Deoxyrhapontigenin, a Natural Stilbene Derivative Isolated From Rheum undulatum L. Induces Endoplasmic Reticulum Stress-Mediated Apoptosis in Human Breast Cancer Cells

Endoplasmic Reticulum Stress Mediates Renal Tubular Vacuolation in BK Polyomavirus-Associated Nephropathy

OBJECTIVE

This study aimed to explore the molecular mechanism of cytoplasmic vacuolation caused by BK polyomavirus (BKPyV) and thus search for potential target for drug repurposing.

METHODS

Morphological features of BK polyomavirus-associated nephropathy (BKPyVAN) were studied under light and electron microscopes. Microarray datasets GSE75693, GSE47199, and GSE72925 were integrated by ComBat, and differentially expressed genes (DEGs) were analyzed using limma. Furthermore, the endoplasmic reticulum (ER)-related genes obtained from GenCLiP 2.0 were intersected with DEGs. GO and KEGG enrichment pathways were performed with intersection genes by R package clusterProfiler. The single-cell RNA sequencing (scRNA-seq) from a BKPyVAN recipient was analyzed with a dataset (GSE140989) downloaded from Gene Expression Omnibus (GEO) as control for gene set variation analysis (GSVA). Immunohistochemistry and electron microscopy of kidney sections from drug-induced ERS mouse models were performed to explore the association of ERS and renal tubular vacuolation. Protein-protein interaction (PPI) network of the intersection genes was constructed to identify hub target. AutoDock was used to screen Food and Drug Administration (FDA)-approved drugs that potentially targeted hub gene.

RESULTS

Light and electron microscopes exhibited obvious intranuclear inclusions, vacuoles, and virus particles in BKPyV-infected renal tubular cells. Transcriptome analysis revealed 629 DEGs between samples of BKPyVAN and stable transplanted kidneys, of which 16 were ER-associated genes. GO analysis with the intersection genes illustrated that ERS-related pathways were significantly involved, and KEGG analysis showed a prominent enrichment of MAPK, Toll-like receptor, and chemokine signaling pathways. GSVA analysis of the proximal tubule revealed similar pathways enrichment. An electron microscope image of the kidney from ERS mouse models showed an obvious renal tubular vacuolation with prominent activation of ERS markers verified by immunohistochemistry. Furthermore, DDIT3 was identified as the hub gene based on PPI analysis, and ZINCOOOOO1531009 (Risedronate) was indicated to be a potential drug for DDIT3.

CONCLUSION

ERS was involved in renal tubular cytoplasmic vacuolation in BKPyVAN recipients. Risedronate was screened as a potential drug for BKPyVAN by targeting DDIT3.

Review On Documented Medicinal Plants Used For The Treatment Of Cancer

Background:

Cancer is a frightful disease and it is the second leading cause of death worldwide. Naturally derived compounds are gaining interest of research workers as they have less toxic side effects as compared to currently used treatments such as chemotherapy. Plants are the pool of chemical compounds which provides a promising future for research on cancer.

Objective:

This review paper provides updated information gathered on medicinal plants and isolated phytoconstituents used as anticancer agents and summarises the plant extracts and their isolated chemical constituents exhibiting anticancer potential on clinical trials.

Methods:

An extensive bibliographic investigation was carried out by analysing worldwide established scientific databases like SCOPUS, PUBMED, SCIELO, ScienceDirect, Springerlink, Web of Science, Wiley, SciFinder and Google Scholar etc. In next few decades, herbal medicine may become a new epoch of medical system.

Results:

Many researches are going on medicinal plants for the treatment of cancer but it is a time to increase further experimental studies on plant extracts and their chemical constituents to find out their mechanism of action at molecular level.

Conclusion:

The article may help many researchers to start off further experimentation that might lead to the drugs for the cancer treatment.

Desoxyrhapontigenin attenuates neuronal apoptosis in an isoflurane-induced neuronal injury model by modulating the TLR-4/cyclin B1/Sirt-1 pathway

This study investigated the protective effect of desoxyrhapontigenin (DOP) against isoflurane (ISF)-induced neuronal injury in rats. Neuronal injury was induced in pups by exposing them to 0.75% ISF on postnatal day 7 with 30% oxygen for 6 h. The pups were treated with DOP 10 mg/kg, i.p., for 21 days after ISF exposure. The protective effect of DOP was estimated by assessing cognitive function using the neurological score and the Morris water maze. Neuronal apoptosis was assessed in the hippocampus using the TUNEL assay, and protein expression of caspase-3, Bax, and Bcl-2 was measured by Western blotting. The levels of cytokines and oxidative stress parameters were assessed by ELISA. Western blotting and RT-PCR were performed to measure the expression of NF-kB, TLR-4, Sirt-1, and cyclin B1 protein in the brain. The cognitive function and neurological function scores were improved in the DOP group compared with the ISF group. Moreover, DOP treatment reduced the number of TUNEL-positive cells and the expression of caspase-3, Bax, and Bcl-2 protein in the brains of rats with neuronal injury. The levels of mediators of inflammation and oxidative stress were reduced in the brain tissue of the DOP group. Treatment with DOP attenuated the protein expression of TLR-4, NF-kB, cyclin B1, and Sirt-1 in the brain tissue of rats with neuronal injury. In conclusion, DOP ameliorates neuronal apoptosis and improves cognitive function in rats with ISF-induced neuronal injury. Moreover, DOP treatment can prevent neuronal injury by regulating the TLR-4/cyclin B1/Sirt-1 pathway.

Stilbenes contribute to the anticancer effects of Rheum undulatum L. through activation of apoptosis

Rheum undulatum L. (R. undulatum) is a medicinal plant used for the treatment of inflammatory diseases in East Asian countries. Numerous stilbenes isolated from R. undulatum have been revealed to possess anticancer effects. The aim of the present study was to evaluate the effect of extracts and compounds isolated from R. undulatum on human gastric cancer cell viability and to elucidate their molecular mechanism of action on the apoptosis pathway. The results demonstrated that aloe-emodin and chrysophanol 1-O-β-D-glucopyranoside, isolated from the methanolic extract of dried rhizomes of R. undulatum, exhibited anti-proliferative effects on the human gastric carcinoma cell line AGS, with IC₅₀ values of 84.66±0.44 and 68.28±0.29 µM, respectively. The percentage of apoptotic cells increased significantly following treatment with each compound at a concentration of 100 µM, compared with that in the non-treated group in the image-based cytometry assay. Western blot analysis revealed that these compounds activated the caspase cascade and inhibited B-cell lymphoma-2, an anti-apoptotic protein.

Lipid Peroxidation and Antioxidant Activities of the Aqueous Rhizome Extract of Rheum officinale Baillon

Generation of reactive oxygen species (ROS) is associated with dysregulation of antioxidant defense mechanisms and incidence of human diseases. The specific aim of this study was to investigate the lipid oxidation and antioxidant activity of aqueous extract of Rheum officinale Baillon rhizome in order to evaluate its potential as a future novel natural antioxidant resource and a functional ingredient in food and pharmaceutical formations. Total phenolic and flavonoid contents of Rheum rhizome extract were dose dependently increased. Consistent with this, radical scavenging activities of Rheum rhizome extract as determined by 2,2-diphenyl-1-picrylhydrazyl assay and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity were significantly elevated as the concentration increased. In addition, the treatment of aqueous Rheum rhizome extract significantly increased ferric reducing and copper chelating activities. According to results of thiobarbituric acid reactive substance analysis, Rheum rhizome extract significantly delayed lipid oxidation. Preincubation with Rheum rhizome extract significantly inhibited tert-butyl hydroperoxide- (t-BHP-) induced ROS generation. Moreover, superoxide anion production was significantly lower in Rheum rhizome extract-treated RAW264.7 macrophage cells than t-BHP-incubated cells (p<0.05). These findings suggest that Rheum officinale Baillon rhizome extract has a potential as an excellent natural antioxidant agent.

A promising natural product, pristimerin, results in cytotoxicity against breast cancer stem cells in vitro and xenografts in vivo through apoptosis and an incomplete autopaghy in breast cancer

Several natural products have been suggested as effective agents for the treatment of cancer. Given the important role of CSCs (Cancer Stem Cells) in cancer, which is a trendy hypothesis, it is worth investigating the effects of pristimerin on CSCs as well as on the other malignant cells (MCF-7 and MDA-MB-231) of breast cancer. The anti-growth activity of pristimerin against MCF-7 and MCF-7s (cancer stem cell enriched population) cells was investigated by real time viability monitorization (xCELLigence System^®) and ATP assay, respectively. Mode of cell death was evaluated using electron and fluorescence microscopies, western blotting (autophagy, apoptosis and ER-stress related markers) and flow cytometry (annexin-V staining, caspase 3/7 activity, BCL-2 and PI3K expressions). Pristimerin showed an anti-growth effect on cancer cells and cancer stem cells with IC₅₀ values ranging at 0.38-1.75μM. It inhibited sphere formation at relatively lower doses (<1.56μM). Apoptosis was induced in MCF-7 and MCF-7s cells. In addition, extensive cytoplasmic vacuolation was observed, implying an incompleted autophagy as evidenced by the increase of autophagy-related proteins (p62 and LC3-II) with an unfolded protein response (UPR). Pristimerin inhibited the growth of MCF-7 and MDA-MB-231-originated xenografts in NOD.CB17-Prkdc^scid/J mice. In mice, apoptosis was further confirmed by cleavage of PARP, activation of caspase 3 and/or 7 and TUNEL staining. Taken together, pristimerin shows cytotoxic activity on breast cancer both in vitro and in vivo. It seems to represent a robust promising agent for the treatment of breast cancer. Pristimerin's itself or synthetic novel derivatives should be taken into consideration for novel potent anticancer agent(s).