Schinus terebinthifolia Raddi leaf lectin is an antiangiogenic agent for Coturnix japonica embryos.

Angiogenesis (budding of new blood vessels) is involved in several processes, including the development of embryos and growth of tumors. Schinus terebinthifolia leaves express an antitumor lectin (SteLL). This work hypothesized that SteLL can interfere with the formation of a vascular network from preexisting vessels. To test this hypothesis, the effect of SteLL on the angiogenesis process was assessed using an in vivo model of yolk sac membrane of Coturnix japonica embryos. SteLL was isolated with purification factor of 46.6. As expected, polyacrylamide gel electrophoresis (PAGE) for native basic proteins confirmed the homogeneity and PAGE in presence of dodecyl sodium sulphate revealed a single 14-kDa polypeptide band. The fractal analysis by box counting and information dimension measurements indicated that SteLL at 1.35 mg/mL significantly decreased by ca. 12% the angiogenesis within the C. japonica yolk sac membrane regarding the control. The inhibition of the vascular network formation in the yolk sac membrane resulted in decreased blood supply to the embryos. Consequently, the area of embryos was significantly reduced by 9.2% regarding the control, which corroborated with the antiangiogenic activity of SteLL. The findings implicate SteLL as an antiangiogenic agent and add to the panel of biological activities of this lectin.

Fractal analysis of extra-embryonic vascularization in Japanese quail embryos exposed to extremely low frequency magnetic fields.

Magnetic fields (MF) can alter the dynamic behavior of vascular tissue and may have a stimulatory or inhibitory effect on blood vessel growth. Fractal geometry has been used in several studies as a tool to describe the development of blood vascular networks. Due to its self-similarity, irregularity, fractional dimension, and dependence on the scale of vessel dimensions, vascular networks can be taken as fractal objects. In this work, we calculated the fractal dimension by the methods of box counting (D(bc)) and information dimension (D(inf)) to evaluate the development of blood vessels of the yolk sac membrane (YSM) from quail embryos exposed to MF with a magnetic flux density of 1 mT and a frequency of 60 Hz. The obtained results showed that when the MF was applied to embryos aged between 48 and 72 h, in sessions of 2 h (6 h/day) and 3 h (9 h/day) with exposure intervals between 6 and 5 h, respectively, blood vascular formation was inhibited. Exposure sessions shorter than 2 h or longer than 3 h had no observable change on the vascular process. In contrast, the magnetic field had no observable change on the YSM vascular network for embryos aged between 72 and 96 h, irrespective of the exposure time. In conclusion, these results show a "window effect" regarding exposure time.