Activity of Aloe arborescens leaf extracts: in vitro effects on Human Adenocarcinoma HT-29 cell line and free-radical species.

Aloe arborescens Mill. (syn. Candelabra Aloe; Xanthorrhoeaceae) is native to South Africa; in Italy it is grown for ornamental, therapeutic and cosmetic uses. Various Aloe spp. have been used since ancient times and have a well-documented history of use as medicines. Nowadays, it is widely studied as potential anticancer, antidiabetic, antimicrobial and for several other uses. The presence of aloin, aloe-emodin, polysaccharides, mannose and acemannan was reported in whole-leaf preparations. The aim of the present research was to study Aloe arborescens leaf extracts, also to improve the uses of Aloe since many products are marketed also in Western countries. For this purpose, methanolic and ethanolic extracts were obtained from freeze-dried leaves, and then studied using: a) HPLC-DAD analysis to determine aloins and aloe-emodin contents, b) two radical-scavenging assays to assess the radical scavenger activity, and 3) MTT assay on colorectal adenocarcinoma cell line (HT29 cells) to evaluate cell viability

[Complex ventricular arrhythmias in ischemic cardiopathy].

Analisi sperimentale di tracciati di elettrocardiografia dinamica alo scopo di valutare l'effettoprognostico del prolasso mitralico. Pi\uf9 tardi il prof. Casiglia sar\ue0 responsabile del Centro di Alta Specializzazione in Elettrocardiografia Basale e Dinamica al Dipartimento di Medicina dell'Universit\ue0 di Padova

[Complex rhythm disorders in mitral valve prolapse].

Analisi sperimentale di tracciati di elettrocardiografia dinamica alo scopo di valutare l'effetto prognostico del prolasso mitralico. Pi\uf9 tardi il prof. Casiglia sar\ue0 responsabile del Centro di Alta Specializzazione in Elettrocardiografia Basale e Dinamica al Dipartimento di Medicina dell'Universit\ue0 di Padova

Folic acid-targeted paclitaxel-polymer conjugates exert selective cytotoxicity and modulate invasiveness of colon cancer cells

Although selective tumor delivery of anticancer drugs has been sought by exploiting either passive targeting or by ligand-mediated targeting, a selective anticancer therapy remains an unmet medical need. Despite the advances which have been achieved by nanomedicines, nanosystems such as polymer-drug conjugates still miss the goal of clinical efficacy. In this study, we demonstrated that polymer-drug conjugates require a thoroughly chemical design and the right targeting agent/polymer ratio to be selective and effective towards cancer cells. In particular, two PEG conjugates carrying paclitaxel and targeted with different folic acid (FA)/PEG ratios (one or three) were investigated. The cytotoxicity study in positive (HT-29) and negative (HCT-15) FA receptor (FR)-cell lines demonstrated that the conjugates with one or three FAs were 4-or 28-fold more active in HT-29 cells, respectively. The higher activity of the 3-FA conjugate was confirmed by its strong impact on cell cycle arrest. Furthermore, FA targeting had a clear effect on migration and invasiveness of HT-29 cells, which were significantly reduced by both conjugates. Interestingly, the 3-FA conjugate showed also an improved pharmacokinetic profile in mice. The results of this study indicate that thorough investigations are needed to optimize and tune drug delivery and achieve the desired selectivity and activity towards cancer cells

In Vitro and In Vivo Sucrosomial® Berberine Activity on Insulin Resistance

Background: Berberine is a natural alkaloid with hypoglycemic properties. However, its therapeutic use is limited by a very low oral bioavailability. Here we developed a new oral formulation of berberine based on Sucrosomial® technology and tested its effect on insulin resistance. Methods: Sucrosomial® berberine was first tested in vitro in the hepatoma cell line Huh7 to assess its effect on proteins involved in glucose homeostasis and insulin resistance. The pharmacokinetics and efficacy on insulin resistance were then studied in C57BL/6 mice fed with standard (SD) and high-fat diet (HFD) for 16 weeks and treated daily during the last 8 weeks with oral gavage of Sucrosomial® berberine or berberine. Results: Sucrosomial® berberine did not affect Huh7 cell viability at concentrations up to 40 µM. Incubation of Huh7 with 20 µM of Sucrosomial® and control berberine induced glucokinase (GK) and the phosphorylation of 5′-adenosine monophosphate (AMP)-activated protein kinase (AMPK), both known targets for the control of insulin resistance. In vivo, we observed an 8-fold higher plasma concentration after 3 weeks of oral administration of 50 mg/kg/day of Sucrosomial® formulation compared to berberine. HFD, compared to SD, induced insulin resistance in mice as determined by oral glucose tolerance test (OGTT). The treatment with a 6.25 mg/kg/daily dose of Sucrosomial® berberine significantly reduced the area under the curve (AUC) of OGTT (73,103 ± 8645 vs. 58,830 ± 5597 mg/dL × min), while control berberine produced the same effects at 50 mg/Kg/day (51518 ± 1984 mg/dL × min). Under these conditions, the two formulations resulted in similar berberine plasma concentration in mice. Nevertheless, a different tissue distribution of metabolites was observed with a significant accumulation of reduced, demethylated and glucuronide berberine in the brain after the oral administration of the Sucrosomial® form. Glucuronide berberine plasma concentration was higher with Sucrosomial® berberine compared to normal berberine. Finally, we observed similar increases of AMPK phosphorylation in the liver in response to the treatment with Sucrosomial® berberine and berberine. Conclusions: The Sucrosomial® formulation is an innovative and effective technology to improve berberine gastrointestinal (GI) absorption with proven in vitro and in vivo activity on insulin resistance

Tyrosine kinase inhibitor prodrug-loaded liposomes for controlled release at tumor microenvironment

Tyrosine kinase inhibitors (TKIs) represent one of the most advanced class of therapeutics for cancer treatment. Most of them are also cytochrome P450 (CYP) inhibitors and/or substrates thereof. Accordingly, their efficacy and/or toxicity can be affected by CYP-mediated metabolism and by metabolism-derived drug-drug interactions. In order to enhance the therapeutic performance of these drugs, we developed a prodrug (Pro962) of our TKI TK962 specifically designed for liposome loading and pH-controlled release in the tumor. A cholesterol moiety was linked to TK962 through pH-sensitive hydrazone bond for anchoring to the liposome phospholipid bilayer to prevent leakage of the prodrug from the nanocarrier. Bioactivity studies performed on isolated target kinases showed that the prodrug maintains only partial activity against them and the release of TK962 is required. Biopharmaceutical studies carried out with prodrug loaded liposomes showed that the prodrug was firmly associated with the vesicles and the drug release was prevented under blood-mimicking conditions. Conversely, conventional liposome loaded with TK962 readily released the drug. Flow cytometric studies showed that liposomes efficiently provided for intracellular prodrug delivery. The use of the hydrazone linker yielded a pH-controlled drug release, which resulted in about 50% drug release at pH 4 and 5 in 2 h. Prodrug, prodrug loaded liposomes and active lead compound have been tested against cancer cell lines in either 2D or 3D models. The liposome formulation showed higher cytotoxicity than the unformulated lead TK962 in both 2D and 3D models. The stability of prodrug, prodrug loaded liposomes and active lead compound in human serum and against human, mouse, and rat microsomes was also assessed, demonstrating that liposome formulations impair the metabolic reactions and protect the loaded compounds from catabolism. The results suggest that the liposomal formulation of pH releasable TKI prodrugs is a promising strategy to improve the metabolic stability, intracellular cancer cell delivery and release, and in turn the efficacy of this class of anticancer drugs