was tentatively named “Cylindan”. It showed about 70% of tumor inhibition against the solid form of sarcoma 180 when a dose of 30 mg/kg/day was intraperitoneally injected into ICR mice. When each fraction was examined by chemical analysis, Cylindan consisted of 85% polysaccharide, 3% protein and 1% hexosamine. Its polysaccharide moiety contained glucose, mannose, fucose and galactose and its protein moiety contained the comparatively large amounts of aspartic acid and glycine, and other 11 amino acids.

Male Sprague-Dawley rats deprived of water for 72 h (a rat model of dehydration) showed no change in protein expression of the hepatic microsomal cytochrome P450 (CYP) 1A2, 2B1/2, 2C11, or 3A1/2, but an increase in protein expression (3-fold) and mRNA level (2.6-fold) of CYP2E1. Glucose feeding instead of food normalized CYP2E1 protein expression during dehydration. Here, we review how dehydration can change the pharmacokinetics of drugs reported in the literature via changing CYP isozyme levels. We also discuss how dehydration changes the pharmacokinetics of drugs that are metabolized via renal DHP-I, or are mainly excreted in the urine and bile, and form conjugates.

Toll-like receptors (TLRs) belong to a class of pattern-recognition receptors that play an important role in host defense against pathogens by recognizing a wide variety of pathogen-associated molecular patterns (PAMPs). Besides driving inflammatory responses, TLRs also regulate cell proliferation and survival by expanding useful immune cells and integrating inflammatory responses and tissue repair processes. TLR signaling, which is centrally involved in the initiation of both innate and adaptive immune responses, has been thought to be restricted to immune cells. However, recent studies have shown that functional TLRs are expressed not only on immune cells, but also on cancer cells, thus implicating a role of TLRs in tumor biology. Increasing bodies of evidence have suggested that TLRs act as a double-edged sword in cancer cells because uncontrolled TLR signaling provides a microenvironment that is necessary for tumor cells to proliferate and evade the immune response. Alternatively, TLRs can induce an antitumor immune response in order to inhibit tumor progression. In this review, we summarize the dual roles of TLRs in tumor cells and, more importantly, delve into the therapeutic potential of TLRs in the context of tumorigenesis.

Chimeric antigen receptor-modified T cells (CAR-T) have emerged as a new modality for cancer immunotherapy due to their potent efficacy against terminal cancers. CAR-Ts are reported to exert higher efficacy than monoclonal antibodies and antibody–drug conjugates, and act via mechanisms distinct from T cell receptor-engineered T cells. These cells are constructed by transducing genes encoding fusion proteins of cancer antigen-recognizing single-chain Fv linked to intracellular signaling domains of T cell receptors. CAR-Ts are classified as first-, second- and third-generation, depending on the intracellular signaling domain number of T cell receptors. This review covers the current status of CAR-T research, including basic proof-of-concept investigations at the cell and animal levels. Currently ongoing clinical trials of CAR-T worldwide are additionally discussed. Owing to the lack of existing approved products, several unresolved concerns remain with regard to safety, efficacy and manufacturing of CAR-T, as well as quality control issues. In particular, the cytokine release syndrome is the major side-effect impeding the successful development of CAR-T in clinical trials. Here, we have addressed the challenges and regulatory perspectives of CAR-T therapy.