Piperine: role in prevention and progression of cancer

Preparation, pungency and bioactivity transduction of piperine from black pepper (Piper nigrum L.): A comprehensive review

Piperine, derived from black pepper (Piper nigrum L.), is responsible for the pungent sensation. The diverse bioactivities of piperine underscores its promising potential as a functional food ingredient. This review presents a comprehensive overview of the research progress in extraction, synthesis, pungency transduction mechanism and bioactivities of piperine. Piperine can be extracted through various methods, such as traditional, modern, and innovative extraction techniques. Its synthesis mainly included both chemical and biosynthetic approaches. It exhibits a diverse range of bioactivities, including anticancer, anticonvulsant, antidepressant, anti-inflammatory, antioxidant, immunomodulatory, anti-obesity, neuroprotective, antidiabetic, hepatoprotective, and cardiovascular protective activities. Piperine can bind to TRPV1 receptor to elicit pungent sensation. Overall, the present review can provide a theoretical reference for advancing the potential application of piperine in the field of food science.

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.

Piperine, a black pepper compound, induces autophagy and cellular senescence mediated by NF-κB and IL-6 in acute leukemia

Acute leukemia is characterized by abnormal white blood cell proliferation with rapid onset and severe complications. Natural compounds, which are alternative treatments, are widely used in cancer treatment. Piperine, an alkaloid compound from black pepper, exerts anticancer effects through the cell death signaling pathway. Autophagy and senescence signaling pathways are considered target signaling pathways for cancer treatment. In this study, we investigated the effects of piperine via autophagy and senescence signaling pathways in NB4 and MOLT-4 cells. The MTT assay results demonstrated that piperine significantly decreased the viability of NB4 and MOLT-4 cells. Piperine induced autophagy by increasing LC3, Beclin-1 and ULK1 and decreasing mTOR and NF-κB1 expression in NB4 and MOLT-4 cells. In addition, piperine increased senescence-associated beta-galactosidase fluorescence intensity by increasing p21 and IL-6 expression while decreasing CDK2 expression in NB4 and MOLT-4 cells. In conclusion, our study provides additional information about the induction of autophagy and senescence by piperine in acute leukemia.

Alkaloids in Cancer therapy: Targeting the tumor microenvironment and metastasis signaling pathways

The use of phytomedicine in cancer therapy is a growing field of research that takes use of the medicinal properties of plant-derived compounds. Under the domain of cancer therapy and management, alkaloids, a prominent group of natural compounds, have showed significant potential. Alkaloids often affect a wide range of essential cellular mechanisms involved in cancer progression. These multi-targeting capabilities, can give significant advantages to alkaloids in overcoming resistance mechanisms. For example, berberine, an alkaloid found in Berberis species, is widely reported to induce apoptosis by activating caspases and regulating apoptotic pathways. Notably, alkaloids like as quinine have showed promise in inhibiting the formation of new blood vessels required for tumor growth. In addition, alkaloids have shown anti-proliferative and anticancer properties mostly via modulating key signaling pathways involved in metastasis, including those regulating epithelial-mesenchymal transition. This work provides a comprehensive overview of naturally occurring alkaloids that exhibit anticancer properties, with a specific emphasis on their underlying molecular mechanisms of action. Furthermore, many methods to modify previously reported difficult physicochemical properties using nanocarriers in order to enhance its systemic bioavailability have been discussed as well. This study also includes information on newly discovered alkaloids that are now being studied in clinical trials for their potential use in cancer treatment. Further, we have also briefly mentioned on the application of high-throughput screening and molecular dynamics simulation for acceleration on the identification of potent alkaloids based compounds to target and treat cancer.

Natural Products and Altered Metabolism in Cancer: Therapeutic Targets and Mechanisms of Action

Cancer is characterized by uncontrolled cell proliferation and the dysregulation of numerous biological functions, including metabolism. Because of the potential implications of targeted therapies, the metabolic alterations seen in cancer cells, such as the Warburg effect and disruptions in lipid and amino acid metabolism, have gained attention in cancer research. In this review, we delve into recent research examining the influence of natural products on altered cancer metabolism. Natural products were selected based on their ability to target cancer's altered metabolism. We identified the targets and explored the mechanisms of action of these natural products in influencing cellular energetics. Studies discussed in this review provide a solid ground for researchers to consider natural products in cancer treatment alone and in combination with conventional anticancer therapies.

Michael Acceptors as Anti-Cancer Compounds: Coincidence or Causality?

Michael acceptors represent a class of compounds with potential anti-cancer properties. They act by binding to nucleophilic sites in biological molecules, thereby disrupting cancer cell function and inducing cell death. This mode of action, as well as their ability to be modified and targeted, makes them a promising avenue for advancing cancer therapy. We are investigating the molecular mechanisms underlying Michael acceptors and their interactions with cancer cells, in particular their ability to interfere with cellular processes and induce apoptosis. The anti-cancer properties of Michael acceptors are not accidental but are due to their chemical structure and reactivity. The electrophilic nature of these compounds allows them to selectively target nucleophilic residues on disease-associated proteins, resulting in significant therapeutic benefits and minimal toxicity in various diseases. This opens up new perspectives for the development of more effective and precise cancer drugs. Nevertheless, further studies are essential to fully understand the impact of our discoveries and translate them into clinical practice.

Molecular Aspects of Piperine in Signaling Pathways Associated with Inflammation in Head and Neck Cancer

Piperine, an active plant alkaloid from black pepper (Piper nigrum), has several pharmacological effects, namely antioxidant, anti-inflammatory and immunomodulatory effects, which involve inhibiting molecular events associated with various stages of cancer development. The aim of this study was to investigate the molecular mechanisms of action of piperine in relation to its potential anticancer effect on head and neck cancer cells. Parameters related to neoplastic potential and cytokine, protein and gene expression were investigated in head and neck cancer cell lines (HEp-2 and SCC-25) treated with piperine. The results of the tests indicated that piperine modified morphology and inhibited viability and the formation of cell colonies. Piperine promoted genotoxicity by triggering apoptosis and cell cycle arrest in the G2/M and S phases. A decrease in cell migration was also observed, and there was decreased expression of MMP2/9 genes. Piperine also reduced the expression of inflammatory molecules (PTGS2 and PTGER4), regulated the secretion of cytokines (IFN-γ and IL-8) and modulated the expression of ERK and p38. These results suggest that piperine exerts anticancer effects on tumor cells by regulating signaling pathways associated with head and neck cancer.

Investigation on the Effect of Fluorescence Quenching of Calf Thymus DNA by Piperine: Caspase Activation in the Human Breast Cancer Cell Line Studies

In this study, we determined the interaction of piperine and calf thymus DNA (ct DNA) in Tris-HCl buffer solution at pH = 6.8 and also evaluated the binding mechanism through the data of multi-spectroscopic techniques along with thermal melting and viscosity measurements. The outcomes of fluorescence quenching confirmed the occurrence of interactions between piperine and ctDNA and pointed out the role of piperine as the quencher. In addition, the KSV values were measured at three different temperatures of 298, 303, and 308 K to be 4.5 × 107 M-1, 5.65 × 107 M-1, and 9.36 × 107 M-1, respectively, which suggested the dominance of dynamic mechanism as the fluorescence quenching of piperine-ctDNA. The thermodynamic parameters revealed the predominance of hydrophobic forces in the interaction of ctDNA with piperine. According to the resonance light scattering data, the formation of a complex between piperine and ctDNA led to the creation of a larger particle. Ethidium bromide (EB) and acridine orange (AO) displacement studies, along with the ionic effects of NaCl and KI assessments, confirmed the interaction of piperine-ctDNA through a groove binding mode. The melting temperature assay of ctDNA upon the addition of piperine concentration indicated the probable groove binding of piperine to ctDNA, which was affirmed by relative viscosity measurement as well. The lack of detecting any alterations in the circular dichroism (CD) spectrum of CD investigation verified as a characteristic sign of groove binding mechanism and also confirmed all the experimental results with regard to the binding of piperine-ctDNA complex. Next to observing a concentration and time-dependent cytotoxicity in MDA-MB-231 cells, the impact of piperine on increasing lipid peroxidation and decreasing the activity of superoxide dismutase was also noticed. Apparently, piperine is capable of inducing caspase-3 activity as well.

Advanced application of nanotechnology in active constituents of Traditional Chinese Medicines

Traditional Chinese Medicines (TCMs) have been used for centuries for the treatment and management of various diseases. However, their effective delivery to targeted sites may be a major challenge due to their poor water solubility, low bioavailability, and potential toxicity. Nanocarriers, such as liposomes, polymeric nanoparticles, inorganic nanoparticles and organic/inorganic nanohybrids based on active constituents from TCMs have been extensively studied as a promising strategy to improve the delivery of active constituents from TCMs to achieve a higher therapeutic effect with fewer side effects compared to conventional formulations. This review summarizes the recent advances in nanocarrier-based delivery systems for various types of active constituents of TCMs, including terpenoids, polyphenols, alkaloids, flavonoids, and quinones, from different natural sources. This review covers the design and preparation of nanocarriers, their characterization, and in vitro/vivo evaluations. Additionally, this review highlights the challenges and opportunities in the field and suggests future directions for research. Nanocarrier-based delivery systems have shown great potential in improving the therapeutic efficacy of TCMs, and this review may serve as a comprehensive resource to researchers in this field.

Development of Statistically Optimized Piperine-Loaded Polymeric Nanoparticles for Breast Cancer: In Vitro Evaluation and Cell Culture Studies

Piperine (PPN) is a natural alkaloid derived from black pepper (Piper nigrum L.) and has garnered substantial attention for its potential in breast cancer therapy due to its diverse pharmacological properties. However, its highly lipophilic characteristics and poor dissolution in biological fluids limit its clinical application. Therefore, to overcome this limitation, we formulate and evaluate PPN-encapsulated polycaprolactone (PCL) nanoparticles (PPN-PCL-NPs). The nanoparticles were prepared by a single-step nanoprecipitation method and further optimized by a formulation design approach. The influence of selected independent variables PCL (X1), poloxamer 188 (P-188; X2), and stirring speed (SS; X3) were investigated on the particle size (PS), polydispersity index (PDI), and % encapsulation efficiency (EE). The selected optimized nanoparticles were further assessed for stability, in vitro release, and in vitro antibreast cancer activity in the MCF-7 cancer cell line. The PS, PDI, zeta potential, and % EE of the optimized PPN-PCL-NPs were observed to be 107.61 ± 5.28 nm, 0.136 ± 0.011, -20.42 ± 1.82 mV, and 79.53 ± 5.22%, respectively. The developed PPN-PCL-NPs were stable under different temperature conditions with insignificant changes in their pharmaceutical attributes. The optimized PPN-PCL-NPs showed a burst release for the first 6 h and later showed sustained release for 48 h. The PPN-PCL-NPs exhibit exceptional cytotoxic effects in MCF-7 breast tumor cells in comparison with the native PPN. Thus, the formulation of PPN-loaded PCL-NPs can be a promising approach for better therapeutic efficacy against breast cancer.

The anticancer and anti-inflammatory activity screening of pyridazinone-based analogs against human epidermoid skin cancer with detailed mechanistic analyses

3(2H)-Pyridazinone derivatives based on 4-biphenyl, naphtha-2-yl, pyridine, or piperidine moiety were synthesized and characterized using I-R and 1HNMR spectra. The activity and cytotoxicity of some synthesized compounds on the skin epidermoid cancer cell proliferation and progression were investigated. The pyridazine isomer with pyridine revealed a significant decrease in the level of nitric oxide p < 0.01 than the activity of caffeine phenecyl ester. The activity of the three active isomers recorded significant activity for their total antioxidant content that triggers their ability for the scavenging the oxygen free radicals significantly p < 0.01. Moreover, revealing the pharmaceutical activity of the isomers as anti-inflammatory agents, IL-6, IL10, and IL12 have been decreased by variable significant values. Additionally, the active isomers revealed variable actions on the skin cancer cell to induce apoptosis using annexin V-FITC/PI. Pyridine was the highest isomer to induce late apoptosis and necrosis for the skin cancer cells against the use of cisplatin. Importantly, Molecular modeling experiments including docking and dynamic simulations were done for the most active 3 analogs to explore the ligand binding and stability leading to exploring the structure-activity relationship with biological target PARP1 which showed a good binding propensity to pyridazine binding site which supports the in vitro data. In conclusion, the pyridazine moieties with piperdine, naphthayl, and pyridine have pharmacological activities against skin cancer epidermoid by triggering action in inhibition of the proliferation and progression with an up-regulated apoptotic mechanism that evades the emergence of cisplatin resistance among different cancer cells.Communicated by Ramaswamy H. Sarma.

Piperine Induces Apoptosis and Autophagy in HSC-3 Human Oral Cancer Cells by Regulating PI3K Signaling Pathway

Currently, therapies for treating oral cancer have various side effects; therefore, research on treatment methods employing natural substances is being conducted. This study aimed to investigate piperine-induced apoptosis and autophagy in HSC-3 human oral cancer cells and their effects on tumor growth in vivo. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay demonstrated that piperine reduced the viability of HSC-3 cells and 4',6-diamidino-2-phenylindole staining, annexin-V/propidium iodide staining, and analysis of apoptosis-related protein expression confirmed that piperine induces apoptosis in HSC-3 cells. Additionally, piperine-induced autophagy was confirmed by the observation of increased acidic vesicular organelles and autophagy marker proteins, demonstrating that autophagy in HSC-3 cells induces apoptosis. Mechanistically, piperine induced apoptosis and autophagy by inhibiting the phosphatidylinositol-3-kinase (PI3K)/protein kinase B/mammalian target of rapamycin pathway in HSC-3 cells. We also confirmed that piperine inhibits oral cancer tumor growth in vivo via antitumor effects related to apoptosis and PI3K signaling pathway inhibition. Therefore, we suggest that piperine can be considered a natural anticancer agent for human oral cancer.

Natural compounds targeting nuclear receptors for effective cancer therapy

Human nuclear receptors (NRs) are a family of forty-eight transcription factors that modulate gene expression both spatially and temporally. Numerous biochemical, physiological, and pathological processes including cell survival, proliferation, differentiation, metabolism, immune modulation, development, reproduction, and aging are extensively orchestrated by different NRs. The involvement of dysregulated NRs and NR-mediated signaling pathways in driving cancer cell hallmarks has been thoroughly investigated. Targeting NRs has been one of the major focuses of drug development strategies for cancer interventions. Interestingly, rapid progress in molecular biology and drug screening reveals that the naturally occurring compounds are promising modern oncology drugs which are free of potentially inevitable repercussions that are associated with synthetic compounds. Therefore, the purpose of this review is to draw our attention to the potential therapeutic effects of various classes of natural compounds that target NRs such as phytochemicals, dietary components, venom constituents, royal jelly-derived compounds, and microbial derivatives in the establishment of novel and safe medications for cancer treatment. This review also emphasizes molecular mechanisms and signaling pathways that are leveraged to promote the anti-cancer effects of these natural compounds. We have also critically reviewed and assessed the advantages and limitations of current preclinical and clinical studies on this subject for cancer prophylaxis. This might subsequently pave the way for new paradigms in the discovery of drugs that target specific cancer types.

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 Curcumin and Piperine-Loaded Bio-Active Self-Nanoemulsifying Drugs and Investigation of Their Bioactivity in Zebrafish Embryos and Human Hematological Cancer Cell Lines

Purpose

Curcumin (CUR) and piperine (PP) are bioactive compounds with prominent pharmacological activities that have been investigated for the treatment of various diseases. The aim of the present study is to develop Bio-SNEDDS for CUR and PP as a combined delivery system for cancer therapy.

Methods

CUR and PP loaded Bio-SNEDDSs with varying compositions of bioactive lipid oils, surfactants, and cosolvents were prepared at room temperature. Bio-SNEDDSs were characterized using a Zetasizer Nano particle size analyzer and further examined by transmission electron microscopy (TEM) for morphology. The in vivo toxicity of the preparations of Bio-SNEDDS was investigated in wild-type zebrafish embryos and cytotoxicity in THP-1 (human leukemia monocytic cells), Jurkat (human T lymphocyte cells) and HUVEC (non-cancerous normal) cells.

Results

Bio-SNEDDSs were successfully developed with black seed oil, Imwitor 988, Transcutol P and Cremophor RH40 at a ratio of 20/20/10/50 (%w/w). The droplet size, polydispersity index and zeta potential of the optimized Bio-SNEDDS were found to be 42.13 nm, 0.59, and -19.30 mV, respectively. Bio-SNEDDS showed a spherical structure evident by TEM analysis. The results showed that Bio-SNEDDS did not induce toxicity in zebrafish embryos at concentrations between 0.40 and 30.00 μg/mL. In TG (fli1: EGFP) embryos treated with Bio-SNEDDS, there was no change in the blood vessel structure. The O-dianisidine staining of Bio-SNEDDS treated embryos at 48 h post-fertilization also showed a significant reduction in the number of blood cells compared to mock (DMSO 0.1% V/V) treated embryos. Bio-SNEDDS induced significant levels of cytotoxicity in the hematological cell lines THP-1 and Jurkat, while low toxicity in normal HUVEC cell lines was observed with IC50 values of 18.63±0.23 μg/mL, 26.03 ± 1.5 μg/mL and 17.52 ± 0.22 μg/mL, respectively.

Conclusion

Bio-SNEDDS exhibited enhanced anticancer activity and could thus be an important new pharmaceutical formulation to treat leukemia.

Piperine Liposome-Embedded in Hyaluronan Hydrogel as an Effective Platform for Prevention of Postoperative Peritoneal Adhesion

This study aimed to prepare piperine (PIP) loaded liposomes in hyaluronic acid (HA) hydrogel to provide a hybrid superstructure for postoperative adhesion prevention. Liposomes were prepared using thin-film hydration method. The optimised formulation was characterised by size, SEM, TEM, FTIR, encapsulation efficiency (EE)% (w/w), and release pattern. Liposome-in-hydrogel formulation was investigated by rheology, SEM, and release studies. The efficacy was evaluated in a rat peritoneal abrasion model. EE% (w/w) increased with increasing lipid concentration from 10 to 30; however, a higher percentage of Chol reduced EE% (w/w). The optimised liposome (EE: 68.10 ± 4.18% (w/w), average diameter: 513 ± 14.67 nm, PDI: 0.15 ± 0.04) was used for hydrogel embedding. No sign of adhesion in 5/8 rats and no collagen deposition confirmed the in vivo effectiveness of the optimised formulation. Overall, providing a sustained delivery of PIP, the developed liposome-in-hydrogel formulation can be a promising carrier to prevent postoperative adhesion.

Piperine Reduces Neoplastic Progression in Cervical Cancer Cells by Downregulating the Cyclooxygenase 2 Pathway

Cervical cancer is the fourth-most common type of cancer in the world that causes death in women. It is mainly caused by persistent infection by human papillomavirus (HPV) that triggers a chronic inflammatory process. Therefore, the use of anti-inflammatory drugs is a potential treatment option. The effects of piperine, an amino alkaloid derived from Piper nigrum, are poorly understood in cervical cancer inflammation, making it a target of research. This work aimed to investigate the antitumor effect of piperine on cervical cancer and to determine whether this effect is modulated by the cyclooxygenase 2 (PTGS2) pathway using in vitro model of cervical cancer (HeLa, SiHa, CaSki), and non-tumoral (HaCaT) cell lines. The results showed that piperine reduces in vitro parameters associated with neoplastic evolution such as proliferation, viability and migration by cell cycle arrest in the G1/G0 and G2/M phases, with subsequent induction of apoptosis. This action was modulated by downregulation of cyclooxygenase 2 (PTGS2) pathway, which in turn regulates the secretion of cytokines and the expression of mitogen-activated protein kinases (MAPKs), metalloproteinases (MMPs), and their antagonists (TIMPs). These findings indicate the phytotherapeutic potential of piperine as complementary treatment in cervical cancer.

Carboxymethyl starch as a solid dispersion carrier to enhance the dissolution and bioavailability of piperine and 18β-glycyrrhetinic acid

OBJECTIVE

To investigate the applicability of carboxymethyl starch (CMS) as a carrier to prepare solid dispersions (SDs) of piperine (PIP) and 18β-glycyrrhetinic acid (β-GA) (PIP-CMS and β-GA-CMS SDs) and to explore the influence of drug properties on carrier selection.

SIGNIFICANCE

The low oral bioavailability of natural therapeutic molecules, including PIP and β-GA, severely restricts their pharmaceutical applications. Moreover, CMS, a natural polymer, is rarely reported as a carrier for SDs.

METHODS

PIP-CMS and β-GA-CMS SDs were prepared using the solvent evaporation method. Differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) were used for formulation characterization. Additionally, drug release characteristics were investigated.

RESULTS

In vitro dissolution studies showed that the dissolutions of PIP-CMS and β-GA-CMS SDs were 1.90-2.04 and 1.97-2.22 times higher than pure PIP and β-GA, respectively, at a drug:polymer ratio of 1:6. DSC, XRPD, FT-IR, and SEM analyses confirmed the formation of SDs in their amorphous states. Significant improvements in C_max and AUC_0-24 h of PIP-CMS and β-GA-CMS SDs (17.51 ± 8.15 μg/mL and 210.28 ± 117.13 μg·h/mL, respectively) and (32.17 ± 9.45 μg/mL and 165.36 ± 38.75 μg·h/mL, respectively) were observed in the pharmacokinetic study. Compared with weakly acidic β-GA, loading weakly basic PIP seemed to have a profound effect on stability through intermolecular forces.

CONCLUSIONS

Our findings showed CMS could be a promising carrier for SDs, and loading weakly basic drug may be more suitable, especially in binary SDs system.

Role of natural P-gp inhibitor in the effective delivery for chemotherapeutic agents

Multi-drug resistance has shown to be one of the leading threats faced currently in many chemotherapeutic agents. Permeability glycoprotein (P-gp) is an efflux transporter in membrane, an integral part of ATP-binding cassette (ABC) transporters widely distributed in the body for cellular uptake. It is present enormously in cancerous cells and is in charge of generating transporter mediated resistance to treatments of tumorous cells in addition to blocking the entry of chemotherapeutic drugs into the cell. Natural P-gp inhibitors are derived from natural plant sources possessing basic structures like alkaloids, flavonoids, phenolics, terpenoids, saponins, sapogenins, sterols, coumarins and miscellaneous structures acting on P-gp substrate for inhibition of multi-drug resistance via inhibiting the efflux pump. They do not depict their action on the healthy cells and thus it is proven to be more effective and less toxic than synthetic P-gp inhibitor leading to enhancement in bioavailability of chemotherapeutic drugs. The significant objective of the present review is surfing through the impact of natural P-gp inhibitors having basic structures derived from the plant sources and how it inhibits the resistance of chemotherapeutic drugs together with how well it delivers chemotherapy medicines.

Curcumin Hybrid Lipid Polymeric Nanoparticles: Antioxidant Activity, Immune Cellular Response, and Cytotoxicity Evaluation

Poor solubility and short biological half-life present a challenge that needs to be overcome in order to improve the recognized bioactivities of curcumin (CUR), the main phenolic compounds derived from the roots of Curcuma longa. However, drug delivery systems have proven to be an excellent strategy to improve and obtain greater bioavailability. Our previous studies on curcuminoid hybrid nanoparticles have shown promising results by significantly increasing the solubility of desmethoxycurcumin (DMC) and bisdemethoxycurcumin (BDM). In this contribution, we performed a detailed characterization of a CUR as well as in vitro and in vivo studies. The developed method produced CUR loaded nanoparticles with an average size of 49.46 ± 0.80. Moreover, the FT-IR analysis confirmed the encapsulation, and TEM images showed their spherical shape. The NP achieved an encapsulation efficiency greater than 99%. Further, the release studies found that the NPs obtained a significantly higher release than the pure compounds in water. In vivo delayed-type hypersensitivity (DTH) studies showed promising results by enhancing the immune activity response of CUR in NP compared to bulk CUR. Furthermore, we report a significant increase in antioxidant activity for CUR-NP in aqueous solution compared to free CUR. Finally, an important in vitro cytotoxic effect on gastric AGS and colon SW620 adenocarcinoma cell lines was found for CUR-NP while empty carrier nanoparticles are observed to exhibit low cytotoxicity, indicating the potential of these CUR-PLU NPs for further studies to assess their phytotherapeutic applications.

Pectin coated Nanostructured Lipid Carriers for Targeted Piperine Delivery to Hepatocellular Carcinoma

Piperine (PIP) is a herbal drug with well-known anticancer activity against different types of cancer including hepatocellular carcinoma. However, low aqueous solubility and extensive first-pass metabolism limit its clinical use. In this study, positively charged PIP-loaded nanostructured lipid carriers (PIP-NLCs) were prepared via melt-emulsification and ultra-sonication method followed by pectin coating to get novel pectin-coated NLCs (PIP-P-NLCs) targeting hepatocellular carcinoma. Complete in vitro characterization was performed. In addition, cytotoxicity and cellular uptake of nanosystems in HepG2 cells were evaluated. Finally, in vivo anticancer activity was tested in the diethylnitrosamine-induced hepatocellular carcinoma mice model. Successful pectin coating was confirmed by an increased particle size of PIP-NLCs from 150.28±2.51 nm to 205.24±5.13 nm and revered Zeta potential from 33.34±3.52 mV to -27.63±2.05 mV. Nanosystems had high entrapment efficiency, good stability, spherical shape, and sustained drug release over 24 hours. Targeted P-NLCs enhanced the cytotoxicity and cellular uptake compared to untargeted NLCs. Furthermore, PIP-P-NLCs improved in vivo anticancer effect of PIP as proved by histological examination of liver tissues, suppression of liver enzymes and oxidative stress environment in the liver, and alteration of cell cycle regulators. To conclude, PIP-P-NLCs can act as a promising approach for targeted delivery of PIP to hepatocellular carcinoma.

Anticancer Applications and Pharmacological Properties of Piperidine and Piperine: A Comprehensive Review on Molecular Mechanisms and Therapeutic Perspectives

Piperine and piperidine are the two major alkaloids extracted from black pepper (Piper nigrum); piperidine is a heterocyclic moiety that has the molecular formula (CH₂)₅NH. Over the years, many therapeutic properties including anticancer potential of these two compounds have been observed. Piperine has therapeutic potential against cancers such as breast cancer, ovarian cancer, gastric cancer, gliomal cancer, lung cancer, oral squamous, chronic pancreatitis, prostate cancer, rectal cancer, cervical cancer, and leukemia. Whereas, piperidine acts as a potential clinical agent against cancers, such as breast cancer, prostate cancer, colon cancer, lung cancer, and ovarian cancer, when treated alone or in combination with some novel drugs. Several crucial signalling pathways essential for the establishment of cancers such as STAT-3, NF-κB, PI3k/Aκt, JNK/p38-MAPK, TGF-ß/SMAD, Smac/DIABLO, p-IκB etc., are regulated by these two phytochemicals. Both of these phytochemicals lead to inhibition of cell migration and help in cell cycle arrest to inhibit survivability of cancer cells. The current review highlights the pharmaceutical relevance of both piperine and piperidine against different types of cancers.

Therapeutic spectrum of piperine for clinical practice: a scoping review

Translation of traditional knowledge of herbs into a viable product for clinical use is still an uphill task. Piperine, a pungent alkaloid molecule derived from Piper nigrum and Piper longum possesses diverse pharmacological effects. Traditionally, pepper is used for arthritis, bronchitis, gastritis, diarrhea, snake bite, menstrual pain, fever, and bacterial infections, etc. The anti-inflammatory, antioxidant and immunomodulatory actions of piperine are the possible mechanisms behind its therapeutic potential. Various in-silico and experimental studies have shown piperine as a possible promising molecule in coronavirus disease (COVID-19), ebola, and dengue due to its immunomodulatory and antiviral activities. The other important clinical applications of piperine are due to its bio enhancing effect on drugs, by modulating, absorption in the gastrointestinal tract, altering activities of transporters like p-glycoprotein substrates, and modulating drug metabolism by altering the expression of cytochrome P450 or UDP-glucuronosyltransferase enzymes. Piperine attracted clinicians in treating patients with arthritis, metabolic syndrome, diabetes, skin infections, gastric and liver disorders. This review focused on systematic, evidence-based insight into the use of piperine in clinical settings and mechanistic details behind its therapeutic actions. Also, highlights a number of clinical trials of piperine at various stages exploring its clinical application in cancer, neurological, respiratory, and viral disease, etc.

Piperine for treating breast cancer: A review of molecular mechanisms, combination with anticancer drugs, and nanosystems

Piperine (PIP) is an alkaloid found primarily in Piper longum, and this natural compound has been shown to exert effects on proliferation and survival against various types of cancer. In particular, PIP has potent inhibitory effects on breast cancer (BC), the most prevalent type of cancer in women worldwide. PIP targets numerous signaling pathways associated with the therapy of BC cells through the following mechanisms: (a) induction of arrest of the cell cycle and apoptosis; (b) alteration of the signaling protein expression; (c) reduction in transcription factors; and (d) inhibition of tumor growth. BC cells have the ability to resist conventional drugs, so one of the strategies is the combination of PIP with other phytochemicals such as paclitaxel, thymoquinone, hesperidin, bee venom, tamoxifen, mitoxantrone, piperlongumin, and curcumin. Nanotechnology-based drug encapsulation systems are currently used to enhance the release of PIP. This includes polymer nanoparticles, carbon nanotubes, and liposomes. In the present review, the chemistry and bioavailability of PIP, its molecular targets in BC, and nanotechnological strategies are discussed. Future research directions are also discussed to further understand this promising natural product.

Brito L, Figueiredo MR, Soeiro MDNC. In Vitro Phenotypic Activity and In Silico Analysis of Natural Products from Brazilian Biodiversity on Trypanosoma cruzi

Chagas disease (CD) affects more than 6 million people worldwide. The available treatment is far from ideal, creating a demand for new alternative therapies. Botanical diversity provides a wide range of novel potential therapeutic scaffolds. Presently, our aim was to evaluate the mammalian host toxicity and anti-Trypanosoma cruzi activity of botanic natural products including extracts, fractions and purified compounds obtained from Brazilian flora. In this study, 36 samples of extracts and fractions and eight pure compounds obtained from seven plant species were evaluated. The fraction dichloromethane from Aureliana fasciculata var. fasciculata (AFfPD) and the crude extract of Piper tectoniifolium (PTFrE) showed promising trypanosomicidal activity. AFfPD and PTFrE presented EC50 values 10.7 ± 2.8 μg/mL and 12.85 ± 1.52 μg/mL against intracellular forms (Tulahuen strain), respectively. Additionally, both were active upon bloodstream trypomastigotes (Y strain), exhibiting EC50 2.2 ± 1.0 μg/mL and 38.8 ± 2.1 μg/mL for AFfPD and PTFrE, respectively. Importantly, AFfPD is about five-fold more potent than Benznidazole (Bz), the reference drug for CD, also reaching lower EC90 value (7.92 ± 2.2 μg/mL) as compared to Bz (23.3 ± 0.6 μg/mL). Besides, anti-parasitic effect of eight purified botanic substances was also investigated. Aurelianolide A and B (compounds 1 and 2) from A. fasciculata and compound 8 from P. tuberculatum displayed the best trypanosomicidal effect. Compounds 1, 2 and 8 showed EC50 of 4.6 ± 1.3 μM, 1.6 ± 0.4 μM and 8.1 ± 0.9 μM, respectively against intracellular forms. In addition, in silico analysis of these three biomolecules was performed to predict parameters of absorption, distribution, metabolism and excretion. The studied compounds presented similar ADMET profile as Bz, without presenting mutagenicity and hepatotoxicity aspects as predicted for Bz. Our findings indicate that these natural products have promising anti-T. cruzi effect and may represent new scaffolds for future lead optimization.

Inhibitory effects of piperine on proliferation, migration, and invasion of human colon cancer SW480 cells

BACKGROUND

Many recent reports have shown that piperine has anticancer activity, but the specific roles and biological mechanisms of piperine in colon cancer are not well studied.

AIM

To investigate the effects and potential mechanisms of piperine on the proliferation, migration, and invasion of human colon cancer SW480 cells.

METHODS

SW480 cells were treated with 0 (blank control), 5, 10, and 20 μg/mL piperine for 24 h, respectively. Cell viability was detected by cell counting kit-8 (CCK-8) assay. Proliferation was detected by 5-ethynyl-2'-deoxyuridine (EDU) staining. Cell migration and invasion were detected by Transwell assay. The protein expression levels of microtubule-associated light chain 3 (LC3), p53, B cell lymphoma/lewkmia-2 (Bcl-2), Bcl-2 associated X protein (Bax), and cleaved cysteine aspartate proteinase-3 (Cleaved caspase 3) were detected by Western blotting.

RESULTS

Piperine inhibited cell viability, proliferation, migration, and invasion in a concentration-dependent manner. Western blot analysis showed that piperine increased the expression of p53, Bax, and Cleaved caspase 3 but decreased the expression of Bcl-2 in SW480 cells compared with control cells.

CONCLUSION

Piperine can inhibit the proliferation, migration, and invasion of SW480 cells, and the mechanism may be related to the up-regulation of p53 signaling pathway and the induction of autophagic cell death.

Piperine synergistically enhances the effect of temozolomide against temozolomide-resistant human glioma cell lines

Temozolomide (TMZ) is an alkylating chemotherapy agent used in the clinical treatment of glioblastoma multiforme (GBM) patients. Piperine (PIP) is a naturally occurring pungent nitrogenous substance present in the fruits of peppers. We investigated the anti-cancer efficacies of PIP alone and in combination with TMZ in GBM cellsusingparameters such as cell proliferation, cellular apoptosis,caspase-8/-9/-3 activities, cell cycle kinetics, wound-healing ability, and loss of mitochondrial membrane potential (MMP). Treatment with PIP and alow concentration of PIP-TMZ, inhibited cell growth, similar to TMZ.PIP-TMZ promoted apoptosis by activation of caspase-8/-9/-3, MMP loss, and inhibition of in vitro wound-healing motility. Reverse transcription polymerase chain reaction analysis showed significant inhibition of Cyclin-dependent kinases (CDK)4/6−cyclin D and CDK2−cyclin-E expression upon treatment with a low concentration PIP-TMZ, suggesting an S to G1 arrest. Our findings provide insight into the apoptotic potential of the combination of a low concentration of PIP-TMZ, though further in vivo study will be needed for its validation.

Formulation of Piperine-Chitosan-Coated Liposomes: Characterization and In Vitro Cytotoxic Evaluation

The present research work is designed to prepare and evaluate piperine liposomes and piperine–chitosan-coated liposomes for oral delivery. Piperine (PPN) is a water-insoluble bioactive compound used for different diseases. The prepared formulations were evaluated for physicochemical study, mucoadhesive study, permeation study and in vitro cytotoxic study using the MCF7 breast cancer cell line. Piperine-loaded liposomes (PLF) were prepared by the thin-film evaporation method. The selected liposomes were coated with chitosan (PLFC) by electrostatic deposition to enhance the mucoadhesive property and in vitro therapeutic efficacy. Based on the findings of the study, the prepared PPN liposomes (PLF3) and chitosan coated PPN liposomes (PLF3C1) showed a nanometric size range of 165.7 ± 7.4 to 243.4 ± 7.5, a narrow polydispersity index (>0.3) and zeta potential (−7.1 to 29.8 mV). The average encapsulation efficiency was found to be between 60 and 80% for all prepared formulations. The drug release and permeation study profile showed biphasic release behavior and enhanced PPN permeation. The in vitro antioxidant study results showed a comparable antioxidant activity with pure PPN. The anticancer study depicted that the cell viability assay of tested PLF3C2 has significantly (p < 0.001)) reduced the IC₅₀ when compared with pure PPN. The study revealed that oral chitosan-coated liposomes are a promising delivery system for the PPN and can increase the therapeutic efficacy against the breast cancer cell line.

Circulating amino acids and amino acid-related metabolites and risk of breast cancer among predominantly premenopausal women

Known modifiable risk factors account for a small fraction of premenopausal breast cancers. We investigated associations between pre-diagnostic circulating amino acid and amino acid-related metabolites (N = 207) and risk of breast cancer among predominantly premenopausal women of the Nurses' Health Study II using conditional logistic regression (1057 cases, 1057 controls) and multivariable analyses evaluating all metabolites jointly. Eleven metabolites were associated with breast cancer risk (q-value < 0.2). Seven metabolites remained associated after adjustment for established risk factors (p-value < 0.05) and were selected by at least one multivariable modeling approach: higher levels of 2-aminohippuric acid, kynurenic acid, piperine (all three with q-value < 0.2), DMGV and phenylacetylglutamine were associated with lower breast cancer risk (e.g., piperine: ORadjusted (95%CI) = 0.84 (0.77-0.92)) while higher levels of creatine and C40:7 phosphatidylethanolamine (PE) plasmalogen were associated with increased breast cancer risk (e.g., C40:7 PE plasmalogen: ORadjusted (95%CI) = 1.11 (1.01-1.22)). Five amino acids and amino acid-related metabolites (2-aminohippuric acid, DMGV, kynurenic acid, phenylacetylglutamine, and piperine) were inversely associated, while one amino acid and a phospholipid (creatine and C40:7 PE plasmalogen) were positively associated with breast cancer risk among predominately premenopausal women, independent of established breast cancer risk factors.

Piperine Targets Different Drug Resistance Mechanisms in Human Ovarian Cancer Cell Lines Leading to Increased Sensitivity to Cytotoxic Drugs

Our goal was to examine the anticancer effects of piperine against the resistant human ovarian cancer cells and to explore the molecular mechanisms responsible for its anticancer effects. Our study used drug-sensitive ovarian cancer cell line W1 and its sublines resistant to paclitaxel (PAC) and topotecan (TOP). We analyzed the cytotoxic effect of piperine and cytostatic drugs using an MTT assay. The impact of piperine on protein expression was determined by immunofluorescence and Western blot. We also examined its effect on cell proliferation and migration. We noticed a different level of piperine resistance between cell lines. Piperine increases the cytotoxic effect of PAC and TOP in drug-resistant cells. We observed an increase in PTPRK expression correlated with decreased pTYR level after piperine treatment and downregulation of P-gp and BCRP expression. We also noted a decrease in COL3A1 and TGFBI expression in investigated cell lines and increased COL3A1 expression in media from W1PR2 cells. The expression of Ki67 protein and cell proliferation rate decreased after piperine treatment. Piperine markedly inhibited W1TR cell migration. Piperine can be considered a potential anticancer agent that can increase chemotherapy effectiveness in cancer patients.

Piperine protects oxidative modifications in human erythrocytes

OBJECTIVES

Piperine (1-piperoyl piperidine), a major alkaloid constituent of Piper nigrum L. and Piper longum L. has pleiotropic biological effects, but the mechanism(s) involved remain to be elucidated. The current study was conducted to examine the efficacy of antioxidant ability of piperine on t-BHP induced markers of oxidative stress in human erythrocytes.

METHODS

Healthy human erythrocytes and erythrocytes membrane was stressed with free radical inducer chemical; t-BHP (10^-5 M), and the effects of piperine was measured against free radical mediated modification in lipid and protein content, -SH and GSH value with antioxidant potential.

RESULTS

The results demonstrate that treatment of erythrocytes with piperine (10^-5 to 10^-7 M) significantly (p<0.05) ameliorated the adverse consequences of oxidative stress as evidenced by prevention of oxidation of erythrocyte reduced glutathione, membrane thiols, proteins, and peroxidation of lipids; the effects were in correlation with ferric reducing and radical scavenging abilities of piperine.

CONCLUSIONS

The study concludes that piperine possesses potent anti-oxidant potential which may explain many of its observed biological effects.

Piperine Regulates Nrf-2/Keap-1 Signalling and Exhibits Anticancer Effect in Experimental Colon Carcinogenesis in Wistar Rats

Colon cancer is the most common cancer in men and women globally, killing millions of people annually. Though there widespread development has been made in the management of colorectal cancer, still there is an urgent need to find novel targets for its effective treatment. Piperine is an alkaloid found in black pepper having anticancer, anti-inflammatory activities, safe and nutritive for human consumption. Nuclear factor-erythroid 2-kelch-like ECH-associated protein 1(Nrf-2/Keap-1)/Heme-oxygenase1 (HO-1) signaling pathway plays a vital part in shielding cells from intracellular oxidative stress and inflammation. A potential cross-talk between the Nrf-2 and NF-κB pathways is recognized during cancerous growth and expansion. We studied this pathway extensively in the present study to discover novel targets in the prevention of chemically induced colon cancer with piperine to simulate human colon cancer pathology. Animals were divided into four groups. Groups1 and 2 were used as a negative control and positive control where 1,2-Dimethylhydrazine, DMH was administered in group 2, while group 3 and 4 were prevention groups where piperine at two different doses was given two weeks prior to DMH and continued until end of experiment. We found that piperine inhibited NF-κB by the activation of Nrf-2, blocking downstream inflammatory mediators/cytokines (TNF-α, IL-6, IL-1β, Cox-2, PGE-2, iNOS, NO, MPO), triggering an antioxidant response machinery (HO-1, NQO-1, GSH, GR, GPx, CAT, SOD), scavenging ROS, and decreasing lipid peroxidation. Histological findings further validated our molecular findings. It also downregulates CEA, MDF and ACF, markers of precancerous lesions in colon, alleviates infiltration of mast cells and depletes the mucous layer. Our results indicate that piperine may be an effective molecule for the prophylactic treatment of colon carcinogenesis by targeting the NF-κB/Nrf-2/Keap-1/HO-1 pathway as a progressive strategy in the preclusion and effective treatment of colorectal cancer.

Piperine: A review of its biological effects

Medicinal plants have been used for years as a source of food, spices, and, in traditional medicine, as a remedy to numerous diseases. Piper nigrum, belonging to the family Piperaceae is one of the most widely used spices all over the world. It has a distinct sharp flavor attributed to the presence of the phytochemical, piperine. Apart from its use as a spice, P. nigrum is frequently used for medicinal, preservation, and perfumery purposes. Black pepper contains 2-7.4% of piperine, varying in content is associated with the pepper plant. Piperine displays numerous pharmacological effects such as antiproliferative, antitumor, antiangiogenesis, antioxidant, antidiabetic, anti-obesity, cardioprotective, antimicrobial, antiaging, and immunomodulatory effects in various in vitro and in vivo experimental trials. Furthermore, piperine has also been documented for its hepatoprotective, anti-allergic, anti-inflammatory, and neuroprotective properties. This review highlights and discusses the medicinal and health-promoting effects of piperine, along with possible mechanisms of its action in health promotion and disease prevention. In addition, the present review summarizes the recent literature related to piperine as a therapeutic agent against several diseases.

Chemical constituents from the fruits of Piper longum L. and their vascular relaxation effect on rat mesenteric arteries

Eight compounds were obtained from the dry fruits of Piper longum L., and their potential vascular relaxant activities were explored. The present study first revealed the access of Rosin (7) and Piperchabaoside (8) in the medicinal plant Piper longum L. The vessel tension studies showed that Piperine (2), (2E,4E,14Z)-N-isobutyleicosa-2,4,14-trienamide (3), and Piperlonguminine (6) exerted significant inhibitory effects on PE-induced mesenteric artery vasoconstriction. Furthermore, Calcium Imaging studies were applied to observe the effect of Piperine on the intracellular calcium in mesenteric artery smooth muscle cells (MASMCs). Piperine (2) was observed to promote the influx of extracellular calcium in MASMCs, and via an endothelium-independent mechanism involving Ca²⁺ entry. Piper longum L. might have a great potential to be further studied as a vascular relaxant, even to be a drug candidate of anti-hypertension.

Ornithine decarboxylase inhibition downregulates multiple pathways involved in the formation of precancerous lesions of esophageal squamous cell cancer

The high incidence and mortality of esophageal squamous cell cancer (ESCC) is a major health problem worldwide. Precancerous lesions of ESCC may either progress to cancer or revert to normal epithelium with appropriate interventions; the bidirectional instability of the precancerous lesions of ESCC provides opportunities for intervention. Reports suggest that the upregulation of ornithine decarboxylase (ODC) is closely related to carcinogenesis. In this study, we investigated whether ODC may act as a target for chemoprevention in ESCC. Immunohistochemistry (IHC) assays indicate that ODC expression is higher in esophageal precancerous lesions compared with normal tissue controls. Its overexpression promotes cell proliferation and transformation of normal esophageal epithelial cells, and its activity is increased after N-nitrosomethylbenzylamine (NMBA) induction in Shantou human embryonic esophageal cell line (SHEE) and human immortalized cells (Het1A) cells. In addition, p38 α, extracellular regulated kinase (ERK1/2) in the mitogen-activated protein kinase pathway and protein kinase B (AKT)/mammalian target of rapamycin (mTOR)/ribosomal protein S6 kinase (p70S6K) pathways are activated in response to NMBA treatment. Difluoromethylornithine (DFMO) is an ODC inhibitor, which inhibits NMBA-induced activation of p38 α, ERK1/2 and AKT/mTOR/p70S6K pathways; this has been verified by Western blotting. DFMO was also found to suppress the development of esophageal precancerous lesions in an NMBA-induced rat model; IHC demonstrated p38 α, ERK1/2, and AKT/mTOR/p70S6K pathways to be downregulated in these rats. These findings indicate the mechanisms by which ODC inhibition suppresses the development of esophageal precancerous lesions by downregulating p38 α, ERK1/2, and AKT/mTOR/p70S6k signaling pathways, ODC may be a potential target for chemoprevention in ESCC.

Dichloroacetate (DCA) and Cancer: An Overview towards Clinical Applications

An extensive body of literature describes anticancer property of dichloroacetate (DCA), but its effective clinical administration in cancer therapy is still limited to clinical trials. The occurrence of side effects such as neurotoxicity as well as the suspicion of DCA carcinogenicity still restricts the clinical use of DCA. However, in the last years, the number of reports supporting DCA employment against cancer increased also because of the great interest in targeting metabolism of tumour cells. Dissecting DCA mechanism of action helped to understand the bases of its selective efficacy against cancer cells. A successful coadministration of DCA with conventional chemotherapy, radiotherapy, other drugs, or natural compounds has been tested in several cancer models. New drug delivery systems and multiaction compounds containing DCA and other drugs seem to ameliorate bioavailability and appear more efficient thanks to a synergistic action of multiple agents. The spread of reports supporting the efficiency of DCA in cancer therapy has prompted additional studies that let to find other potential molecular targets of DCA. Interestingly, DCA could significantly affect cancer stem cell fraction and contribute to cancer eradication. Collectively, these findings provide a strong rationale towards novel clinical translational studies of DCA in cancer therapy.