Pholidonone, an active stilbene derivative from Pholidota cantonensis, exhibits pro-apoptotic effect via induction of endoplasmic reticulum stress in human gastric cancer

Comprehensive Screening and Characterization of α-glucosidase Inhibitory Components in the Edible Medicinal Plant Pholidota cantonensis Rolfe Using UPLC-Q-TOF-MS/MS Analysis and Molecular Docking

Pholidota cantonensis Rolfe is an edible medicinal plant in the genus Pholidota of the family Orchidaceae. This plant is used to prepare medicated food in China and has been reported to possess anti-α-glucosidase activity. To date, little is known about the active substances responsible for the observed anti-α-glucosidase activity. In the present study, we aimed to screen and characterize the α-glucosidase inhibitory fraction of P. cantonensis using ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) analysis and molecular docking. As a result, the 50% ethanol fraction obtained from D101 macroporous adsorption resin column chromatography (D50 fraction) had the highest total phenol content (353.83 ± 6.06 mg GAE/g) and the most prominent α-glucosidase inhibitory activity (IC50 = 30.01 ± 7.30 µg/mL). Forty-five compounds were identified from the D50 fraction by using UPLC-Q-TOF-MS/MS analysis. Molecular docking results showed that six main constituents, namely, crepidatin, 2,7-dihydroxy-4-methoxyl-9,10-dihydrophenylene, 4,4',5,6-tetrahydroxystilbene, 4,7-dihydroxy-2-methoxyl-9,10-dihydrophenylene, (-)-lariciresinol, and thunalbene, in the D50 fraction occupied the catalytic sites of α-glucosidase through strong hydrophobic interactions, hydrogen bonding, and other patterns. The binding energies were between - 29.95 and - 11.41 kJ/mol, indicating good binding between the tested compounds and α-glucosidase. The active ingredients responsible for the α-glucosidase inhibitory activity may include phenanthrenes, stilbenes, dibenzyls, and lignans. The D50 fraction has potential value for developing innovative drugs for the prevention and treatment of diabetes mellitus (DM) and is worthy of in-depth research.

1,5,6-Trimethoxy-2,7-dihydroxyphenanthrene from Dendrobium officinale Exhibited Antitumor Activities for HeLa Cells

Natural products are irreplaceable reservoirs for cancer treatments. In this study, 12 phenanthrene compounds were extracted and isolated from Dendrobium officinale. Each chemical structure was identified using comprehensive NMR analysis. All compounds were evaluated for their cytotoxic activities against five tumor cell lines, i.e., HeLa, MCF-7, SK-N-AS, Capan-2 and Hep G2. Compound 5, 1,5,6-trimethoxy-2,7-dihydroxyphenanthrene, displayed the most significant cytotoxic effect against HeLa and Hep G2 cells, with an IC50 of 0.42 and 0.20 μM. For Hela cells, further experiments demonstrated that compound 5 could obviously inhibit cell migration, block cell cycle in the G0/G1 phase and induce apoptosis. Expression measurements for p53 indicated that knock down of p53 by siRNA could mitigate the apoptosis induced by compound 5. Therefore, the compound 5 is a potential candidate drug for HeLa cells in cervical cancer.

Chebulagic acid suppresses gastric cancer by inhibiting the AURKA/β-catenin/Wnt pathway

Gastric cancer (GC) is a prevalent malignant neoplasm that poses a serious threat to human health. Overexpression of Aurora A (AURKA) is frequently associated with the self-renewal and tumorigenicity of various cancers. Chebulagic acid (CA) has been examined as a potential tumor suppressor based on its ability against numerous tumor biological activities. However, the possible mechanisms of CA inhibition of the progression of GC by mediating the AURKA/β-catenin/Wnt signaling pathway have not been investigated. The present study investigated the level of AURKA expression in GC. We further examined the effect of CA on cell proliferation, migration, and apoptosis in the MKN1 and NUGC3 GC cell lines, and its efficacy in suppressing tumor growth was assessed in tumor bearing mice model. We demonstrated that AURKA was highly expressed in GC and associated with poor prognosis. We demonstrated that treatment with CA significantly inhibited the proliferation and migration of GC cells and induced apoptosis. Compared to the vehicle group, CA treatment severely diminished the volume and weight and the metastasis of tumors. CA also inhibited the expression of AURKA and the AURKA/β-catenin/Wnt signaling pathway in vitro and in vivo. Collectively, the present results demonstrated that high expression of AURKA may be an independent factor of poor prognosis in patients with GC, and CA significantly suppressed the tumor biological functions of GC and inhibited the AURKA/β-catenin/Wnt pathway.

Ursolic Acid Derivative UA232 Promotes Tumor Cell Apoptosis by Inducing Endoplasmic Reticulum Stress and Lysosomal Dysfunction

Due to increased drug and radiation tolerance, there is an urgent need to develop novel anticancer agents. In our previous study, we performed a series of structural modifications of ursolic acid (UA), a natural product of pentacyclic triterpenes, and found UA232, a derivative with stronger anti-tumor activity. In vitro experiments showed that UA232 inhibited proliferation, induced G0/G1 arrest, and promoted apoptosis in human breast cancer and cervical cancer cells. Mechanistic studies revealed that UA232 promoted apoptosis and induced protective autophagy via the protein kinase R-like endoplasmic reticulum kinase/activating transcription factor 4/C/EBP homologous protein-mediated endoplasmic reticulum stress. In addition, we also found that UA232 induced lysosomal biogenesis, increased lysosomal membrane permeability, promoted lysosomal protease release, and led to lysosome-dependent cell death. Furthermore, UA232 suppressed tumor growth in a mouse xenograft model. In conclusion, our study revealed that UA232 exerts multiple pharmacological effects against breast and cervical cancers by simultaneously triggering endoplasmic reticulum stress and lysosomal dysfunction. Thus, UA232 may be a promising drug candidate for cancer treatment.

Exosomes: Potential Player in Endothelial Dysfunction in Cardiovascular Disease

Exosomes are spherical bilayer membrane vesicles with an average diameter of 40-100 nm. These particles perform a wide range of biological activities due to their contents, including proteins, nucleic acids, lipids, lncRNA, and miRNA. Exosomes are involved in inflammation induction, oxidative stress and apoptosis, which can be effective in endothelial dysfunction. Due to the induction of mentioned processes in the endothelial cells, the intercellular connections are destroyed, cell permeability increases and finally cell efficiency decreases and functional defects occur. Cardiovascular disease (CVDs) are of consequences of endothelial dysfunction. Thus by identifying the exosome signaling pathways, which induce inflammation, oxidative stress, and apoptosis, endothelial dysfunction and subsequently CVDs can be reduced; exosomes can be used for appropriate target therapy.

Orchidaceae-Derived Anticancer Agents: A Review

Simple Summary

Orchids are commonly used in folk medicine for the treatment of infections and tumors but little is known about the actual chemical composition of these plants and their anticancer properties. In this paper, the most recent literature on orchid-derived bioactive substances with anticancer properties is reviewed. According to the published data, numerous species of orchids contain potential antitumor chemicals. Still, a relatively insignificant number of species of orchids have been tested for their bioactive properties and most of those studies were on Asian taxa. Broader research, ’including American and African species, as well as the correct identification of samples, is essential for evaluating the usefulness of orchids as a plant family with huge anticancer potential.

Abstract

Species of orchids, which belong to the largest family of flowering plants, are commonly used in folk medicine for the treatment of infections and tumors. However, little is known about the actual chemical composition of these plants and their anticancer properties. In this paper, the most recent literature on orchid-derived bioactive substances with anticancer properties is reviewed. For the assessment, previous papers on the anticancer activity of Orchidaceae published since 2015 were considered. The papers were found by exploring electronic databases. According to the available data, many species of orchids contain potential antitumor chemicals. The bioactive substances in a relatively insignificant number of orchids are identified, and most studies are on Asian taxa. Broader research on American and African species and the correct identification of samples included in the experiments are essential for evaluating the usefulness of orchids as a plant family with vast anticancer potential.

Chemical Constituents and their Antioxidant, Anti-Inflammatory and Anti-Acetylcholinesterase Activities from Pholidota cantonensis

Alzheimer's disease (AD) has the third highest health expenditures after heart disease and cancer. It has emerged as a serious global health issue. The discovery of new drugs to prevent and treat AD is of utmost importance. Pholidota cantonensis is an edible medicinal plant consumed in China. It is widely used in traditional Chinese medicine to treat various diseases. P. cantonensis has been reported to have antioxidant, anti-inflammatory, antitumor and antibacterial activities. Among these properties, its potent antioxidant activity has attracted our attention, since oxidative stress is one of the important pathological mechanisms involved in AD. This study aimed to isolate the compounds from the active extract and evaluate their bioactivities. Fifteen compounds, including one new compound, were obtained. The isolates were tested for 2,2'-diphenyl-1-picrylhydrazyl (DPPH)/2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities, anti-acetylcholinesterase (anti-AChE) activities and inhibitory effects on nitrogen monoxide (NO) release in the BV-2 cells. Compounds 1, 2, 4, 6, 8, and 13-15 exhibited two kinds of AD-associated bioactivities. More importantly, compound 13 showed more potent NO inhibitory activity (IC₅₀ = 0.72 ± 0.08 μM) than the positive control quercetin (IC₅₀ = 12.94 ± 0.08 μM). Compound 13 also had a higher inhibitory rate (99.59 ± 0.43%) on AChE than that of the positive control galantamine (78.32 ± 1.16%) at the concentrate of 50 μg/mL. Our studies provide new insights into this plant in terms of its potential in the development of new multi-target anti-Alzheimer's disease (anti-AD) drugs.