Mechanism of piperine in affecting apoptosis and proliferation of gastric cancer cells via ROS-mitochondria-associated signalling pathway

Piperine and its nanoformulations: A mechanistic review of their anti-cancer activities

Piperine, an active compound found in black pepper, exhibits promising anti-cancer properties by targeting critical signaling pathways involved in cancer cell proliferation, migration, and invasion. This review explores the diverse mechanisms through which piperine exerts its effects, including inhibition of the PI3K/Akt/mTOR and ERK1/2 pathways, activation of p38 and JNK pathways, and suppression of NF-kB/AP-1 signaling. Piperine disrupts Wnt/β-catenin signaling by inhibiting β-catenin nuclear translocation and TCF binding, thereby impairing cancer cell growth and metastasis. Additionally, piperine demonstrates anti-inflammatory actions by reducing CXCL8 expression and modulating the p38 MAPK and JNK pathways. To overcome the issues of low solubility and bioavailability, several nanoformulations of piperinewere developed, such as polymer nanoparticles, nanoemulsion, liposomes, micelles, metal-organic frameworks and inorganic carriers, establishing promising cytotoxicity, prolonged-release, enhanced cellular influx, and directed drug delivery. The mechanisms involve G₀ and G₂/M arrest of the cell cycle, mitochondria-mediated apoptosis (involving Bax/Bcl-2 modulation and caspase activation), and cancer celldeath. In vivo studies underscore the efficacy of piperine, while synergistic effects with other natural products and chemotherapy highlight its potential as a versatile therapeutic agent as an anticancer agent. These findings underscore piperine's potential as a multifaceted therapeutic agent for cancer treatment, emphasizing its diverse mechanisms of action and promising role in oncology.

Integrative analysis and prognostication in gastric cancer: unveiling the role of mitochondrial genomics with the MLRScore model

Gastric cancer, a leading cause of cancer-related mortality globally, presents significant challenges in prognosis and treatment due to its heterogeneity. This study aimed to elucidate the role of mitochondrial-related genes (MRGs) in gastric cancer and develop a prognostic model. We analyzed RNA sequencing data and clinical information of 412 gastric cancer samples from The Cancer Genome Atlas (TCGA). A comprehensive list of 1136 MRGs was curated from the MitoCarta3.0 database, leading to the identification of 110 differentially expressed MRGs between gastric cancer and normal tissues. Using univariate and multivariate Cox regression analyses, we constructed the Mitochondrial-Related Risk Score (MLRScore), a prognostic model incorporating five key MRGs. The model was validated in training and testing cohorts and exhibited promising prognostic capability. Additionally, we investigated the relationship between MLRScore and immune cell infiltration, somatic mutations, tumor mutation burden (TMB), and response to chemotherapy. The MLRScore was found to correlate with distinct immune landscapes and chemotherapeutic sensitivities, suggesting its potential utility in guiding personalized treatment strategies. Our study not only provides a novel tool for prognostic assessment in gastric cancer but also underscores the importance of mitochondrial dynamics in tumor biology and patient stratification.

Piperine inhibits fungal growth and protects against pyroptosis in Aspergillus fumigatus keratitis by regulating the mTOR/HIF-1α pathway

PURPOSE

To confirm the antifungal ability of piperine (PIP) and to assess its therapeutic potential in the treatment of Aspergillus fumigatus (A. fumigatus) keratitis.

METHODS

The toxicity of PIP was measured to determine the optimal therapeutic concentration both in human corneal epithelial cells (HCECs), RAW264.7 cells and mice fungal keratitis models. The antifungal efficacy of PIP was confirmed through the minimum inhibitory concentration (MIC) test, biofilm formation inhibition test, Calcofluor white and PI staining, and anti-adhesion of A. fumigatus conidia test. Hematoxylin-eosin (HE) staining, corneal fungal load assay, RT-qPCR, western blot, and Elisa were used to assess the therapeutic effect and anti-inflammatory ability of PIP in fungal keratitis. The significance of the mTOR/HIF-1α signal pathway after PIP treatment of A. fumigatus keratitis was evaluated.

RESULTS

PIP had no obvious toxicity to HCECs, RAW 264.7 cells, or mouse cornea at the concentration of 30 µg/mL. PIP effectively inhibited A. fumigatus from growing and showed synergistic effects when combined with NATA. PIP not only reduced fungal load and the aggregation of inflammatory cells, but also dramatically reduced the expression levels of NLRP3, caspase-1, cleaved caspase-1, GSDMD, GSDMD-N, IL-18, and IL-1β, which were linked to pyroptosis. Additionally, PIP decreased mTOR phosphorylation and HIF-1α expression. The pretreatment with mTOR agonists reversed the inhibition of NLRP3, caspase-1, cleaved caspase-1, GSDMD, GSDMD-N, IL-18, and IL-1β protein levels caused by PIP.

CONCLUSION

PIP exhibited antifungal and anti-inflammatory properties, and alleviated pyroptosis in A. fumigatus keratitis via inhibiting the mTOR/HIF-1α signaling pathway.

Design and Mechanism Study of 6c, a Novel Artesunate Derivatives, for Anti-Hepatocellular Carcinoma

Objective

Artesunate can inhibit the proliferation of various tumor cells and has practical value in developing anti-tumor drugs. However, its biological activity against hepatocellular carcinoma is weak. The efficacy of its anti-tumor effect needs to be improved.

Methods

11 compounds of three types were designed and synthesized. Their antitumor activity was detected by MTT assay in vitro and subcutaneous xenograft model in vivo. Then, DCFH-DA probe detection and NAC intervention experiments were used to detect ROS levels. The ferroptosis inhibitor (Liproxstatin-1) was used to study the effect of compound 6c in inducing ferroptosis. Western blot was used to observe the expression of apoptosis-related proteins. The ability of 6c to induce apoptosis was detected by Annexin V-FITC/PI double staining and Hoechst 33342 staining experiment. The effect of 6c on cycle arrest was detected by flow cytometry. Molecular simulations of several hybrids with vascular endothelial growth factor receptor 2 (VEGFR-2) and Transferrin receptor protein 1 (TFR1) were performed using MOE molecular docking software.

Results

A series of new artemisinin-4-(4-substituted phenoxy) pyridine derivatives were synthesized and their anticancer activities were tested in three lines of hepatocellular carcinoma (HCC) cells. Among the hybrid hits with anticancer activity, a representative 6c compound increased the reactive oxygen species (ROS) level in hepatocellular carcinoma cells and activated mitochondrial apoptosis and ferroptosis, leading to cell cycle arrest at G2/M phase. Molecular docking shows the binding of 6c compound to oncogenic vascular endothelial growth factor receptor 2 (VEGFR-2) and Transferrin receptor protein 1 (TFR1) that are overexpressed in malignant epithelial tumors.

Conclusion

Taken together, our identification of the promising compound 6c may hold developmental potential for therapy of hepatocellular carcinoma.

Piperine inhibits the proliferation of colorectal adenocarcinoma by regulating ARL3-mediated endoplasmic reticulum stress

Colorectal adenocarcinoma (COAD) is a significant cause of cancer-related mortality worldwide, necessitating the identification of novel therapeutic targets and treatments. This research aimed to investigate the role of ARL3 in COAD progression and to explore the effects of Piperine on ARL3 expression, cell proliferation, epithelial-mesenchymal transition (EMT), and endoplasmic reticulum (ER) stress. Bioinformatics analysis of The Cancer Genome Atlas (TCGA)-COAD, GSE39582, and GSE44861 datasets assessed ARL3 expression levels. Immunohistochemical data from the Human Protein Atlas (HPA) database confirmed ARL3 overexpression in COAD. The association of ARL3 with COAD clinical parameters and prognosis was also examined. COAD cells were treated with Piperine, and in vitro assays evaluated cell proliferation, apoptosis, EMT marker expression, and ER stress (ERS) responses. ARL3 overexpression in COAD correlated with poor prognosis and varied across pathological stages. Piperine treatment inhibited COAD cell proliferation in a concentration- and time-dependent manner, as indicated by reduced Ki-67 levels and decreased colony-forming ability. Piperine induced S-phase cell cycle arrest and facilitated apoptosis in COAD cells, evidenced by changes in Bax, Bcl-2, cleaved caspase-3, and cleaved Poly (ADP-ribose) polymerase (PARP) levels. Moreover, Piperine downregulated ARL3 expression in COAD cells, thereby suppressing transforming growth factor beta (TGF-β)-induced EMT. Additionally, Piperine attenuated the ARL3-mediated ER stress response, significantly reducing binding immunoglobulin protein (BiP), inositol-requiring enzyme 1 alpha (p-IRE1α), activating transcription factor 6 (ATF6), and C/EBP homologous protein (CHOP) levels. Piperine exerts anti-cancer effects in COAD by modulating ARL3 expression, disrupting cell cycle progression, inhibiting the EMT pathway, and regulating ERS. These findings suggest that Piperine holds promise as a therapeutic agent for COAD through its targeting of ARL3.

Plant Secondary Metabolites as Modulators of Mitochondrial Health: An Overview of Their Anti-Oxidant, Anti-Apoptotic, and Mitophagic Mechanisms

Plant secondary metabolites (PSMs) are a diverse group of bioactive compounds, including flavonoids, polyphenols, saponins, and terpenoids, which have been recognised for their critical role in modulating cellular functions. This review provides a comprehensive analysis of the effects of PSMs on mitochondrial health, with particular emphasis on their therapeutic potential. Emerging evidence shows that these metabolites improve mitochondrial function by reducing oxidative stress, promoting mitochondrial biogenesis, and regulating key processes such as apoptosis and mitophagy. Mitochondrial dysfunction, a hallmark of many pathologies, including neurodegenerative disorders, cardiovascular diseases, and metabolic syndrome, has been shown to benefit from the protective effects of PSMs. Recent studies show that PSMs can improve mitochondrial dynamics, stabilise mitochondrial membranes, and enhance bioenergetics, offering significant promise for the prevention and treatment of mitochondrial-related diseases. The molecular mechanisms underlying these effects, including modulation of key signalling pathways and direct interactions with mitochondrial proteins, are discussed. The integration of PSMs into therapeutic strategies is highlighted as a promising avenue for improving treatment efficacy while minimising the side effects commonly associated with synthetic drugs. This review also highlights the need for future research to elucidate the specific roles of individual PSMs and their synergistic interactions within complex plant matrices, which may further optimise their therapeutic utility. Overall, this work provides valuable insights into the complex role of PSMs in mitochondrial health and their potential as natural therapeutic agents targeting mitochondrial dysfunction.

Piperine: an emerging biofactor with anticancer efficacy and therapeutic potential

Anticancer drug discovery needs serious attention to overcome the high mortality rate caused by cancer. There are still many obstacles to treating this disease, such as the high cost of chemotherapeutic drugs, the resulting side effects from the drug, and the occurrence of multidrug resistance. Herbaceous plants are a reservoir of natural compounds that can be anticancer drugs with novel mechanisms of action. Piperine, a bioactive compound derived from Piper species, is gaining attention due to its unique dual role in directly inhibiting tumor growth and enhancing the bioavailability of chemotherapeutic drugs. Unlike conventional treatments, Piperine exhibits a novel mechanism of action by modulating multiple signaling pathways, including apoptosis and autophagy, with low toxicity. Additionally, Piperine acts as a bioenhancer by improving the absorption and effectiveness of other anticancer agents, reducing the required dosage, and minimizing side effects. Therefore, this review aims to visualize a summary of Piperine sources, phytochemistry, chemical structure-anticancer activity relationship, anticancer activities of semi-synthetic derivatives, pharmacokinetic and bioavailability, in vitro and in vivo preclinical studies, mechanism of antitumor action, human clinical trials, toxicity, side effects, and safety of Piperine. References were collected from the Pubmed/MedLine database (https://pubmed.ncbi.nlm.nih.gov/) with the following keywords: "Piperine anticancer," "Piperine derivatives," "Piperine antitumor mechanism" and "Piperine pharmacokinetic and bioavailability," after filter process by inclusion and exclusion criteria, 101 were selected from 444 articles. From 2013 to 2023, there were numerous studies regarding preclinical studies of Piperine of various cell lines, including breast cancer, prostate cancer, lung cancer, melanoma, cervical cancer, gastric cancer, osteosarcoma, colon cancer, hepatocellular carcinoma, ovarian cancer, leukemia, colorectal cancer, and hypopharyngeal carcinoma. In vivo, the anticancer study has also been conducted on some animal models, such as Ehrlich carcinoma-bearing mice, Ehrlich ascites carcinoma cells-bearing Balbc mice, hepatocellular carcinoma-bearing Wistar rat, A375SM cells-bearing mice, A375P cells-bearing mice, SNU-16 cells-bearing BalbC mice, and HGC-27-bearing baby mice. Treatment with this compound leads to cell proliferation inhibition and induction of apoptosis. Piperine has been used for clinical trials of diseases, but no cancer patient report exists. Various semi-synthetic derivatives of Piperine show efficacy as an anticancer drug across multiple cell lines. Piperine shows promise for use in cancer clinical trials, either as a standalone treatment or as a bioenhancer. Its bioenhancer properties may enhance the efficacy of existing chemotherapeutic agents, providing a valuable foundation for developing new anticancer therapies.

Human blood metabolites and gastric cancer: a Mendelian randomization analysis

BACKGROUND

Gastric cancer (GC) remains one of the predominant malignant tumors within the digestive tract, yet its underlying biological mechanisms remain elusive. The primary objective of this study is to delineate the causal relationship between circulating metabolites and GC.

METHOD

The primary Mendelian randomization (MR) analysis was based on three large GWAS datasets. While the inverse variance weighted served as the primary analysis technique for investigating causal relationships, additional sensitivity analyses were facilitated through methods such as MR-PRESSO, the weighted median, and MR-Egger. Subsequently, replication, meta-analysis, and multivariable MR were executed using another GC GWAS.

RESULTS

The results of this study indicated significant associations between three metabolites 3-methyl-2-oxovalerate (OR 5.8, 95%CI: 1.53-22.05, p = 0.0099), piperine (OR 2.05, 95%CI: 1.13-3.7, p = 0.0175), Phe-Phe dipeptide (OR 0.16, 95%CI: 0.03-0.93, p = 0.0409) and GC.

CONCLUSION

The present study provides evidence supporting a causal relationship between these three circulating metabolites and GC risk. Elevated levels of 3-methyl-2-oxovalerate and piperine may increase the risk of GC, while Phe-Phe dipeptide may have a protective effect. By integrating genomics and metabolomics, we offer a novel perspective on the biological mechanisms underlying GC. Such insights have the potential to enhance strategies for the screening, prevention, and treatment of GC.

Mechanisms of traditional Chinese medicine in the treatment and prevention of gastric cancer

BACKGROUND

Gastric cancer (GC) ranks as the fifth most prevalent malignancy worldwide. Conventional treatments, including radiotherapy and chemotherapy, often induce severe side effects and significant adverse reactions, and they may also result in drug resistance. Consequently, there is a critical need for the development of new therapeutic agents. Traditional Chinese Medicine (TCM) and natural products are being extensively researched due to their low toxicity, multi-targeted approaches, and diverse pathways. Scholars are increasingly focusing on identifying active anticancer components within TCM.

PURPOSE

This review aims to summarise research conducted over the past 14 years on the treatment of GC using TCM. The focus is on therapeutic targets, mechanisms, and efficacy of Chinese medicine and natural products, including monomer compounds, extracts or analogues, and active ingredients.

METHODS

Relevant articles on TCM and GC were retrieved from PubMed using appropriate keywords. The collected articles were screened and classified according to the types of TCM, with an emphasis on the molecular mechanisms underlying the treatment of GC.

RESULTS

The research on TCM indicates that TCM and natural products can effectively inhibit the metastasis, proliferation, and invasion of tumour cells. They can also induce apoptosis, autophagy and improve the chemosensitivity of drug-resistant cells. Additionally, injections derived from Chinese herbal medicine, when used as an adjunct to conventional chemotherapy, can significantly improve the prognosis of GC patients by reducing chemotherapy toxicity.

CONCLUSION

This review summarises the progress of TCM treatment of GC over the past 14 years, and discusses its therapeutic application of GC, which proves that TCM is a promising treatment strategy for GC in the future.

Nrf2: A critical participant in regulation of apoptosis, ferroptosis, and autophagy in gastric cancer

Nuclear factor erythroid 2-related factor-2 (Nrf2) is a specific transcription factor that maintains redox homeostasis by regulating the expression of anti-oxidative stress-related genes. Hyperactivation of Nrf2 is involved in tumor progression and is associated with chemoresistance in a large number of solid tumors. Programmatic cell death (PCD), such as apoptosis, ferroptosis, and autophagy, plays a crucial role in tumor development and chemotherapy sensitivity. Accumulating evidence suggests that some anti-tumor compounds and genes can induce massive production of reactive oxygen species (ROS) via inhibiting Nrf2 expression, which exacerbates oxidative stress and promotes Gastric cancer (GC) cell death, thereby enhancing the sensitivity of GC cells to chemotherapy-induced PCD. In this review, we summarize the role of antitumor drugs in interfering in three different types of PCD (apoptosis, ferroptosis, and autophagy) in GC cells by modulating Nrf2 expression, as well as the molecular mechanisms through which targeting Nrf2 brings about PCD and chemosensitivity. It is reasonable to believe that Nrf2 serves as a potential therapeutic target, and targeting Nrf2 by drug or gene regulation could provide a new strategy for the treatment of GC.

Piperine induces autophagy of colon cancer cells: Dual modulation of AKT/mTOR signaling pathway and ROS production

BACKGROUND

Colorectal cancer (CRC) is a prevalent malignancy and poses a significant clinical challenge. Piperine, an alkaloid molecule extracted from Piper nigrum and Piper longum, has emerged as a promising anticancer agent. However, the molecular mechanisms of piperine' antitumor effects in CRC need to be further elucidated.

METHODS

Human colorectal cancer cells were treated with piperine in vitro. CCK-8 and clone formation assays were adopted to detect cell viability. The accumulation of autophagosomes was assessed by Western blotting and immunofluorescence. Apoptosis and reactive oxygen species (ROS) levels were analyzed by flow. In vivo, a xenograft tumor mouse model was constructed using CT26 cells.

RESULTS

Piperine inhibited CRC cell viability and suppressed tumor weight and volume in a mouse model. Additionally, piperine treatment induced the accumulation of autophagosomes in CRC cells. This effect was attributed to the inhibition of the AKT/mTOR pathway and the accumulation of ROS. activation of AKT or clearance of ROS attenuated piperine-mediated tumor suppression.

CONCLUSION

This study shows that piperine induces autophagy-dependent cell death in CRC cells by increasing ROS production and inhibiting Akt/mTOR signaling.

Multiple effects of spicy flavors on neurological diseases through the intervention of TRPV1: a critical review

The spicy properties of foods are contributed by various spicy flavor substances (SFs) such as capsaicin, piperine, and allicin. Beyond their distinctive sensory characteristics, SFs also influence health conditions and numerous studies have associated spicy flavors with disease treatment. In this review, we enumerate different types of SFs and describe their role in food processing, with a specific emphasis on critically examining their influence on human wellness. Particularly, detailed insights into the mechanisms through which SFs enhance physiological balance and alleviate neurological diseases are provided, and a systematic analysis of the significance of transient receptor potential vanilloid type-1 (TRPV1) in regulating metabolism and nervous system homeostasis is presented. Moreover, enhancing the accessibility and utilization of SFs can potentially amplify the physiological effects. This review aims to provide compelling evidence for the integration of food flavor and human health.

Anti-tyrosinase and anti-melanogenic effects of piperine isolated from Piper nigrum on B16F10 mouse melanoma cells

The essential function of melanin is to protect our skin against harmful environmental factors. However, excessive melanin production can cause undesirable hyperpigmentation issues, such as freckles and melasma. Although several compounds are used to control melanin production by inhibiting tyrosinase (TYR), their efficacy is limited by skin-related adverse effects and cytotoxicity concerns. Consequently, searching for new natural compounds with an effective TYR inhibitor (TYR-I) activity but less harmful effects continues. Plant-based natural extracts are an alternative that are in great demand due to their safety and diverse biological properties. This study assessed ten isolated plant compounds for their TYR-I activities using an in vitro mushroom TYR inhibition assay. Among these compounds, piperine (400 μM) demonstrated the highest TYR-I activity, with a potency of 36.27 ± 1.96 %. Hence, this study examined the effect of piperine on melanogenesis in melanocyte stimulating hormone-treated B16F10 melanoma cells and using kojic acid as a positive reference. Cell viability was evaluated through the standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Measurements of cellular TYR activity and melanin content were performed and related to changes in the transcriptional expression levels of melanogenesis-related genes, assessed via quantitative real-time reverse transcriptase (RT-q)PCR analysis. The results revealed that piperine at a concentration of 44 μM significantly reduced cellular TYR activity by 21.51 ± 2.00 % without causing cytotoxicity. Additionally, at the same concentration, piperine significantly decreased the intracellular melanin content by 37.52 ± 2.53 % through downregulating transcription levels of TYR and TYR-related protein 1 (TRP-1) but not TRP-2. Kojic acid, at a concentration of 1407 μM, induced a significant decrease in the melanin content and cellular TYR activity by suppressing all three melanogenesis-related genes. These findings suggest that piperine has potential as a potent depigmenting agent.

An Overview of the Spices Used for the Prevention and Potential Treatment of Gastric Cancer

Gastric cancer (GC) ranks third in terms of cancer-related deaths and is the fifth most commonly diagnosed type of cancer. Its risk factors include Helicobacter pylori infection, Epstein-Barr virus infection, the consumption of broiled and charbroiled animal meats, salt-preserved and smoke-enhanced foods, alcohol drinking, tobacco smoking, exposure to ionizing radiation, and positive family history. The limited effectiveness of conventional therapies and the widespread risk factors of GC encourage the search for new methods of treatment and prevention. In the quest for cheap and commonly available medications, numerous studies focus on herbal medicine, traditional brews, and spices. In this review, we outline the potential use of spices, including turmeric, ginger, garlic, black cumin, chili pepper, saffron, black pepper, rosemary, galangal, coriander, wasabi, cinnamon, oregano, cardamom, fenugreek, caraway, clove, dill, thyme, Piper sarmentosum, basil, as well as the compounds they contain, in the prevention and treatment of GC. We present the potential molecular mechanisms responsible for the effectivity of a given seasoning substance and their impact on GC cells. We discuss their potential effects on proliferation, apoptosis, and migration. For most of the spices discussed, we also outline the unavailability and side effects of their use.

Comprehensive review of the phytochemistry, pharmacology, pharmacokinetics, and toxicology of alkamides (2016-2022)

Alkamides refer to a class of natural active small-molecule products composed of fatty acids and amine groups. These compounds are widely distributed in plants, and their unique structures and various pharmacological activities have caught the attention of scholars. This review provides a collection of literatures related to the phytochemistry, pharmacological effects, pharmacokinetics, and toxicity of alkamides published in 2016-2022 and their summary to provide references for further development of this class of ingredients. A total of 234 components (including chiral isomers) were summarized, pharmacological activities, such as anti-inflammatory, antitumor, antidiabetic, analgesic, neuroprotective, insecticidal, antioxidant, and antibacterial, and miscellaneous properties of alkamides were discussed. In addition, the pharmacokinetic characteristics and toxicity of alkamides were reviewed. However, information on the pharmacological mechanisms of the action, drug safety, and pharmacokinetics of alkamides is limited and thus requires further investigation and evaluation.

Limosomes versus hyalurolimosomes loaded with piperine for management of skin cancer

Skin cancer is considered the fifth most commonly occurring cancer worldwide hampering both health and economy. Piperine had proven efficacy in fighting skin cancer cells. Unfortunately, this natural agent had limited ability to penetrate the skin. The aim of the current study was to formulate piperine-loaded limosomes and hyalurolimosomes incorporating limonene as an edge activator and hyaluronic acid as bioactive gelling agent for managing skin cancer. Titration method followed by homogenization was adopted to prepare the nanoliposomal formulations. Characterization involved size, & zeta potential measurements, examination using transmission electron microscope (TEM) and stability study. Biological evaluation of the antitumor activity of piperine nanoliposomal formulations against Ehrlich's (EAC) solid tumor was also performed. Drug loaded limosomes and hyalurolimosomes had particle size; 346.55 ± 8.55 & 372.70 ± 10.83 nm, respectively. Zeta potential was high enough to ensure their stability. TEM micrographs detected the surrounding layer of Hyaluronic acid formed around the spherical limosomal nano-carrier ensuring the formation of Hyalurolimosomes. All stored formulations showed non-significant differences compared with freshly prepared ones at p < 0.05. In addition, A DAD-HPLC method was developed and validated for Piperine analysis in the skin. Upon application of this method, it was found that hyalurolimosomes deliver double the concentration delivered by limosomes. The piperine hyalurolimosome group showed a significant reduction in tumor size with a smaller AUC compared to piperine gel, which was confirmed by in vivo studies. Consequently, hyalurolimosomes loaded with piperine is considered a promising nanocarrier system and a step forward better management of skin cancer introducing new hope in beating this deadly disease.

The mechanisms of action of mitochondrial targeting agents in cancer: inhibiting oxidative phosphorylation and inducing apoptosis

The tumor microenvironment affects the structure and metabolic function of mitochondria in tumor cells. This process involves changes in metabolic activity, an increase in the amount of reactive oxygen species (ROS) in tumor cells compared to normal cells, the production of more intracellular free radicals, and the activation of oxidative pathways. From a practical perspective, it is advantageous to develop drugs that target mitochondria for the treatment of malignant tumors. Such drugs can enhance the selectivity of treatments for specific cell groups, minimize toxic effects on normal tissues, and improve combinational treatments. Mitochondrial targeting agents typically rely on small molecule medications (such as synthetic small molecules agents, active ingredients of plants, mitochondrial inhibitors or autophagy inhibitors, and others), modified mitochondrial delivery system agents (such as lipophilic cation modification or combining other molecules to form targeted mitochondrial agents), and a few mitochondrial complex inhibitors. This article will review these compounds in three main areas: oxidative phosphorylation (OXPHOS), changes in ROS levels, and endogenous oxidative and apoptotic processes.

Investigation of target genes and potential mechanisms related to compound Xiao-ai-fei honey ointment based on network pharmacology and bioinformatics analysis

BACKGROUND

Compound Xiao-ai-fei honey ointment (CXHO) is an anticancer preparation with a long history in Uyghur folk medicine in China and has been used for the treatment of gastric cancer (GC) in Xinjiang, China. Nevertheless, the mechanism of its anticancer effect remains to be investigated.

METHODS

Bioactive ingredients of CXHO were retrieved from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform database. Target genes of ingredients were acquired via the PubChem and Swiss target prediction database. Gene expression profiling of GC was obtained from GSE54129 in the GEO database and analyzed using the limma package in R. The hub genes associated with CXHO in GC were validated using the TIMER2.0 database, GEPIA2 database and Auto Dock tools. The effect of CXHO on migration of GC cells was detected by Transwell chamber assay and Wound healing assay. The effect of CXHO on expression levels of MMP2/MMP9 and NF-κb, PI3K/AKT signaling pathway was detected by Western blot assay.

RESULTS

Forty-five bioactive ingredients and their 819 related genes were found. A total of 462 differentially expressed genes were identified between GC patients and healthy controls. Seventeen common target genes were identified as hub genes CXHO against GC. Among them, MMP2 and MMP9 were significantly associated with tumor immune infiltrates and had good binding affinity with effective ingredients. Moreover, we validated the mRNA and protein expression levels and prognostic value of MMP2 and MMP9 by different databases. In addition, Kyoto encyclopedia of genes and genomes and gene ontology analyses showed that the 17 common target genes were mainly involved in steroid hormone biosynthesis and cancer-related pathways. Experimental results showed that CXHO inhibited migration of GC cells and down regulated the expression levels of MMP2/MMP9, NF-κb. In addition, CXHO can inhibited PI3K/AKT signaling pathway.

CONCLUSION

We identified and experimental validated 2 pivotal target genes of CXHO against GC and preliminarily analyzed the potential mechanisms by which CXHO inhibits the development of GC. All these findings support CXHO as a promising drug for the treatment of GC.

Extraction, Characterization, and Evaluation of the Cytotoxic Activity of Piperine in Its Isolated form and in Combination with Chemotherapeutics against Gastric Cancer

Gastric cancer is one of the most frequent types of neoplasms worldwide, usually presenting as aggressive and difficult-to-manage tumors. The search for new structures with anticancer potential encompasses a vast research field in which natural products arise as promising alternatives. In this scenario, piperine, an alkaloid of the Piper species, has received attention due to its biological activity, including anticancer attributes. The present work proposes three heating-independent, reliable, low-cost, and selective methods for obtaining piperine from Piper nigrum L. (Black pepper). Electronic (SEM) and optical microscopies, X-ray diffraction, nuclear magnetic resonance spectroscopies (¹³C and ¹H NMR), and optical spectroscopies (UV-Vis, photoluminescence, and FTIR) confirm the obtention of piperine crystals. The MTT assay reveals that the piperine samples exhibit good cytotoxic activity against primary and metastasis models of gastric cancer cell lines from the Brazilian Amazon. The samples showed selective cytotoxicity on the evaluated models, revealing higher effectiveness in cells bearing a higher degree of aggressiveness. Moreover, the investigated piperine crystals demonstrated the ability to act as a good cytotoxicity enhancer when combined with traditional chemotherapeutics (5-FU and GEM), allowing the drugs to achieve the same cytotoxic effect in cells employing lower concentrations. These results establish piperine as a promising molecule for therapy investigations in aggressive gastric cancer, both in its isolated form or as a bioenhancer.

Development of o-aminobenzamide salt derivatives for improving water solubility and anti-undifferentiated gastric cancer

Background: Gastric cancer is one of the cancers with wide incidence, difficult treatment and high mortality in the world, especially in Asia and Africa. In our previous work, a novel o-aminobenzamide analogue F8 was identified as an early preclinical candidate for treatment of undifferentiated gastric cancer (IC₅₀ of 0.26 μM for HGC-27). However, the poor water solubility of compound F8 prevents its further progress in preclinical studies. Aim: To improve the water solubility and drug-likeness of F8 via salt formation. Method: Different acids and F8 were reacted to obtain different salt forms. Physicochemical property screening, pharmacokinetic property research, and antitumor biological activity evaluation in vitro and in vivo were used to obtain the optimal salt form with the best druggability. Results: our continuous efforts have finally confirmed F8·2HCl as the optimal salt form with maintained in vitro antitumor activity, improved water solubility and pharmacokinetic properties. Importantly, the F8·2HCl displayed superior in vivo antitumor efficacy (TGI of 70.1% in 75 mg/kg) in HGC-27 xenograft model. The further immunohistochemical analysis revealed that F8·2HCl exerts an antitumor effect through the regulation of cell cycle-related protein (CDK2 and p21), apoptosis-related protein Cleaved Caspase-3, proliferation marker Ki67, and cell adhesion molecule E-cadherin. In addition, F8·2HCl showed acceptable safety in the in vivo acute toxicity assay. Conclusion: Salting is an effective means to improve the drug-like properties of compound F8, and F8·2HCl can serve as a promising therapeutic agent against undifferentiated gastric cancer.

Natural products targeting signaling pathways associated with regulated cell death in gastric cancer: Recent advances and perspectives

Gastric cancer (GC) is one of the most serious gastrointestinal malignancies with high morbidity and mortality. The complexity of GC process lies in the multi-phenotypic linkage regulation, in which regulatory cell death (RCD) is the core link, which largely dominates the fate of GC cells and becomes a key determinant of GC development and prognosis. In recent years, increasing evidence has been reported that natural products can prevent and inhibit the development of GC by regulating RCDs, showing great therapeutic potential. In order to further clarify its key regulatory characteristics, this review focused on specific expressions of RCDs, combined with a variety of signaling pathways and their crosstalk characteristics, sorted out the key targets and action rules of natural products targeting RCD. It is highlighted that a variety of core biological pathways and core targets are involved in the decision of GC cell fate, including the PI3K/Akt signaling pathway, MAPK-related signaling pathways, p53 signaling pathway, ER stress, Caspase-8, gasdermin D (GSDMD), and so on. Moreover, natural products target the crosstalk of different RCDs by modulating above signaling pathways. Taken together, these findings suggest that targeting various RCDs in GC with natural products is a promising strategy, providing a reference for further clarifying the molecular mechanism of natural products treating GC, which warrants further investigations in this area.

Natural products in digestive tract tumors metabolism: Functional and application prospects

Digestive tract diseases are presently the hotspot of clinical diagnosis and treatment, and the incidence of digestive tract tumor is increasing annually. Surgery remains the main therapeutic schedule for digestive tract tumor. Though benefits were brought by neoadjuvant chemotherapy, a part of patients lose the chance of surgery because of late detection or inappropriate intervention. Therefore, the treatment of inoperable patients has become an urgent need. At the same time, tumor metabolism is an extremely complex and diverse process. Natural products are confirmed effective to inhibit the development of tumors in vitro and in vitro. There are many kinds of natural products and their functions remain not clear. However, some natural products such as polyphenols have been proven to have definite anti-cancer effects, and some terpenoids have definite anti-inflammatory, anti-ulcer, anti-tumor, and other effects. Therefore, the anti-tumor characteristics of natural products should arouse our high attention. Although there are many obstacles to study the activities of natural products in tumor, including the difficulty in detection or distinguishing each component due to their low levels in tumor tissue, etc., the emergence of highly sensitive and locatable spatial metabolomics make the research and application of natural products a big step forward. In this review, natural products such as phenols, terpenoids and biotinoids were summarized to further discuss the development and therapeutic properties of natural metabolites on digestive tract tumors.

Promising Strategy of mPTP Modulation in Cancer Therapy: An Emerging Progress and Future Insight

Cancer has been progressively a major global health concern. With this developing global concern, cancer determent is one of the most significant public health challenges of this era. To date, the scientific community undoubtedly highlights mitochondrial dysfunction as a hallmark of cancer cells. Permeabilization of the mitochondrial membranes has been implicated as the most considerable footprint in apoptosis-mediated cancer cell death. Under the condition of mitochondrial calcium overload, exclusively mediated by oxidative stress, an opening of a nonspecific channel with a well-defined diameter in mitochondrial membrane allows free exchange between the mitochondrial matrix and the extra mitochondrial cytosol of solutes and proteins up to 1.5 kDa. Such a channel/nonspecific pore is recognized as the mitochondrial permeability transition pore (mPTP). mPTP has been established for regulating apoptosis-mediated cancer cell death. It has been evident that mPTP is critically linked with the glycolytic enzyme hexokinase II to defend cellular death and reduce cytochrome c release. However, elevated mitochondrial Ca2+ loading, oxidative stress, and mitochondrial depolarization are critical factors leading to mPTP opening/activation. Although the exact mechanism underlying mPTP-mediated cell death remains elusive, mPTP-mediated apoptosis machinery has been considered as an important clamp and plays a critical role in the pathogenesis of several types of cancers. In this review, we focus on structure and regulation of the mPTP complex-mediated apoptosis mechanisms and follow with a comprehensive discussion addressing the development of novel mPTP-targeting drugs/molecules in cancer treatment.

Piperine improves the sensitivity of osteosarcoma cells to doxorubicin by inducing apoptosis and inhibiting the PI3K/AKT/GSK-3β pathway

BACKGROUND

Osteosarcoma is a primary bone malignancy associated with the highest incidence rate. Chemotherapy for osteosarcoma has not substantially changed, and survival of patients with metastatic tumours has reached a plateau. Doxorubicin (DOX) is a broad-spectrum anti-osteosarcoma drug; however, its application is limited due to its high cardiotoxicity. Piperine (PIP) has been verified to drive certain cancer cell death and increases chemosensitivity of DOX. However, the effects of PIP in promoting the chemosensitivity of osteosarcoma to DOX have not been studied.

METHODS

We examined the combined effect of PIP and DOX on U2OS and 143B osteosarcoma cells. CCK-8 assays, scratch assays, flow cytometry analysis, and western blotting were performed. Furthermore, the effect of PIP combined with DOX on osteosarcoma tumours was observed in vivo using nude mice.

RESULTS

PIP can increase the chemosensitivity of U2OS and 143B cells to DOX. Both in vitro and in vivo results showed the dramatic inhibition of cell proliferation and tumour growth by the combined therapy group compared to monotherapy groups. Apoptosis analysis revealed that PIP augments DOX-induced cell apoptosis by upregulating BAX and P53 expression, as well as reducing Bcl-2 expression. Furthermore, PIP also attenuated the initiation of the PI3K/AKT/GSK-3β signaling pathway in osteosarcoma cells by altering the expression levels of P-AKT, P-PI3K and P-GSK3β.

CONCLUSIONS

This study revealed for the first time that PIP can potentiate the sensitivity and cytotoxicity of DOX during osteosarcoma therapy in vitro and in vivo, which probably achieved by inhibiting the PI3K/AKT/GSK-3β signalling pathway.

Immunometabolic attributes and mitochondria-associated signaling of Tumor-Associated Macrophages in tumor microenvironment modulate cancer progression

Macrophages are specialized immune cells, which have the capacity to phagocytize and destroy the target cells, including tumor cells. Some macrophages, however on their way to devour the cancer cells undergo a change due to a complex set of signaling pathways. They are induced to change into a polarized state known as M2. The M2 macrophages help in metastasis, tumor suppression, and angiogenesis. The macrophage which gets associated with this TME, are referred to as tumor-associated macrophages (TAMs). TAMS undergo a metabolic reprogramming toward oxidative metabolism for bioenergetic purposes (OXPHOS), fatty acid oxidation (FAO), decreased glycolysis, decreased metabolism via the PPP, and upregulation of arginase 1 (ARG1) which triggers immunosuppressive pro-tumor signaling in the tumor microenvironment (TME) in which mitochondria plays an instrumental role. Reports have suggested that a complex series of interactions and exchange of materials, such as cytokines, metabolic intermediates and sometimes even transfer of mitochondria take place between TAMS and other TME components most importantly cancer cells that reprogram their metabolism to encourage cell growth, division, epithelial to mesenchymal transition, that ultimately play an important role in tumor progression. This review will try to focus on the crosstalk between the TAMs with several other components of TME, what instrumental role mitochondria play in that and also try to explore some of the therapeutic options available in cancer patients.

Anti-tumor pharmacology of natural products targeting mitosis

Cancer has been an insurmountable problem in the history of medical science. The uncontrollable proliferation of cancer cells is one of cancer’s main characteristics, which is closely associated with abnormal mitosis. Targeting mitosis is an effective method for cancer treatment. This review summarizes several natural products with anti-tumor effects related to mitosis, focusing on targeting microtubulin, inducing DNA damage, and modulating mitosis-associated kinases. Furthermore, the main disadvantages of several typical compounds, including drug resistance, toxicity to non-tumor tissues, and poor aqueous solubility and pharmacokinetic properties, are also discussed, together with strategies to address them. Improved understanding of cancer cell mitosis and natural products may pave the way to drug development for the treatment of cancer.

Design and Synthesis of Novel Celastrol Derivatives as Potential Anticancer Agents against Gastric Cancer Cells

Gastric cancer (GC) is a common malignant disease worldwide, and finding novel agents and strategies for the treatment of GC are of urgent need. Celastrol (CEL) is a well-known natural product with antineoplastic activity. In this study, pyrazole analogues were introduced at the C-29 position of CEL. A total of 24 new derivatives were designed, synthesized, and evaluated for their mechanism and antitumor activity in vitro and in vivo. Among them, compound 21 exhibited the best activity against BGC-823 cells (IC₅₀ = 0.21 ± 0.01 μM). Further biological studies showed that 21 significantly raised the reactive oxygen species (ROS) levels to activate the apoptotic pathway, causing mitochondrial dysfunction in BGC-823 cells. In addition, 21 also arrested cells in the G2/M phase to induce tumor cell apoptosis. In a nude mouse tumor xenograft model, 21 exhibited a better tumor inhibition rate (89.85%) than CEL (inhibition rate 76.52%). Taken together, the present study has provided an anticancer lead compound candidate, 21, and has revealed that increased ROS generation may be an effective strategy in the treatment of GC.

Mechanism of piperine in affecting apoptosis and proliferation of gastric cancer cells via ROS-mitochondria-associated signalling pathway

Piperine (PIP), the main active ingredient in pepper, belongs to the cinnamamide alkaloid. PIP has been found to have functions, including anti-oxidation, immune regulation, anti-tumour and promotion of drug metabolism. The present study was mainly designed to reveal the anti-tumour effect of PIP against gastric cancer and the relevant mechanism. In brief, the undifferentiated human gastric cancer cell HGC-27 was used, which was treated with different concentrations of PIP. As a result, PIP could inhibit proliferation and induce apoptosis of HGC-27 cells in a dose-dependent manner. The mechanism of PIP was associated with ROS increase and mitochondrial damage, simultaneously, the expression of key proteins of apoptosis was affected, including Bcl-2, Bax, Cyt-c, Caspase-9 and Caspase-3. Pre-treatment of ROS scavenger NAC HGC-27 cells could significantly reduce PIP-induced apoptosis and inhibit the activation of apoptotic signals. Consistently, PIP could induce ROS to increase and activate apoptotic signals in the animal model. Therefore, the present study showed that PIP can induce the generation of ROS, thereby promoting the activation of mitochondrial apoptotic pathway and exerting anti-tumour effects.