Ion (Figure 5a). Flow cytometryViability changes on glutathione supplementationThe effect of MMGP1 on the viability of C. albicans cells after glutathione supplementation is shown in Figure 7. No significant increase in the growth of C. albicans cells treated with MMGP1 in the absence of glutathione was observed, whereas the cells treated with MMGP1 in the presence ofAntifungal Mechanism of Title Loaded From File MMGPFigure 4. In vitro transcription inhibition by MMGP1. (a) Expression of mouse -actin gene in the presence of different concentrations of MMGP1 C-no peptide, 1-0.576 , 2-0.288 , 3- 0.144 M, 4- 0.072; 5- 0.036 at 37 for 1 h under in vitro condition. The 15481974 transcribed product of 304 bases were analysed on 5 denaturing polyacrylamide gel. (b) Quantitative measurement of mouse -actin gene expression in the presence of varying concentrations of MMGP1 by gel densitometry analysis.doi: 10.1371/journal.pone.0069316.gglutathione showed an increase in cell viability as glutathione concentration increases.24 h of treatment with the peptide, suggesting the oxidation of inner mitochondrial protein cardiolipin, which could be attributed to the loss in mitochondrial respiratory potential.Oxidation of proteins and lipidsAn irreversible oxidation of proteins and lipids is the secondary effect of ROS produced within the cells. These deleterious modifications of proteins and lipids have lethal effects on target cells and lead to cell death. Therefore, the oxidation of intracellular proteins by ROS was studied by the examination of the cell lysates of C. albicans cells treated with MMGP1 at different time intervals. The results clearly indicated a time-dependent increase in the level of protein carbonyls in the treated cells (Figure 8a). In addition, the oxidation of lipids by ROS was investigated in MMGP1-treated C. albicans cells at different time intervals, and a time-dependent increase in production of TBARS was observed (Figure 8b). These Title Loaded From File consistent increases in the level of protein carbonyls and TBARS concentration at different time intervals indicate that the peptide induced oxidation of proteins and lipids.DNA damageThe in vivo DNA damage in C. albicans was analysed by TUNEL staining. At 6 h of incubation with the peptide, no TUNEL positive nuclei (green fluorescence) were observed, whereas, the number of TUNEL positive nuclei increased after 12 and 24 h of treatment with the peptide (Figure 10a). FACS analysis of TUNEL-stained MMGP1 treated C. albicans cells are shown in Figure 10b. No TUNEL-positive cells were observed after 6 h of treatment, whereas, 9.7 and 99.9 of TUNEL-positive cells were observed after 12 and 24 h of treatment, respectively, which is an indicative of DNA damage induced by MMGP1 in C. albicans.HemolysisThe hemolytic activity of the peptide against human erythrocytes is considered as the major index of toxicity toward human cells. Hemolysis was observed at a peptide concentration of 11.84 , which was relatively higher that the MIC of C. albicans.Disruption of mitochondrial membrane potentialDissipation of mitochondrial membrane potential in C. albicans cells by MMGP1 treatment was clearly evident from flow cytometry analyses. After 6 h of treatment with MMGP1, 73 of cells exhibited rhodamine fluorescence, whereas 43.9 of cells exhibited fluorescence after 12 h and only 17 of the cells showed rhodamine fluorescence after 24 h of treatment, which clearly indicate that the mitochondrial membrane potential is lost in 82 of the cell.Ion (Figure 5a). Flow cytometryViability changes on glutathione supplementationThe effect of MMGP1 on the viability of C. albicans cells after glutathione supplementation is shown in Figure 7. No significant increase in the growth of C. albicans cells treated with MMGP1 in the absence of glutathione was observed, whereas the cells treated with MMGP1 in the presence ofAntifungal Mechanism of MMGPFigure 4. In vitro transcription inhibition by MMGP1. (a) Expression of mouse -actin gene in the presence of different concentrations of MMGP1 C-no peptide, 1-0.576 , 2-0.288 , 3- 0.144 M, 4- 0.072; 5- 0.036 at 37 for 1 h under in vitro condition. The 15481974 transcribed product of 304 bases were analysed on 5 denaturing polyacrylamide gel. (b) Quantitative measurement of mouse -actin gene expression in the presence of varying concentrations of MMGP1 by gel densitometry analysis.doi: 10.1371/journal.pone.0069316.gglutathione showed an increase in cell viability as glutathione concentration increases.24 h of treatment with the peptide, suggesting the oxidation of inner mitochondrial protein cardiolipin, which could be attributed to the loss in mitochondrial respiratory potential.Oxidation of proteins and lipidsAn irreversible oxidation of proteins and lipids is the secondary effect of ROS produced within the cells. These deleterious modifications of proteins and lipids have lethal effects on target cells and lead to cell death. Therefore, the oxidation of intracellular proteins by ROS was studied by the examination of the cell lysates of C. albicans cells treated with MMGP1 at different time intervals. The results clearly indicated a time-dependent increase in the level of protein carbonyls in the treated cells (Figure 8a). In addition, the oxidation of lipids by ROS was investigated in MMGP1-treated C. albicans cells at different time intervals, and a time-dependent increase in production of TBARS was observed (Figure 8b). These consistent increases in the level of protein carbonyls and TBARS concentration at different time intervals indicate that the peptide induced oxidation of proteins and lipids.DNA damageThe in vivo DNA damage in C. albicans was analysed by TUNEL staining. At 6 h of incubation with the peptide, no TUNEL positive nuclei (green fluorescence) were observed, whereas, the number of TUNEL positive nuclei increased after 12 and 24 h of treatment with the peptide (Figure 10a). FACS analysis of TUNEL-stained MMGP1 treated C. albicans cells are shown in Figure 10b. No TUNEL-positive cells were observed after 6 h of treatment, whereas, 9.7 and 99.9 of TUNEL-positive cells were observed after 12 and 24 h of treatment, respectively, which is an indicative of DNA damage induced by MMGP1 in C. albicans.HemolysisThe hemolytic activity of the peptide against human erythrocytes is considered as the major index of toxicity toward human cells. Hemolysis was observed at a peptide concentration of 11.84 , which was relatively higher that the MIC of C. albicans.Disruption of mitochondrial membrane potentialDissipation of mitochondrial membrane potential in C. albicans cells by MMGP1 treatment was clearly evident from flow cytometry analyses. After 6 h of treatment with MMGP1, 73 of cells exhibited rhodamine fluorescence, whereas 43.9 of cells exhibited fluorescence after 12 h and only 17 of the cells showed rhodamine fluorescence after 24 h of treatment, which clearly indicate that the mitochondrial membrane potential is lost in 82 of the cell.