Cytotoxicity and apoptosis induction in breast cancer, skin cancer and glioblastoma cells by plant extracts.

Medicinal plants can be candidate as a common alternative for cancer treatment according to natural landscaping and native plants in each country. The aim of this study was the evaluations of cytotoxicity, apoptosis, and cell cycle arrest induction by using seven leaves extracts of Catharanthus roseus, Calystegia sepium, Berberis integerrima, Mahonia fortunei, Melia azedarach, Plantago major, Betula pendula and one bulb extract of Narcissus tazetta. Extracts were assessed on three cancer cell lines including MCF-7 breast cancer cells, A431 epidermal cell line, and U87-MG glioma cell line that were compared to HGF-1 as normal cells. According to analysis of MTT, methanolic extract of C. sepium leaves increased significantly the rate of cell death in all cancer cell lines when compared to HGF-1 as normal cells. Among different extracts, methanolic extract of C. roseus leaves and methanolic extract of C. sepium leaves indicated a crucial role in apoptosis of cancer cells according to evidences from MTT assay, cell cycle analysis, and apoptosis assay. Doxorubicin has been used as standard drug to compare with IC50 s of different extracts. In addition, the encapsulation of methanolic and ethanolic extracts in small unilamellar vesicles form (SUV) increased the cytotoxicity on cancer cell lines and normal cells. Our results indicated that different extracts can differently affect the cytotoxicity rate in variety of cancer cell lines.

Changes in the expression of some genes involved in the biosynthesis of secondary metabolites in Cuminum cyminum L. under UV stress.

Biotic and abiotic stresses cause special defense reactions in plant organs, which after a series of reactions, these stresses produce secondary metabolites. The effect of ultraviolet radiation on the expression of key genes involved in the biosynthesis of secondary metabolites (Phenylalanine ammonia lyase (PAL), Hydroxymethylglutaryl-CoA reductase (HMG-CoA reductase), GPP synthases, Deoxyribonino heptulosinate 7-phosphate synthase (DAHP), and Deoxy Xylose Phosphate Synthase (DXS)), and the association of these genes with different amounts of secondary metabolites (phenol, terpene, flavonoids, anthocyanins, alkaloids, lycopene, and beta-carotene) was investigated in this study. The results of this study showed that the application of UV-B stress significantly increased the expression of GPPs, HMG-CoA reductase, DXS, DAHPs, and PAL genes compared to the control plants. The expression of two key genes involved in the biosynthesis of phenylpropanoids, including DAHPs and PAL, increased with UV-B stress, and the highest expression was related to the PAL gene. The results revealed that UV-B stress caused a significant increase in total levels of terpenoids, phenols, flavonoids, anthocyanins, alkaloids, beta-carotene, and lycopene. The highest relative expression of all genes was obtained in treatment A (UV-B radiation for 1 h), while in treatment B (UV-B radiation for 2 h), no significant changes were observed in the expression of the genes.

Different physiobiochemical and transcriptomic reactions of rice (Oryza sativa L.) cultivars differing in terms of salt sensitivity under salinity stress.

Salinity stress is the most important and common environmental stresses throughout the world, including Iran. The aim of this study was to investigate the expression of several important genes involved in the salinity tolerance of the rice cultivars differing in salt sensitivity. In this research, the expression of four mitochondrial genes, H2O2, malondialdehyde (MDA), proline, sodium, potassium and superoxide dismutase (SOD), was measured in Iranian rice cultivars and two well-known international varieties as checks in response to 100 mM salt stress. The results show that the activity of SOD in the tolerant cultivars is much higher than in the susceptible ones under saline conditions (100 mM NaCl). The study of the gene expression in the tolerant and sensitive cultivars also showed that the expression of the genes increased in the early hours of the stress, with the exception of the OsGR1. Moreover, the amount of the expression in the tolerant cultivars was far more than the susceptible ones. The result of this study showed that the function of a set of antioxidant enzymes can lead to detoxification of the reactive oxygen species, so in order to better understand ROS scavengers, a comprehensive study on the antioxidant system should be conducted.

An efficient protocol for isolation of inhibitor-free nucleic acids even from recalcitrant plants.

For fast and easy isolation of inhibitor-free genomic DNA even from the toughest plant leaf samples, including those high in polyphenols and polysaccharides, a protocol has been developed. To prevent the solubility of polysaccharides in the DNA extract, high salt concentration (1.4 M) was used in the extraction buffer. Polyvinylpyrrolidone (PVP) was used for the removal of polyphenols as polymerase chain reaction (PCR) inhibitors. Proteins like various enzymes were degraded by proteinase K and removed by centrifugation from plant extracts during the isolation process resulting in pure DNA and RNA ready to use in downstream applications including PCR, quantitative polymerase chain reaction (qPCR), ligation, restriction and sequencing. This protocol yielded a high molecular weight DNA and RNA isolated from leaves and roots of recalcitrant plants which was free from contamination and color. The average yields of total RNA from roots and shoot of Betula and Grape ranged from 285 to 364 ng/µl with A260/A280 between 1.9 and 2.08. The RNA isolated with this protocol was verified to be suitable for PCR, quantitative real-time PCR, semi-quantitative reverse transcription polymerase chain reaction, cDNA synthesis and expression analysis. This protocol shown here is reproducible and can be used for a broad spectrum of plant species which have polyphenols and polysaccharide compounds.