Modulation of expression of heat shock proteins and apoptosis by Flueggea leucopyrus (Willd) decoction in three breast cancer phenotypes

Plant-Based HSP90 Inhibitors in Breast Cancer Models: A Systematic Review

Breast cancer, the most invasive cancer in women globally, necessitates novel treatments due to prevailing limitations of therapeutics. Search of news anticancer targets is more necessary than ever to tackle this pathology. Heat-Shock Protein 90 (HSP90), a chaperone protein, is implicated in breast cancer pathogenesis, rendering it an appealing target. Looking for alternative approach such as Plant-based compounds and natural HSP90 inhibitors offer promising prospects for innovative therapeutic strategies. This study aims to identify plant-based compounds with anticancer effects on breast cancer models and elucidate their mechanism of action in inhibiting the HSP90 protein. A systematic review was conducted and completed in January 2024 and included in vitro, in vivo, and in silico studies that investigated the effectiveness of plant-based HSP90 inhibitors tested on breast cancer models. Eleven studies were included in the review. Six plants and 24 compounds from six different classes were identified and proved to be effective against HSP90 in breast cancer models. The studied plant extracts showed a dose- and time-dependent decrease in cell viability. Variable IC50 values showed antiproliferative effects, with the plant Tubocapsicum anomalum demonstrating the lowest value. Withanolides was the most studied class. Fennel, Trianthema portulacastrum, and Spatholobus suberectus extracts were shown to inhibit tumor growth and angiogenesis and modulate HSP90 expression as well as its cochaperone interactions in breast cancer mouse models. The identified plant extracts and compounds were proven effective against HSP90 in breast cancer models, and this inhibition showed promising effects on breast cancer biology. Collectively, these results urge the need of further studies to better understand the mechanism of action of HSP90 inhibitors using comparable methods for preclinical observations.

In vitro anti-proliferative effect of capecitabine (Xeloda) combined with mocetinostat (MGCD0103) in 4T1 breast cancer cell line by immunoblotting

Objectives

Mouse breast cancer cell line 4T1 can accurately mimic the response to immune receptors and targeting therapeutic agents. Combined therapy has emerged as an important strategy with reduced side effects and maximum therapeutic effect. Mocetinostat (MGCD0103) is one of the members of Class I Histone Deacetylase Inhibitors (HDACi) and its mechanism of action has not been defined, yet. Capecitabine (Xeloda) is an antimetabolite and currently is widely utilized to treat a wide range of solid tumors. The aim of this study was to investigate the effects of the capecitabine, mocetinostat and their combined application on the 4T1 cell line.

Materials and Methods

The effects of combined administration of mocetinostat and capecitabine on 4T1 cells were investigated by cell viability and migration assays, apoptosis analysis, and Western blotting technique.

Results

The concentrations of drugs that give a half-maximal response (IC₅₀) were detected for capecitabine (1700 µM), mocetinostat (3,125 µM), and 50 µM Capecitabine+1,5 µM Mocetinostat for 48 hr. In capecitabine+mocetinostat combine group, we observed that cell migration decreased, DNA fragmentation increased compared to the control group. capecitabine + mocetinostat group induced apoptosis by decreasing Bcl-2, PI3K, Akt, c-myc protein levels, while increasing Bax, Caspase-3, PTEN, cleaved-PARP, Caspase-7, Caspase-9, p53, cleaved-Cas-9 protein levels in 4T1 cells.

Conclusion

Capecitabine and mocetinostat played a toxic role through inducing apoptosis on 4T1 cancer cells in a time- and concentration-dependent manner. These results showed that combined therapy with low concentrations were detected to be more effective than that with high-concentration alone drug treatment.

Evaluation of the geroprotective effects of withaferin A in Drosophila melanogaster

Withanolides are a class of compounds usually found in plant extracts which are an attractive geroprotective drug design starting point. We evaluated the geroprotective properties of Withaferin A (WA) in vivo using the Drosophila model. Flies were supplemented by nutrient medium with WA (at a concentration of 1, 10, or 100 μM dissolved in ethanol) for the experiment group and 30 μM of ethanol for the control group. WA treatment at 10 and 100 μM concentrations prolong the median life span of D. melanogaster's male by 7.7, 9.6% (respectively) and the maximum life span (the age of death 90% of individuals) by 11.1% both. Also WA treatment at 1, 10 and 100 μM improved the intestinal barrier permeability in older flies and affected an expression of genes involved in antioxidant defense (PrxV), recognition of DNA damage (Gadd45), heat shock proteins (Hsp68, Hsp83), and repair of double-strand breaks (Ku80). WA was also shown to have a multidirectional effect on the resistance of flies to the prooxidant paraquat (oxidative stress) and 33° C hyperthermia (heat shock). WA treatment increased the resistance to oxidative stress in males at 4 and 7 week old and decreased it at 6 weeks old. It increased the male's resistance to hyperthermia at 2, 4 and 7 weeks old and decreased it at 3, 5 and 8 weeks old. WA treatment decreased the resistance to hyperthermia in females at 1, 2 and 3 weeks old and not affected on their resistance to oxidative stress.

Evaluation of anticancer effects of a pharmaceutically viable extract of a traditional polyherbal mixture against non-small-cell lung cancer cells

OBJECTIVE

The present work tested organic solvents to prepare an extract with anticancer properties from a polyherbal mixture containing Nigella sativa (seeds), Hemidesmus indicus (roots) and Smilax glabra (rhizomes). We evaluate anticancer effects in non-small-cell lung cancer cells (NCI-H292), and discuss optimization for pharmaceutical use in the context of efficacy, yield and toxicity.

METHODS

Using different organic solvents, six extracts were prepared from the polyherbal mixture. Based on the cytotoxic effects of these extracts on NCI-H292 cells and normal lung cells (MRC-5), as evaluated by the sulphorhodamine B assay, the total ethyl acetate (T-EA) extract was selected for further analysis. The possible anticancer mechanisms were assessed by evaluating the extract's effects on apoptosis (through fluorescent microscopic analysis, DNA fragmentation analysis, caspase 3/7 assay and analysis of expression levels of apoptosis-related genes p53, Bax, survivin, Hsp70 and Hsp90), colony formation and antioxidant activity.

RESULTS

The extract had cytotoxic effects against NCI-H292 cells in a time- and dose-dependent manner. Significant antioxidant activity and inhibition of colony formation were also observed. The expression level of caspase 3/7 significantly (P < 0.001) increased in NCI-H292 cells treated with 50 μg/mL of the extract. The same dosage led to a significant increase in expression levels of Bax and p53 (P < 0.05 and P < 0.01 respectively), accompanied by a significant decrease (P < 0.0001) in survivin, Hsp70 and Hsp90.

CONCLUSION

T-EA extract of the above polyherbal mixture has cytotoxicity against NCI-H292 cells via induction of apoptosis, antioxidant effects and inhibition of colony formation.

Isolation of a New Sesquiterpene Lactone From Vernonia Zeylanica (L) Less and its Anti-Proliferative Effects in Breast Cancer Cell Lines

Background/Objective:

Vernonia zeylanica (L) less is an endemic plant to Sri Lanka. The present study was designed to isolate potential cytotoxic compound/s from chloroform and ethyl acetate extracts of V. zeylanica by bio-activity guided isolation and to evaluate its anti-proliferative effects in three breast cancer phenotypes (MCF -7, MDA-MB-231, SKBR-3).

Methods:

Combined chloroform and ethyl acetate extracts were subjected to chromatographic separations to isolate a compound (1) and the structure of the isolated compound was elucidated using 1H, 13C and mass spectroscopic techniques. Cytotoxic effects of the compound were evaluated by the sulforhodamine B (SRB) and the MTT (3- (4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays. Effects of the compound on apoptosis were evaluated by fluorescent microscopy, caspase 3/7 activation, DNA fragmentation and real time PCR. Effects of the compound on the expression of heat shock protein complex were also evaluated by real time PCR and immunofluorescence.

Results:

Isolated compound was identified as a new sesquiterpene lactone (vernolactone). The compound mediated significant cytotoxic effects in SKBR-3 and MDA-MB-231 breast cancer cells, with little effect in MCF-7 and normal mammary epithelial MCF-10A cells. Morphological changes, DNA fragmentation, increased caspase 3/7 activities and up-regulation of p53, Bax and down regulation of Survivin confirmed the proapoptotic effects of the compound. Significant inhibition of HSP complex related genes were also observed in SKBR-3 and MDA-MB-231 breast cancer cells.

Conclusion:

Overall results indicate that vernolactone can mediate its cytotoxic effects via apoptosis and modulating the HSP complex.

Cytotoxic and Apoptotic Effects of Govaniadine Isolated from Corydalis govaniana Wall. Roots on Human Breast Cancer (MCF-7) Cells

Current breast cancer therapies have limitations in terms of increased drug resistance resulting in short-term efficacy, thus demanding the discovery of new therapeutic agents. In this study, cytotoxic activity and apoptotic effects of govaniadine isolated from Corydalis govaniana Wall. roots were determined on human breast cancer (MCF-7) cells. The SRB assay result revealed that govaniadine led to dose- and time-dependent cytotoxic effect in MCF-7 cells along with less cytotoxicity against MCF-10A cells. Govaniadine-induced apoptosis was also accompanied by upregulation of Bax, p53, and Survivin mRNA expression as assessed by real time PCR analysis. Flow cytometric analysis with Annexin V and PI staining indicated that govaniadine is a potent inducer of apoptosis in MCF-7 cell lines. Distinctive morphological changes contributed to apoptosis and DNA laddering were observed in govaniadine-treated MCF-7 cells. Caspase-7 was significantly activated in treated MCF-7 cells. Govaniadine-treated MCF-7 cells also showed enhanced levels of intracellular reactive oxygen species (ROS) and glutathione S-transferase (GST) and decreased levels of glutathione (GSH). The results indicate that govaniadine has potent and selective cytotoxic effects against MCF-7 cells and the potential to induce caspase 7 dependent apoptosis in MCF-7 cells by activation of pathways that lead to oxidative stress.