Furanodiene Induces Extrinsic and Intrinsic Apoptosis in Doxorubicin-Resistant MCF-7 Breast Cancer Cells via NF-κB-Independent Mechanism

Potential roles and molecular mechanisms of bioactive ingredients in Curcumae Rhizoma against breast cancer

BACKGROUND

Breast cancer is the most prevalent cancer worldwide, with high morbidity and mortality. Despite great advances in the therapeutic strategies, the survival rate in the past decades of patients with breast cancer remains unsatisfactory. Growing evidence has demonstrated that Curcumae Rhizoma, called Ezhu in Chinese, showed various pharmacological properties, including anti-bacterial, anti-oxidant, anti-inflammatory and anti-tumor activities. It has been widely used in Chinese medicine to treat many types of human cancer.

PURPOSE

To comprehensively summarize and analyze the effects of active substances in Curcumae Rhizoma on breast cancer malignant phenotypes and the underlying mechanisms, as well as discuss its medicinal value and future perspectives.

METHOD

We used "Curcumae Rhizoma" or the name of crude extracts and bioactive components in Curcumae Rhizoma in combination with "breast cancer" as key words. Studies focusing on their anti-breast cancer activities and mechanisms of action were extracted from Pubmed, Web of Science and CNKI databases up to October 2022. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 guideline was followed.

RESULTS

Crude extracts and 7 main bioactive phytochemicals (curcumol, β-elemene, furanodiene, furanodienone, germacrone, curdione and curcumin) isolated from Curcumae Rhizoma have shown many anti-breast cancer pharmacological properties, including inhibiting cell proliferation, migration, invasion and stemness, reversing chemoresistance, and inducing cell apoptosis, cycle arrest and ferroptosis. The mechanisms of action were involved in regulating MAPK, PI3K/AKT and NF-κB signaling pathways. In vivo and clinical studies demonstrated that these compounds exhibited high anti-tumor efficacy and safety against breast cancer.

CONCLUSION

These findings provide strong evidence that Curcumae Rhizoma acts as a rich source of phytochemicals and has robust anti-breast cancer properties.

2,3,5,4′-Tetrahydroxystilbene-2-O-β-glucoside Attenuates Reactive Oxygen Species-Dependent Inflammation and Apoptosis in Porphyromonas gingivalis-Infected Brain Endothelial Cells

We recently reported that the periodontopathic bacteria Porphyromonas gingivalis (P. gingivalis) initiates an inflammatory cascade that disrupts the balance of reactive oxygen species (ROS), resulting in apoptotic cell death in brain endothelial cells. An extract from Polygonum multiflorum Thunb., 2,3,5,4′-Tetrahydroxystilbene-2-O-β-glucoside (THSG) has been well-reported to diminish the inflammation in many disease models. However, the effects of THSG in the area of the brain–oral axis is unknown. In this study, we examined the effects of THSG in P. gingivalis-stimulated inflammatory response and apoptotic cell death in brain endothelial cells. THSG treatment remarkably lessened the upregulation of IL-1β and TNF-α proteins in bEnd.3 cells infected with P. gingivalis. Treatment of THSG further ameliorated brain endothelial cell death, including apoptosis caused by P. gingivalis. Moreover, the present study showed that the inhibitory effects on NF-κB p65 and antiapoptotic properties of THSG is through inhibiting the ROS pathway. Importantly, the ROS inhibitory potency of THSG is similar to a ROS scavenger N-Acetyl-L-Cysteine (NAC) and NADPH oxidase inhibitor apocynin. Furthermore, the protective effect of THSG from P. gingivalis infection was further confirmed in primary mouse brain endothelial cells. Taken together, this study indicates that THSG attenuates an ROS-dependent inflammatory response and cell apoptosis in P. gingivalis-infected brain endothelial cells. Our results also suggest that THSG could be a potential herbal medicine to prevent the risk of developing cerebrovascular diseases from infection of periodontal bacteria.

Carbon quantum dots-Annexin V probe: photoinduced electron transfer mechanism, phosphatidylserine detection, and apoptotic cell imaging

An annexin V-based probe is designed and fabricated using carbon quantum dot as highly stable and biocompatible fluorescent crystals for real-time fluorescence imaging of apoptotic cells. Carbon quantum dots were synthesized, characterized, and conjugated to annexin V. The fluorescence of CQDs at 450 nm (excitation at 350 nm) is quenched due to the photoinduced electron transfer between "carbon quantum dots" and two amino acids (tyrosine and tryptophan) in the annexin structure as quencher. The probe shows very strong and bright fluorescence emission in the presence of phosphatidylserine on the outer layer of the apoptotic cell membrane. It was shown that using fluorescence spectroscopy, the probe can be applied to sensitive phosphatidylserine determination and using fluorescence microscopy, it is possible to monitor cell apoptosis in real time.

RBM38 is negatively regulated by miR-320b and enhances Adriamycin resistance in breast cancer cells

Breast cancer (BC) is a common type of malignant tumor that is frequently accompanied by drug resistance, which is a significant challenge in the treatment of BC. Adriamycin (ADM) is a commonly used drug for the treatment of BC. The aim of the present study was to demonstrate the association between RNA binding motif protein 38 (RBM38) and ADM resistance in BC. The results revealed that the expression levels of RBM38 were significantly upregulated in ADM-resistant BC tissues and the ADM-resistant cell line, MCF-7/A, as demonstrated using reverse transcription-quantitative PCR and western blotting. In addition, the results of the MTT assay revealed that the overexpression of RBM38 enhanced the resistance of MCF-7/A cells to ADM, promoted invasiveness, as determined using a Transwell assay, inhibited the apoptosis of resistant cells, as determined using flow cytometry, and accelerated cell cycle progression from the G₀ to the S phase. The results of the dual luciferase reporter assay demonstrated the binding relationship between microRNA (miR)-320b and RBM38, and the expression levels of miR-320b were significantly downregulated in ADM-resistant BC tissues and MCF-7/A cells. Overexpression of miR-320b reversed ADM resistance, suppressed invasiveness, promoted apoptosis and arrested MCF-7/A cells in the G₀ phase. In addition, RBM38 was discovered to be negatively regulated by miR-320b, which was able to restore the sensitivity of BC cells to ADM by downregulating RBM38. Further exploration of the underlying regulatory mechanism revealed that the miR-320b/RBM38 signaling axis mediated the development of ADM resistance in BC by altering the expression of cell cycle-, drug resistance- and PI3K/AKT signaling pathway-related proteins. In conclusion, the results of the present study suggested that RBM38 may be negatively regulated by miR-320b, which accelerates drug resistance in BC.

Terpenoids from Curcumae Rhizoma: Their anticancer effects and clinical uses on combination and versus drug therapies

Cancer is a fatal disease with high mortality and low survival rate worldwide. At present, there is still no known cure for most cancers. Traditional Chinese medicine (TCM) represents a noteworthy reservoir for anticancer agents in drug discovery and development. Curcumae Rhizoma (called Ezhu in Chinese) is widely prescribed in TCM for anticancer therapy owing to its broad-spectrum antineoplastic activities. Especially, the terpenoids isolated from the essential oil of Curcumae Rhizoma form an integral part of cancer research and are well established as a potential anticancer agent. For example, β-elemene has been developed into a new drug for the treatment of solid tumors in China, and is currently undergoing clinical trials in the United States. The review aims to systematically summarize the recent advances on the anticancer effects and related molecular mechanisms of Curcumae Rhizoma, and its terpenoids (β-elemene, Furanodiene, Furanodienone, Germacrone, Curcumol, Curdione). In addition, we evaluated and compared the anticancer efficacy and clinical use of the terpenoids with combination therapies and traditional therapies. Therefore, this review provides sufficient evidence for the anticancer therapeutic potential of Curcumae Rhizoma and its terpenoids, and will contribute to the development of potential anticancer drugs.

UFL1 Alleviates LPS-Induced Apoptosis by Regulating the NF-κB Signaling Pathway in Bovine Ovarian Granulosa Cells

Ubiquitin-like modifier 1 ligating enzyme 1 (UFL1) is an E3 ligase of ubiquitin fold modifier 1 (UFM1), which can act together with its target protein to inhibit the apoptosis of cells. Lipopolysaccharides (LPS) can affect the ovarian health of female animals by affecting the apoptosis of ovarian granulosa cells. The physiological function of UFL1 on the apoptosis of bovine (ovarian) granulosa cells (bGCs) remains unclear; therefore, we focused on the modulating effect of UFL1 on the regulation of LPS-induced apoptosis in ovarian granulosa cells. Our study found that UFL1 was expressed in both the nucleus and cytoplasm of bGCs. The results here demonstrated that LPS caused a significant increase in the apoptosis level of bGCs in cows, and also dramatically increased the expression of UFL1. Furthermore, we found that UFL1 depletion caused a significant increase in apoptosis (increased the expression of BAX/BCL-2 and the activity of caspase-3). Conversely, the overexpression of UFL1 relieved the LPS-induced apoptosis. In order to assess whether the inhibition of bGCs apoptosis involved in the nuclear factor-κB (NF-κB) signaling pathway resulted from UFL1, we detected the expression of NF-κB p-p65. LPS treatment resulted in a significant upregulation in the protein concentration of NF-κB p-p65, and knockdown of UFL1 further increased the phosphorylation of NF-κB p65, while UFL1 overexpression significantly inhibited the expression of NF-κB p-p65. Collectively, UFL1 could suppress LPS-induced apoptosis in cow ovarian granulosa cells, likely via the NF-κB pathway. These results identify a novel role of UFL1 in the modulation of bGC apoptosis, which may be a potential signaling target to improve the reproductive health of dairy cows.

Eriocalyxin B Induces Apoptosis and Autophagy Involving Akt/Mammalian Target of Rapamycin (mTOR) Pathway in Prostate Cancer Cells

Background

Eriocalyxin B (EriB), a diterpenoid isolated from the plant Isodon eriocalyx, has been shown to possess anti-tumor properties. However, few systematic studies of the mechanism underlying the anti-tumor activity of Eriocalyxin B in prostate cancer cells have been published. The aim of this study was to investigate the effect of Eriocalyxin B on prostate cancer cells.

Material/Methods

In the present study, the PC-3 (androgen-independent) and 22RV1 (androgen-dependent) human prostate cancer cell lines were cultured with and without increasing doses of Eriocalyxin B. MTT assay was used to measure cell viability. Western blotting was performed to measure levels of proteins associated with apoptosis and autophagy. Flow cytometry was used to assess changes in cell apoptosis and cycle. Fluorescence microscopy was used to capture images of autophagy-related proteins.

Results

Treatment of human prostate cancer cells with Eriocalyxin B resulted in apoptosis in a dose- and time-dependent manner. Eriocalyxin B also induced autophagy, with elevated LC3B-II protein expression and punctuate patterns. Additionally, autophagy protected prostate cancer cells from apoptosis induced by Eriocalyxin B, which was demonstrated by addition of chloroquine (CQ). Moreover, the results indicated that Eriocalyxin B could inhibit the phosphorylation of Akt and mTOR. Eriocalyxin B induced apoptosis and autophagy by inhibition of the Akt/mTOR pathway.

Conclusions

Eriocalyxin B induces apoptosis and autophagy involving the Akt/mTOR pathway in prostate cancer cells in vitro. These findings provide evidence for Eriocalyxin B as a potent therapeutic for the treatment of prostate cancer.

Anti-inflammatory activities of Sigesbeckia glabrescens Makino: combined in vitro and in silico investigations

BACKGROUND

Sigesbeckia glabrescens Makino (SG) is one of the important plant origins of Sigesbeckiae herba and has been widely used for the treatment of chronic inflammatory diseases in China. However, the underlying anti-inflammatory mechanism of SG is rarely investigated and reported. There are more than 40 kinds of chemical constituents in SG, but the action of the bioactive compounds of SG is still unclear. Therefore, we aimed to systemically investigate the mechanisms behind the anti-inflammatory properties of SG by combining in vitro and in silico investigations.

METHODS

Cytotoxicity was measured using the 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. Nitric oxide (NO) release was detected using the Griess assay. The secretion of pro-inflammatory cytokines and the expression of relevant proteins were assessed using ELISA kits and Western blots, respectively. Molecular docking was performed and scored using AutoDock via a comparison with the molecular docking of N-acetyl-d-glucosamine (NAG).

RESULTS

In lipopolysaccharides (LPS)-stimulated macrophages, SG significantly inhibited NO, MCP-1, and IL-6 secretion; iNOS expression; and NF-κB activation but did not significantly affect MAPK signalling (p38, ERK, and JNK). Moreover, the results from the molecular docking prediction suggested that over 10 compounds in SG could likely target TLR4, p105, and p65.

CONCLUSIONS

These findings suggest that the anti-inflammatory effects of SG are highly related to the inactivation of NF-κB. Moreover, this study provides a novel approach to investigate the effects of herbal medicine using combined in vitro and in silico investigations.

Anti-cancer effects of Rhizoma Curcumae against doxorubicin-resistant breast cancer cells

Background

Chemotherapy is a primary approach in cancer treatment after routine surgery. However, chemo-resistance tends to occur with chemotherapy in clinic, resulting in poor prognosis and recurrence. Nowadays, Chinese medicine may shed light on design of new therapeutic modes to overcome chemo-resistance. Although Rhizoma Curcumae possesses anti-cancer activities in various types of cancers, the effects and underlying mechanisms of its bioactive components against chemo-resistance are not clear. Therefore, the present study aims to explore the potential effects of Rhizoma Curcumae on doxorubicin-resistant breast cancer cells.

Methods

The expression and function of ABC transporters in doxorubicin-resistant MCF-7 breast cancer cells were measured by western blotting and flow cytometry. Cell viability was detected using MTT assay. The combination index was analyzed using the CalcuSyn program (Biosoft, Ferguson, MO), based on the Chou–Talalay method.

Results

In our present study, P-gp was overexpressed at protein level in doxorubicin-resistant MCF-7 cell line, but short of MRP1 and BCRP1. Essential oil of Rhizoma Curcumae and the main bioactive components were assessed on doxorubicin-resistant MCF-7 cell line. We found that the essential oil and furanodiene both display powerful inhibitory effects on cell viability, but neither of these is the specific inhibitor of ABC transporters. Moreover, furanodiene fails to enhance the efficacy of doxorubicin to improve multidrug resistance.

Conclusion

Overall, our findings fill the gaps of the researches on chemo-resistance improvement of Rhizoma Curcumae and are also beneficial for Rhizoma Curcumae being developed as a promising natural product for cancer adjuvant therapy in the future.

Electronic supplementary material

The online version of this article (10.1186/s13020-018-0203-z) contains supplementary material, which is available to authorized users.