Silymarin induces a multi-targeted cell death process in the human colon cancer cell line HT-29.

This study investigated the Silymarin (SM) effects on growth of HT-29 human colon cancer cell line and its cellular death mechanism. HT-29 cells were treated by 25µM/ml of SM for 48h. HT-29 cells were also pretreated with 10mmol zVAD (apoptosis inhibitor), 10mmol 3-MA (autophagy inhibitor) and 3mmol Nec (necroptosis inhibitor) for evaluation cell death induced by apoptosis, outophagy and necroptosis. MTT and clonogenicity assays revealed that the SM without inhibitors induced a significant decrease in cell viability and proliferation of HT-29 cells (p<0.05). SM in presence of Nec and 3-MA significantly decreased viability and proliferation of HT-29 cells. Apoptotic indexes were significantly increased compare to other groups. SM in presence of zVAD and 3-MA significantly decreased viability and proliferation of HT-29 cells, and expression of RIPK1 and RIPK3 in compare to absence the inhibitors. Necroptotic index was also increased. zVAD could not completely blocked apoptosis. This indicate that SM may stimulate both caspase-dependent and caspase-independent apoptotic pathways. SM in presence of zVAD and Nec significantly decreased cell viability and proliferation of HT-29 cells in compare to control and other experimental groups. LC3-II positive cells were significantly increased in this group in compare to the control and SM without inhibitors treatment. Our results revealed that the high SM toxicity to HT-29 cells depends on multiple cell death pathways, which involved mainly autophagy.

Use of topical liposomes containing meglumine antimoniate (Glucantime) for the treatment of L. major lesion in BALB/c mice.

Treatment of cutaneous leishmaniasis (CL) is a dream for the patients, health care authorities and scientists. The aim of this study was to develop a topical liposomal meglumine antimoniate (MA, Glucantime™) (Lip-MA) formulation and evaluate the therapeutic effects of the preparation on lesion induced by Leishmania major in BALB/c mice. Liposomes containing 22.5% MA (6.4% Sb(+5)) with and without oleic acid (LMA-OA and LMA) were formulated using fusion method plus homogenization and characterized for the size and encapsulation efficiency. The penetration of MA from the LMA-OA and LMA formulations through and into the skin was checked in vitro using Franz diffusion cells fitted with mouse skin at 37°C for 8h. The in vitro permeation data showed that almost 1.5% of formulations applied in the mouse skin were penetrated and the amount retained in the skin was about 65%. The 50% effective dose of LMA and LMA-OA against amastigotes of L. major was 46.36 and 41.01 µg/ml, respectively. LMA or LMA-OA was used topically twice a day for 4 weeks to treat the lesion induced by L. major in susceptible BALB/c mice. The results showed a significantly (P<0.001) smaller lesion size in the treated groups of mice compared to the control groups which received either empty liposomes or phosphate-buffered saline (PBS). The spleen parasite burden was significantly (P<0.001) lower in the treated groups compared to the control groups receiving either empty liposomes or PBS at the end of the treatment period. However, when the treatment was stopped, the lesion size progressed and spleen parasite burden increased in LMA and LMA-OA groups, but still was significantly less than the control groups (P<0.05). There was no significant difference between the two formulations of LMA and LMA-OA. The results suggested that topical liposomes containing MA might be an appropriate choice for clinical trials for the treatment of CL.