Toxicological evaluation of precocene II isolated from Ageratum conyzoides L. (Asteraceae) in Sprague Dawley rats

Precocene II (6,7-dimethoxy-2,2-dimethyl-2-chromene) was the main constituent isolated from Ageratum conyzoides L. and reportedly possessed antifungal activity. The study investigated the isolation, purification and toxicological effects of precocene II from A. conyzoides in Sprague Dawley rats. Precocene II was isolated from the petroleum ether fraction of the plant and the structure was determined by 1H-,13C-,DEPT-NMR and MS spectral techniques. Three groups of eight rats per group were used for the study. While groups B and C were respectively administered with 25 and 50 mg/kg of precocene II in 0.25% CMC-Na for 11 days by gastric intubation, group A was administered with 0.25% CMC-Na and served as the control group. After the last treatment, animals were fasted overnight and on the 12th day, they were injected intravenously with 0.2 ml/kg body weight of phenobarbital. Animals were subsequently dissected from the abdominal region; blood was collected from the pulmonary vein into EDTA anti-coagulated and non anti-coagulated tubes. The liver, kidney and spleen tissues were extracted into separate bottles for histopathological examinations. Results from hematological study indicated that the white blood cell (WBC), red blood cell (RBC), plateletcrit (PCT) and mean corpuscular hemoglobin count (MCHC) were significantly higher across the treated groups. Biochemical result showed that serum glucose level was significantly reduced in the treated groups. No apparent damage was noticed in the liver, kidney and spleen tissues. The result therefore suggests that precocene II possesses hypoglycemic property and could alter some hematopoietic elements but was not toxic to the liver, kidney and spleen tissues

Scalar Induced Gravitational Waves from Finslerian Inflation and Pulsar Timing Arrays Observations

The recent data from NANOGrav provide strong evidence of the existence of the \acp{SGWB}. We investigate \acp{SIGW} from Finslerian inflation as a potential source of stochastic gravitational wave background. Small-scale ($\lesssim$1 Mpc) statistically anisotropic primordial scalar perturbations can be generated in Finslerian inflation. The second order \acp{SIGW} from Finslerian inflation are also anisotropic on small scales. After spatially averaging the small-scale anisotropic \acp{SIGW}, we obtain the large-scale isotropic \acp{SGWB}. We find that the parameters of small-scale anisotropic primordial power spectrum generated by Finslerian inflation affect the \acp{PTA} observations of large-scale isotropic gravitational wave background

Second order scalar perturbations induced by primordial curvature and tensor perturbations

The primordial perturbations will inevitably generate higher order perturbations. We study the second order scalar perturbations generated by the primordial curvature and tensor perturbations in the radiation-dominated era. After presenting all the possible second-order source terms, we obtain the explicit expressions of the kernel functions and the power spectra of the second order scalar perturbations. The contributions from the initial second-order perturbations are considered. We calculate the power spectra of second order scalar perturbations for different tensor-to-scalar ratio $r$

Functional Effects of let-7g Expression in Colon Cancer Metastasis.

MicroRNA regulation is crucial for gene expression and cell functions. It has been linked to tumorigenesis, development and metastasis in colorectal cancer (CRC). Recently, the let-7 family has been identified as a tumor suppressor in different types of cancers. However, the function of the let-7 family in CRC metastasis has not been fully investigated. Here, we focused on analyzing the role of let-7g in CRC. The Cancer Genome Atlas (TCGA) genomic datasets of CRC and detailed data from a Taiwanese CRC cohort were applied to study the expression pattern of let-7g. In addition, in vitro as well as in vivo studies have been performed to uncover the effects of let-7g on CRC. We found that the expression of let-7g was significantly lower in CRC specimens. Our results further supported the inhibitory effects of let-7g on CRC cell migration, invasion and extracellular calcium influx through store-operated calcium channels. We report a critical role for let-7g in the pathogenesis of CRC and suggest let-7g as a potential therapeutic target for CRC treatment