Grape seed procyanidin B2 promotes the autophagy and apoptosis in colorectal cancer cells via regulating PI3K/Akt signaling pathway

Lysosomes and LAMPs as Autophagy Drivers of Drug Resistance in Colorectal Cancer

Colorectal cancer (CRC) is among the most malignant pathologies worldwide. A major factor contributing to the poor prognosis of neoplastic diseases is the development of drug resistance. It significantly reduces the utility of most therapeutic protocols and necessitates the search for novel biomarkers and treatment strategies to combat cancer. An evolutionarily conserved catabolic mechanism, autophagy maintains nutrient recycling and metabolic adaptation and is also closely related to carcinogenesis, playing a dual role. Autophagy inhibition can limit the growth of tumors and improve the response to cancer therapeutics. Lysosomes, key players in autophagy, are also considered promising targets for anticancer treatment. There are still insufficient data on the role of poorly studied glycoproteins related to autophagy, such as the lysosome-associated membrane glycoproteins (LAMPs). They can act as multifunctional molecules involved in a multitude of processes like autophagy and cancer development. In the current review, we summarize the recent data on the double-faceted role of autophagy in cancer with a focus on drug resistance in CRC and on the roles of lysosomes and LAMPs in these interconnected processes. Several lysosomotropic drugs are discussed as options to overcome cancer cell chemoresistance. The complex networks that underline defined autophagic pathways in the context of CRC carcinogenesis and the role of autophagy, especially of LAMPs as drivers of drug resistance, are outlined.

RNA-seq and metabolomic analyses of beneficial plant phenol biochemical pathways in red alder

Red alder (Alnus rubra) has highly desirable wood, dye pigment, and (traditional) medicinal properties which have been capitalized on for thousands of years, including by Pacific West Coast Native Americans. A rapidly growing tree species native to North American western coastal and riparian regions, it undergoes symbiosis with actinobacterium Frankia via their nitrogen-fixing root nodules. Red alder's desirable properties are, however, largely attributed to its bioactive plant phenol metabolites, including for plant defense, for its attractive wood and bark coloration, and various beneficial medicinal properties. Integrated transcriptome and metabolome data analyses were carried out using buds, leaves, stems, roots, and root nodules from greenhouse grown red alder saplings with samples collected during different time-points (Spring, Summer, and Fall) of the growing season. Pollen and catkins were collected from field grown mature trees. Overall plant phenol biochemical pathways operative in red alder were determined, with a particular emphasis on potentially identifying candidates for the long unknown gateway entry points to the proanthocyanidin (PA) and ellagitannin metabolic classes, as well as in gaining better understanding of the biochemical basis of diarylheptanoid formation, i.e. that help define red alder's varied medicinal uses, and its extensive wood and dye usage.

Autophagy regulates apoptosis of colorectal cancer cells based on signaling pathways

Colorectal cancer is a common malignant tumor of the digestive system. Its morbidity and mortality rank among the highest in the world. Cancer development is associated with aberrant signaling pathways. Autophagy is a process of cell self-digestion that maintains the intracellular environment and has a bidirectional regulatory role in cancer. Apoptosis is one of the important death programs in cancer cells and is able to inhibit cancer development. Studies have shown that a variety of substances can regulate autophagy and apoptosis in colorectal cancer cells through signaling pathways, and participate in the regulation of autophagy on apoptosis. In this paper, we focus on the relevant research on autophagy in colorectal cancer cells based on the involvement of related signaling pathways in the regulation of apoptosis in order to provide new research ideas and therapeutic directions for the treatment of colorectal cancer.

Targeted magnetochemotherapy modified by 5-Fu-loaded thermally on/off switching nanoheaters for the eradication of CT26 murine colon cancer by inducing apoptotic and autophagic cell death

Despite significant breakthroughs in diagnosis and treatment of colorectal cancer (CRC), the extent of morbidity and mortality secondary to CRC is still concerning. In this study, we evaluated the efficacy of our new tumor-selective nanoplatforms at induction of apoptosis and autophagy, which was tested using active 5-fluorouracil (5-Fu)-based targeting of tumor cells in a BALB/c murine model of CRC combined with magnetic thermal therapy. Nanoparticles were synthesized and characterized by zeta sizer, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The cytotoxicity and tissue uptake of 5-Fu-loaded folic acid (Fa)-modified magnetic nanoparticles (5-Fu/MNPs-Fa) was assessed using MTT, ICP-OES, and HPLC. The rate of apoptosis and autophagy, as two major indicators of antitumor activity, was measured based on protein expression of Bax, Bcl2, Caspase 3, mTOR, P-mTOR, Beclin-1, and LC3B in CT-26 murine CRC, along with tumor volume and survival time. The spherical 5-Fu/MNPs-Fa exhibited sustained thermal on/off switching drug release and higher therapeutic index compared to free 5-Fu. Our de novo synthetized magnetic nanoheaters successfully delivered the therapeutic agent to the tumor site, enhanced the conversion of radio frequency energy to heat in tumor cells, exhibited higher antitumor efficiency based on Bax/Bcl2 ratio and overexpression of Beclin-1 and LC3B, increased the survival time, and decreased the tumor volume (P < 0.05). Our findings indicated that magnetochemotherapy (MHC) was substantially more effective than hyperthermia and/or chemotherapy alone. From a translational standpoint, the 5-Fu/MNPs-Fa would be a promising candidate sustained drug targeting system that could improve cancer cell therapy via inducing apoptosis and autophagy.

Graphical Abstract

Proanthocyanidin enhances the endogenous regeneration of alveolar bone by elevating the autophagy of PDLSCs

OBJECTIVE

This study aimed to investigate the effect of proanthocyanidin (PA) on osteogenesis mediated by periodontal ligament stem cells (PDLSCs) and endogenous alveolar bone regeneration.

BACKGROUND

Leveraging the osteogenic potential of resident stem cells is a promising strategy for alveolar bone regeneration. PA has been reported to be effective in osteogenesis. However, the effect and mechanism of PA on the osteogenic differentiation of PDLSCs remain elusive.

METHODS

Human PDLSCs were treated with various doses of PA to assess the cell proliferation using Cell Counting Kit-8. The osteogenic differentiation ability was detected by qRT-PCR analysis, western blot analysis, Alizarin red S staining, and Alkaline Phosphatase staining. The level of autophagy was evaluated by confocal laser scanning microscopy, transmission electron microscopy, and western blot analysis. RNA sequencing was utilized to screen the potential signaling pathway. The alveolar bone defect model of rats was created to observe endogenous bone regeneration.

RESULTS

PA activated intracellular autophagy in PDLSCs, resulting in enhanced osteogenic differentiation. Moreover, this effect could be abolished by the autophagy inhibitor 3-Methyladenine. Mechanistically, the PI3K/Akt/mTOR pathway was negatively correlated with PA-mediated autophagy activation. Lastly, PA promoted the alveolar bone regeneration in vivo, and this effect was reversed when the autophagy process was blocked.

CONCLUSION

PA may activate autophagy by inhibiting PI3K/Akt/mTOR signaling pathway to promote the osteogenesis of PDLSCs and enhance endogenous alveolar bone regeneration.

Procyanidin B2 alleviates uterine toxicity induced by cadmium exposure in rats: The effect of oxidative stress, inflammation, and gut microbiota

Environmental exposure to hazardous materials causes enormous socioeconomic problems due to its deleterious impacts on human beings, agriculture and animal husbandry. As an important hazardous material, cadmium can promote uterine oxidative stress and inflammation, leading to reproductive toxicity. Antioxidants have been reported to attenuate the reproductive toxicity associated with cadmium exposure. In this study, we investigated the potential protective effect of procyanidin oligosaccharide B2 (PC-B2) and gut microbiota on uterine toxicity induced by cadmium exposure in rats. The results showed that the expression levels of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were reduced in utero. Proinflammatory cytokines (including tumor necrosis factor-α, interleukin-1β and interleukin-6), the NLRP3 inflammasome, Caspase-1 and pro-IL-1β were all involved in inflammatory-mediated uterine injury. PC-B2 prevented CdCl2-induced oxidative stress and inflammation in uterine tissue by increasing antioxidant enzymes and reducing proinflammatory cytokines. Additionally, PC-B2 significantly reduced cadmium deposition in the uterus, possibly through its significant increase in MT1, MT2, and MT3 mRNA expression. Interestingly, PC-B2 protected the uterus from CdCl2 damage by increasing the abundance of intestinal microbiota, promoting beneficial microbiota, and inhibiting harmful microbiota. This study provides novel mechanistic insights into the toxicity of environmental cadmium exposure and indicates that PC-B2 could be used in the prevention of cadmium exposure-induced uterine toxicity.

Procyanidin B2: A promising multi-functional food-derived pigment for human diseases

Natural edible pigments play a paramount part in the food industry. Procyanidin B2 (PB2), one of the most representative naturally occurring edible pigments, is usually isolated from the seeds, fruits, and leaves of lots of common plants, such as grapes, Hawthorn, black soybean, as well as blueberry, and functions as a food additive in daily life. Notably, PB2 has numerous bioactivities and possesses the potential to treat/prevent a wide range of human diseases, such as diabetes mellitus, diabetic complications, atherosclerosis, and non-alcoholic fatty liver disease, and the underlying mechanisms were partially elucidated, including mediating signaling pathways like NF-κB, MAPK, PI3K/Akt, apoptotic axis, and Nrf-2/HO-1. This paper presents a review of the natural sources, bioactivities, and the therapeutic/preventive potential of PB2 and the possible mechanisms, with the aim of promoting the development of PB2 as a functional food and providing references for its clinical application in the treatment of diseases.

The perception and influencing factors of astringency, and health-promoting effects associated with phytochemicals: A comprehensive review

Astringency as the complex sensory of drying or shrinking can be perceived from natural foods, including abundant phenolic compounds. Up to now, there have been two possible astringency perception mechanisms of phenolic compounds. The first possible mechanism involved chemosensors and mechanosensors and took salivary binding proteins as the premise. Although piecemeal reports about chemosensors, friction mechanosensor's perception mechanisms were absent. There might be another perception way because a part of astringent phenolic compounds also triggered astringency although they could not bind with salivary proteins, however, the specific mechanism was unclear. Structures caused the differences in astringency perception mechanisms and intensities. Except for structures, other influencing factors also changed astringency perception intensity and aimed to decrease it, which probably ignored the health-promoting effects of phenolic compounds. Therefore, we roundly summarized the chemosensor's perception processes of the first mechanism. Meanwhile, we speculated that friction mechanosensor's probably activated Piezo2 ion channel on cell membranes. Phenolic compounds directly binds with oral epithelial cells, activating Piezo2 ion channel probably the another astringency perception mechanism. Except for structure, the increase of pH values, ethanol concentrations, and viscosity not only lowered astringency perception but were beneficial to improve the bioaccessibility and bioavailability of astringent phenolic compounds, which contributed to stronger antioxidant, anti-inflammatory, antiaging and anticancer effects.

Dihydroartemisinin inhibited stem cell-like properties and enhanced oxaliplatin sensitivity of colorectal cancer via AKT/mTOR signaling

Colorectal cancer (CRC) is a common tumor with high morbidity and mortality. The use of oxaliplatin (L-OHP) as a first-line treatment for CRC is limited due to chemoresistance. Growing evidence have revealed that the existence of cancer stem-like cells (CSLCs) is one of the important reasons for drug resistance and recurrence of cancers. Dihydroartemisinin (DHA), a derivative of artemisinin, has showed anticancer effects on a variety of malignancies, in addition to its antimalarial effects. However, the effect and mechanism of DHA on CSLCs and chemosensitivity in CRC cells remains unclear. In this study, we found that DHA inhibited cell viability in HCT116 and SW620 cells. Moreover, DHA decreased cell clonogenicity, and improved L-OHP sensitivity. Furthermore, DHA treatment attenuated tumor sphere formation, and the expressions of stem cell surface marker (CD133 and CD44) and stemness-associated transcription factor (Nanog, c-Myc, and OCT4). Mechanistically, the present findings showed that DHA inhibited of AKT/mTOR signaling pathway. The activation of AKT/mTOR signaling reversed DHA-decreased cell viability, clonogenicity, L-OHP resistance, tumor sphere, and expressions of stemness-associated protein in CRC. The inhibitory effect of DHA on tumorigenicity of CRC cells has also been demonstrated in BALB/c nude mice. In conclusion, this study revealed that DHA inhibited CSLCs properties in CRC via AKT/mTOR signaling, suggesting that DHA may be used as a potential therapeutic agent for CRC.

Antinutrients and metabolomic compounds of Bambara groundnut (Vigna subterranean) as affected by traditional processing by smallholder farmers

Bambara groundnut (BG) (Vigna subterranean) is an underutilized, indigenous crop in South Africa that has nutritional and associated health benefits. Decreasing the antinutrients in food sources can potentially increase the digestibility of proteins and mineral absorption. To determine the effect of traditional processing (cooking) on the antinutrient content and metabolome of this crop, BG was sampled from 12 rural farms in three districts of the Mpumalanga province, South Africa. The four main colors that were identified (cream, orange, brown, and purple) were pooled together according to the district they were obtained from. One-half of each color sample obtained from each of the three districts was dehulled, color sorted, milled, and subjected to subsequent antinutrient and metabolome analyses, while the other half was cooked, air-dried, and milled prior to analyses. Samples were analyzed for phytate and tannins (antinutrients) by hydrochloric acid extraction methods as well as metabolome constituents by ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). Phytate, tannins, as well as other metabolomic constituents, namely, catechin, epicatechin, procyanidin, as well as citric acid, were identified in all raw and cooked BG samples. The cooking process resulted in a significant decrease (p < 0.05) in the phytate and tannin content as well as an increase in the health-associated phenolic compounds.

Advances in mitophagy and mitochondrial apoptosis pathway-related drugs in glioblastoma treatment

Glioblastoma (GBM) is the most common malignant tumor of the central nervous system (CNS). It is a leading cause of death among patients with intracranial malignant tumors. GBM exhibits intra- and inter-tumor heterogeneity, leading to drug resistance and eventual tumor recurrence. Conventional treatments for GBM include maximum surgical resection of glioma tissue, temozolomide administration, and radiotherapy, but these methods do not effectively halt cancer progression. Therefore, development of novel methods for the treatment of GBM and identification of new therapeutic targets are urgently required. In recent years, studies have shown that drugs related to mitophagy and mitochondrial apoptosis pathways can promote the death of glioblastoma cells by inducing mitochondrial damage, impairing adenosine triphosphate (ATP) synthesis, and depleting large amounts of ATP. Some studies have also shown that modern nano-drug delivery technology targeting mitochondria can achieve better drug release and deeper tissue penetration, suggesting that mitochondria could be a new target for intervention and therapy. The combination of drugs targeting mitochondrial apoptosis and autophagy pathways with nanotechnology is a promising novel approach for treating GBM.This article reviews the current status of drug therapy for GBM, drugs targeting mitophagy and mitochondrial apoptosis pathways, the potential of mitochondria as a new target for GBM treatment, the latest developments pertaining to GBM treatment, and promising directions for future research.

Unraveling the Antioxidant Capacity of Spatholobi caulis in Nonalcoholic Fatty Liver Disease: A Multiscale Network Approach Integrated with Experimental Validation

Nonalcoholic fatty liver disease (NAFLD) is a global health problem that is closely associated with obesity and metabolic syndrome. Spatholobi caulis (SC) is a herbal medicine with potential hepatoprotective effects; however, its active compounds and underlying mechanisms have not been fully explored. In this study, we combined a multiscale network-level approach with experimental validation to investigate SC's antioxidant properties and their impact on NAFLD. Data collection and network construction were performed, and active compounds and key mechanisms were identified through multi-scale network analysis. Validation was conducted using in vitro steatotic hepatocyte models and in vivo high-fat diet-induced NAFLD models. Our findings revealed that SC treatment improved NAFLD by modulating multiple proteins and signaling pathways, including AMPK signaling pathways. Subsequent experiments showed that SC treatment reduced lipid accumulation and oxidative stress. We also validated SC's effects on AMPK and its crosstalk pathways, emphasizing their role in hepatoprotection. We predicted procyanidin B2 to be an active compound of SC and validated it using a lipogenesis in vitro model. Histological and biochemical analyses confirmed that SC ameliorated liver steatosis and inflammation in mice. This study presents SC's potential use in NAFLD treatment and introduces a novel approach for identifying and validating active compounds in herbal medicine.

Ethnobotany, phytochemistry and pharmacological properties of Fagopyri Dibotryis Rhizoma: A review

Fagopyri Dibotryis Rhizoma (FDR) is an effective Chinese herbal medicine with a long history of use in China. FDR is effective in heat clearing and detoxifying, promotion of blood circulation, relieving carbuncles, dispelling wind, and removing dampness. Its seeds also have high nutritional value, are rich in protein, and contain a variety of mineral elements and vitamins. Therefore, FDR is considered a natural product with medical and economic benefits, and its chemical composition and pharmacological activity are of interest to scientists. The current review provides an overview of the available scientific information on FDR, particularly its botany, chemical constituents, and pharmacological activities. Various sources of valid and comprehensive relevant information were consulted, including the China National Knowledge Infrastructure, Web of Science, and PubMed. Among the keywords used were "Fagopyri Dibotryis Rhizoma", "botanical features", "chemical composition", and "pharmacological activity" in combination. Various ailments are treated with FDR, such as diabetes, tumor, sore throat, headache, indigestion, abdominal distension, dysentery, boils, carbuncles, and rheumatism. FDR is rich in organic acids, tannins, flavonoids, steroids, and triterpenoids. Experiments performed in vitro and in vivo showed that FDR extracts or fractions had a wide range of pharmacological activities, including antitumor, anti-inflammatory, immunomodulatory, antioxidant, antimicrobial, and antidiabetic. The current review provides an integrative perspective on the botany, phytochemistry and pharmacological activities of FDR. FDR may be used as a medicine and food. Based on its chemical composition and pharmacological effects, the main active ingredients of FDR are organic acids, tannins, and flavonoids, and it has obvious antitumor pharmacological activity against a variety of malignant tumors. Therefore, FDR is worthy of further study and application as a potential antitumor drug.

Selected Seeds as Sources of Bioactive Compounds with Diverse Biological Activities

Seeds contain a variety of phytochemicals that exhibit a wide range of biological activities. Plant-derived compounds are often investigated for their antioxidant, anti-inflammatory, immunomodulatory, hypoglycemic, anti-hypercholesterolemic, anti-hypertensive, anti-platelet, anti-apoptotic, anti-nociceptive, antibacterial, antiviral, anticancer, hepatoprotective, or neuroprotective properties. In this review, we have described the chemical content and biological activity of seeds from eight selected plant species-blackberry (Rubus fruticosus L.), black raspberry (Rubus coreanus Miq.), grape (Vitis vinifera L.), Moringa oleifera Lam., sea buckthorn (Hippophae rhamnoides L.), Gac (Momordica cochinchinensis Sprenger), hemp (Cannabis sativa L.), and sacha inchi (Plukenetia volubilis L). This review is based on studies identified in electronic databases, including PubMed, ScienceDirect, and SCOPUS. Numerous preclinical, and some clinical studies have found that extracts, fractions, oil, flour, proteins, polysaccharides, or purified chemical compounds isolated from the seeds of these plants display promising, health-promoting effects, and could be utilized in drug development, or to make nutraceuticals and functional foods. Despite that, many of these properties have been studied only in vitro, and it's unsure if their effects would be relevant in vivo as well, so there is a need for more animal studies and clinical trials that would help determine if they could be applied in disease prevention or treatment.

The Impact of Oxidative Stress and AKT Pathway on Cancer Cell Functions and Its Application to Natural Products

Oxidative stress and AKT serine-threonine kinase (AKT) are responsible for regulating several cell functions of cancer cells. Several natural products modulate both oxidative stress and AKT for anticancer effects. However, the impact of natural product-modulating oxidative stress and AKT on cell functions lacks systemic understanding. Notably, the contribution of regulating cell functions by AKT downstream effectors is not yet well integrated. This review explores the role of oxidative stress and AKT pathway (AKT/AKT effectors) on ten cell functions, including apoptosis, autophagy, endoplasmic reticulum stress, mitochondrial morphogenesis, ferroptosis, necroptosis, DNA damage response, senescence, migration, and cell-cycle progression. The impact of oxidative stress and AKT are connected to these cell functions through cell function mediators. Moreover, the AKT effectors related to cell functions are integrated. Based on this rationale, natural products with the modulating abilities for oxidative stress and AKT pathway exhibit the potential to regulate these cell functions, but some were rarely reported, particularly for AKT effectors. This review sheds light on understanding the roles of oxidative stress and AKT pathway in regulating cell functions, providing future directions for natural products in cancer treatment.

Inhibition and potential treatment of colorectal cancer by natural compounds via various signaling pathways

Colorectal cancer (CRC) is a common type of malignant digestive tract tumor with a high incidence rate worldwide. Currently, the clinical treatment of CRC predominantly include surgical resection, postoperative chemotherapy, and radiotherapy. However, these treatments contain severe limitations such as drug side effects, the risk of recurrence and drug resistance. Some natural compounds found in plants, fungi, marine animals, and bacteria have been shown to inhibit the occurrence and development of CRC. Although the explicit molecular mechanisms underlying the therapeutic effects of these compounds on CRC are not clear, classical signaling transduction pathways such as NF-kB and Wnt/β-catenin are extensively regulated. In this review, we have summarized the specific mechanisms regulating the inhibition and development of CRC by various types of natural compounds through nine signaling pathways, and explored the potential therapeutic values of these natural compounds in the clinical treatment of CRC.

Procyanidin B2 inhibits angiogenesis and cell growth in oral squamous cell carcinoma cells through the vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR2) pathway

This study aimed to explore the therapy role of procyanidin B2 (PB2) in inhibiting angiogenesis and cell growth in oral squamous cell carcinoma. After oral mucosa epithelial cell (OMEC) and human oral squamous cell carcinoma (OSCC) cell line (SCC-25) were treated with PB2 or SCC-25 were treated with PB2 and rhVEGF, cell counting kit-8 (CCK-8) assay was used to determine the cell viability. The apoptosis, migration, invasion and angiogenesis of SCC-25 after indicated treatment were detected by Tunel, wound healing, transwell and tube formation assays. The protein expression related to apoptosis, metastasis and epithelial-mesenchymal transition (EMT) and changed expression of vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR2) signaling was analyzed by Western blot. As a result, PB2 inhibited viability, invasion, migration and EMT and promoted apoptosis of SCC-25 cells. In addition, PB2 inhibited VEGF/VEGFR2 signaling and tumor itangiogenesis in OSCC. As expected, activation of VEGF/VEGFR2 signaling suppressed the effect of PB2 on growth and metastasis of OSCC cells. In conclusion, PB2 inhibited the VEGF/VEGFR2 pathway to suppress the angiogenesis and cell growth of SCC-25 cells.

Procyanidin A1 alleviates DSS-induced ulcerative colitis via regulating AMPK/mTOR/p70S6K-mediated autophagy

Ulcerative colitis (UC) is a recurrent chronic inflammatory disease. The symptom of UC is mainly diarrhea including bloody stools. Increasing evidence has suggested that procyanidin A1 (PCA1) exerts an anti-inflammatory effect in several diseases. However, the role of PCA1 in UC is still a mystery. In our study, we explored the effect of PCA1 in dextran sulfate sodium (DSS)-induced UC mice and lipopolysaccharide (LPS)-stimulated HT-29 and IEC-6 cells. Then, cell proliferation, apoptosis, the production of proinflammatory cytokines, and autophagy-related markers were determined. Furthermore, the AMPK/mTOR/p70S6K signaling pathway was assayed by Western blot assay. In in vivo study, we found that PCA1 administration alleviated DSS-induced UC, as evidenced by reducing weight loss, clinical scores, colon weight/length ratio, histological damage, proinflammatory cytokines, and apoptosis. Moreover, we showed that the expression of Beclin-1 and LC3II/I ratio was increased, whereas the level of p62 was decreased after PCA1 treatment in vivo. Meanwhile, the reduced AMP/ATP ratio, enhanced expression of p-AMPK, and decreased p-p70S6K and p-mTOR levels indicate the activation of AMPK/mTOR/p70S6K signaling pathway. In in vitro study, PCA1 promoted cell proliferation and inhibited cell apoptosis in LPS-stimulated HT-29 and IEC-6 cells. Pro-inflammatory cytokines and autophagy-related factors exhibited the same trend as in in vivo results. Mechanically, PCA1 activated the AMPK/mTOR/p70S6K signaling pathway. The treatment with an AMPK inhibitor compound C significantly reversed the anti-inflammatory effect of PCA1 in LPS-stimulated cells. Taken together, these data indicated that PCA1 alleviated UC through induction of AMPK/mTOR/p70S6K-mediated autophagy.

Co-delivery of proanthocyanidin and mitoxantrone induce synergistic immunogenic cell death to potentiate cancer immunotherapy

Immunological checkpoint inhibitors provide a revolutionary method for cancer treatment. However, due to low tumor mutations and insufficient infiltration of immune cells in the tumor microenvironment, 85% of colorectal cancer...

The PI3K/Akt/mTOR axis in colorectal cancer: Oncogenic alterations, non-coding RNAs, therapeutic opportunities, and the emerging role of nanoparticles

Colorectal cancer (CRC) is one of the deadliest human malignancies worldwide. Several molecular pathways have been demonstrated to be involved in the initiation and development of CRC which among them, the overactivation of the phosphatidyl-inositol 3-kinase (PI3K)/Akt/mTOR axis is of importance. The current review aims to unravel the mechanisms by which the PI3K/Akt/mTOR pathway affects CRC progression; and also, to summarize the original data obtained from international research laboratories on the oncogenic alterations and polymorphisms affecting this pathway in CRC. Besides, we provide a special focus on the regulatory role of noncoding RNAs targeting the PI3K/Akt/mTOR pathway in this malignancy. Questions on how this axis is involved in the inhibition of apoptosis, in the induction of drug resistance, and the angiogenesis, epithelial to mesenchymal transition, and metastasis are also responded. We also discussed the PI3K/Akt pathway-associated prognostic and predictive biomarkers in CRC. In addition, we provide a general overview of PI3K/Akt/mTOR pathway inhibition whether by chemical-based drugs or by natural-based medications in the context of CRC, either as monotherapy or in combination with other therapeutic agents; however, those treatments might have life-threatening side effects and toxicities. To the best of our knowledge, the current review is one of the first ones highlighting the emerging roles of nanotechnology to overcome challenges related to CRC therapy in the hope that providing a promising platform for the treatment of CRC.

Natural substances derived from herbs or plants are promising sources of anticancer agents against colorectal cancer via triggering apoptosis

OBJECTIVES

Nowadays, one of the most common gastrointestinal cancers is colorectal cancer (CRC). Chemotherapy is still one of the main methods to treat cancer. However, the currently available synthetic chemotherapy drugs often cause serious adverse reactions. Apoptosis is generally considered as an ideal way for induction the death of tumour cells without the body's inflammatory response, and it is reported that lots of natural agents could trigger various cancer cells to apoptosis. The overarching aim of this project was to elucidate the specific mechanisms by which natural substances induce apoptosis in CRC cells and to be used as an alternative therapeutic option in the future.

KEY FINDINGS

The mechanisms for the pro-apoptotic effects of natural substances derived from herbs or plants include death receptor pathway, mitochondrial pathway, endoplasmic reticulum stress pathway, related signal transduction pathways (PI3K/Akt, MAPK, p53 signalling), and so on.

SUMMARY

This paper updated this information regarding the anti-tumour effects of natural agents via induction of apoptosis against CRC, which would be beneficial for future new drug research regarding natural products from herbs or plants.

Procyanidin B2 induces apoptosis and autophagy in gastric cancer cells by inhibiting Akt/mTOR signaling pathway

Background

Procyanidin B2 (PB2), a unique component of the grape seed and other medicinal plants. PB2 has shown wide anticancer activity in various human cancer cells. However, it remains unclear about the biological effects and associated mechanisms of PB2 on gastric cancer cells.

Methods

Cell proliferation was measured by CCK8 assay, and cellular lactate dehydrogenase (LDH) release was measured in the culture medium. Cellular apoptosis was observed via TUNEL staining assay and measured by caspase-3 and -9 activities. Autophagy was observed by LC3 staining. Western blot analysis was performed to verify autophagy-associated proteins (Beclin1 and Atg5) and Akt-mTOR pathway.

Results

PB2 reduced the viability of BGC-823 and SGC-7901 cells in a concentration-dependent manner. Furthermore, PB2 induced increased apoptosis rate of gastric cancer cells and enhanced caspase-3 and -9 activities. Simultaneously, PB2 triggered autophagy in gastric cancer cells, with enhanced LC3 staining and increased expression of Beclin1 and Atg5, while the inhibition of autophagy by 3-MA reversed the PB2-induced suppression on cell viability. In addition, PB2 significantly decreased p-Akt and p-mTOR protein expression of gastric cancer cells.

Conclusion

PB2 exerts anti-proliferative and apoptotic effects and induces autophagy by modulating Akt/mTOR signaling pathway. PB2 may be developed as a potential therapeutic drug for gastric cancer.

Hexameric procyanidins inhibit colorectal cancer cell growth through both redox and non-redox regulation of the epidermal growth factor signaling pathway

Dietary proanthocyanidins (PAC) consumption is associated with a decreased risk for colorectal cancer (CRC). Dysregulation of the epidermal growth factor (EGF) receptor (EGFR) signaling pathway is frequent in human cancers, including CRC. We previously showed that hexameric PAC (Hex) exert anti-proliferative and pro-apoptotic actions in human CRC cells. This work investigated if Hex could exert anti-CRC effects through its capacity to regulate the EGFR pathway. In proliferating Caco-2 cells, Hex acted attenuating EGF-induced EGFR dimerization and NADPH oxidase-dependent phosphorylation at Tyr 1068, decreasing EGFR location at lipid rafts, and inhibiting the downstream activation of pro-proliferative and anti-apoptotic pathways, i.e. Raf/MEK/ERK1/2 and PI3K/Akt. Hex also promoted EGFR internalization both in the absence and presence of EGF. While Hex decreased EGFR phosphorylation at Tyr 1068, it increased EGFR Tyr 1045 phosphorylation. The latter provides a docking site for the ubiquitin ligase c-Cbl and promotes EGFR degradation by lysosomes. Importantly, Hex acted synergistically with the EGFR-targeted chemotherapeutic drug Erlotinib, both in their capacity to decrease EGFR phosphorylation and inhibit cell growth. Thus, dietary PAC could exert anti-CRC actions by modulating, through both redox- and non-redox-regulated mechanisms, the EGFR pro-oncogenic signaling pathway. Additionally, Hex could also potentiate the actions of EGFR-targeted drugs.

Chinese herbal medicine promote tissue differentiation in colorectal cancer by activating HSD11B2

BACKGROUND

Colorectal cancer is a common malignant tumor of the digestive tract. In recent years, the incidence rate has increased year by year and is showing a younger trend. The application of Chinese herbal medicine (CHM) is one of the important methods for the treatment of colorectal cancer. CHM refers to the main therapeutic drugs based on traditional Chinese medicine (TCM), which is still valued. Many effective anticancer small-molecule compounds are derived from CHMs, and their effective anticancer ingredients and targets must be clarified and to further understand the molecular mechanisms by which CHM affects cancer.

METHODS

We analyzed the ingredients in CHM that were found to be effective against colorectal cancer and constructed an interaction network among these ingredients and the target protein. By analyzing the number of connections in the network and their type of interaction, we identified the key target protein Corticosteroid 11-beta-dehydrogenase isozyme 2, the enzyme encoded by HSD11B2. Analyses of HSD11B2 expression, survival curve, and co-expressed genes helped clarify the correlation between HSD11B2 and colorectal cancer as well as its underlying molecular mechanism.

RESULTS

We determined that the anticancer ingredients contained in Sanguisorba officinalis, Patrinia scabiosaefolia, and Smilax china had more connections to the target proteins found in colorectal cancer. In the interaction network, eight small-molecule compounds had an activating effect on HSD11B2. The expression of the HSD11B2 was markedly decreased in colorectal cancer tissues and was positively correlated with the overall survival time of patients. In addition, co-expression analyses showed a close relationship between HSD11B2 and tissue-specific genes in colorectal tissues. The expression levels of HSD11B2 in well-, moderately, and poorly differentiated tissues progressively decreased.

CONCLUSION

The HSD11B2 protein was a key CHM target for treating colorectal cancer. The key role of CHM may lie in activating HSD11B2 and further promoting tissue differentiation in colorectal cancer.

Grape (Vitis vinifera L.) Seed Oil: A Functional Food from the Winemaking Industry

Wine production is an ancient human activity that generates several by-products, which include some constituents known for their potential in health care and for their role in the food or cosmetic industries. Any variety of grape (Vitis vinifera L.) contains nutrients and bioactive compounds available from their juice or solid parts. Grape seed extract has demonstrated many activities in disease prevention, such as antioxidant effects, which make it a potential source of nutraceuticals. Grape seed is a remarkable winery industry by-product due to the bioactivity of its constituents. Methods for recovery of oil from grape seeds have evolved to improve both the quantity and quality of the yield. Both the lipophilic and hydrophilic chemicals present in the oil of V. vinifera L. make this wine by-product a source of natural nutraceuticals. Food and non-food industries are becoming novel targets of oil obtained from grape seeds given its various properties. This review focuses on the advantages of grape seed oil intake in our diet regarding its chemical composition in industries not related to wine production and the economic and environmental impact of oil production.

Lycopene attenuates high glucose-mediated apoptosis in MPC5 podocytes by promoting autophagy via the PI3K/AKT signaling pathway

Podocyte injury serves an important role during the progression of diabetic nephropathy (DN), and lycopene (Lyc) may display a potential protective effect against DN progression. The effects of Lyc on high glucose (HG)-induced podocyte apoptosis and the underlying mechanisms are not completely understood; therefore, the present study aimed to investigate the effects of Lyc on HG-induced MPC5 podocyte apoptosis and the underlying mechanism. In the present study, MPC5 podocytes were exposed to HG and different doses of Lyc. MPC5 podocyte viability and apoptosis were assessed by performing the MTT assay and flow cytometry, respectively. To explore the effects of Lyc on the PI3K/AKT signaling pathway and autophagy, LY294002 (LY) and 3-methyladenine (3-MA) were used as PI3K and autophagy inhibitors, respectively. The expression levels of nephrin, podocin, apoptosis-related proteins (Bax, Bcl-2 and cleaved caspase-3), autophagy-related proteins [Beclin-1 and microtubule associated protein 1 light chain 3 (LC3)II/LC3I] and certain key proteins involved in the PI3K/AKT signaling pathway were measured via western blotting. The results suggested that Lyc reversed the inhibitory effect of HG on cell viability, and the protein expression levels of nephrin and podocin, as well as the promoting effect of HG on MPC5 podocyte apoptosis. In addition, under HG conditions, Lyc upregulated the phosphorylation levels of PI3K and AKT, and reduced HG- and LY-mediated MPC5 podocyte apoptosis. Moreover, Lyc further increased HG-induced protein expression levels of Beclin-1 and LC3II/LC3I, and attenuated LY-mediated inhibition of HG-induced MPC5 podocyte autophagy. In addition, the effects of Lyc on HG-mediated MPC5 podocyte apoptosis were alleviated by 3-MA. Therefore, the present study suggested that Lyc may protect against HG-induced MPC5 podocyte apoptosis by promoting autophagy activity via activation of the PI3K/AKT signaling pathway.

Anti-proliferative and anti-apoptotic effects of grape seed extract on chemo-resistant OVCAR-3 ovarian cancer cells

Background and purpose:

Ovarian cancer is the deadliest cancer in women. The main challenge in the inhibition of ovarian cancer cells is chemo-resistance. Seeking to overcome this issue, several strategies have been suggested, including the administration of natural products. Grape seed extract (GSE) is a good source of polyphenols and its anticancer effects have been reported by many studies. In this study we aimed to evaluate the effects of GSE on OVCAR-3, a chemo-resistant ovarian cancer line.

Experimental approach:

OVCAR-3 cells were treated with GSE (71 μg/mL) for 24 and 48 h. Cell viability and cell apoptosis were measured by MTT and flow cytometry. The real-time polymerase chain reaction was used to determine the expression of genes involved in the cell cycle (PTEN, DACT1, AKT, MTOR, GSK3B, C-MYC, CCND1, and CDK4) and apoptosis (BAX, BCl2, CASP3, 8 and 9). The expression of CASP3 protein was evaluated by the CASP3 assay.

Findings / Results:

The results showed that treatment of OVCAR-3 cells with GSE, increased the expression level of PTEN and DACT1 tumor suppressor genes, as well as apoptotic genes, CASP3, 8, and 9 (P < 0.001). Also, the induction of tumor suppressor genes expression was associated with an increase in the expression of BAX/BCL2 gene ratio as pro- and anti-apoptotic genes. The expression of the genes involved in the cell cycle, CCND1 and CDK4, was inhibited (P < 0.001). The results indicated that GSE induced cell apoptosis in a time-dependent manner (P < 0.001). Also, the GSE treatment resulted in the CASP3 protein expression (P < 0.001).

Conclusion and implications:

According to the results of this study, GSE may exert anti-tumorigenic effects on chemo-resistant OVCAR-3 ovarian cancer cells which might be mediated by the expression of tumor suppressor genes that interact with cell signaling pathways, cell cycle, and cell apoptosis. Hence, the consumption of GSE extract during chemotherapy may overcome part of chemo-resistance in ovarian cancer.

AMPK/mTOR/ULK1 Axis-Mediated Pathway Participates in Apoptosis and Autophagy Induction by Oridonin in Colon Cancer DLD-1 Cells

BACKGROUND

Oridonin has been demonstrated to exert strong antitumor activities in various types of human cancers. Our previous study established that oridonin induced the apoptosis of and exerted an inhibitory effect on colon cancer cells in vitro and in vivo. However, the mechanisms behind the antitumor effects of oridonin on colorectal cancer are not clearly known. This study explored whether autophagy was involved in antitumorigenesis effects caused by the usage of oridonin in colon cancer and examined whether the AMPK/mTOR/ULK1 signaling pathway was involved in this process.

METHODS

Cell viability was determined using CCK-8 assay. The distribution of cell apoptosis was evaluated using flow cytometry. RT-PCR and Western blotting analysis were conducted to identify the key target genes and proteins involved in the AMPK/mTOR cascade. AMPK siRNA was used to disturb AMPK expression. A DLD-1 cell orthotopic transplantation tumor model was established to explore the anti-cancer effects in vivo.

RESULTS

Oridonin exhibited a suppressive effect on DLD-1 cells in a concentration- and time-dependent manner. Additionally, in a dose-dependent manner, oridonin induced cell apoptosis via inducing the protein expression levels of cleaved caspase-3, cleaved PARP and stimulated autophagy by increasing protein expression levels of Becin1, LC3-II, decreasing protein expression levels of LC3-I, p62, which were respectively attenuated and elevated by autophagy inhibitor 3-MA. Furthermore, oridonin upregulated the expression level of p-AMPK and downregulated the expression levels of p-mTOR, p-ULK1 in the DLD-1 cells in a dose-dependent manner. Moreover, knockdown of AMPK by a specific siRNA reversed the expression levels of proteins involved in the AMPK/mTOR pathway, autophagy and apoptosis. In addition, outcomes from the in vivo experiments also showed that oridonin treatment significantly repressed tumorigenic growth of DLD-1 cells without any side effects, which was accompanied by the upregulation of p-AMPK, LC3-II, active caspase-3 protein expression levels and the downregulation of p-mTOR and p-ULK1 protein expression levels.

CONCLUSION

This study demonstrated that oridonin induced apoptosis and autophagy of colon cancer DLD-1 cells via regulating the AMPK/mTOR/ULK1 pathway, which indicated that oridonin may be used as a novel therapeutic intervention for patients with colorectal cancer.

Mapping Pharmacological Network of Multi-Targeting Litchi Ingredients in Cancer Therapeutics

Considerable pharmacological studies have demonstrated that the extracts and ingredients from different parts (seeds, peels, pulps, and flowers) of Litchi exhibited anticancer effects by affecting the proliferation, apoptosis, autophagy, metastasis, chemotherapy and radiotherapy sensitivity, stemness, metabolism, angiogenesis, and immunity via multiple targeting. However, there is no systematical analysis on the interaction network of “multiple ingredients-multiple targets-multiple pathways” anticancer effects of Litchi. In this study, we summarized the confirmed anticancer ingredients and molecular targets of Litchi based on published articles and applied network pharmacology approach to explore the complex mechanisms underlying these effects from a perspective of system biology. The top ingredients, top targets, and top pathways of each anticancer function were identified using network pharmacology approach. Further intersecting analyses showed that Epigallocatechin gallate (EGCG), Gallic acid, Kaempferol, Luteolin, and Betulinic acid were the top ingredients which might be the key ingredients exerting anticancer function of Litchi, while BAX, BCL2, CASP3, and AKT1 were the top targets which might be the main targets underling the anticancer mechanisms of these top ingredients. These results provided references for further understanding and exploration of Litchi as therapeutics in cancer as well as the application of “Component Formula” based on Litchi’s effective ingredients.

Ganoderma lucidum Polysaccharide Enzymatic Hydrolysate Suppresses the Growth of Human Colon Cancer Cells via Inducing Apoptosis

Ganoderma lucidum is a popular traditional Chinese medicine used in China to improve health. Previous researches have revealed that the polysaccharide from G. lucidum could exert diversity activities, including immunomodulation, antioxidant, and antitumor effects. However, the effect of enzymatically hydrolyzed G. lucidum polysaccharide (EGLP) in colorectal cancer (CRC) progression remains unknown. The present research aimed to investigate the antitumor mechanism of EGLP in human colon cancer cells. For this purpose, the cytotoxic effects of EGLP were measured by the (3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) method. The apoptosis was evoked upon EGLP treatment, which was assayed using flow cytometry. The results indicated that EGLP may induce apoptosis in human colon cancer cell (HCT-116) cells via the upregulation of BCL-2 associated X protein (Bax), phospho-extracellular regulated protein kinases (P-ERK), and cleaved caspase-3 expression and downregulation of B-cell lymphoma-2 (Bcl-2), phospho-serine/threonine kinase 1 (p-Akt1), and cyclo-oxygen-ase (COX-2) expression. The obtained findings indicated EGLP as a new therapeutic agent in fighting CRC.