In vitro antioxidant and anticancer activities of ethanolic extract of selenium-enriched green tea

Selenium-enriched green tea is now being increasingly produced in China and is well known as a bioactive beverage, due to its high content of active components. In this study, the antioxidant and anticancer activities of an ethanolic extract and an aqueous extract of Se-enriched green tea were investigated. The results indicated that the ethanolic extract possessed significantly higher antioxidant activity than the aqueous extract and the positive control α-tocopherol, by both α,α-diphenyl-β-picrylhydrazyl (DPPH) radical-scavenging and ferric thiocyanate (FTC) assays. The ethanolic extract inhibited the proliferation of human cervical adenocarcinoma HeLa cell and possessed a significantly higher antitumour activity than the aqueous extract and the positive control 5-fluorouracil (5-FU), in the dose range of 62.5–250 μg/ml. Moreover, the ethanolic extract could significantly inhibit the growth of lung carcinoma A549 and hepatoma HepG2 in a concentration-dependent manner, with IC₅₀ values of 278.6 μg/ml and 431.6 μg/ml, respectively. Selenium, tea polyphenols and polyphenols constituents, especially epigallocatechin gallate (EGCG), were significantly higher in the ethanolic extract than in the aqueous extract, which were possibly responsible for the higher antioxidant and antitumour activities of the ethanolic extract.     

甘氨酸铂配合物的合成与表征

氯亚铂酸钾与甘氨酸在水溶液中合成了甘氨酸铂配合物。通过薄层色谱、差动热分析、红外、元素分析和体外抗癌活性实验对甘氨酸铂配合物进行了初步表征。     

Folic acid-functionalized niosomal nanoparticles for selective dual-drug delivery into breast cancer cells: An in-vitro investigation

In this study, a folic acid-functionalized niosome was formulated and loaded with letrozole and curcumin as a promising drug carrier system for chemotherapy of the breast cancer cells. The formulation process was optimized by varying the type of Span 80 and total lipid to drug ratio, where Span 80 and lipid to drug molar ratio of 10 resulted in the niosomes with maximum encapsulation of both drugs but minimum size. The developed niosomal formulation showed a great storage stability up to one month with the small changes in drug encapsulation efficiency and size during the storage. In addition, they showed a pH-dependent release behaviour with slow drug release at physiological pH (7.4) while considerable drug release in acidic conditions (pH = 3), making it a promising candidate for breast cancer treatment. The cytotoxicity study shows the niosomal formulation has high biocompatibility with HEK-293 healthy cells, while having remarkable inhibitory effects on MCF-7 and MDA-MB-231 breast cancer cells due to the presence of folic acid in formulation, and in turn, selective internalization of the as-developed nanocarrier through folate receptor-mediated endocytosis. The double drug-loaded niosomes affect the gene expression by studied breast cancer cell lines; down-regulates the expression of Bcl2, cyclin D, and cyclin E genes while they up-regulate the expression of p53, Bax, caspase-3, and caspase-9 genes. The flow cytometry results showed that letrozole/curcumin-loaded niosomes enhanced the apoptosis rate in both MCF-7 and MDA-MB-231 cells compared to the mixture of letrozole and curcumin, which was due to the synergic effect between the two drugs as well as higher cell uptake by niosomal formulation. The findings of our study show the importance of developing highly biocompatible niosomal formulations in the future of nanomedicine that enables the co-delivery of two hydrophobic drugs into the cancer cells improves the efficiency of chemotherapy due to the synergic effect between the drugs.     

Synergistic anticancer effect of green synthesized nickel nanoparticles and quercetin extracted from Ocimum sanctum leaf extract

Leaf extract of medicinally important plant Ocimum sanctum(O. sanctum) has been used for the synthesis of nickel nanoparticles(Ni Gs) and extraction of quercetin(Qu). Qu has been conjugated with Ni Gs for enhanced anticancer effect on human breast cancer MCF–7 cells. Extracted Qu was conjugated with polyethylene glycol(PEG) coated Ni Gs(Qu–PEG–Ni Gs) which was used as carriers for breast cancer treatment. Anticancer activity of Qu–PEG–Ni Gs was evaluated by assessing cell viability, reactive oxygen species(ROS) production, caspase activity, mitochondrial membrane potential(MMP) and changes in nuclear morphology(staining methods). 0.85 mg of quercetin was extracted from 1 g of leaves with retention time(R_t) of 2.914 min. Loading and encapsulation efficiency of quercetin onto PEG–Ni Gs was 15.04% and 82% respectively and Qu–PEG–Ni Gs has shown a sustained release of Qu of about 84% after 48 h. Qu and Qu–PEG–Ni Gs showed dose dependent(1.56–50 μg/m L) anticancer effect against MCF–7 cells with IC50 values of 50 and 6.25 μg/m L respectively which was mediated by oxidative stress due to ROS over-production that induced loss of mitochondrial membrane potential, capsase-9,-7 activities leading to apoptosis. The present study validates that Qu–PEG–Ni Gs can be used as a potential anticancer agent for cancer therapy.     

第三代铂抗癌药物研究评论

本文评论顺铂和卡铂之后的第三代铂抗癌药物的研究状况。报道其配合物的抗肿瘤活性、限量毒性、交叉耐药性和其中四种配合物的Ⅱ期临床结果。这些配合物的总体水平并不优于顺铂和卡铂。研究抗癌机理与顺铂和卡铂不同的新型铂配合物是增加该类药物的抗肿瘤活性和克服交叉耐药性的途径之一。     

Enhanced anticancer effect of quercetin microparticles formulation obtained by spray drying

This study unravels a formulation made of food-based microparticles (MPs) able to control the release of quercetin, a natural anticancer compound, which activity is only limited by its poor aqueous solubility and consequent low bioavailability. To solve this issue, a spray-dried micro delivery system was developed using a bench mini spray dryer B290 Buchi. The resulting MPs were only manufactured with food-derived ingredients such as whey proteins and milk, avoiding the use of any other synthetic material. These microparticles were characterised with a testing campaign encompassing either the physical–chemical characterisation with SEM, DSC and DLS, or the technological and biological features with in vitro, ex vivo and in vivo studies, the latter being characterised by a human colon cancer xenograft model. These studies showed as the quercetin solubility and release rate improved when tested in condition mimicking oral administration, resulting in a general improvement of its bioavailability and the consequent anticancer activity. This study shows as the whey proteins may serves as natural adjuvant able to provide valuable technological features when used to manufactures micro carriers by spray drying.     

Surface functionalization of SBA-15 nanorods for anticancer drug delivery

SBA-15 nanorods with high surface area (1010 m² g⁻¹) were functionalized by post grafting method with three different alkoxysilanes including (3-aminopropyl) triethoxysilane (APTES), 3-[bis(2-hydroxyethyl)amino] propyl triethoxysilane (HAPS) and 3-[2-(2-aminoethylamino) ethylamino] propyl trimethoxysilane (AEPS). The prepared materials were used as nanocarriers for an anticancer drug (gemcitabine). The obtained samples were characterized by SAXS, elemental analysis, TGA, N₂ adsorption/desorption, SEM, TEM, FTIR and UV spectroscopies. The adsorption and release properties of all samples were investigated. It was found that the surface functionalization increases the interaction between the carrier and gemcitabine and results in the loading enhancement of the drug. In addition, the adsorption of gemcitabine on the modified mesoporous matrix depends on the type and the amount of alkoxysilanes groups. The maximum content of the deposited drug in the modified SBA-15 nanorods is close to 22 wt.%. The rate of the drug release from the modified samples containing NH₂ groups on their surfaces is pH dependent.     

Ultrathin polyaniline film coated on an indium–tin oxide cell-based chip for study of anticancer effect

Polyaniline emeraldine base (EB) coated indium–tin oxide (ITO) electrode was prepared for the construction of a cell-based chip. Ultrathin polyaniline PANI film on an ITO was electroactive at neutral pH without co-deposition of an acidic counterion. HeLa cells were cultured on a PANI/ITO substrate and utilized to assess the biological toxicity of anticancer drugs. Cell growth, cell viability and drug-related cell toxicity were evaluated by a cyclic voltammetry (CV) method under a neutral pH. We demonstrated the functionality of a PANI coated ITO electrode for use as a cell chip and found that PANI was a good surface for the HeLa cells to grow without any significant morphological changes.