No abstract

Curcumin is a polyphenol obtained from the plant Curcuma longa (called turmeric) that displays several pharmacological activities, including anti-inflammatory, antioxidant, antimicrobial and antitumoral activity, but clinical use has been limited by its poor solubility in water and, consequently, minimal systemic bioavailability. We have therefore formulated the drug into nanocarrier systems in an attempt to improve its therapeutic properties. This study evaluates the effect of intraperitoneally administered nanocapsules containing curcumin on subcutaneous melanoma in mice inoculated with B16-F10 cells, and on the cytotoxicity activity against B16-F10 cells in vitro. Phagocytic uptake of formulations was also evaluated upon incubation with macrophage J774 cells by fluorescence microscopy. Lipid and polymeric nanocapsules were prepared by the phase inversion and nanoprecipitation methods, respectively. The uptake of the lipid nanocapsules prepared using Solutol HS15 was significantly reduced in J774 cells. Curcumin, as free drug or as drug-loaded nanocapsules, was administrated at a dose of 6 mg/kg twice a week for 21 days. Free drug and curcuminloaded nanocapsules significantly reduced tumor volume (P < 0.05 vs. control), but no difference was found in the antitumor activity displayed by lipid and polymeric nanocapsules. This assumption was supported by the in vitro study, in which free curcumin as well as loaded into nanocapsules caused significant reduction of cell viability in a concentration-and time-dependent manner.

No abstract

Acute leukemia is a disorder of the hematopoietic system characterized by the expansion of a clonal population of cells blocked from differentiating into mature cells. Recent studies have shown that chalcones and their derivatives induce apoptosis in different cell lines. Since new compounds with biological activity are needed, the aim of this study was to evaluate the cytotoxic effect of three synthetic chalcones, derived from 1-naphthaldehyde and 2-naphthaldehyde, on human acute myeloid leukemia K562 cells and on human acute lymphoblastic leukemia Jurkat cells. Based on the results, the most cytotoxic compound (A1) was chosen for further analysis in six human acute leukemia cells and in a human colon adenocarcinoma cell line (HT-29). Chalcone A1 significantly reduced the cell viability of K562, Jurkat, Kasumi, U937, CEM and NB4 cells in a concentration and time-dependent manner when compared with the control group (IC50 values between ∼1.5 μM and 40 μM). It was also cytotoxic to HL-29 cells. To further examine its effect on normal cells, peripheral blood lymphocytes collected from healthy volunteers were incubated with the compound. It has also been incubated with human fibroblasts cultured from bone marrow (JMA). Chalcone A1 is non-cytotoxic to PBL cells and to JMA cells. A1 caused significant cell cycle arrest in all phases according to the cell line, and increased the proportion of cells in the sub G0/G1 phase. To evaluate whether this chalcone induced cell death via an apoptotic or necrotic pathway, cell morphology was examined using fluorescence microscopy. Cells treated with A1 at IC50 demonstrated the morphological characteristic of apoptosis, such as chromatin condensation and formation of apoptotic bodies. Apoptosis was confirmed by externalization of phosphatidylserine, which was detected by the Annexin V-FITC method, and by DNA fragmentation. The results suggest that chalcone A1 has potential as a new lead compound for cancer therapy.

No abstract