Anti-cancer natural products isolated from chinese medicinal herbs

In recent years, a number of natural products isolated from Chinese herbs have been found to inhibit proliferation, induce apoptosis, suppress angiogenesis, retard metastasis and enhance chemotherapy, exhibiting anti-cancer potential both in vitro and in vivo. This article summarizes recent advances in in vitro and in vivo research on the anti-cancer effects and related mechanisms of some promising natural products. These natural products are also reviewed for their therapeutic potentials, including flavonoids (gambogic acid, curcumin, wogonin and silibinin), alkaloids (berberine), terpenes (artemisinin, β-elemene, oridonin, triptolide, and ursolic acid), quinones (shikonin and emodin) and saponins (ginsenoside Rg3), which are isolated from Chinese medicinal herbs. In particular, the discovery of the new use of artemisinin derivatives as excellent anti-cancer drugs is also reviewed

Discrepancies in resistant starch and starch physicochemical properties between rice mutants similar in high amylose content

The content of resistant starch (RS) was considered positively correlated with the apparent amylose content (AAC). Here, we analyzed two Indica rice mutants, RS111 and Zhedagaozhi 1B, similar in high AAC and found that their RS content differed remarkably. RS111 had higher RS3 content but lower RS2 content than Zhedagaozhi 1B; correspondingly, cooked RS111 showed slower digestibility. RS111 had smaller irregular and oval starch granules when compared with Zhedagaozhi 1B and the wild type. Zhedagaozhi 1B showed a B-type starch pattern, different from RS111 and the wild type, which showed A-type starch. Meantime, RS111 had more fa and fb1 but less fb3 than Zhedagaozhi 1B. Both mutants showed decreased viscosity and swelling power when compared with the parents. RS111 had the lowest viscosity, and Zhedagaozhi 1B had the smallest swelling power. The different fine structures of amylopectin between RS111 and Zhedagaozhi 1B led to different starch types, gelatinization properties, paste viscosity, and digestibility. In addition to enhancing amylose content, modifications on amylopectin structure showed great potent in breeding rice with different RS2 and RS3 content, which could meet the increasing needs for various rice germplasms

SIK2 inhibition enhances PARP inhibitor activity synergistically in ovarian and triple-negative breast cancers

Poly(ADP-ribose) polymerase inhibitors (PARP inhibitors) have had an increasing role in the treatment of ovarian and breast cancers. PARP inhibitors are selectively active in cells with homologous recombination DNA repair deficiency caused by mutations in BRCA1/2 and other DNA repair pathway genes. Cancers with homologous recombination DNA repair proficiency respond poorly to PARP inhibitors. Cancers that initially respond to PARP inhibitors eventually develop drug resistance. We have identified salt-inducible kinase 2 (SIK2) inhibitors, ARN3236 and ARN3261, which decreased DNA double-strand break (DSB) repair functions and produced synthetic lethality with multiple PARP inhibitors in both homologous recombination DNA repair deficiency and proficiency cancer cells. SIK2 is required for centrosome splitting and PI3K activation and regulates cancer cell proliferation, metastasis, and sensitivity to chemotherapy. Here, we showed that SIK2 inhibitors sensitized ovarian and triple-negative breast cancer (TNBC) cells and xenografts to PARP inhibitors. SIK2 inhibitors decreased PARP enzyme activity and phosphorylation of class-IIa histone deacetylases (HDAC4/5/7). Furthermore, SIK2 inhibitors abolished class-IIa HDAC4/5/7–associated transcriptional activity of myocyte enhancer factor-2D (MEF2D), decreasing MEF2D binding to regulatory regions with high chromatin accessibility in FANCD2, EXO1, and XRCC4 genes, resulting in repression of their functions in the DNA DSB repair pathway. The combination of PARP inhibitors and SIK2 inhibitors provides a therapeutic strategy to enhance PARP inhibitor sensitivity for ovarian cancer and TNBC

Mitigated Greenhouse Gas Emissions in Cropping Systems by Organic Fertilizer and Tillage Management

Cultivating ecological benefits in agricultural systems through greenhouse gas emission reduction will offer extra economic benefits for farmers. The reported studies confirmed that organic fertilizer application could promote soil carbon sequestration and mitigate greenhouse gas emissions under suitable tillage practices in a short period of time. Here, a field experiment was conducted using a two-factor randomized block design (organic fertilizers and tillage practices) with five treatments. The results showed that the application of microbial fertilizers conserved soil heat and moisture, thereby significantly reducing CO2 emissions (6.9–18.9%) and those of N2O and CH4 fluxes during corn seasons, compared with chemical fertilizer application. Although deep tillage increased total CO2 emissions by 4.9–37.7%, it had no significant effect on N2O and CH4 emissions. Application of microbial organic fertilizer increased corn yield by 21.5%, but it had little effect on the yield of wheat. Overall, application of microbial fertilizers significantly reduced soil GHG emission and concurrently increased yield under various tillage practices in a short space of time. With this, it was critical that microbial fertilizer be carefully studied for application in wheat–corn cropping systems

Mitigated Greenhouse Gas Emissions in Cropping Systems by Organic Fertilizer and Tillage Management

Cultivating ecological benefits in agricultural systems through greenhouse gas emission reduction will offer extra economic benefits for farmers. The reported studies confirmed that organic fertilizer application could promote soil carbon sequestration and mitigate greenhouse gas emissions under suitable tillage practices in a short period of time. Here, a field experiment was conducted using a two-factor randomized block design (organic fertilizers and tillage practices) with five treatments. The results showed that the application of microbial fertilizers conserved soil heat and moisture, thereby significantly reducing CO2 emissions (6.9–18.9%) and those of N2O and CH4 fluxes during corn seasons, compared with chemical fertilizer application. Although deep tillage increased total CO2 emissions by 4.9–37.7%, it had no significant effect on N2O and CH4 emissions. Application of microbial organic fertilizer increased corn yield by 21.5%, but it had little effect on the yield of wheat. Overall, application of microbial fertilizers significantly reduced soil GHG emission and concurrently increased yield under various tillage practices in a short space of time. With this, it was critical that microbial fertilizer be carefully studied for application in wheat–corn cropping systems

Soil Microbes from Saline–Alkali Farmland Can Form Carbonate Precipitates

The formation of soil inorganic carbon in saline–alkali lands is of great significance for enhancing soil carbon sequestration. As for the formation mechanisms, in addition to the discovered abiotic mechanisms, the microbial mechanisms remain unclear. To address this, soil microbes were isolated from the saline–alkali farmland of the Yellow River Delta in north China. Then, their capacity for carbonate precipitation formation was determined. Ten microbial strains were obtained from the soil. Of these, seven strains (four bacterial strains and three fungal strains), belonging to Rhodococcus sp., Pseudomonas sp., Bacillus sp., Streptomyces sp., Aspergillus sp., Cladosporium sp., and Trichoderma sp., formed carbonate precipitates in the range of 89.77~383.37 mg. Moreover, the formation of carbonate precipitates was related to specific metabolisms by which microbes can raise the pH (from 7.20 to >8.00), suggesting that soil microbes that can enhance pH values by specific metabolisms containing the function of carbonate formation. Although an in situ experiment is needed to confirm such capacity, these results showed that soil bacteria and fungi existing in the saline–alkali farmland soil can form carbonate precipitates. The present study provided a microbial perspective for the mechanism of soil inorganic carbon formation, further implying a microbial potential of soil carbon sequestration in saline–alkali farmlands

Soil Microbes from Saline–Alkali Farmland Can Form Carbonate Precipitates

The formation of soil inorganic carbon in saline–alkali lands is of great significance for enhancing soil carbon sequestration. As for the formation mechanisms, in addition to the discovered abiotic mechanisms, the microbial mechanisms remain unclear. To address this, soil microbes were isolated from the saline–alkali farmland of the Yellow River Delta in north China. Then, their capacity for carbonate precipitation formation was determined. Ten microbial strains were obtained from the soil. Of these, seven strains (four bacterial strains and three fungal strains), belonging to Rhodococcus sp., Pseudomonas sp., Bacillus sp., Streptomyces sp., Aspergillus sp., Cladosporium sp., and Trichoderma sp., formed carbonate precipitates in the range of 89.77~383.37 mg. Moreover, the formation of carbonate precipitates was related to specific metabolisms by which microbes can raise the pH (from 7.20 to >8.00), suggesting that soil microbes that can enhance pH values by specific metabolisms containing the function of carbonate formation. Although an in situ experiment is needed to confirm such capacity, these results showed that soil bacteria and fungi existing in the saline–alkali farmland soil can form carbonate precipitates. The present study provided a microbial perspective for the mechanism of soil inorganic carbon formation, further implying a microbial potential of soil carbon sequestration in saline–alkali farmlands

Increase in Soil Carbon Pool Stability Rather Than Its Stock in Coastal Saline—Alkali Ditches following Reclamation Time

Extensive drainage ditches are constructed to reduce soil salinity in reclaimed saline–alkali farmland, consequently forming plant growth hotspots and impacting soil carbon stocks therein. However, the investigation into changes in soil carbon stocks remains limited in these ditches. To address this, soil samples were collected from drainage ditches, which originated from the reclamation of saline–alkali farmland, at different reclamation years (the first, seventh, and fifteenth year). Moreover, fractions were separated from soil samples; a particle size separation method (particulate organic matter, POM; mineral–associated organic matter, MAOM) and a spatio–temporal substitution method were conducted to analyze the variations in soil carbon components and the underlying mechanisms. The results indicate that there were no significant variations in the contents and stocks of soil organic carbon (SOC) and soil inorganic carbon (SIC) following the increase in reclamation time. However, in the POM fraction, the SOC content (SOCPOM) and stock significantly decreased from 2.24 to 1.12 g kg−1 and from 19.02 to 12.71 Mg ha−1, respectively. Conversely, in the MAOM fraction, the SOC content (SOCMAOM) and stock significantly increased from 0.65 to 1.70 g kg−1 and from 5.30 to 12.27 Mg ha−1, respectively. The different changes in SOCPOM and SOCMAOM, as well as the result of the structural equation model, showed a possible transformation process from SOCPOM to SOCMAOM in the soil carbon pool under the driving force of reclamation time. The results in terms of the changes in soil carbon components demonstrate the stability rather than the stock of the soil carbon pool increase in coastal saline–alkali ditches following the excavation formation time. Although more long time series and direct evidence are needed, our findings further provide a case study for new knowledge about changes in the soil carbon pool within saline–alkali ditches and reveal the potential processes involved in the transformation of soil carbon components

Plant Rhizospheres Harbour Specific Fungal Groups and Form a Stable Co-Occurrence Pattern in the Saline-Alkali Soil

Soil salinisation has been considered a substantial ecosystem issue with negative effects on sustainable agricultural practices. Practices of vegetation restoration are widely conducted for coping with saline soil degradation, especially in saline-alkali abandoned farmland. Compared with bulk soils, the rhizosphere soils of plants have different microbial community structures. However, how associations and functions of microbes vary in the rhizosphere and bulk soils of salt-tolerant plants remains unclear, limiting the successful implementation and efficacy of vegetation in restoring saline-alkali lands. Here, we analysed the fungal community composition, functional guilds, and co-occurrence networks in both rhizosphere and bulk soils of typical plant species in the abandoned farmland of the Yellow River Delta, China. Not all plant species had significantly different fungal community compositions and relative functional guild abundances between the rhizosphere and bulk soil. Soil nutrient concentrations explained more variance in the soil fungal community. Network analyses indicated that the rhizosphere fungal network had more nodes and links, more negative links, and higher modularity; however, fewer species were involved in the meta-module than those in the bulk soil network, indicating a more complex topology and niche differentiation therein. More generalist species and indicator taxa essential for carbon and nitrogen cycling (e.g., Sordariomycetes and Dothideomycetes) were identified in the salt-tolerant plant rhizosphere network. Overall, the salt-tolerant plants’ rhizosphere had a more stable fungal co-occurrence network and recruited more keystone species compared to the bulk soil, which could benefit soil nutrient cycling and soil restoration in abandoned farmlands