Naringenin suppresses epithelial ovarian cancer by inhibiting proliferation and modulating gut microbiota.

BACKGROUND: Ovarian cancer has the highest mortality among all gynecological malignancies; currently, no effective therapeutics are available for its treatment. Naringenin has been shown to inhibit the progression of various cancers, but its inhibitory effect on ovarian cancer remains unknown. PURPOSE: This study aimed to evaluate the inhibitory effects of naringenin on ovarian cancer and elucidate the underlying mechanisms. METHODS: Cancer cell proliferation was detected by cell counting kit-8 and crystal violet assays, and the migration capability was determined by wound healing and transwell assays. Western blotting and immunohistochemistry assays were employed to determine the expression levels of the epidermal growth factor receptor, phosphatidylinositol 3-kinase (PI3K) and cyclin D1 in vitro and in vivo, respectively. An ES-2 xenograft nude mouse model was established for the in vivo experiments, and fecal samples were collected for intestinal microbiota analysis by 16S rDNA sequencing. RESULTS: Naringenin suppressed the proliferation and migration of A2780 and ES-2 cancer cell lines and downregulated PI3K in vitro. In animal experiments, naringenin treatment significantly decreased the tumor weight and volume, and oral administration exhibited greater effects than intraperitoneal injection. Additionally, naringenin treatment ameliorated the population composition of the microbiota in animals with ovarian cancer and significantly increased the abundances of Alistipes and Lactobacillus. CONCLUSION: Naringenin suppresses epithelial ovarian cancer by inhibiting PI3K pathway expression and ameliorating the gut microbiota, and the oral route is more effective than parenteral administration.

Silicon fertilization influences microbial assemblages in rice roots and decreases arsenic concentration in grain: A five-season in-situ remediation field study.

Microbial mechanism of in-situ remediation of arsenic (As) in As-contaminated paddy fields by silicon (Si) fertilization has been rarely reported, especially under continuous rice cultivation and Si applications. In this study, two Si fertilizers were applied for three phases in five consecutive rice seasons to investigate the long-lasting impacts on in-situ remediation of As, and the underpinning microbial mechanism of root-associated compartments (bulk soil, rhizosphere and endosphere) was explored using the last double-cropping rice. Repeated application of Si fertilizers as base manure had a long-lasting effect on reducing As concentrations in rice grains. Application of Si fertilizer at an adequate amount resulted in an extended in-situ remediation effect from endosphere to rhizosphere. The microbial diversity and richness in rhizosphere soil and endosphere were significantly impacted by Si fertilization, the effects depending on application doses and prolonged seasons. Si fertilization can immobilize As in the root or rhizosphere, and Fe concentrations and the As- and Fe-transforming microorganisms (i.e. Geobacteraceae) are the determinants of As uptake in rice. We recommend more extensive supplementation of Si fertilizer at a higher rate to decrease grain As concentration for in-situ remediation. This study sheds light on the microbial-mediated mechanism underlying Si fertilization effect on decreased As uptake in paddy fields.

[Remedying Effects of a Combined Amendment for Paddy Soil Polluted with Cd for Spring and Autumn Rice].

An in-situ paddy experiment was conducted to study the remedying effects of a combined amendment(calcium carbonate+diatomite+ferric sulfate) on Cd bioavailability in soil and Cd accumulation in rice for spring and autumn rice planted in a certain Cd contaminated paddy soil in Beishan Town, Changsha, Hunan Province. The results showed that:Application of the combined amendment significantly increased soil pH and CEC values in both cultivated seasons, but decreased soil OM contents for the spring rice. During the experiment, the contents of TCLP-extractable Cd and CaCl2-extractable Cd in soil were reduced by 18.0%-33.0% and 5.4%-57.9%, respectively. The Cd contents in brown rice, husk, leave and root for the spring rice decreased by 29.6%-56.1%, 52.1%-54.0%, 18.1%-80.7% and 24.4%-41.6%, respectively, due to application of the combined amendment. There were significant differences in Cd transport capacity between spring rice and autumn rice, and the transportation of soil Cd in autumn rice was smoother than that in spring rice. For the autumn rice, the effects of the combined amendment were not significant(P>0.05), except that the Cd content in husk increased a little after applying 2 g·kg-1 of the combined amendment. Significant positive correlations were found between the Cd contents in brown rice and the contents of TCLP-extractable Cd or CaCl2-extractable Cd in soil. Application of the combined amendment effectively inhibited Cd uptake by rice root and reduced Cd content in brown rice for the spring rice; however, these remedying effects were significantly weakened for the autumn rice due to loss of the combined amendment with the movement of irrigation water in the spring season. Therefore, we suggest that supplement of the combined amendment is necessary between two rice cultivated seasons.