Bafetinib (INNO-406) reverses multidrug resistance by inhibiting the efflux function of ABCB1 and ABCG2 transporters.

ATP-Binding Cassette transporters are involved in the efflux of xenobiotic compounds and are responsible for decreasing drug accumulation in multidrug resistant (MDR) cells. Discovered by structure-based virtual screening algorithms, bafetinib, a Bcr-Abl/Lyn tyrosine kinase inhibitor, was found to have inhibitory effects on both ABCB1- and ABCG2-mediated MDR in this in-vitro investigation. Bafetinib significantly sensitized ABCB1 and ABCG2 overexpressing MDR cells to their anticancer substrates and increased the intracellular accumulation of anticancer drugs, particularly doxorubicin and [(3)H]-paclitaxel in ABCB1 overexpressing cells; mitoxantrone and [(3)H]-mitoxantrone in ABCG2 overexpressing cells, respectively. Bafetinib stimulated ABCB1 ATPase activities while inhibited ABCG2 ATPase activities. There were no significant changes in the expression level or the subcellular distribution of ABCB1 and ABCG2 in the cells exposed to 3 µM of bafetinib. Overall, our study indicated that bafetinib reversed ABCB1- and ABCG2-mediated MDR by blocking the drug efflux function of these transporters. These findings might be useful in developing combination therapy for MDR cancer treatment.

Tea nanoparticle, a safe and biocompatible nanocarrier, greatly potentiates the anticancer activity of doxorubicin.

An infusion-dialysis based procedure has been developed as an approach to isolate organic nanoparticles from green tea. Tea nanoparticle (TNP) can effectively load doxorubicin (DOX) via electrostatic and hydrophobic interactions. We established an ABCB1 overexpressing tumor xenograft mouse model to investigate whether TNP can effectively deliver DOX into tumors and bypass the efflux function of the ABCB1 transporter, thereby increasing the intratumoral accumulation of DOX and potentiating the anticancer activity of DOX. MTT assays suggested that DOX-TNP showed higher cytotoxicity toward CCD-18Co, SW620 and SW620/Ad300 cells than DOX. Animal study revealed that DOX-TNP resulted in greater inhibitory effects on the growth of SW620 and SW620/Ad300 tumors than DOX. In pharmacokinetics study, DOX-TNP greatly increased the SW620 and SW620/Ad300 intratumoral concentrations of DOX. But DOX-TNP had no effect on the plasma concentrations of DOX. Furthermore, TNP is a safe nanocarrier with excellent biocompatibility and minimal toxicity. Ex vivo IHC analysis of SW620 and SW620/Ad300 tumor sections revealed evidence of prominent antitumor activity of DOX-TNP. In conclusion, our findings suggested that natural nanomaterials could be useful in combating multidrug resistance (MDR) in cancer cells and potentiating the anticancer activity of chemotherapeutic agents in cancer treatment.

Exploring naturally occurring ivy nanoparticles as an alternative biomaterial.

Arabinoglactan protein (AGP)-rich nanoparticles obtained from the sticky exudates of Hedera helix (English ivy), have shown promising potential to be used in nanomedicine owing to their excellent aqueous solubility, low intrinsic viscosity, biocompatibility, and biodegradability. In this study, the feasibilities of utilizing ivy nanoparticles (INPs) as nano-carriers for delivering chemotherapeutic drugs in cancer therapy and as nano-fillers to develop novel scaffolds for tissue engineering in regenerative medicine are evaluated. Via electrostatic and hydrophobic interactions, pH-responsive nanoconjugates are formed between the INPs and the doxorubicin (DOX) with an entrapment ratio of 77.9±3.9%. While the INPs show minimal cytotoxicity, the formed INP-DOX conjugates exhibit substantially stronger cytotoxic activity than free DOX against multiple cancer cell lines, suggesting a synergistic effect is established upon conjugation. The anti-cancer effects of the INP-DOX conjugates are further evaluated via in vivo xenograft assays by subcutaneously implanting DOX resistant cell line, SW620/Ad-300, into nude mice. The tumor volumes in mice treated with the INP-DOX conjugates are significantly less than those of the mice treated with free DOX. In addition, the INPs are further exploited as nano-fillers to develop fibrous scaffolds with collagen, via mimicking the porous matrix where the INPs are embedded under natural condition. Enhanced adhesion of smooth muscle cells (SMCs) and accelerated proliferation of mouse aortic SMCs are observed in this newly constructed scaffold. Overall, the results obtained from the present study suggest great potential of the INPs to be used as biocompatible nanomaterials in nanomedicine. The AGP-rich INP renders a glycoprotein architecture that is amenable for modification according to the functional designs, capable of being developed as versatile nanomaterials for extensive biomedical applications. STATEMENT OF SIGNIFICANCE: Naturally occurring organic nanomaterials have drawn increasing interest for their potential biomedical applications in recent years. In this study, a new type of naturally occurring nanoparticles obtained from the sticky exudates on the adventitious roots of English ivy (H. helix), was explored for its potential biomedical application. In particular, the feasibilities of utilizing ivy nanoparticles (INPs) as nano-carriers for delivering chemotherapeutic drugs in cancer therapy and as nano-fillers to develop novel scaffolds for tissue engineering in regenerative medicine were evaluated both in vitro and in vivo. Overall, the results obtained from the present study suggest the great potential of the INPs to be used as biocompatible nanomaterials in nanomedicine. This study may open a totally new frontier for exploring the biomedical application of naturally occurring nanomaterials.

ß-Elemene, a compound derived from Rhizoma zedoariae, reverses multidrug resistance mediated by the ABCB1 transporter.

In the present in vitro study, we examined the effect of the compound ß-elemene on the response of KB-C2 cells overexpressing the ABCB1 transporter to specific antineoplastic compounds. The MTT assay was used to determine the effects of ß-elemene in combination with other anticancer drugs on ABCB1-overexpressing cancer cell lines. Furthermore, we used [3H]-paclitaxel accumulation, efflux assay, immunofluorescence experiments, western blot assays and docking analysis to ascertain the mechanism of action of ß-elemene. The incubation of KB-C2 cells overexpressing ABCB1 transporter with ß-elemene (100 µM) significantly augmented the antineoplastic efficacy of colchicine, vinblastine and paclitaxel when compared to KB-C2 cells incubated with these drugs alone. In HEK293 cells overexpressing the ABCB1 transporter, ß-elemene significantly increased the cytotoxicity of paclitaxel. In addition, 100 µM of ß-elemene significantly increased the accumulation of [3H]-paclitaxel and this was due to a decrease in [3H]-paclitaxel efflux when compared to controls. The incubation of KB-C2 cells with ß-elemene (100 µM) for 72 h did not significantly alter the expression of ABCB1 protein levels. Immunofluorescence experiments indicated that ß-elemene did not significantly alter the subcellular localization of the ABCB1 transporter. Docking analysis indicated that ß-elemene binds to the drug-binding site of ABCB1 transporter. Finally, ß-elemene at 100 µM partially (~50%) increased the sensitivity of the BCRP-overexpressing cell line, NCI-H460/MX20, to mitoxantrone, but ß-elemene did not significantly alter the resistance of MRP1-transfected HEK293/MRP1 cells to vincristine. Overall, our in vitro findings indicated that ß-elemene potentiates the cytotoxic effects of various antineoplastic drugs in cell lines overexpressing the ABCB1 transporter and that this is due to the inhibition of the efflux component of the ABCB1 transporter.

[Effect of Zhibai Dihuang Pill on uPA of Uu-infection infertility patients].

OBJECTIVE: To study the effect of Zhibai Dihuang Pill (ZBDHP) on urokinase-type plasminogen activator (uPA) and sperm quality in ureaplasma urealyticum (Uu) infection infertile patients. METHODS: Recruited were 80 infertility patients with Uu infection at Andriatrics Clinics and Department of Reproduction, including 130 cases of positive Uu semen and 50 cases of negative Uu semen. Patients with positive Uu semen were randomly assigned to the observation group (72 cases) and the control group (58 cases) according to the visit sequence. All patients took antibiotics for 2 weeks. Patients in the observation group additionally took ZBDHP, 6 g each time, twice daily. Those in the control group additionally took Vit E (100 mg each time, twice per day) and ATP (40 mg each time, twice per day). The therapeutic course for all was 90 days. Semen parameters and uPA contents of the sperm membrane were detected and comparatively analyzed. RESULTS: The sperm membrane uPA content, the sperm motility, the sperm viability, and the percentage of normal morphology sperm in Uu positive infected patients were lower than those in Uu negative infected patients with statistical difference (P < 0.05), but with no significant difference in the sperm density between the two groups (P > 0.05). There was no statistical difference in pre-treatment sperm membrane uPA contents and sperm parameters between the two groups (P > 0.05). Compared with before treatment in the same group, the sperm membrane uPA content, the sperm motility, the sperm viability, and the percentage of normal morphology sperm obviously increased in the two groups with statistical difference (P < 0.05). After treatment, the sperm membrane uPA content increased more obviously in the observation group, with statistical difference when compared with the control group (P < 0.05). CONCLUSIONS: Infection with Uu leads to decreased uPA content of sperm membrance and the sperm motility. ZBDHP could effectively treat Uu infected infertility possibly through fighting against Uu damaged sperm membrane and make the sperm membrane uPA content return to normal, and elevate the fertilizability of sperms.

[Treatment of rheumatoid arthritis arthralgia by xiaoyan zhitong paste: a clinical observation].

OBJECTIVE: To formulate a comprehensive treatment program for rheumatoid arthritis arthralgia by clinical observing the efficacy of Xiaoyan Zhitong Paste (XZP). METHODS: Adopted was stratified, block randomized, double-blinded, placebo parallel controlled method. Subjects were assigned to the treatment group and the placebo group. Those in the treatment group were treated by external application of XZP, one to two pastes each time, covering the painful area, exchange once per 24 h, with one-day interval during a 7-day consecutive medication, two 7-days of treatment consisting of one therapeutic course. XZP placebos were applied for those in the placebo group in the same medication way. Joint pain and VAS were taken as main indices for observing the clinical efficacy of XZP. RESULTS: The improvement of the analgesic effect and the Chinese medical syndrome efficacy of XZP were superior to that of the placebo. CONCLUSION: XZP showed obvious effect in treating rheumatoid arthritis arthralgia with no obvious adverse reaction.

[Protective effects of Astragalus membranaceus on free fatty acid-induced vascular endothelial cell dysfunction].

OBJECTIVE: To investigate whether Astragalus membranaceus (AM) can protect endothelium-dependent vasodilatation (EDV) function of aorta from the damage induced by high level of free fatty acid (FFA). METHODS: Ten male SD rats, 8 weeks old and 250-300 g in weight, were sacrificed and thoracic aorta were harvested. Aorta rings incubated in organ baths were divided into three groups, Control group, FFA group and FFA+ AM group. The control group was incubated in 20 mL Krebs-Henseleit solution; the FFA group was incubated in 20 mL KH solution mixed with FFA(800 micromol/L) the FFA + AM group was incubated in 20 mL KH solution mixed with FFA (800 micromol/L) and AM (4 g/L). The relaxation levels of aorta rings response to acetylcholine and sodium nitroprusside were measured, the expression of NF-kappaB and the level of NOx in the organ bath were analyzed by immunohistochemistry. RESULTS: Severe endothelial dysfunction were induced in FFA group (maximal vasorelaxation in response to Ach: 61.1% +/- l6.9% vs. 93.1% +/- 2.7% in control, P < 0.05), while EDV in FFA+AM group was significantly improved by the incubation with AM (P < 0.05). Compared with the control group (104.1 +/- 14.2) micromol/g, NOx levels of FFA group was (83.1 +/- 8.4) micromol/g (P < 0.05), and the treatment of AM increased the levels of NOx (98.8 +/- 10.7) micromol/g (P < 0.05). The control vascular ring had a little NF-kappaB expression in endothelial nucleus, FFA increased the activation of NF-kappaB, while the treatment of AM lower the elevated NF-kappaB level. CONCLUSION: FFA can directly injure EDV, while AM may ameliorate it, with the possible mechanism related to the signal pathway of NF-kappaB and NO.