Wan-Ling Chang

Shikonin, a dietary naphthoquinone phytochemical from the roots of Lithospermum erythrorhizon, has gained attention for its anticancer potential. Preclinical studies show that shikonin regulates multiple programmed cell death pathways, including apoptosis, necroptosis, ferroptosis, and pyroptosis, through mechanisms involving reactive oxygen species (ROS) accumulation, mitochondrial dysfunction, and kinase-mediated signalling. Beyond cytotoxicity, shikonin suppresses metastasis by blocking epithelial–mesenchymal transition (EMT) and downregulating matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). It also disrupts tumour metabolism by targeting pyruvate kinase isoform M2 (PKM2) and modulating the Warburg effect. Evidence further indicates that shikonin can enhance the efficacy of chemotherapy, targeted therapy, immunotherapy, and radiotherapy, thereby contributing to the reversal of therapeutic resistance. To address limitations related to solubility and bioavailability, novel formulations such as nanoparticles, liposomes, and derivatives like β,β-dimethylacrylshikonin have been developed, showing improved pharmacological profiles and reduced toxicity in experimental models. Overall, the current literature identifies shikonin as a promising dietary phytochemical with diverse anticancer activities, therapeutic synergy, and formulation advances, while highlighting the need for clinical studies to establish its translational potential.

Shikonin, a naphthoquinone from Lithospermum erythrorhizon, exhibits broad anticancer potential through multiple regulated cell death pathways. It induces apoptosis via mitogen-activated protein kinase (MAPK) signalling, reactive oxygen species (ROS) accumulation, endoplasmic reticulum (ER) stress, and p53 activation, and also triggers necroptosis through receptor-interacting protein kinase 1 (RIPK1), receptor-interacting protein kinase 3 (RIPK3), and mixed lineage kinase domain-like protein (MLKL), as well as ferroptosis and pyroptosis. Beyond cytotoxicity, shikonin suppresses metastasis by blocking epithelial–mesenchymal transition (EMT) and downregulating matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). It further disrupts tumour metabolism by targeting pyruvate kinase isoform M2 (PKM2) and modulating the Warburg effect. In combination, shikonin enhances the efficacy of chemotherapy (cisplatin, paclitaxel), targeted therapy (tamoxifen), and immunotherapy (anti-programmed cell death protein 1 [anti-PD-1]), thereby overcoming resistance. To address poor bioavailability, nanoparticles, liposomes, and derivatives such as β, β-dimethylacrylshikonin have been developed to improve potency and reduce toxicity. Preclinical studies show strong tumour regression in melanoma, breast, and ovarian cancer models. Although clinical validation remains limited, shikonin’s multifaceted actions, favourable safety, and therapeutic synergy highlight the need for rigorous clinical trials to define its oncological value.

Piperine, a phytochemical alkaloid, exhibits notable anticancer properties in several cancer cell types. In this study, we investigated the mechanisms by which piperine induces cell death and apoptosis in colorectal cancer (CRC) cells, focusing on oxidative stress and key signaling pathways. Using MTT assay, flow cytometry, gene overexpression, and Western blot analysis, we observed that piperine significantly reduced cell viability, triggered G1 phase cell cycle arrest, and promoted apoptosis in DLD-1 cells. In addition, piperine effectively suppressed cell viability and induced apoptosis in other CRC cell lines, including SW480, HT-29, and Caco-2 cells. These effects were associated with increased intracellular reactive oxygen species (ROS) generation, mediated by the regulation of mitochondrial complex III, NADPH oxidase, and xanthine oxidase. Additionally, piperine modulated signaling pathways by inhibiting phosphoinositide 3-kinase (PI3K)/Akt, activating p38 and p-extracellular signal-regulated kinase (ERK). Pretreatment with antimycin A, apocynin, allopurinol, and PD98059, and the overexpression of p-Akt significantly recovered cell viability and reduced apoptosis, confirming the involvement of these pathways. This study is the first to demonstrate piperine induces apoptosis in CRC cells through a multifaceted oxidative stress mechanism and by critically modulating PI3K/Akt and ERK signaling pathways.

Piperine, a phytochemical alkaloid, exhibits anticancer properties on several cancer cells. The present study explored the important oxidative stress and signaling mechanisms by which piperine provokes cell death and apoptosis in colorectal DLD-1 cancer cells. We investigated the cell viability, cell cycle, and apoptosis-inducing of piperine by performing MTT assay, flow cytometry, gene overexpression, and Western blot analysis. Piperine treatment of DLD-1 cells diminished cell viability, and stimulated cell cycle G1 arrest and apoptosis. Piperine induced intracellular reactive oxygen species (ROS) generation by regulating mitochondrial complex III, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and xanthine oxidase. Piperine inhibited the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway and activated the p-38 and p-extracellular signal-regulated kinase (ERK) pathways. Pretreatment with antimycin A (a mitochondrial complex III inhibitor), apocynin (an NADPH oxidase inhibitor), allopurinol (a xanthine oxidase inhibitor), and PD98059 (an ERK inhibitor) and the overexpression of p-Akt significantly recovered cell viability and reduced apoptosis. This study was the first to demonstrate a multiple oxidative stress mechanism and the critical regulating PI3K/Akt and ERK signaling pathways of piperine, inducing apoptosis on colorectal cancer cells.

In this study, we discovered the mechanisms underlying parecoxib and resveratrol combination’s anti-cancer characteristics against human colorectal cancer DLD-1 cells. We studied its anti-proliferation and apoptosis-provoking effect by utilizing cell viability 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, fluorescence microscope, gene overexpression, Western blot, and flow cytometry analyses. Parecoxib enhanced the ability of resveratrol to inhibit cell viability and increase apoptosis. Parecoxib in combination with resveratrol strongly enhanced apoptosis by inhibiting the expression of thioredoxin domain containing 5 (TXNDC5) and Akt phosphorylation. Parecoxib enhanced resveratrol-provoked c-Jun N-terminal kinase (JNK) and p38 phosphorylation. Overexpression of TXNDC5 and repression of JNK and p38 pathways significantly reversed the inhibition of cell viability and stimulation of apoptosis by the parecoxib/resveratrol combination. This study presents evidence that parecoxib enhances the anti-cancer power of resveratrol in DLD-1 colorectal cancer cells via the inhibition of TXNDC5 and Akt signaling and enhancement of JNK/p38 MAPK pathways. Parecoxib may be provided as an efficient drug to sensitize colorectal cancer by resveratrol.

Colorectal cancer is one of the most common causes of cancer mortality worldwide, and innovative drugs for the treatment of colorectal cancer are continually being developed. 5-Fluorouracil (5-FU) is a common clinical chemotherapeutic drug. Acquired resistance to 5-FU is a clinical challenge in colorectal cancer treatment. Parecoxib is a selective COX-2-specific inhibitor that was demonstrated to inhibit metastasis in colorectal cancers in our previous study. This study aimed to investigate the synergistic antimetastatic activities of parecoxib to 5-FU in human colorectal cancer cells and determine the underlying mechanisms. Parecoxib and 5-FU synergistically suppressed metastasis in colorectal cancer cells. Treatment with the parecoxib/5-FU combination induced an increase in E-cadherin and decrease in β-catenin expression. The parecoxib/5-FU combination inhibited MMP-9 activity, and the NF-κB pathway was suppressed as well. Mechanistic analysis denoted that the parecoxib/5-FU combination hindered the essential molecules of the PI3K/Akt route to obstruct metastatic colorectal cancer. Furthermore, the parecoxib/5-FU combination could inhibit reactive oxygen species. Our work showed the antimetastatic capacity of the parecoxib/5-FU combination for treating colorectal cancers via the targeting of the PI3K/Akt/NF-κB pathway.

Colorectal cancer is one of the most common causes of cancer mortality worldwide, and innovative drugs for the treatment of colorectal cancer are continually being revealed. 5-Fluorouracil (5-FU) is a common clinical chemotherapeutic drug. Acquired resistance to 5-FU is a clinical challenge in colorectal cancer. Parecoxib is a selective COX-2-specific inhibitor, which has been demonstrated to inhibit metastasis in colorectal cancers in our previous study. This study aimed to investigate the synergistic antimetastatic activities of parecoxib to 5-FU in human colorectal cancer cells and determine the underlying mechanism. parecoxib and 5-FU synergistically suppressed metastasis in colorectal cancer cells. Treatment with the parecoxib /5-FU combination induced an increase in E-cadherin and decrease in β-catenin. The parecoxib/5-FU combination could inhibit MMP-9 and MMP-2 expression and MMP-9 activity, and the NF-κB pathway might be suppressed as well. Mechanistic analysis denoted that the parecoxib/5-FU combination hindered the essential molecules of the PI3K/Akt route to obstruct metastatic colorectal cancer. Furthermore, the parecoxib/5-FU combination could inhibit reactive oxygen species. Our work showed the antimetastatic capacity of the parecoxib/5-FU combination for colorectal cancers via targeting the PI3K/Akt /NF-κB pathway.