Tectorigenin Inhibits Glioblastoma Proliferation by G0/G1 Cell Cycle Arrest

Naringin Induces ROS-Stimulated G1 Cell-Cycle Arrest and Apoptosis in Nasopharyngeal Carcinoma Cells

Naringin, a bioflavonoid compound from grapefruit or citrus, exerts anticancer activities on cervical, thyroid, colon, brain, liver, lung, thyroid, and breast cancers. The present investigation addressed exploring the anticancer effects of naringin on nasopharyngeal carcinoma (NPC) cells. Naringin exhibits a cytotoxic effect on NPC-TW 039 and NPC-TW 076 cells with IC50 372/328 and 394/307 μM for 24 or 48 h, respectively, while causing little toxicity toward normal gingival epithelial (SG) cells (>500/500 μM). We established that naringin triggered G1 arrest is achieved by suppressing cyclin D1, cyclin A, and CDK2, and upregulating p21 protein in NPC cells. Exposure of NPC cells to naringin caused a series of events leading to apoptosis including morphology change (cell shrinkage and membrane blebbing) and chromatin condensation. Annexin V and PI staining indicated that naringin treatment promotes necrosis and late apoptosis in NPC cells. DiOC6 staining showed a decline in the mitochondrial membrane potential by naringin treatment, which was followed with cytochrome c release, Apaf-1/caspase-9/-3 activation, PARP cleavage, and EndoG expression in NPC cells. Naringin upregulated proapoptotic Bax and decreased antiapoptotic Bcl-xL expression, and dysregulated Bax/Bcl-xL ratio in NPC cells. Notably, naringin enhanced death receptor-related t-Bid expression. Furthermore, an increased Ca2+ release by naringin treatment which instigated endoplasmic reticulum stress-associated apoptosis through increased IRE1, ATF-6, GRP78, GADD153, and caspase-12 expression in NPC cells. In addition, naringin triggers ROS production, and inhibition of naringin-induced ROS generation by antioxidant N-acetylcysteine resulted in the prevention of G1 arrest and apoptosis in NPC cells. Naringin-induced ROS-mediated G1 arrest and mitochondrial-, death receptor-, and endoplasmic reticulum stress-mediated apoptosis may be a promising strategy for treating NPC.

Regulated cell death in glioma: promising targets for natural small-molecule compounds

Gliomas are prevalent malignant tumors in adults, which can be categorized as either localized or diffuse gliomas. Glioblastoma is the most aggressive and deadliest form of glioma. Currently, there is no complete cure, and the median survival time is less than one year. The main mechanism of regulated cell death involves organisms coordinating the elimination of damaged cells at risk of tumor transformation or cells hijacked by microorganisms for pathogen replication. This process includes apoptosis, necroptosis, autophagy, ferroptosis, pyroptosis, necrosis, parthanayosis, entosis, lysosome-dependent death, NETosis, oxiptosis, alkaliptosis, and disulfidaptosis. The main goal of clinical oncology is to develop therapies that promote the effective elimination of cancer cells by regulating cell death are the main goal of clinical oncology. Recently, scientists have utilized pertinent regulatory factors and natural small-molecule compounds to induce regulated cell death for the treatment of gliomas. By analyzing the PubMed and Web of Science databases, this paper reviews the research progress on the regulation of cell death and the role of natural small-molecule compounds in glioma. The aim is to provide help for the treatment of glioblastoma.

Pro-apoptotic effect of chloroform fraction of Moraea sisyrinchium bulb against glioblastoma cells

INTRODUCTION

Glioblastoma is a common malignant brain tumor, with limited therapeutic options. In our previous study, the Moraea sisyrinchium plant showed cytotoxicity against glioblastoma and hepatocellular carcinoma cells. Among different parts of this plant (flower, stem, and bulb), the bulb showed better anticancer potential. The present work aimed to test the anticancer activity of different fractions of the bulb extract, to determine its phytochemicals, and to study its mechanism action on glioblastoma.

METHODS

The bulb extract was partitioned into different fractions using immiscible solvents. The U87 glioblastoma cells were incubated with the obtained fractions. Then, the cell proliferation assay (MTT), cell migration test (scratch), cell cycle analysis (propidium iodide staining), apoptosis/necrosis assay (annexin V/propidium iodide staining), and real-time PCR (PTEN, Akt, mTOR, BAX and BCL-2 genes) were performed. Phytochemicals were determined using liquid chromatography-mass spectroscopy.

RESULTS

The chloroform fraction showed more antiproliferative effect than n-hexane, ethyl acetate, and n-butanol fractions. Also, chloroform fraction induced cell cycle arrest, increased apoptosis, and inhibited cell migration ability (P < 0.05). The expression of PTEN, mTOR, and BAX genes was significantly up-regulated, while the expression of Akt and Bcl-2 showed down-regulation. The phytochemicals identified in the chloroform fraction were mainly xanthones, phytosterols, and isoflavones.

CONCLUSION

The chloroform fraction of Moraea sisyrinchium bulb inhibits the proliferation and migration of glioblastoma cells by inducing cell cycle arrest and apoptosis by upregulation of the PTEN gene and Bax/Bcl-2 ratio. The identified compounds in the chloroform fraction are potential candidates for further investigation as anticancer agents against glioblastoma.

Moraea sisyrinchium inhibits proliferation, cell cycle, and migration of cancerous cells, and decreases angiogenesis in chick chorioallantoic membrane

Objectives

Experimental studies reported that some plants in the genus of Moraea (Iridaceae family) show anticancer potential. This study aimed to evaluate the effects of Moraea sisyrinchium on U87 glioblastoma multiforme and HepG2 liver cancer cells.

Materials and Methods

The cells were incubated for 24 hr with hydroalcoholic extract of the stem, flower, and bulb of M. sisyrinchium. Then, the cell proliferation (MTT) assay, cell cycle analysis (propidium iodide staining), cell migration test (scratch), Western blotting (Bax and Bcl-2 expression), and gelatin zymography (for matrix metalloproteinases, MMPs) were performed. Oxidative stress was evaluated by determining the levels of reactive oxygen species and lipid peroxidation. Angiogenesis was evaluated on chick embryo chorioallantoic membrane.

Results

The extracts of the flower, stem, and bulb significantly decreased the proliferation of HepG2 and U87 cells. This effect was more for U87 than HepG2 and for the bulb and stem than the flower. In U87 cells, the bulb extract increased oxidative stress, cell cycle arrest, and the Bax/Bcl-2 ratio. Also, this extract suppressed the migration ability of HepG2 and U87 cells, which was associated with the inhibition of MMP2 activity. In addition, it significantly reduced the number and diameter of vessels in the chorioallantoic membrane. Liquid chromatography-mass spectrometry revealed the presence of xanthones (bellidifolin and mangiferin), flavonoids (quercetin and luteolin), isoflavones (iridin and tectorigenin), and phytosterols (e.g., stigmasterol) in the bulb.

Conclusion

M. sisyrinchium bulb decreased the proliferation and survival of cancer cells by inducing oxidative stress. It also reduced the migration ability of the cells and inhibited angiogenesis.

Tectorigenin: A Review of Its Sources, Pharmacology, Toxicity, and Pharmacokinetics

Tectorigenin is a well-known natural flavonoid aglycone and an active component that exists in numerous plants. Growing evidence suggests that tectorigenin has multiple pharmacological effects, such as anticancer, antidiabetic, hepatoprotective, anti-inflammatory, antioxidative, antimicrobial, cardioprotective, and neuroprotective. These pharmacological properties provide the basis for the treatment of many kinds of illnesses, including several types of cancer, diabetes, hepatic fibrosis, osteoarthritis, Alzheimer's disease, etc. The purpose of this paper is to provide a comprehensive summary and review of the sources, extraction and synthesis, pharmacological effects, toxicity, pharmacokinetics, and delivery strategy aspects of tectorigenin. Tectorigenin may exert certain cytotoxicity, which is related to the administration time and concentration. Pharmacokinetic studies have demonstrated that the main metabolic pathways in rats for tectorigenin are glucuronidation, sulfation, demethylation and methoxylation, but that it exhibits poor bioavailability. From our perspective, further research on tectorigenin should cover: exploring the pharmacological targets and mechanisms of action; finding an appropriate concentration to balance pharmacological effects and toxicity; attempting diversified delivery strategies to improve the bioavailability; and structural modification to obtain tectorigenin derivatives with higher pharmacological activity.

Tectorigenin inhibits inflammation in keratinocytes by inhibition of NLRP3 inflammasome regulated by the TLR4/NF-κB pathway

BACKGROUND

Psoriasis is a prevalent inflammatory skin disease characterized by excessive proliferation and abnormal differentiation of keratinocytes, and infiltration of inflammatory cells into the epidermis. However, the underlying mechanisms remain unclear. Tectorigenin is an active ingredient in traditional medicines and has anti-inflammatory activity. This research explored the effects of tectorigenin on the anti-inflammatory property, autophagy, and the underlying mechanisms in M5 ([IL-22, IL-17A, oncostatin M, IL-1α, and TNF-α])-stimulated HaCaT cells.

METHODS

The in vitro model of mixed M5 cytokines-stimulated HaCaT keratinocytes was established to investigate the phenotypic features in psoriasis. Cell viability was assessed by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay, cell proliferative rate by EdU (5-ethynyl-2'-deoxyuridine) assay, and autophagy was detected by immunofluorescence staining. After M5 exposure, the proliferative rate, protein expression of autophagy, and signaling activities of NLR family pyrin domain containing 3 (NLRP3) inflammasome and toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) were measured. The latter were quantitated using quantitative PCR and western blot, respectively. The inflammatory response was detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Tectorigenin exerted a protective effect in ameliorating the hyperproliferation and inflammation of HaCaT keratinocytes induced by M5 cytokines. Furthermore, tectorigenin on keratinocytes seemed to inactivate NLRP3 inflammasome and inhibit cell proliferation and inflammation response via suppression of TLR4/NF-κB pathway.

CONCLUSION

This study proves that tectorigenin may be a potential therapeutic candidate for psoriasis treatment in future.

Mechanisms of Cell Cycle Arrest and Apoptosis in Glioblastoma

Cells of glioblastoma, the most frequent primary malignant brain tumor, are characterized by their rapid growth and infiltration of adjacent healthy brain parenchyma, which reflects their aggressive biological behavior. In order to maintain their excessive proliferation and invasion, glioblastomas exploit the innate biological capacities of the patients suffering from this tumor. The pathways involved in cell cycle regulation and apoptosis are the mechanisms most commonly affected. The following work reviews the regulatory pathways of cell growth in general as well as the dysregulated cell cycle and apoptosis relevant mechanisms observed in glioblastomas. We then describe the molecular targeting of the current established adjuvant therapy and present ongoing trials or completed studies on specific promising therapeutic agents that induce cell cycle arrest and apoptosis of glioblastoma cells.

Natural Compounds in Glioblastoma Therapy: Preclinical Insights, Mechanistic Pathways, and Outlook

Simple Summary

Glioblastoma (GBM) is a tumor of the brain or spinal cord with poor clinical prognosis. Current interventions, such as chemotherapy and surgical tumor resection, are constrained by tumor invasion and cancer drug resistance. Dietary natural substances are therefore evaluated for their potential as agents in GBM treatment. Various substances found in fruits, vegetables, and other natural products restrict tumor growth and induce GBM cell death. These preclinical effects are promising but remain constrained by natural substances’ varying pharmacological properties. While many of the reviewed substances are available as over-the-counter supplements, their anti-GBM efficacy should be corroborated by clinical trials moving forward.

Abstract

Glioblastoma (GBM) is an aggressive, often fatal astrocyte-derived tumor of the central nervous system. Conventional medical and surgical interventions have greatly improved survival rates; however, tumor heterogeneity, invasiveness, and chemotherapeutic resistance continue to pose clinical challenges. As such, dietary natural substances—an integral component of the lifestyle medicine approach to chronic diseases—are examined as potential chemotherapeutic agents. These heterogenous substances exert anti-GBM effects by upregulating apoptosis and autophagy, inducing cell cycle arrest, interfering with tumor metabolism, and inhibiting proliferation, neuroinflammation, chemoresistance, angiogenesis, and metastasis. Although these beneficial effects are promising, natural substances’ efficacy in GBM is constrained by their bioavailability and blood–brain barrier permeability; various chemical formulations are proposed to improve their pharmacological properties. Many of the reviewed substances are available as over-the-counter dietary supplements, underscoring their viability as lifestyle interventions. However, clinical trials remain necessary to substantiate the in vitro and in vivo properties of natural substances.