Capsaicin Induces Autophagy and Apoptosis in Human Nasopharyngeal Carcinoma Cells by Downregulating the PI3K/AKT/mTOR Pathway

The Therapeutic Effects of Bioactive Compounds on Colorectal Cancer via PI3K/Akt/mTOR Signaling Pathway: A Critical Review

Understanding the molecular signaling pathways of colorectal cancer (CRC) can be accepted as the first step in treatment strategy. Permanent mTOR signaling activation stimulates the CRC process via various biological processes. It supplies the survival of CRC stem cells, tumorigenesis, morbidity, and decreased response to drugs in CRC pathogenesis. Therefore, inhibition of the mTOR signaling by numerous bioactive components may be effective against CRC. The study aims to discuss the therapeutic capacity of various polyphenols, terpenoids, and alkaloids on CRC via the PI3K/Akt/mTOR pathway. The potential molecular effects of bioactive compounds on the mTOR pathway's upstream and downstream targets are examined. Each bioactive component causes various physiological processes, such as triggering free radical production, disruption of mitochondrial membrane potential, cell cycle arrest, inhibition of CRC stem cell migration, and suppression of glycolysis through mTOR signaling inhibition. As a result, carcinogenesis is inhibited by inducing apoptosis and autophagy. However, it should be noted that studies are primarily in vitro dose-dependent treatment researchers. This study raises awareness about the role of phenolic compounds in treating CRC, contributing to their future use as anticancer agents. These bioactive compounds have the potential to be developed into food supplementation to prevent and treat various cancer types including CRC. This review has the potential to lead to further development of clinical studies. In the future, mTOR inhibition by applying several bioactive agents using advanced drug delivery systems may contribute to CRC treatment with 3D cell culture and in vivo clinical studies.

Capsaicin Promotes Apoptosis and Inhibits Cell Migration via the Tumor Necrosis Factor-Alpha (TNFα) and Nuclear Factor Kappa B (NFκB) Signaling Pathway in Oral Cancer Cells

Background Oral squamous cell carcinoma (OSCC) is a highly prevalent cancer worldwide. Microbial infections, poor oral hygiene, and chronic viral infections such as human papillomavirus (HPV) contribute to its incidence. Capsaicin, known for its presence in chili peppers, has demonstrated potential antiproliferative effects in cancer cells. It operates by inducing programmed cell death, regulating the expression of transcription factors, halting cell cycle progression, and influencing growth signal transduction pathways. These findings suggest capsaicin's promising role as a candidate for further exploration in combating oral cancer. Aim This study intends to identify and evaluate the anticancer properties of capsaicin on oral cancer cells through in vitro investigations. Methodology Using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) technique, the cell viability of oral cancer cells treated with capsaicin was evaluated. Capsaicin was applied to the KB1 cells in a range of concentrations (25-150 µg/mL) over 24 hours. The morphological alterations of the cells were assessed using a phase contrast microscope. Nuclear factor kappa B (NFκB) and tumor necrosis factor-alpha (TNFα) were subjected to quantitative real-time polymerase chain reaction (PCR) gene expression analysis. To investigate nuclear morphological changes, oral cancer cells were stained with acridine orange/ethidium bromide (AO/EtBr). The apoptotic nuclei were visualized using a fluorescent microscope. A scratch wound healing test was performed to check for capsaicin's anti-migratory potential. Result In our investigation of oral cancer cells treated with capsaicin, there was a significant drop in cell viability between the control and treatment groups (p < 0.05). The inhibitory concentration (IC50) was found to be 74.4 μM/mL in oral cancer cells. Following treatment, fewer cells were present, and those that were present shriveled and exhibited cytoplasmic membrane blebbing. Under AO/EtBr staining, treated cells exhibited chromatin condensation and nuclear disintegration. Furthermore, the migration of capsaicin-treated cells was significantly lower than that of control cells. The results of gene expression analysis demonstrated a considerable downregulation of TNFα and NFκB following capsaicin administration. Conclusion The study's findings suggest that capsaicin may have anti-tumor properties in oral cancer cells. More research is desperately needed to fully understand the mechanism underlying capsaicin's anticancer potential and therapeutic applicability.

Capsaicin combined with cisplatin inhibits TGF-β1-induced EMT and TSCC cells migration via the Claudin-1/PI3K/AKT/mTOR signaling pathway

Tongue squamous cell carcinoma (TSCC) is one of the most common malignant tumors among oral cancers, and its treatment is based on radio-chemotherapy and surgery, which always produces more serious side effects and sequelae. Traditional medicine can compensate for the shortcomings of modern medical treatments and play a better therapeutic role. Currently, active ingredients derived from plants are attracting the attention of researchers and clinical professionals. We examined capsaicin (CAP), an active ingredient isolated from Capsicum annuum (family Solanaceae), and explored the effect of CAP combined with cisplatin (DDP) on epithelial-mesenchymal transition (EMT) and TSCC cells migration. Our results demonstrated that Transforming growth factor-β1(TGF-β1) induced EMT and promoted cell migration in TSCC cells. CAP combined with DDP inhibits non-TGF-β1-induced or TGF-β1-induced EMT and migration. Mechanistically, the inhibition of non-TGF-β1-induced EMT and migration by CAP combined with DDP was mediated by the AMPK/mTOR pathway, whereas TGF-β1-induced EMT and migration were regulated by the Claudin-1/PI3K/AKT/mTOR pathway. A nude lung metastasis mouse model was established for in vivo validation. These results support our hypothesis that the combination of CAP and DDP inhibits TSCC metastasis. These data set the stage for further studies aimed at validating CAP as an effective active ingredient for enhancing chemotherapy efficacy and reducing the dosage and toxicity of chemotherapeutic drugs, ultimately paving the way for translational research and clinical trials for TSCC eradication.

Evaluation of Cytotoxic and Anti-cancer Potential of Capsaicin on Lung Cancer Cell Line: An In Vitro Investigation

Background The leading cause of cancer-related deaths worldwide is lung cancer. Approximately 1.8 million new cases were diagnosed, and 1.6 million individuals died. Available treatment options are inefficient leading to tumour recurrence. Hence there is a need for novel therapeutic advancements in lung cancer treatment. Capsaicin, a naturally occurring protoalkaloid, was found to possess several potential benefits. Aim The aim of the study was to examine capsaicin's cytotoxic and anti-cancer effects in the lung cancer cell line (A549). Materials and methods The cell viability of lung cancer cells treated with capsaicin was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. A549 cells were treated with capsaicin at concentrations ranging from 25 to 150 µM/mL for 24 hours. Changes in cell morphology were observed using a phase-contrast microscope. Nuclear morphological alterations in the lung cancer cells were examined through acridine orange/ethidium bromide (AO/EtBr) staining and viewed under a fluorescent microscope to identify apoptotic nuclei. Gene expression analysis was performed using quantitative real-time PCR (Polymerase Chain Reaction) to evaluate the expression of apoptotic genes, transforming growth factor-beta (TGF-β), and suppressor of mothers against decapentaplegic 2 (SMAD2). Capsaicin's anti-migratory properties were assessed using a scratch wound healing assay. Result Our study demonstrated that treating lung cancer cells with capsaicin dramatically decreased their vitality, with a statistically significant difference (p<0.05) between the treatment and control groups. In lung cancer cells, we measured the inhibitory concentration (IC-50) at 101.2μM/ml. Following treatment, the number of cells decreased, and those that remained exhibited cytoplasmic membrane blebbing and shrunk. With AO/EtBr staining, treated cells showed an increased number of apoptotic cells. The study's findings showed that after receiving capsaicin, there was a significant downregulation of TGF-β and SMAD2. Moreover, when compared to control cells, capsaicin-treated cells' migration was markedly reduced. Through modification of the TGF-β/SMAD2 signaling system, capsaicin therapy dramatically promotes apoptosis and inhibits migration. Conclusion In conclusion, the study's results indicate that capsaicin may have anti-tumor effects on lung cancer cells. To fully comprehend the mechanism underlying capsaicin's anticancer potential and its therapeutic application, further studies are much needed.

Capsaicin: Emerging Pharmacological and Therapeutic Insights

Capsaicin, the most prominent pungent compound of chilli peppers, has been used in traditional medicine systems for centuries; it already has a number of established clinical and industrial applications. Capsaicin is known to act through the TRPV1 receptor, which exists in various tissues; capsaicin is hepatically metabolised, having a half-life correlated with the method of application. Research on various applications of capsaicin in different formulations is still ongoing. Thus, local capsaicin applications have a pronounced anti-inflammatory effect, while systemic applications have a multitude of different effects because their increased lipophilic character ensures their augmented bioavailability. Furthermore, various teams have documented capsaicin's anti-cancer effects, proven both in vivo and in vitro designs. A notable constraint in the therapeutic effects of capsaicin is its increased toxicity, especially in sensitive tissues. Regarding the traditional applications of capsaicin, apart from all the effects recorded as medicinal effects, the application of capsaicin in acupuncture points has been demonstrated to be effective and the combination of acupuncture and capsaicin warrants further research. Finally, capsaicin has demonstrated antimicrobial effects, which can supplement its anti-inflammatory and anti-carcinogenic actions.

Capsaicin: A chili pepper bioactive phytocompound with a potential role in suppressing cancer development and progression

Cancer profoundly influences morbidity and fatality rates worldwide. Patients often have dismal prognoses despite recent improvements in cancer therapy regimens. However, potent biomolecules derived from natural sources, including medicinal and dietary plants, contain biological and pharmacological properties to prevent and treat various human malignancies. Capsaicin is a bioactive phytocompound present in red hot chili peppers. Capsaicin has demonstrated many biological effects, including antioxidant, anti-inflammatory, antimicrobial, and anticarcinogenic capabilities. This review highlights the cellular and molecular pathways through which capsaicin exhibits antineoplastic activities. Our work also depicts the synergistic anticancer properties of capsaicin in conjunction with other natural bioactive components and approved anticancer drugs. Capsaicin inhibits proliferation in various cancerous cells, and its antineoplastic actions in numerous in vitro and in vivo carcinoma models impact oncogenesis, tumor-promoting and suppressor genes, and associated signaling pathways. Capsaicin alone or combined with other phytocompounds or approved antineoplastic drugs triggers cell cycle progression arrest, generating reactive oxygen species and disrupting mitochondrial membrane integrity, ultimately stimulating caspases and promoting death. Furthermore, capsaicin alone or in combination can promote apoptosis in carcinoma cells by enhancing the p53 and c-Myc gene expressions. In conclusion, capsaicin alone or in combination can have enormous potential for cancer prevention and intervention, but further high-quality studies are needed to firmly establish the clinical efficacy of this phytocompound.

Nonivamide inhibits proliferation of human corneal epithelial cells by inducing cell cycle arrest and oxidative stress

Nonivamide, an agonist of transient receptor potential vanilloid type 1 (TRPV1), is widely used as a riot control agent, police incapacitant spray and pesticide. Although generally considered non-fatal, eye discomfort and even ocular injuries caused by such products are common. Little research has been conducted on the effects of nonivamide on corneal epithelial cells. Cell viability, impedance, flow cytometry, western blotting, and real-time fluorescence analyses were performed to investigate the effects of nonivamide on human corneal epithelial cells (HCE-T cells). We found that nonivamide impaired proliferation at subtoxic doses (100 μM and 200 μM) in HCE-T cells. Next, we described the mechanisms of action of nonivamide. Nonivamide caused cell cycle arrest by increasing p21 and decreasing cyclin D1. TRPV1 was activated by nonivamide, leading to an influx of Ca2+. Enhanced Ca2+ influx partially contributed to oxidative stress. Mitochondrial membrane potential (MMP) also decreased. All combined stress resulted in the inhibition of cell proliferation in HCE-T cells. In summary, nonivamide inhibited the proliferation of HCE-T cells at sub-toxic doses by inducing cell cycle arrest and oxidative stress. Our data demonstrate the corneal toxicity of nonivamide and explain the mechanisms underlying nonivamide-induced corneal injury.

Natural medicinal compounds target signal transduction pathways to overcome ABC drug efflux transporter-mediated multidrug resistance in cancer

ATP-binding cassette (ABC) transporters such as ABCB1, ABCG2, and ABCC1 are the major players in drug efflux-mediated multidrug resistance (MDR), which severely affects the efficacy of chemotherapy. Several synthetic compounds block the drug transport by ABC transporters; however, they exhibit a narrow therapeutic window, and produce side effects in non-target normal tissues. Conversely, the downregulation of the expression of ABC drug transporters seems to be a promising strategy to reverse MDR in cancer cells. Several signaling pathways, such as NF-κB, STAT3, Gli, NICD, YAP/TAZ, and Nrf2 upregulate the expression of ABC drug transporters in drug-resistant cancers. Recently, natural medicinal compounds have gained importance to overcome the ABC drug-efflux pump-mediated MDR in cancer. These compounds target transcription factors and the associated signal transduction pathways, thereby downregulating the expression of ABC transporters in drug-resistant cancer cells. Several potent natural compounds have been identified as lead candidates to synergistically enhance chemotherapeutic efficacy, and a few of them are already in clinical trials. Therefore, modulation of signal transduction pathways using natural medicinal compounds for the reversal of ABC drug transporter-mediated MDR in cancer is a novel approach for improving the efficiency of the existing chemotherapeutics. In this review, we discuss the modulatory role of natural medicinal compounds on cellular signaling pathways that regulate the expression of ABC transporters in drug-resistant cancer cells.

Capsaicin suppresses the migration and invasion of human nasopharyngeal carcinoma cells through the modulation of mTOR signaling pathway

Nasopharyngeal carcinoma (NPC), a malignancy of the nasopharynx, is prevalent in Southeast Asia and Southern China. The prognosis of NPC is poor and local recurrence and metastasis often occur. Capsaicin (tran-8-methyl-N-vanillyl-6-nonenamide), a pungent constituent of hot chili peppers, shows anti-cancer activities such as anti-proliferation and anti-metastasis. Currently, the role of capsaicin in cell metastasis of NPC is not well understood. We tested whether capsaicin has anti-metastatic activity in NPC cell lines. Capsaicin suppressed cell proliferation in dose-dependent manner. Moreover, capsaicin inhibited cell metastasis as shown by wound healing assay and decreased the expressions of MMP-2 and MMP-9. In addition, the phosphorylation of mTOR was downregulated by capsaicin. Combination of capsaicin and rapamycin (mTOR inhibitor) treatments led to increasing of anti-growth and anti-metastatic activities. Therefore, capsaicin has potential to be used as an optional therapeutic drug for treatment of NPC.

Identification of galactosamine-(N-acetyl)-6-sulfatase (GALNS) as a novel therapeutic target in progression of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a commonly diagnosed malignancy in southern China and southeast Asia. Previous studies have identified galactosamine-(N-acetyl)-6-sulfatase (GALNS) as a potential biomarker for multiple cancers. However, it is unknown whether GALNS plays a role in NPC development, and the underlying mechanisms remain unclear. In this study, we found that GALNS is overexpressed in NPC cell lines and tissues compared to the normal nasopharyngeal counterparts. Knocking down GALNS expression in the NPC cells significantly decreased their proliferation in vitro, and inhibited xenograft growth in a mouse model. Mechanistically, the anti-proliferative effect of GALNS silencing was the result of autophagy induction via the inhibition of PI3K-AKT-mTOR signaling pathway. Taken together, GALNS drives the progression of NPC via PI3K-AKT-mTOR signaling-mediated autophagy, and is therefore a promising therapeutic target.

Overcoming Acquired Drug Resistance to Cancer Therapies through Targeted STAT3 Inhibition

Anti-neoplastic agents for cancer treatment utilize many different mechanisms of action and, when combined, can result in potent inhibition of cancer growth. Combination therapies can result in long-term, durable remission or even cure; however, too many times, these anti-neoplastic agents lose their efficacy due to the development of acquired drug resistance (ADR). In this review, we evaluate the scientific and medical literature that elucidate STAT3-mediated mechanisms of resistance to cancer therapeutics. Herein, we have found that at least 24 different anti-neoplastic agents-standard toxic chemotherapeutic agents, targeted kinase inhibitors, anti-hormonal agents, and monoclonal antibodies-that utilize the STAT3 signaling pathway as one mechanism of developing therapeutic resistance. Targeting STAT3, in combination with existing anti-neoplastic agents, may prove to be a successful therapeutic strategy to either prevent or even overcome ADR to standard and novel cancer therapies.

M, K M, Dey T, Zargar MI, Singh J. Recent advance of herbal medicines in cancer- a molecular approach

Bioactive compounds are crucial for an extensive range of therapeutic uses, and some exhibit anticancer activity. Scientists advocate that phytochemicals modulate autophagy and apoptosis, involved in the underlying pathobiology of cancer development and regulation. The pharmacological aiming of the autophagy-apoptosis signaling pathway using phytocompounds hence offers an auspicious method that is complementary to conventional cancer chemotherapy. The current review aims to explore the molecular level of the autophagic-apoptotic pathway to know its implication in the pathobiology of cancer and explore the essential cellular process as a druggable anticancer target and therapeutic emergence of naturally derived phytocompound-based anticancer agents. The data in the review were collected from scientific databases such as Google search, Web of Science, PubMed, Scopus, Medline, and Clinical Trials. With a broad outlook, we investigated their cutting-edge scientifically revealed and/or searched pharmacologic effects, a novel mechanism of action, and molecular signaling pathway of phytochemicals in cancer therapy. In this review, the evidence is focused on molecular pharmacology, specifically caspase, Nrf2, NF-kB, autophagic-apoptotic pathway, and several mechanisms to understand their role in cancer biology.

CircLASP1 silence strengthens the therapeutic effects of MK-2206 on nasopharyngeal cancer through upregulating miR-625

Therapeutic effects of MK-2206 are largely limited due to the complexity of the pathogenesis of nasopharyngeal cancer (NPC). Here, we aimed to investigate whether and how circLASP1 is involved in the therapeutic effects of MK-2206 on NPC. We showed circLASP1 was increased while miR-625 was decreased in NPC tissues and cell lines. CircLASP1 silence strengthened the therapeutic effects of MK-2206 via suppressing NPC cell proliferation and inducing autophagy and apoptosis in vitro. In mechanism analyses, we found that circLASP1 indirectly released AKT by directly binding to miR-625 in NPC cells, and miR-625 acted as a tumor suppressor in NPC and activated cell autophagy through inhibiting the AKT/mTOR pathway. Most importantly, knockdown of circLASP1 was revealed to enhance the therapeutic effects of MK-2206 on NPC in vivo. Our results suggest that the circLASP1/miR-625 axis is involved the therapeutic effects of MK-2206 on NPC by regulating autophagy, proliferation, and apoptosis through the AKT/mTOR pathway. miR-625 is involved in NPC tumorigenesis.

Activities of (Poly)phenolic Antioxidants and Other Natural Autophagy Modulators in the Treatment of Sanfilippo Disease: Remarkable Efficacy of Resveratrol in Cellular and Animal Models

Sanfilippo disease, caused by mutations in the genes encoding heparan sulfate (HS) (a glycosaminoglycan; GAG) degradation enzymes, is a mucopolysaccharidosis (MPS), which is also known as MPS type III, and is characterized by subtypes A, B, C, and D, depending on identity of the dysfunctional enzyme. The lack of activity or low residual activity of an HS-degrading enzyme leads to excess HS in the cells, impairing the functions of different types of cells, including neurons. The disease usually leads to serious psychomotor dysfunction and death before adulthood. In this work, we show that the use of molecules known as dietary (poly)phenolic antioxidants and other natural compounds known as autophagy activators (genistein, capsaicin, curcumin, resveratrol, trehalose, and calcitriol) leads to accelerated degradation of accumulated HS in the fibroblasts of all subtypes of MPS III. Both the cytotoxicity tests we performed and the available literature data indicated that the use of selected autophagy inducers was safe. Since it showed the highest effectivity in cellular models, resveratrol efficacy was tested in experiments with a mouse model of MPS IIIB. Urinary GAG levels were normalized in MPS IIIB mice treated with 50 mg/kg/day resveratrol for 12 weeks or longer. Behavioral tests indicated complete correction of hyperactivity and anxiety in these animals. Biochemical analyses indicated that administration of resveratrol caused autophagy stimulation through an mTOR-independent pathway in the brains and livers of the MPS IIIB mice. These results indicate the potential use of resveratrol (and possibly other autophagy stimulators) in the treatment of Sanfilippo disease.

Targeting the PI3K/AKT/mTOR and RAF/MEK/ERK pathways for cancer therapy

The PI3K/AKT/mTOR and RAF/MEK/ERK pathways are commonly activated by mutations and chromosomal translocation in vital targets. The PI3K/AKT/mTOR signaling pathway is dysregulated in nearly all kinds of neoplasms, with the component in this pathway alternations. RAF/MEK/ERK signaling cascades are used to conduct signaling from the cell surface to the nucleus to mediate gene expression, cell cycle processes and apoptosis. RAS, B-Raf, PI3K, and PTEN are frequent upstream alternative sites. These mutations resulted in activated cell growth and downregulated cell apoptosis. The two pathways interact with each other to participate in tumorigenesis. PTEN alterations suppress RAF/MEK/ERK pathway activity via AKT phosphorylation and RAS inhibition. Several inhibitors targeting major components of these two pathways have been supported by the FDA. Dozens of agents in these two pathways have attracted great attention and have been assessed in clinical trials. The combination of small molecular inhibitors with traditional regimens has also been explored. Furthermore, dual inhibitors provide new insight into antitumor activity. This review will further comprehensively describe the genetic alterations in normal patients and tumor patients and discuss the role of targeted inhibitors in malignant neoplasm therapy. We hope this review will promote a comprehensive understanding of the role of the PI3K/AKT/mTOR and RAF/MEK/ERK signaling pathways in facilitating tumors and will help direct drug selection for tumor therapy.

Capsaicin decreases fecundity in the Asian malaria vector Anopheles stephensi by inhibiting the target of rapamycin signaling pathway

BACKGROUND

Mosquito-borne diseases threaten human health, but mosquito control faces various challenges, such as resistance to chemical insecticides. Thus, there is an urgent need for more effective and environment-friendly control agents. Capsaicin can downregulate the mTOR signaling pathway of tumor cells. The TOR signaling pathway can mediate the expression of vitellogenin (Vg) to regulate the fecundity of insects. Whether capsaicin has the potential to inhibit fecundity of mosquitoes by regulating TOR pathway and Vg expression is currently unclear.

METHODS

Anopheles stephensi were fed with blood of mice administered capsaicin by gavage or sugar containing capsaicin followed by a blood feeding with normal mice. Then, the engorged female mosquitoes were tubed individually and underwent oviposition. The eggs and individuals in the subsequent development stages, including larvae, pupae, and emerging adults, were counted and compared between the capsaicin treatment and control groups. Additionally, total RNA and protein were extracted from the engorged mosquitoes at 24 h post blood feeding. Real-time PCR and western blot were performed to detect the transcriptional level and protein expression of the key fecundity-related molecules of mosquitoes. Finally, TOR signaling pathway was inhibited via rapamycin treatment, and changes in fecundity and the key molecule transcription and protein expression levels were examined to verify the role of TOR signaling pathway in the effect of capsaicin on mosquito fecundity.

RESULTS

The laid and total eggs (laid eggs plus retained eggs) of An. stephensi were significantly reduced by feeding on the blood of capsaicin-treated mice (P < 0.01) or capsaicin-containing sugar (P < 0.01) compared with those in the control group. Moreover, the transcription and protein expression or phosphorylation levels of fecundity-related molecules, such as Akt, TOR, S6K, and Vg, were significantly decreased by capsaicin treatment. However, the effects disappeared between control group and CAP group after the TOR signaling pathway was inhibited by rapamycin.

CONCLUSIONS

Capsaicin can decrease the fecundity of An. stephensi by inhibiting the TOR signaling pathway. These data can help us to not only understand the effect of capsaicin on the reproductive ability of An. stephensi and its underlying mechanism, but also develop new efficient, safe, and pollution-free mosquito vector control agents.

Anti-cancer activity of sustained release capsaicin formulations

Capsaicin (trans-8-methyl-N-vanillyl-6-noneamide) is a hydrophobic, lipophilic vanilloid phytochemical abundantly found in chili peppers and pepper extracts. Several convergent studies show that capsaicin displays robust cancer activity, suppressing the growth, angiogenesis and metastasis of several human cancers. Despite its potent cancer-suppressing activity, the clinical applications of capsaicin as a viable anti-cancer drug have remained problematic due to its poor bioavailability and aqueous solubility properties. In addition, the administration of capsaicin is associated with adverse side effects like gastrointestinal cramps, stomach pain, nausea and diarrhea and vomiting. All these hurdles may be circumvented by encapsulation of capsaicin in sustained release drug delivery systems. Most of the capsaicin-based the sustained release drugs have been tested for their pain-relieving activity. Only a few of these formulations have been investigated as anti-cancer agents. The present review describes the physicochemical properties, bioavailability, and anti-cancer activity of capsaicin-sustained release agents. The asset of such continuous release capsaicin formulations is that they display better solubility, stability, bioavailability, and growth-suppressive activity than the free drug. The encapsulation of capsaicin in sustained release carriers minimizes the adverse side effects of capsaicin. In summary, these capsaicin-based sustained release drug delivery systems have the potential to function as novel chemotherapies, unique diagnostic imaging probes and innovative chemosensitization agents in human cancers.

Capsaicin Inhibits Shigella flexneri Intracellular Growth by Inducing Autophagy

Antibiotic treatment plays an essential role in preventing Shigella infection. However, incidences of global rise in antibiotic resistance create a major challenge to treat bacterial infection. In this context, there is an urgent need for newer approaches to reduce S. flexneri burden. This study largely focuses on the role of the herbal compound capsaicin (Caps) in inhibiting S. flexneri growth and evaluating the molecular mechanism behind bacterial clearance. Here, we show for the first time that Caps inhibits intracellular S. flexneri growth by inducing autophagy. Activation of autophagy by Caps is mediated through transcription factor TFEB, a master regulator of autophagosome biogenesis. Caps induced the nuclear localization of TFEB. Activation of TFEB further induces the gene transcription of autophagosomal genes. Our findings revealed that the inhibition of autophagy by silencing TFEB and Atg5 induces bacterial growth. Hence, Caps-induced autophagy is one of the key factors responsible for bacterial clearance. Moreover, Caps restricted the intracellular proliferation of S. flexneri-resistant strain. The efficacy of Caps in reducing S. flexneri growth was confirmed by an animal model. This study showed for the first time that S. flexneri infection can be inhibited by inducing autophagy. Overall observations suggest that Caps activates TFEB to induce autophagy and thereby combat S. flexneri infection.

How Should the Worldwide Knowledge of Traditional Cancer Healing Be Integrated with Herbs and Mushrooms into Modern Molecular Pharmacology?

Traditional herbal medicine (THM) is a "core" from which modern medicine has evolved over time. Besides this, one third of people worldwide have no access to modern medicine and rely only on traditional medicine. To date, drugs of plant origin, or their derivates (paclitaxel, vinblastine, vincristine, vinorelbine, etoposide, camptothecin, topotecan, irinotecan, and omacetaxine), are very important in the therapy of malignancies and they are included in most chemotherapeutic regimes. To date, 391,000 plant and 14,000 mushroom species exist. Their medical and biochemical capabilities have not been studied in detail. In this review, we systematized the information about plants and mushrooms, as well as their active compounds with antitumor properties. Plants and mushrooms are divided based on the regions where they are used in ethnomedicine to treat malignancies. The majority of their active compounds with antineoplastic properties and mechanisms of action are described. Furthermore, on the basis of the available information, we divided them into two priority groups for research and for their potential of use in antitumor therapy. As there are many prerequisites and some examples how THM helps and strengthens modern medicine, finally, we discuss the positive points of THM and the management required to transform and integrate THM into the modern medicine practice.

Capsaicin: A Two-Decade Systematic Review of Global Research Output and Recent Advances Against Human Cancer

Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is one of the most important natural products in the genus Capsicum. Due to its numerous biological effects, there has been extensive and increasing research interest in capsaicin, resulting in increased scientific publications in recent years. Therefore, an in-depth bibliometric analysis of published literature on capsaicin from 2001 to 2021 was performed to assess the global research status, thematic and emerging areas, and potential insights into future research. Furthermore, recent research advances of capsaicin and its combination therapy on human cancer as well as their potential mechanisms of action were described. In the last two decades, research outputs on capsaicin have increased by an estimated 18% per year and were dominated by research articles at 93% of the 3753 assessed literature. In addition, anti-cancer/pharmacokinetics, cytotoxicity, in vivo neurological and pain research studies were the keyword clusters generated and designated as thematic domains for capsaicin research. It was evident that the United States, China, and Japan accounted for about 42% of 3753 publications that met the inclusion criteria. Also, visibly dominant collaboration nodes and networks with most of the other identified countries were established. Assessment of the eligible literature revealed that the potential of capsaicin for mitigating cancer mainly entailed its chemo-preventive effects, which were often linked to its ability to exert multi-biological effects such as anti-mutagenic, antioxidant and anti-inflammatory activities. However, clinical studies were limited, which may be related to some of the inherent challenges associated with capsaicin in the limited clinical trials. This review presents a novel approach to visualizing information about capsaicin research and a comprehensive perspective on the therapeutic significance and applications of capsaicin in the treatment of human cancer.

Cadmium induces apoptosis and autophagy in swine small intestine by downregulating the PI3K/Akt pathway

Cadmium (Cd) is an environmental contaminant, which is potentially toxic. It is well known that Cd can accumulate in the liver and kidney and cause serious damage. However, few studies have investigated the mechanism of intestinal damage induced by Cd in swine. Here, we established Cd poisoning models in vivo and in vitro to explore the mechanism of intestinal injury induced by Cd in swine. The morphology of intestinal tissue cells was observed by TUNEL staining and electron microscopy, and the morphology of IPEC-J2 cells was observed by flow cytometry, Hoechst staining, and MDC staining. Cell morphological observations revealed that Cd treatment induced ileal apoptosis and autophagy. The effects of Cd on the PI3K/Akt pathway, as well as on apoptosis and autophagy-related protein expression in intestinal cells, were analyzed by western blot (WB) and the expression of mRNA was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The results showed that Cd induced autophagy by increasing the levels of autophagy markers Beclin1, Autophagy-associated gene 5 (ATG5), Autophagy-associated gene 16 (ATG16), and Microtubule-associated protein light chains 3-2 (LC3-II), and by reducing the expression levels of Mechanistic target of rapamycin kinase (mTOR) and Microtubule-associated protein light chains 3-1 (LC3-I). Cell apoptosis was induced by increasing the expression of apoptosis markers Bcl-2 associated X protein (Bax), Cysteinyl aspartate specific proteinase 9 (Caspase9), cleaved Caspase9, Cysteinyl aspartate specific proteinase 3 (Caspase3), and cleaved Caspase3, and by reducing the expression of B cell lymphoma/leukemia 2 (Bcl-2). At the same time, Cd decreased the expression of phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), and their phosphorylation. We treated IPEC-J2 cells with the PI3K activator 740Y-P and analyzed the morphological changes as well as autophagy and apoptosis-related gene expression. The results showed that 740Y-P could reduce apoptosis and autophagy induced by Cd. In conclusion, our findings suggest that Cd induces intestinal apoptosis and autophagy in swine by inactivating the PI3K/Akt signaling pathway.

Targeting cancer signaling pathways by natural products: Exploring promising anti-cancer agents

Cancer is one of the leading causes of death and significantly burdens the healthcare system. Due to its prevalence, there is undoubtedly an unmet need to discover novel anticancer drugs. The use of natural products as anticancer agents is an acceptable therapeutic approach due to accessibility, applicability, and reduced cytotoxicity. Natural products have been an incomparable source of anticancer drugs in the modern era of drug discovery. Along with their derivatives and analogs, natural products play a major role in cancer treatment by modulating the cancer microenvironment and different signaling pathways. These compounds are effective against several signaling pathways, mainly cell death pathways (apoptosis and autophagy) and embryonic developmental pathways (Notch pathway, Wnt pathway, and Hedgehog pathway). The historical record of natural products is strong, but there is a need to investigate the current role of natural products in the discovery and development of cancer drugs and determine the possibility of natural products being an important source of future therapeutic agents. Many target-specific anticancer drugs failed to provide successful results, which accounts for a need to investigate natural products with multi-target characteristics to achieve better outcomes. The potential of natural products to be promising novel compounds for cancer treatment makes them an important area of research. This review explores the significance of natural products in inhibiting the various signaling pathways that serve as drivers of carcinogenesis and thus pave the way for developing and discovering anticancer drugs.

MicroRNAs: Important Regulatory Molecules in Acute Lung Injury/Acute Respiratory Distress Syndrome

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is an overactivated inflammatory response caused by direct or indirect injuries that destroy lung parenchymal cells and dramatically reduce lung function. Although some research progress has been made in recent years, the pathogenesis of ALI/ARDS remains unclear due to its heterogeneity and etiology. MicroRNAs (miRNAs), a type of small noncoding RNA, play a vital role in various diseases. In ALI/ARDS, miRNAs can regulate inflammatory and immune responses by targeting specific molecules. Regulation of miRNA expression can reduce damage and promote the recovery of ALI/ARDS. Consequently, miRNAs are considered as potential diagnostic indicators and therapeutic targets of ALI/ARDS. Given that inflammation plays an important role in the pathogenesis of ALI/ARDS, we review the miRNAs involved in the inflammatory process of ALI/ARDS to provide new ideas for the pathogenesis, clinical diagnosis, and treatment of ALI/ARDS.

Metformin alleviates dexamethasone-induced apoptosis by regulating autophagy via AMPK/mTOR/p70S6K in osteoblasts

Glucocorticoid (GC)-induced osteoporosis (GIOP) is the most common type of secondary osteoporosis. Osteoblast apoptosis induced by GCs is now considered as a crucial factor for GIOP. Many clinical, in vivo, and in vitro studies have shown that metformin has a beneficial effect on bone metabolism and bone formation. To investigate whether metformin could be used to treat GIOP, we explored the influence of metformin on dexamethasone (Dex)-induced apoptosis of osteoblasts and its underlying mechanisms. In this study, the CCK8 assay was used to determine the optimal metformin concentration and processing time. The expression levels of target proteins were examined by Western blot and immunofluorescence; the expression levels of target genes were tested by quantitative PCR. Apoptotic cells were detected using flow cytometry. Characteristics of autophagy were observed by transmission electron microscopy. An autophagy inhibitor was administered to investigate whether autophagy decreases apoptosis. Sh-AMPK transfection and an mTOR activator were used to investigate the role of AMPK/mTOR signaling in metformin-induced autophagy. The results showed that metformin alleviated Dex-induced apoptosis of osteoblasts accompanied by increased autophagy. Treatment with the autophagy inhibitor 3-methyladenine (3-MA) attenuated the effect of metformin on apoptosis, autophagy, and the AMPK/mTOR/p70S6K signaling pathway. The anti-apoptotic effect of metformin on osteoblasts is associated with the promotion of autophagy. Furthermore, sh-AMPK transfection and the mTOR activator MHY1485 impaired metformin-mediated inhibition of osteoblast apoptosis and promotion of autophagy. The AMPK/mTOR/p70S6K signaling pathway plays a role in metformin-mediated apoptosis suppression and autophagy promotion. In conclusion, metformin can alleviate Dex-induced osteoblast apoptosis by inducing autophagy via the AMPK/mTOR/p70S6K pathway. This study highlights the potential value of metformin in the treatment of GIOP.

Oxygen-sensitive methylation of ULK1 is required for hypoxia-induced autophagy

Hypoxia is a physiological stress that frequently occurs in solid tissues. Autophagy, a ubiquitous degradation/recycling system in eukaryotic cells, renders cells tolerant to multiple stressors. However, the mechanisms underlying autophagy initiation upon hypoxia remains unclear. Here we show that protein arginine methyltransferase 5 (PRMT5) catalyzes symmetrical dimethylation of the autophagy initiation protein ULK1 at arginine 170 (R170me2s), a modification removed by lysine demethylase 5C (KDM5C). Despite unchanged PRMT5-mediated methylation, low oxygen levels decrease KDM5C activity and cause accumulation of ULK1 R170me2s. Dimethylation of ULK1 promotes autophosphorylation at T180, a prerequisite for ULK1 activation, subsequently causing phosphorylation of Atg13 and Beclin 1, autophagosome formation, mitochondrial clearance and reduced oxygen consumption. Further, expression of a ULK1 R170K mutant impaired cell proliferation under hypoxia. This study identifies an oxygen-sensitive methylation of ULK1 with an important role in hypoxic stress adaptation by promoting autophagy induction.

Controlled Activation of TRPV1 Channels on Microglia to Boost Their Autophagy for Clearance of Alpha-Synuclein and Enhance Therapy of Parkinson's Disease

Parkinson's disease (PD) is characterized with accumulation of Lewy bodies with a major component of fibrillar alpha-synuclein (α-syn). Herein, boosting PD therapeutic efficacy by enhancing the autophagy of microglia to phagocytose and degrade α-syn via controlled opening of their surface TRPV1 channels with rationally designed photothermal nanoagent is reported. The Cu_{2- x} Se-anti-TRPV1 nanoparticles (CS-AT NPs) are fabricated to target the microglia and open their surface TRPV1 channels under the second near infrared (NIR-II) laser irradiation to cause influx of Ca²⁺ to activate ATG5 and Ca²⁺ /CaMKK2/AMPK/mTOR signaling pathway, which promote phagocytosis and degradation of α-syn. The CS-AT NPs are efficiently delivered by focused ultrasound into striatum of PD mice with high expression of TRPV1 receptors. The athletic ability of PD mice treated by CS-AT NPs and NIR-II irradiation is significantly improved due to the phagocytotic clearance of α-syn by microglia with enhanced autophagy. The enzyme tyrosine hydroxylase, ionized calcium binding adapter protein 1, glial fibrillary acidic protein, and pSer129-α-syn (p-α-syn) of treated PD mice are almost recovered to the normal levels of healthy mice. This study provides insights into the activation of microglial autophagy by targeting surface ion channels to improve the treatment of PD and other neurodegenerative diseases.

Capsaicin Alters the Expression of Genetic and Epigenetic Molecules In Hepatocellular Carcinoma Cell

Capsaicin is a natural product which is extracted from pepper and has the potential to be used in cancer treatment because of its anti- proliferative effects. The aim of the study was to determine the effect of capsaicin on the hepatocellular carcinoma cell proliferation and the expressions of related genetic markers as Ki-67, PI3K/AKT/mTOR and epigenetic markers as miR-126 and piR-Hep-1. The inhibitory concentration of capsaicin in HepG2 cells was determined. piR-Hep-1 and miR-126 expressions and Ki-67, PI3K, AKT and mTOR gene expressions were examined by RT-PCR. The inhibitory concentration of capsaicin for HepG2 cells was 200 nM and the decreased proliferation was observed at 24th hour. As epigenetic markers, an up regulation of miR-126 and down regulation of piR-Hep-1 expression were determined after treatment. Moreover, Ki-67, PI3K and mTOR gene expressions decreased while AKT gene expression increased after the treatment (p<0.001). According to the obtained data, capsaicin has an impact on proliferation both genetically and epigenetically. Furthermore, treatment of capsaicin effects miR-126 and piR-Hep-1 expressions which effect carcinogenesis in different way. Moreover, there are some clues which indicate that these two small non-coding RNA might affect each other and share the same target molecules post-transcriptionally.

Geraniin inhibits cell growth and promoted autophagy-mediated cell death in the nasopharyngeal cancer C666-1 cells

Background

Nasopharyngeal carcinoma (NPC) is a rare malignant tumor developing from epithelial linings of nasopharynx, and 10–50 out of 100,000 NPC cases were recorded globally particularly in the Asian countries.

Methodology

The cytotoxicity of geraniin against the NPC C666-1 cells were analyzed using MTT assay. The influences of geraniin on the C666-1 cell viability with the presence of ROS and apoptosis inhibitors were also studied. The expressions of PI3K, Akt, mTOR, and autophagic markers LC3, ATG7, P62/SQSTM1 expressions in the C666-1 cells were studied by western blotting analysis. The ROS production was assayed using DCFH-DA staining. The immunofluorescence assay was performed to detect the NF-κB and β-catenin expressions in the C666-1 cells.

Results

The cell viability of C666-1 cells were appreciably prevented by the geraniin. The geraniin treatment also inhibited the C666-1 cell growth with the presence of apoptotic inhibitor Z-VAD-FMK. The geraniin-treatment effectively improved the ROS production and inhibited the NF-κB and β-catenin expressions in the C666-1 cells. Geraniin appreciably modulated the PI3K/Akt/mTOR signaling axis and improved the autophagy-mediated cell death via improving the autophagic markers LC3 and ATG7 expressions in the C666-1 cells.

Conclusion

In conclusion, our results proved that geraniin inhibits C666-1 cell growth and initiated autophagy-mediated cell death via modulating PI3K/Akt/mTOR cascade and improving LC3 and ATG7 expressions in the C666-1. Geraniin and it could be a hopeful and efficient candidate to treat the human NPC in the future.

Capsaicin Protects Against Lipopolysaccharide-Induced Acute Lung Injury Through the HMGB1/NF-κB and PI3K/AKT/mTOR Pathways

Purpose

Capsaicin (8-methyl-N-geranyl-6-nonamide; CAP) is an alkaloid isolated from chili peppers, which has complex pharmacological properties, including beneficial effects against various diseases. The aim of this study was to investigate the role of CAP in lipopolysaccharide (LPS)-induced acute lung injury (ALI), and the possible underlying mechanisms.

Materials and Methods

ALI was induced by intranasal administration of LPS (0.5 mg/kg), and CAP (1 mg/kg) injected intraperitoneally 3 days before exposure to LPS. Then, the histopathological changes were evaluated by hematoxylin and eosin staining. Enzyme-linked immunosorbent assay and qPCR were used to detect pro-inflammatory cytokines in serum and lung tissue. The expressions of HMGB1/NF-κB, PI3K/AKT/mTOR signaling pathways and apoptosis-associated molecules were determined by Western blot and/or qPCR. In addition, the lung cell apoptosis was analyzed by TUNEL staining, and the expression and location of cleaved caspase-3 were detected by immunofluorescence analysis.

Results

CAP pretreatment significantly protected mice from LPS-induced ALI, with reduced lung wet/dry weight ratio, lung histological damage, myeloperoxidase (MPO) activity, malondialdehyde (MDA) content and pro-inflammatory cytokine levels, and significant increased superoxide dismutase (SOD) activity. In addition, CAP pretreatment significantly inhibited the high-mobility group protein B1 (HMGB1) expression, nuclear factor-kappa B (NF-κB) activation, and the PI3K/AKT/mTOR signaling pathway. Furthermore, mice pre-treated with CAP exhibited reduced apoptosis of lung tissues, with associated down-regulation of caspase-3, cleaved caspase-3, and BAX expression, and up-regulation of BCL-2.

Conclusion

Our data demonstrate that CAP can protect against LPS-induced ALI by inhibiting oxidative stress, inflammatory responses and apoptosis through down-regulation of the HMGB1/NF-κB and PI3K/AKT/mTOR pathways.

Anti-Hepatocellular Carcinoma Biomolecules: Molecular Targets Insights

This report explores the available curative molecules directed against hepatocellular carcinoma (HCC). Limited efficiency as well as other drawbacks of existing molecules led to the search for promising potential alternatives. Understanding of the cell signaling mechanisms propelling carcinogenesis and driven by cell proliferation, invasion, and angiogenesis can offer valuable information for the investigation of efficient treatment strategies. The complexity of the mechanisms behind carcinogenesis inspires researchers to explore the ability of various biomolecules to target specific pathways. Natural components occurring mainly in food and medicinal plants, are considered an essential resource for discovering new and promising therapeutic molecules. Novel biomolecules normally have an advantage in terms of biosafety. They are also widely diverse and often possess potent antioxidant, anti-inflammatory, and anti-cancer properties. Based on quantitative structure-activity relationship studies, biomolecules can be used as templates for chemical modifications that improve efficiency, safety, and bioavailability. In this review, we focus on anti-HCC biomolecules that have their molecular targets partially or completely characterized as well as having anti-cancer molecular mechanisms that are fairly described.

Influences of S100A8 and S100A9 on Proliferation of Nasopharyngeal Carcinoma Cells through PI3K/Akt Signaling Pathway

Objective

To investigate the effects of S100A8 and S100A9 on proliferation in nasopharyngeal carcinoma cells and the regulatory effects of PI3K/Akt signaling pathway.

Methods

Nasopharyngeal carcinoma cells (CNE1) were cultured and randomly divided into three groups: control group, S100A8/S100A9 overexpression group, and siRNA S100A8/S100A9 group. CCK-8 method was used to detect the effect of S100A8 and S100A9 on the viability of nasopharyngeal carcinoma cells. The effects of S100A8 and S100A9 on the colony forming ability of nasopharyngeal carcinoma cells were detected by colony forming assay. The effects of S100A8 and S100A9 on the proliferation of nasopharyngeal carcinoma cells were detected by EdU staining. The mRNA levels of PI3K and Akt were detected by RT-PCR. The expression levels of PI3K and Akt in NPC cells were detected by Western blot. Wortmannin, an inhibitor of PI3K/Akt pathway, was used to inhibit the activation of PI3K/Akt pathway.

Results

Compared with the control group, the cell viability, the number of plate clones, the positive rate of EdU staining, and the mRNA and protein levels of PI3K and Akt were increased in the overexpression group. Compared with the control group, the cell viability, the number of plate clones, the positive rate of EdU staining, and the mRNA and protein levels of PI3K and Akt were decreased in the siRNA group. After inhibiting the activation of PI3K/Akt pathway, the viability of NPC cells in the overexpression group decreased significantly at 48 h and 72 h, while that in the siRNA group increased significantly.

Conclusion

SiRNA S100A8 and S100A9 could inhibit the proliferation of nasopharyngeal carcinoma cells, and the underlying mechanism may be related to the inhibition of PI3K/Akt signaling pathway.

Capsaicin exerts therapeutic effects by targeting tNOX-SIRT1 axis and augmenting ROS-dependent autophagy in melanoma cancer cells

Although considered a sporadic type of skin cancer, malignant melanoma has regularly increased internationally and is a major cause of cancer-associated death worldwide. The treatment options for malignant melanoma are very limited. Accumulating data suggest that the natural compound, capsaicin, exhibits preferential anticancer properties to act as a nutraceutical agent. Here, we explored the underlying molecular events involved in the inhibitory effect of capsaicin on melanoma growth. The cellular thermal shift assay (CETSA), isothermal dose-response fingerprint curves (ITDRF_CETSA), and CETSA-pulse proteolysis were utilized to confirm the direct binding of capsaicin with the tumor-associated NADH oxidase, tNOX (ENOX2) in melanoma cells. We also assessed the cellular impact of capsaicin-targeting of tNOX on A375 cells by flow cytometry and protein analysis. The essential role of tNOX in tumor- and melanoma-growth limiting abilities of capsaicin was evaluated in C57BL/6 mice. Our data show that capsaicin directly engaged with cellular tNOX to inhibit its enzymatic activity and enhance protein degradation capacity. The inhibition of tNOX by capsaicin was accompanied by the attenuation of SIRT1, a NAD⁺-dependent deacetylase. The suppression of tNOX and SIRT1 then enhanced ULK1 acetylation and induced ROS-dependent autophagy in melanoma cells. Capsaicin treatment of mice implanted with melanoma cancer cells suppressed tumor growth by down-regulating tNOX and SIRT1, which was also seen in an in vivo xenograft study with tNOX-depleted melanoma cells. Taken together, our findings suggest that tNOX expression is important for the growth of melanoma cancer cells both in vitro and in vivo, and that inhibition of the tNOX-SIRT1 axis contributes to inducting ROS-dependent autophagy in melanoma cells.

The emerging landscape of long non-coding RNAs in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common and aggressive cancers. HCC shows high prevalence and lethality caused by a variety of etiologic factors. However, the underlying mechanisms and the diagnostic markers identifying patients at risk in advance has not been entirely elucidated. Long non-coding RNAs (lncRNAs) are a subgroup of non-coding RNAs greater than 200 nucleotides in length with no protein-coding capability. With the progress in sequencing technologies and bioinformatic tools, the landscape of lncRNAs is being revealed. Numerous discoveries point out that lncRNAs participate in HCC carcinogenesis and metastasis through altering cell proliferation and invasion ability, apoptosis, and chemo- or radio-sensitivity. Moreover, lncRNA is easy to detect compared to the traditional diagnostic methods. This review summarizes the mechanisms of major lncRNAs in HCC discovered in recent years and lncRNAs as early diagnostic markers for HCC.

Capsaicin Potentiates Anticancer Drug Efficacy Through Autophagy-Mediated Ribophorin II Downregulation and Necroptosis in Oral Squamous Cell Carcinoma Cells

The ability of capsaicin co-treatment to sensitize cancer cells to anticancer drugs has been widely documented, but the detailed underlying mechanisms remain unknown. In addition, the role of ribophorin II turnover on chemosensitization is still uncertain. Here, we investigated capsaicin-induced sensitization to chemotherapeutic agents in the human oral squamous carcinoma cell lines, HSC-3 and SAS. We found that capsaicin (200 μM) did not induce remarkable apoptotic cell death in these cell lines; instead, it significantly enhanced autophagy with a concomitant decrease of ribophorin II protein. This capsaicin-induced decrease in ribophorin II was intensified by the autophagy inducer, rapamycin, but attenuated by the autophagy inhibitors, ULK1 inhibitor and chloroquine, indicating that the autophagic process was responsible for the capsaicin-induced down-regulation of ribophorin II. Co-administration of capsaicin with conventional anticancer agents did, indeed, sensitize the cancer cells to these agents. In co-treated cells, the induction of apoptosis was significantly reduced and the levels of the necroptosis markers, phospho-MLKL and phospho-RIP3, were increased relative to the levels seen in capsaicin treatment alone. The levels of DNA damage response markers were also diminished by co-treatment. Collectively, our results reveal a novel mechanism by which capsaicin sensitizes oral cancer cells to anticancer drugs through the up-regulation of autophagy and down-regulation of ribophorin II, and further indicate that the induction of necroptosis is a critical factor in the capsaicin-mediated chemosensitization of oral squamous carcinoma cells to conventional anticancer drugs.

Immunomodulation: An immune regulatory mechanism in carcinoma therapeutics

Cancer has been generally related to the possession of numerous mutations which interrupt important signaling pathways. Nevertheless, deregulated immunological signaling is considered as one of the key factors associated with the development and progression of cancer. The signaling pathways operate as modular network with different components interacting in a switch-like fashion with two proteins interplaying between each other leading to direct or indirect inhibition or stimulation of down-stream factors. Genetic, epigenetic, and transcriptomic alterations maintain the pathological conduit of different signaling pathways via affecting diverse mechanisms including cell destiny. At present, immunotherapy is one of the best therapies opted for cancer treatment. The cancer immunotherapy strategy includes harnessing the specificity and killing mechanisms of the immunological system to target and eradicate malignant cells. Targeted therapies utilizing several little molecules including Galunisertib, Astragaloside-IV, Melatonin, and Jervine capable of regulating key signaling pathways can effectively help in the management of different carcinomas.

Shikonin inhibits growth, invasion and glycolysis of nasopharyngeal carcinoma cells through inactivating the phosphatidylinositol 3 kinase/AKT signal pathway

Nasopharyngeal carcinoma (NPC) is a malignant tumor which is commonly found in East Asia and Africa. The present clinical treatment of NPC is still mainly based on chemotherapeutics and is prone to drug resistance and adverse reactions. Shikonin has been demonstrated to play the antitumor effect in various cancers. However, the specific effects and related regulatory mechanism of Shikonin in NPC have not been clearly declared yet. Cell viability was valued through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and cell proliferation was detected through colony formation assay and Bromodeoxyuridine (BrdU) assay. Hochest 33258 staining was used to value cell apoptosis. Cell migration and invasion were valued through wound healing and transwell invasion assay, respectively. Glucose uptake, lactate release, ATP level and pyruvate kinase M2 isoform (PKM2) activity were measured using corresponding assay kits. Western blotting was used to examine the expression of proteins related to cell proliferation, cell apoptosis, cell migration and the phosphatidylinositol 3 kinase (PI3K)/AKT signal pathway. We found that Shikonin treatment effectively suppressed cell proliferation and induced obvious cell apoptosis compared with the control. Besides, Shikonin treatment suppressed cell migration and invasion effectively. The detection about glycolysis showed that Shikonin treatment suppressed cell glucose uptake, lactate release and ATP level. The activity of PKM2 was also largely inhibited by Shikonin. Further study revealed that the PI3K/AKT signal pathway was inactivated by Shikonin treatment. In addition, the inducer of the PI3K/AKT signal pathway largely abolished the antitumor effect of Shikonin on cell proliferation, cell apoptosis, cell mobility and aerobic glycolysis in NPC cells. Shikonin inhibits growth and invasion of NPC cells through inactivating the PI3K/AKT signal pathway.

Grape seed proanthocyanidin extract ameliorates cisplatin-induced testicular apoptosis via PI3K/Akt/mTOR and endoplasmic reticulum stress pathways in rats

Testicular toxicity is an adverse reaction of the effective chemotherapy drug cisplatin (CIS). Our previous study found that grape seed proanthocyanidin extract (GSPE) had a protective effect on CIS-induced testicular toxicity. However, the protective mechanism of GSPE against CIS-induced testicular toxicity remains unknown. In this study, we aimed to investigate whether GSPE can reduce CIS-induced testicular toxicity and its potential mechanism in rats. The results showed that GSPE ameliorated CIS-induced the apoptosis of testicular cells and inhibited the protein levels of Bad, Cyt c, caspase-9, caspase-3, caspase-12, GRP78, CHOP, IRE1α, p-IRE1α, XBP-1S, PERK, p-PERK, eIF2α, and p-eIF2α. Besides, GSPE reversed the downregulation of PI3K, p-PI3K, Akt, p-Akt, mTOR, and p-mTOR protein expression induced by CIS. These results indicated that GSPE can improve CIS-induced testicular cells apoptosis via activating PI3K/Akt/mTOR and inhibiting Bad/Cyt c/caspase-9/caspase-3 pathways. And GSPE relieved endoplasmic reticulum stress-mediated apoptosis via inhibiting PREK/eIF2α and IRE1α/XBP-1S/caspase-12 pathways. In conclusion, the evidence suggested that GSPE can act as a protective agent against testicular toxicity induced by CIS. PRACTICAL APPLICATIONS: Testicular toxicity was a well-known adverse effect of cisplatin (CIS) in cancer treatment. Grape seed proanthocyanidin extract (GSPE) has been reported to serve as one of the most therapeutic potentials agents. In present study, we explored the regulatory effects of GSPE on the apoptosis induced by CIS, which involved testicular apoptosis mechanisms in rats. Our results indicated that CIS caused testicular toxicity via PI3K/AKT/mTOR and ERS mediated apoptosis pathway in rats. This toxicity was attenuated by GSPE treatment via activated PI3K/Akt/mTOR pathway, and inhibiting Bad/CytC/caspase-9/caspase-3 as well as PREK/eIF2α, IRE1α/XBP-1S/caspase-12 pathways. Our findings suggest that GSPE may be a novel protective agent against testicular toxicity induced by CIS.

Anticarcinogenic Effects of Capsaicin-Loaded Nanoparticles on In vitro Hepatocellular Carcinoma

Background::

Hepatocellular Carcinoma (HCC) is the fifth most frequent cancer worldwide with a low overall survival due to high metastasis and recurrence rates. The aim of this study is to assess and compare the possible anti-neoplastic effect of capsaicin and nanoformulated capsaicin on in vitro HCC human cell line HepG2. The source of the cell line, including when and from where it was obtained. Whether the cell line has recently been authenticated and by what method. Whether the cell line has recently been tested for mycoplasma contamination.

Materials and Methods::

Capsaicin-loaded Trimethyl Chitosan Nanoparticles (CL TMCS NPs) were synthesized by ionotropic gelation of cationic TMCS with capsaicin. The synthesized nanoparticles were characterized through TEM, and zeta analyzer. Human hepatocarcinoma HepG2 cell lines were cultured and treated with 50, 75 & 100 μM of Capsaicin (CAP), plain TMCS NPs and CL-NPs as well as ethanol (control) for 24h and 48h. The induced effects were investigated by flow cytometry, immunocytochemistry assay for Bcl-2, Bax, and caspase proteins and evaluating gene expression levels of Bcl-2, Bax, and MDR-1 mRNA by real-time PCR.

Results::

Our results demonstrated that capsaicin- loaded NPs had the potential to significantly increase capsaicin bioactivity compared with the plain capsaicin formulation either in inducing apoptosis through altering expression of apoptotic regulators or modifying MDR-1 expression.

Conclusions::

TMCs nanoparticles investigated in this study may be a good drug delivery vehicle for capsaicin. Application of capsaicin-loaded NPs in HCC management as an adjunct therapeutic approach may be a novel strategy to improve the treatment efficacy and resistance of the conventionally used chemotherapy.

Chloroform extract from Sophora Tonkinensis Gagnep. inhibit proliferation, migration, invasion and promote apoptosis of nasopharyngeal carcinoma cells by silencing the PI3K/AKT/mTOR signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Sophora Tonkinensis Gagnep. (STG) has been used as a folk medicine for the treatment of different cancers, especially for nasopharyngeal carcinoma, cervical cancer, liver cancer, stomach cancer, lung cancer and leukemia in China. However, the main chemical composition and anticancer mechanism of chloroform extract of STG (CESTG) were still not very clear.

AIM OF STUDY

This work was carried out to investigate the anticancer effects and mechanisms of chloroform extract of STG (CESTG) on NPC.

METHODS

Cultured NPC CNE1, CNE2 and Np69 cells were treated with CESTG. Cells were subjected to cell proliferation, colony-forming, migration and invasion assays. Cell cycle and apoptosis were measured by flow cytometry. Western blotting and morphological analysis were also performed. Tumor xenografts and drug treatments were made in BALB/c nude mice. The main compounds of CESTG was separated by HPLC.

RESULTS

CESTG inhibited cell viability, clonal growth and induced cell apoptosis in a dose-dependent manner by silencing the PI3K/AKT/mTOR signaling pathway, which is associated with upregulation of cleaved PARP, caspase 3/7/8/9, cleaved caspase 3/7/8/9, Bax and downregulation of PARP, P-PI3K, PI3K, P-AKT, AKT, P-mTOR, mTOR and Bcl-2. In addition, CESTG arrested cell cycle in the G1/S phase, correlating with decreased levels of cyclin D1/B1, CDK 4 and 6. CESTG decreased cell migration and invasion which correlated with decreased expression of β-catenin, vimentin and snail. CESTG significantly inhibited the tumor growth without toxicity.

CONCLUSION

The results presented here suggest that CESTG could be use as a potential source of NPC therapeutic drug.

Phytochemicals as a Complement to Cancer Chemotherapy: Pharmacological Modulation of the Autophagy-Apoptosis Pathway

Bioactive plant derived compounds are important for a wide range of therapeutic applications, and some display promising anticancer properties. Further evidence suggests that phytochemicals modulate autophagy and apoptosis, the two crucial cellular pathways involved in the underlying pathobiology of cancer development and regulation. Pharmacological targeting of autophagy and apoptosis signaling using phytochemicals therefore offers a promising strategy that is complementary to conventional cancer chemotherapy. In this review, we sought to highlight the molecular basis of the autophagic-apoptotic pathway to understand its implication in the pathobiology of cancer, and explore this fundamental cellular process as a druggable anticancer target. We also aimed to present recent advances and address the limitations faced in the therapeutic development of phytochemical-based anticancer drugs.

Curry versus cancer: Potential of some selected culinary spices against cancer with in vitro, in vivo, and human trials evidences

Spices are dietary agents with immense potential for cancer chemo-prevention. A wide variety of spices are extensively used as food flavoring agents which possess potent antioxidant, anti-inflammatory, and anticancer properties due to the presence of certain bio-active compounds in them. In vitro, in vivo studies and clinical trials of selected spices against various types of cancer are being specified in this review. Effect of certain putative dietary spices namely turmeric, clove, garlic, ginger, fennel, black cumin, cinnamon, pepper, saffron, rosemary, and chilli along with its role in cancer are being discussed. Literature search was conducted through PubMed, Google scholar, Science direct, and Scopus using the keywords "spice," "cancer," "natural medicine," "herbal compound," "bioactive compounds." About 4,000 published articles and 127 research papers were considered to grab the brief knowledge on spices and their anticancer potential on a predefined inclusion and exclusion criteria. PRACTICAL APPLICATION: Historically, spices and herbs are known for its traditional flavor, odor, and medicinal properties. Intensified risk of chronic and pervasive clinical conditions and increased cost of advanced drug treatments have developed a keen interest among researchers to explore the miscellaneous properties of herbal spices. Cancer is one of the deleterious causes of mortality affecting a huge number of populations worldwide. Arrays of cancer treatments including surgery, chemotherapy, and radiation therapy are used to compromise the disease but effective only when the size of the tumor is small. So, an effective treatment need to be developed that produces less side effects and herbal spices are found to be the promising agents. In this review, we illustrate about different in vitro, in vivo, and clinical studies of wide range of culinary spices having antineoplastic potential.

Capsaicin intake and oral carcinogenesis: A systematic review

Background

Chili is the most heavily and frequently consumed spice, either as a flavouring or colouring agent, and it is also a major source of pro-vitamin A, vitamin E and C. The main capsinoidcapsaicinoid found in chili peppers is capsaicin. It has been demonstrated that capsaicin acts as a cancer-suppressing agent through its antioxidant and anti-inflammatory effects, by blocking several signal transduction pathways. Oral squamous cell carcinoma is one of the most prevalent cancer worldwide. It is noteworthy that in countries where populations of diverse ethnic groups co-exist, differences have been observed in terms of incidence of oral cancer. The variances in their diet could explain, at least in part, these differences. The objective of this systematic review is to explore if there is evidence of a possible relationship between capsaicin intake and the incidence of oral squamous cell carcinoma, and discuss such association.

Material and Methods

A bibliographical search was made in PubMed, Scopus and Web of Science databases, and finally 7 experimental studies were included; OHAT risk of bias tool was used to assess their quality.

Results

allAll the studies confirm that capsaicin is a chemopreventive agent that prevents the development of oral cancer, through inhibition of malignant cell proliferation and increase of apoptosis.

Conclusions

More human studies are needed in order to clarify the real link between consumption of chili (capsaicin) and the prevalence of oral cancer.

Key words:Chili, capsaicin, oral epithelial dysplasia, oral cancer, cell proliferation, apoptosis.

Extraction, purification, bioactivity and pharmacological effects of capsaicin: a review

Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide), a well-known vanilloid, which is the main spicy component in chili peppers, showing several biological activities and the potential applications range from food flavorings to therapeutics. Traditional extraction of capsaicin by organic solvents was time-consuming, some new methods such as aqueous two-phase method and ionic liquid extraction method have been developed. During past few decades, an ample variety of biological effects of capsaicin have been evaluated. Capsaicin can be used in biofilms and antifouling coatings due to its antimicrobial activity, allowing it has a promising application in food packaging, food preservation, marine environment and dental therapy. Capsaicin also play a crucial role in metabolic disorders, including weight loss, pressure lowing and insulin reduction effects. In addition, capsaicin was identified effective on preventing human cancers, such as lung cancer, stomach cancer, colon cancer and breast cancer by inducing apoptosis and inhibiting cell proliferation of tumor cells. Previous research also suggest the positive effects of capsaicin on pain relief and cognitive impairment. Capsaicin, the agonist of transient receptor potential vanilloid type 1 (TRPV1), could selectively activate TRPV1, inducing Ca²⁺ influx and related signaling pathways. Recently, gut microbiota was also involved in some diseases therapeutics, but its influence on the effects of capsaicin still need to be deeply studied. In this review, different extraction and purification methods of capsaicin, its biological activities and pharmacological effects were systematically summarized, as well as the possible mechanisms were also deeply discussed. This article will give an updated and better understanding of capsaicin-related biological effects and provide theoretical basis for its further research and applications in human health and manufacture development.

Decreased drug resistance of bladder cancer using phytochemicals treatment

The aim of the study is to investigate the ability of phytochemicals to overcome the multiple drug resistance (MDR) of bladder cancer. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to evaluate the cytotoxic sensitivity of T24-GCB cells, a GCB resistant cell line, to different phytochemicals, including capsaicin, quercetin, curcumin, and resveratrol, and their combination with gemcitabine. Western blot analysis was used to detect the expression of membranous ABCC2 and metabolic proteins, DCK, TK1, and TK2 in tumor cells. Animal models were used to confirm the treatment efficacy of phytochemicals in combination with gemcitabine to bladder cancer. The observed/expected ratio of cytotoxicity analysis revealed that capsaicin has synergistic effect with gemcitabine to T24-GCB cells in a dose-dependent pattern. Quercetin, curcumin, and resveratrol have additive effect with gemcitabine to T24-GCB cells. Capsaicin and quercetin alone and combination with gemcitabine decreased the expression of ABCC2 and DCK and TKs, in T24-GCB cells. On the contrary, resveratrol and curcumin alone and combination with gemcitabine increased the expression of ABCC2 but decreased cytoplasmic kinases simultaneously. In xenografted subcutaneous tumor model on nude mice, combination treatment of capsaicin and gemcitabine demonstrated the highest tumor suppression effect when compared to capsaicin or gemcitabine treatment alone. The MDR of bladder cancer is closely related to membranous ABCC2, cytoplasmic DCK, and TKs expression. Capsaicin owns the strongest synergistic cytotoxic effect of gemcitabine to T24-GCB cells. This combination regimen may provide as an adjunctive treatment for overcoming MDR in bladder cancer.

Compound TDB (Tricyclic decyl benzoxazole) induces autophagy-dependent apoptosis in the gastric cancer cell line MGC-803 by regulating PI3K/AKT/mTOR

OBJECTIVE

Gastric cancer is a potential malignant tumor. Extensive research has shown that apoptosis and autophagy are important mechanisms of cancer pathogenesis. This study aimed to explore the role and mechanism of TDB in apoptosis and autophagy in MGC-803 cells.

METHODS

In cell experiments, the proliferation, apoptosis and autophagy of MGC-803 cells were evaluated by the MTT assay, TUNEL, flow cytometry, MDC, and TEM. Through molecular experiments, the TDB-induced apoptosis and autophagy effects were evaluated by examining the levels of Cleaved-PARP/PARP, Cleaved-caspase3/procaspase3, Beclin-1, p62 and the ratio of LC3-II/LC3-I. At the animal level, the anti-tumor effect of TDB in vivo was evaluated by assessing tumor volume and bioluminescence value.

RESULTS

Regarding mechanism, TDB induces apoptosis and autophagy through PI3K/AKT/mTOR. At the same time, more importantly, TDB promotes 3-methyladenine or autophagy activator rapamycin-mediated. The induced proliferation inhibition and pro-apoptosis effect, which inhibit autophagy and induce an increase in apoptosis.

CONCLUSION

TDB may up-regulate PARP, Cleaved Caspase-3, Beclin1 and LC3B and down-regulate the expression of P62 and other apoptosis and autophagy genes through the activation of PI3K/AKT/mTOR pathway signalling proteins, leading to autophagy-dependent apoptosis. At the animal level, TDB has good anti-tumor efficacy in vivo. In summary, TDB has potential anti-tumor efficacy in vivo and in vitro.

Combination effect of curcumin with docetaxel on the PI3K/AKT/mTOR pathway to induce autophagy and apoptosis in esophageal squamous cell carcinoma

BACKGROUND

Docetaxel (DTX) is widely used to treat many malignant tumors but has many adverse effects. Curcumin (CUR) also has effects on a variety of tumor cells and can reduce the toxicity and side effects of chemotherapy drugs and the occurrence of drug resistance. However, the combination of CUR and DTX for treating esophageal cancer has not been reported.

METHODS

Human esophageal squamous cell carcinoma (ESCC) KYSE150 and KYSE510 cells were treated with CUR or DTX alone or both drugs and cancer cell viability was detected by CCK8, apoptosis, scratch-healing and migration assays. Electron microscopy and Western blots were used. In vivo experiments were used observe anti-tumor effects.

RESULTS

CUR combined with DTX significantly inhibited the viability and migration of esophageal cancer cells (P<0.01) and further promoted the apoptosis of cancer cells. In addition, CUR induced autophagy in esophageal cancer cells when combined with DTX. DTX combined with CUR may induce apoptosis and autophagy by inhibiting the PI3K/AKT/mTOR signaling pathway. The compound 3-methyladenine (3MA) inhibited the autophagy induced by DTX and CUR (DC), further accelerated apoptosis and inhibited the proliferation of esophageal cancer cells when combined with DC.

CONCLUSION

CUR combined with DTX induced apoptosis and autophagy of ESCC and probably worked through the PI3K/AKT/mTOR signaling pathway. The combination of the autophagy inhibitor, CUR and DTX may become a new treatment strategy for esophageal cancer.

Suppression of proteasome induces apoptosis in APL cells and increases chemo-sensitivity to arsenic trioxide: Proposing a perception in APL treatment

In the last three decades, the pathogenesis of acute promyelocytic leukemia (APL) has been mostly studied with regard to the oncogenic role of PML/RAR fusion protein; however, the latest discoveries have stated that the concerns with the treatment of APL patients would not be resolved until the role of aberrant networks is overlooked. The present study was designed to evaluate the anti-cancer property of second-generation of the proteasome inhibitors carfilzomib (CFZ) on APL-derived NB4 cells. Our results showed that pharmacologic targeting of proteasome in NB4 reduced the proliferative rate of malignant cells through a c-Myc-mediated G2/M cell cycle arrest. Moreover, we found that the suppression of proteasome was coupled with the induction of apoptotic NB4 cell death, which is probably mediated through down-regulation of anti-apoptotic target genes. Interestingly, our results suggested that the suppression of the autophagy system using chloroquine could serve as a mechanism through which the cytotoxicity of CFZ in APL cells was ameliorated. Finally, and consistent with the favorable efficacy of single agent of CFZ, we also noted an intensifying effect of the inhibitor on the anti-leukemic activity of arsenic trioxide (ATO) when it was used in combination. Overall, this study suggests that pharmaceutical targeting of proteasome using CFZ, either as a single agent or in combination with ATO, could be a promising mechanism through which the obstacle on the way of APL would be tackled; however, further investigations are needed to determine the advantages of the inhibitor in clinical applications.

Jervine exhibits anticancer effects on nasopharyngeal carcinoma through promoting autophagic apoptosis via the blockage of Hedgehog signaling

Nasopharyngeal carcinoma (NPC) is a malignant tumor originating from the superior mucosal epithelium of the nasopharynx. However, effective therapies for NPC are still required. Reducing Hedgehog signaling pathway has been shown to suppress tumor growth. In this study, we attempted to explore whether Jervine (JV), an inhibitor of Hedgehog signaling, had anti-cancer effects on NPC, and the underlying mechanisms. Our findings showed that JV treatments markedly reduced the proliferation of NPC cells in a dose- and time-dependent manner. Cell cycle arrest in G2/M phase was significantly enhanced by JV, along with evident DNA damage. Moreover, JV treatment effectively induced apoptosis in NPC cells through improving Caspase-3 activation. Furthermore, ROS production and mitochondrial impairments were detected in JV-incubated NPC cells with elevated releases of Cyto-c from mitochondria. JV also dramatically triggered autophagy through blocking AKT/mTOR and increasing AMPK signaling pathways. Intriguingly, we showed that JV-induced apoptosis was mainly via an autophagy-dependent manner. In addition, the expression levels of SHH, PTCH1, SMO and GLI1 were markedly suppressed in NPC cells, demonstrating the hindered Hedgehog signaling. Importantly, we found that JV-induced apoptosis and autophagy were closely associated with the blockage of Hedgehog signaling. Our in vivo studies confirmed the anti-cancer effects of JV on NPC through inducing autophagy, as evidenced by the markedly reduced tumor growth rate and weight without side effects and toxicity. Taken together, JV may be a promising and effective agent for human NPC treatment through repressing Hedgehog signaling pathway and inducing autophagic cell death.

PI3K/AKT/mTOR signaling in gastric cancer: Epigenetics and beyond

PI3K/AKT/mTOR pathway is one of the most important signaling pathways involved in normal cellular processes. Its aberrant activation modulates autophagy, epithelial-mesenchymal transition, apoptosis, chemoresistance, and metastasis in many human cancers. Emerging evidence demonstrates that some infections as well as epigenetic regulatory mechanisms can control PI3K/AKT/mTOR signaling pathway. In this review, we focused on the role of this pathway in gastric cancer development, prognosis, and metastasis, with an emphasis on epigenetic alterations including DNA methylation, histone modifications, and post-transcriptional modulations through non-coding RNAs fluctuations as well as H. pylori and Epstein-Barr virus infections. Finally, we reviewed different molecular targets and therapeutic agents in clinical trials as a potential strategy for gastric cancer treatment through the PI3K/AKT/mTOR pathway.