T. A. Aghajanzadeh, O. Jazayeri,
Volume 20, Issue 5 (7-2018)
Abstract
Riboflavin (vitamin B2) affects plant growth and development and participates in a variety of redox processes that affect plant defense responses. Two rice cultivars Fajr (improved) and Tarom Mahali (traditional) were foliar sprayed with increasing concentrations of riboflavin (0, 0.5, 1, 1.5 and 2 mM) and subsequently infected by Pyricularia oryzae. Then, leaves were collected at 0, 2, 4, 6 and 8 days after infection and activity of Peroxidase (POD), PolyPhenol Oxidase (PPO), and Phenylalanine Ammonia Lyase (PAL) were measured. Results revealed that lesion size and percentage of infected rice plants in Fajr was higher than Tarom Mahali. In addition, riboflavin-induced resistance was higher in Fajr than in Tarom Mahali due to higher activity of POD, PPO and PAL in Fajr than Tarom Mahali, especially upon exposure of plant to 2 mM riboflavin. The intensity of the bands of peroxidase isoenzymes with low molecular weight was enhanced by increasing concentrations of riboflavin in both rice cultivars, while elevated riboflavin concentration caused the synthesis of three new isoenzymes in Fajr (g, h, i) and one (f) in Tarom Mahali cultivars. It can be concluded that Fajr is more sensitive to infection of P. oryzae than Tarom Mahali. In addition, the activity of POD, PPO, and PAL enhanced intensity of peroxidase isoenzymes bands. Also, the synthesis of new isoenzymes by riboflavin showed that riboflavin-induced resistance was more effective in Fajr than in Tarom Mahali.
Volume 21, Issue 3 (Fall 2018)
Abstract
Aims: Melanoma is one of the most dangerous forms of skin cancer, which is unresponsive to the current chemotherapy drugs. As a natural product purified from spirulina, phycocyanin can inhibit the angiogenesis. The aim of this study was to investigate the anti-angiogenesis effect of C-phycocyanin of spirulina platensis on B16-F10 melanoma tumors in C57BL/6 mouse.
Materials and Methods: In this experimental study, 16 C57BL/6 mice with the age range of 6-8 weeks were randomly divided into two groups, including control and phycocyanin groups. On the day 0 of the study, melanoma cells were injected and all the mice were treated for 20 days. Phycocyanin group received 40mg/kg phycocyanin every day. The tumors were extracted on the day 21 and the effect of phycocyanin on the angiogenesis and proliferation of cancer cells was investigated, using immunohistochemical staining with CD31 and Ki-67, respectively. The data were analyzed, using JMP 11 software by one way ANOVA test.
Findings: In the phycocyanin group, angiogenesis was significantly lower than that of the control group (p<0.01), while the mitotic index was not significantly lower than that of the control group in the mice treated with phycocyanin.
Conclusion: Phycocyanin has ability to inhibit angiogenesis in the B16-F10 melanoma tumors in C57BL/6 mouse, but it is not able to reduce the proliferation of melanoma cells.
