Mechanisms of the In Vivo Antitumor Activity of Polyalthia longifolia Leaf Extract Against HeLa Cell Xenograft Tumor: A Microscopic-Based Histological and Immunohistochemical Microanalyses.

The present study investigated the effects of Polyalthia longifolia leaf extract against the growth of HeLa cell xenograft tumor in nude mice and its underlying mechanism. The nude mice xenografted with HeLa cells were treated with 5% DMSO (vehicle control), 20 mg/kg/body weight of etoposide (positive control), and 500 and 1000 mg/kg/body weight of leaf extract, respectively. Antitumor activity was evaluated with apoptosis, proliferation, and angiogenesis using microscopic-based histological and immunohistochemical microanalyses.

Geometry-Dependent Spectroscopic Contrast in Deep Tissues.

Nano-structures of biological systems can produce diverse spectroscopic effects through interactions with broadband light. Although structured coloration at the surface has been extensively studied, natural spectroscopic contrasts in deep tissues are poorly understood, which may carry valuable information for evaluating the anatomy and function of biological systems. Here we investigated the spectroscopic characteristics of an important geometry in deep tissues at the nanometer scale: packed nano-cylinders, in the near-infrared window, numerically predicted and experimentally proved that transversely oriented and regularly arranged nano-cylinders could selectively backscatter light of the long wavelengths.