Piperlongumine, a piper alkaloid, enhances the efficacy of doxorubicin in breast cancer: involvement of glucose import, ROS, NF-κB and lncRNAs

Development of chromone-thiazolidine-2,4-dione Knoevenagel conjugates as apoptosis inducing agents

Overexpression of Bcl-2 protein is a predominant hallmark of disturbed apoptotic pathway in most of the cancers. Herein, chromone-linked thiazolidinediones were designed and synthesized to target Bcl-2 for regulating anti-apoptotic proteins. The study on in vitro cancer cell lines revealed the presence of compounds 8a, 8k, 8l, and 8n, which were found to have good to moderate anti-proliferative activity (with an IC50 concentration less than 10 µM). Among them, 8l depicted the highest cytotoxicity on the A549 cell line with an IC50 of 6.1 ± 0.02 µM. Aberrantly, the compounds displayed less toxicity towards human embryonic kidney HEK cells underlining its selectivity. The DCFDA study revealed a gradual increase in the ROS generation of 8l, followed by its quantification by flow analysis. Similarly, the studies including DAPI, AO/EtBr and Annexin-V binding clearly elucidated the DNA damage, membrane integrity prospects, and insights for early and late apoptotic phases. Markedly, the Bcl-2-FITC anti-body study revealed that compound 8l reduced the expression of anti-apoptotic proteins by 79.1 % compared to the control at 9 µM concentration. In addition, the molecular docking study provided the impending scope of these hybrids, showing promising interaction with the Mcl-1 target (member of the Bcl-2 family) with comparable binding affinities.

Mini-encyclopedia of mitochondria-relevant nutraceuticals protecting health in primary and secondary care-clinically relevant 3PM innovation

Despite their subordination in humans, to a great extent, mitochondria maintain their independent status but tightly cooperate with the "host" on protecting the joint life quality and minimizing health risks. Under oxidative stress conditions, healthy mitochondria promptly increase mitophagy level to remove damaged "fellows" rejuvenating the mitochondrial population and sending fragments of mtDNA as SOS signals to all systems in the human body. As long as metabolic pathways are under systemic control and well-concerted together, adaptive mechanisms become triggered increasing systemic protection, activating antioxidant defense and repair machinery. Contextually, all attributes of mitochondrial patho-/physiology are instrumental for predictive medical approach and cost-effective treatments tailored to individualized patient profiles in primary (to protect vulnerable individuals again the health-to-disease transition) and secondary (to protect affected individuals again disease progression) care. Nutraceuticals are naturally occurring bioactive compounds demonstrating health-promoting, illness-preventing, and other health-related benefits. Keeping in mind health-promoting properties of nutraceuticals along with their great therapeutic potential and safety profile, there is a permanently growing demand on the application of mitochondria-relevant nutraceuticals. Application of nutraceuticals is beneficial only if meeting needs at individual level. Therefore, health risk assessment and creation of individualized patient profiles are of pivotal importance followed by adapted nutraceutical sets meeting individual needs. Based on the scientific evidence available for mitochondria-relevant nutraceuticals, this article presents examples of frequent medical conditions, which require protective measures targeted on mitochondria as a holistic approach following advanced concepts of predictive, preventive, and personalized medicine (PPPM/3PM) in primary and secondary care.

Piperlongumine: the amazing amide alkaloid from Piper in the treatment of breast cancer

Piperlongumine (PL), an alkaloid found primarily in the fruits and roots of the plant Piper longum L. (Piperaceae), is a natural compound that exhibits potent activity against various cancer cell proliferation. The most frequently caused malignancy in women globally, breast cancer (BC), has been demonstrated to be significantly inhibited by PL. Apoptosis, cell cycle arrest, increased ROS generation, and changes in the signalling protein's expression are all caused by the numerous signalling pathways that PL impacts. Since BC cells resist conventional chemotherapeutic drugs (doxorubicin, docetaxel etc.), researchers have shown that the drugs in combination with PL can exhibit a synergistic effect, greater than the effects of the drug or PL alone. Recently, techniques for drug packaging based on nanotechnology have been employed to improve PL release. The review has presented an outline of the chemistry of PL, its molecular basis in BC, its bioavailability, toxicity, and nanotechnological applications. An attempt to understand the future prospects and direction of research about the compound has also been discussed.

Piperlongumine inhibits antioxidant enzymes, increases ROS levels, induces DNA damage and G2/M cell cycle arrest in breast cell lines

Piperlongumine (PLN) is a biologically active alkaloid/amide derived from Piper longum, with known promising anticancer activity. The aim of this study was to compare the antiproliferative activity of PLN in human breast MCF-7 adenocarcinoma cell line with effects in HB4a normal mammary epithelial non-tumor cell line. The parameters examined were cell growth, viability, reactive oxygen species (ROS) levels and DNA damage, as well as the effects on the modulating targets responsible through regulation of these pathways. PLN increased ROS levels and expression of the SOD1 antioxidant enzyme. PLN inhibited the expression of the antioxidant enzymes catalase, TRx1, and PRx2. The ability of PLN to inhibit antioxidant enzyme expression was associated with the oxidative stress response. PLN induced genotoxicity in both cell lines and upregulated the levels of GADD45A mRNA and p21 protein. The DNA damage response ATR protein was downregulated in both cell lines and contributed to an enhanced PLN genotoxicity. In HB4a cells, Chk1 protein, and mRNA levels were also decreased. In response to elevated ROS levels and DNA damage induction, the cells were arrested at the G2/M phase, probably in an attempt to promote cell survival. Although cell viability was reduced in both cell lines, only HB4a cells underwent apoptotic cell death, whereas other types of cellular death may be involved in MCF-7 cells. Taken together, these data provide insight into the anticancer mechanisms attributed to PLN effects, which acts as an inhibitor of DNA damage response (DDR) proteins and antioxidant enzymes.

SETDB1: Progress and prospects in cancer treatment potential and inhibitor research

SET domain bifurcated methyltransferase 1 (SETDB1) serves as a histone lysine methyltransferase, catalyzing the di- and tri-methylation of histone H3K9. Mounting evidence indicates that the abnormal expression or activity of SETDB1, either through amplification or mutation, plays a crucial role in tumorigenesis and progression. This is particularly evident in the context of tumor immune evasion and resistance to immune checkpoint blockade therapy. Furthermore, there is a robust association between SETDB1 dysregulation and an unfavorable prognosis across various types of tumors. The oncogenic role of SETDB1 primarily arises from its methyltransferase function, which contributes to the establishment of a condensed and transcriptionally inactive heterochromatin state. This results in the inactivation of genes that typically hinder cancer development and silencing of retrotransposons that could potentially trigger an immune response. These findings underscore the substantial potential for SETDB1 as an anti-tumor therapeutic target. Nevertheless, despite significant strides in recent years in tumor biology research, challenges persist in SETDB1-targeted therapy. To better facilitate the development of anti-tumor therapy targeting SETDB1, we have conducted a comprehensive review of SETDB1 in this account. We present the structure and function of SETDB1, its role in various tumors and immune regulation, as well as the advancements made in SETDB1 antagonists. Furthermore, we discuss the challenges encountered and provide perspectives for the development of SETDB1-targeted anti-tumor therapy.

m6A-modified circARHGAP12 promotes the aerobic glycolysis of doxorubicin-resistance osteosarcoma by targeting c-Myc

Chemotherapy resistance accompanied by energy metabolism abnormality functions as one of the main reasons for treatment failure and poor prognosis. However, the function of N6-methyladenosine (m6A)-modified circular RNA (circRNA) on osteosarcoma (OS) is still unclear. Here, present research investigated the potential role and mechanism of circARHGAP12 on OS doxorubicin (Dox) resistance and aerobic glycolysis. Results indicated that circARHGAP12 was a novel m6A-modified circRNA, which was up-regulated in OS cells. Overexpression of circARHGAP12 promoted the Dox resistance half-maximal inhibitory concentration (IC50) and aerobic glycolysis (glucose uptake, lactate and ATP production) in OS cells (Saos-2/Dox, MG63/Dox). Mechanistically, m6A-modified circARHGAP12 could bind with c-Myc mRNA through m6A-dependent manner, thereby enhancing the c-Myc mRNA stability. Thus, these findings revealed the critical function of circARHGAP12 on OS Dox-resistance and aerobic glycolysis. Taken together, our study demonstrated a critical function of circARHGAP12 on OS chemotherapy resistance and energy metabolism abnormality, providing critical roles on OS treatment.

GAS5: A pivotal lncRNA in diabetes mellitus pathogenesis and management

The long non-coding RNA (lncRNA), GAS5, has garnered significant attention recently for its multifaceted involvement in cellular processes, particularly within the context of diabetes. This comprehensive review delves into the intricate molecular interactions associated with GAS5 and their profound implications for understanding, diagnosing, and effectively managing diabetes mellitus. The article begins by highlighting the global prevalence of diabetes and the urgent need for innovative insights into its underlying mechanisms and therapeutic approaches. It introduces GAS5 as a crucial regulator of gene expression, with emerging significance in the context of diabetes-related processes. The core of this review unravels the regulatory network of GAS5 in diabetes, elucidating its impact on various aspects of the disease. It explores how GAS5 influences insulin signaling pathways, glucose metabolism, and the function of β-cells, shedding light on its role in hyperglycemia and insulin resistance. Moreover, the article underscores the clinical relevance of GAS5's interactions by discussing their associations with different diabetes subtypes, predictive value, and potential applications as both diagnostic tools and therapeutic targets. It provides insights into ongoing research endeavours aimed at harnessing the potential of GAS5 for innovative disease management strategies, including the development of RNA-based therapeutics. Concluding with a forward-looking perspective, the abstract highlights the broader implications of GAS5 in the field of diabetes, such as its connection to diabetic complications and its potential for personalized approaches in disease management.

Therapeutic Role of Alkaloids and Alkaloid Derivatives in Cancer Management

Cancer is a neoplastic disease that remains a global challenge with a reported prevalence that is increasing annually. Though existing drugs can be applied as single or combined therapies for managing this pathology, their concomitant adverse effects in human applications have led to the need to continually screen natural products for effective and alternative anticancer bioactive principles. Alkaloids are chemical molecules that, due to their structural diversity, constitute a reserve for the discovery of lead compounds with interesting pharmacological activities. Several in vitro studies and a few in vivo findings have documented various cytotoxic and antiproliferative properties of alkaloids. This review describes chaetocochin J, neopapillarine, coclaurine, reflexin A, 3,10-dibromofascaplysin and neferine, which belong to different alkaloid classes with antineoplastic properties and have been identified recently from plants. Despite their low solubility and bioavailability, plant-derived alkaloids have viable prospects as sources of viable lead antitumor agents. This potential can be achieved if more research on these chemical compounds is directed toward investigating ways of improving their delivery in an active form close to target cells, preferably with no effect on neighboring normal tissues.

Effects of piperlonguminine on lung injury in severe acute pancreatitis <em>via</em> the TLR4/NF-κB pathway

Acute pancreatitis is an inflammatory response in the pancreas, involving activation of pancreatic enzymes. Severe acute pancreatitis (SAP) often causes systemic complications that affect distant organs, including the lungs. The aim of this study was to explore the therapeutic potential of piperlonguminine on SAP-induced lung injury in rat models. Acute pancreatitis was induced in rats by repetitive injections with 4% sodium taurocholate. Histological examination and biochemical assays were used to assess the severity of lung injury, including tissue damage, and levels of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4), reactive oxygen species (ROS), and inflammatory cytokines. We found that piperlonguminine significantly ameliorated pulmonary architectural distortion, hemorrhage, interstitial edema, and alveolar thickening in rats with SAP. In addition, NOX2, NOX4, ROS, and inflammatory cytokine levels in pulmonary tissues were notably decreased in piperlonguminine-treated rats. Piperlonguminine also attenuated the expression levels of toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB). Together, our findings demonstrate for the first time that piperlonguminine can ameliorate acute pancreatitis-induced lung injury via inhibitory modulation of inflammatory responses by suppression of the TLR4/NF-κB signaling pathway.

Identification of Piperlongumine as Potent Inhibitor of Necroptosis

Purpose

Excessive necroptosis contributes to the pathogenesis of several inflammatory and neurodegenerative diseases. Here, using a high-throughput screening approach, we investigated the anti-necroptosis effects of piperlongumine, an alkaloid isolated from the long pepper plant, in vitro and in a mouse model of systemic inflammatory response syndrome (SIRS).

Methods

A natural compound library was screened for anti-necroptosis effects in cellular. The underlying mechanism of action of the top candidate piperlongumine was explored by quantifying the necroptosis marker phosphorylated receptor-interacting protein kinase 1 (p-RIPK1) by Western blotting. The anti-inflammatory effect of piperlongumine was assessed in a tumor necrosis factor α (TNFα)-induced SIRS model in mice.

Results

Among the compounds investigated, piperlongumine significantly rescued cell viability. The half maximal effective concentration (EC₅₀) of piperlongumine for inhibiting necroptosis was 0.47 μM in HT-29 cells, 6.41 μM in FADD-deficient Jurkat cells, and 2.33 µM in CCRF-CEM cells, while the half maximal inhibitory concentration (IC₅₀) was 95.4 µM in HT-29 cells, 93.02 µM in FADD-deficient Jurkat cells, and 161.1 µM in CCRF-CEM cells. Piperlongumine also significantly inhibited TNFα-induced intracellular RIPK1 Ser166 phosphorylation in cell lines and significantly prevented decreases in body temperature and improved survival in SIRS mice.

Conclusion

As a potent necroptosis inhibitor, piperlongumine prevents phosphorylation of RIPK1 at its activation residue Ser166. Piperlongumine thus potently inhibits necroptosis at concentrations safe enough for human cells in vitro and inhibits TNFα-induced SIRS in mice. Piperlongumine has potential clinical translational value for the treatment of the spectrum of diseases associated with necroptosis, including SIRS.