Synthesis, biological function and evaluation of Shikonin in cancer therapy

Targeting glucose metabolism for HPV-associated cervical cancer: A sweet poison

More than 99 % of precancerous cervical lesions are associated with human papillomavirus (HPV) infection, with HPV types 16 and 18 (especially type 16) found in over 70 % of cervical cancer cases globally. The growth of HPV-positive cervical cancer depends on the sustained expression of the viral oncogenes E6 and E7, which are key factors in maintaining the malignant phenotype of HPV-positive tumor cells. E6 and E7 oncoproteins can cause the degradation of the tumor suppressor gene p53 and the inactivation of pRb, respectively, thereby inducing carcinogenesis. However, the inhibition of p53 and pRb cannot fully explain the oncogenic mechanism of cervical cancer. Although the development of the HPV vaccine has controlled the incidence of HPV infection, its application and widespread adoption remain limited. In addition, many developing countries cannot afford the cost of vaccines. More importantly, the vaccine only prevents HPV infection and does not provide an effective treatment for patients who are already infected or have cervical cancer. Therefore, HPV-related diseases, especially cervical cancer, remain a serious challenge. This article reviews the role of glucose metabolism changes and key molecular events in HPV-induced cervical cancer, summarizes potential targets for the treatment of cervical cancer, and provides strategies for future clinical treatment. It also offers a theoretical basis for research into cervical cancer and other HPV-related tumors. Furthermore, we discuss potential treatments for HPV-associated cervical cancer through targeted metabolic pathways and analyze the risks and challenges of current targeted glucose metabolism therapies for cervical cancer.

Shikonin Induces Autophagy and Apoptosis in Esophageal Cancer EC9706 Cells by Regulating the AMPK/mTOR/ULK Axis

Shikonin is a plant medicine extracted from Lithospermum, which dominate influential antioxidant and antitumor effect. Here, we report that shikonin was capable of inducing human esophageal cancer EC9706 cell apoptosis and autophagy, in a time- and dose-dependent manner. Shikonin exposure repressed cell viability and migration and invasion capabilities and caused EC9706 cell autophagy and apoptosis by activating the AMPK/mTOR/ULK axis. Autophagy inhibition secured EC9706 cells against shikonin-induced autophagy and apoptosis and reversed the upregulation of AMPK and ULK phosphorylation and downregulation of mTOR phosphorylation provoked by shikonin. In summary, shikonin instigates EC9706 cell apoptosis and autophagy using the target AMPK/mTOR/ULK signal pathway axis, which provides a potential new target to treat human esophageal cancer.

Rapid identification and determination of adulteration in medicinal Arnebiae Radix by combining near infrared spectroscopy with chemometrics

The medicinal Arnebia Radix (AR) is one of widely-used Chinese herbal medicines (CHMs), usually adulterated with non-medicinal species that seriously compromise the quality of AR and affect patients' health. Detection of these adulterants is usually performed by using expensive and time-consuming analytical instruments. In this study, a rapid, non-destructive, and effective method was proposed to identify and determine the adulteration in the medicinal AR by near-infrared (NIR) spectroscopy coupled with chemometrics. 37 batches of medicinal AR samples originated from Arnebia euchroma (Royle) Johnst., 11 batches of non-medicinal AR samples including Onosma paniculatum Bur. et Franch and Arnebia benthamii (Wall. ex G. Don) Johnston, and 72 batches of adulterated AR samples were characterized by NIR spectroscopy. The data driven-soft independent modeling by class analogy (DD-SIMCA) and partial least squares-discriminant analysis (PLS-DA) were separately used to differentiate the authentic from adulterated AR samples. Then the PLS and support vector machine (SVM) were applied to predict the concentration of the adulteration in the adulterated AR samples, respectively. As a result, the classification accuracies of DD-SIMCA and PLS-DA models were 100% for the calibration set, and 96.7% vs. 100% for the prediction set. Moreover, the relative prediction deviation (RPD) values of PLS models reached 11.38 and 7.75 for quantifying two adulterants species, which were obviously superior to the SVM models. It can be concluded that the NIR spectroscopy coupled with chemometrics is feasible to identify the authentic from adulterated AR samples and quantify the adulteration in adulterated AR samples.

Shikonin blocks CAF-induced TNBC metastasis by suppressing mitochondrial biogenesis through GSK-3β/NEDD4-1 mediated phosphorylation-dependent degradation of PGC-1α

BACKGROUND

Triple-negative breast cancer (TNBC) is characterized by its high metastatic potential, which results in poor patient survival. Cancer-associated fibroblasts (CAFs) are crucial in facilitating TNBC metastasis via induction of mitochondrial biogenesis. However, how to inhibit CAF-conferred mitochondrial biogenesis is still needed to explore.

METHODS

We investigated metastasis using wound healing and cell invasion assays, 3D-culture, anoikis detection, and NOD/SCID mice. Mitochondrial biogenesis was detected by MitoTracker green FM staining, quantification of mitochondrial DNA levels, and blue-native polyacrylamide gel electrophoresis. The expression, transcription, and phosphorylation of peroxisome-proliferator activated receptor coactivator 1α (PGC-1α) were detected by western blotting, chromatin immunoprecipitation, dual-luciferase reporter assay, quantitative polymerase chain reaction, immunoprecipitation, and liquid chromatography-tandem mass spectrometry. The prognostic role of PGC-1α in TNBC was evaluated using the Kaplan-Meier plotter database and clinical breast cancer tissue samples.

RESULTS

We demonstrated that PGC-1α indicated lymph node metastasis, tumor thrombus formation, and poor survival in TNBC patients, and it was induced by CAFs, which functioned as an inducer of mitochondrial biogenesis and metastasis in TNBC. Shikonin impeded the CAF-induced PGC-1α expression, nuclear localization, and interaction with estrogen-related receptor alpha (ERRα), thereby inhibiting PGC-1α/ERRα-targeted mitochondrial genes. Mechanistically, the downregulation of PGC-1α was mediated by synthase kinase 3β-induced phosphorylation of PGC-1α at Thr295, which associated with neural precursor cell expressed developmentally downregulated 4e1 recognition and subsequent degradation by ubiquitin proteolysis. Mutation of PGC-1α at Thr295 negated the suppressive effects of shikonin on CAF-stimulated TNBC mitochondrial biogenesis and metastasis in vitro and in vivo.

CONCLUSIONS

Our findings indicate that PGC-1α is a viable target for blocking TNBC metastasis by disrupting mitochondrial biogenesis, and that shikonin merits potential for treatment of TNBC metastasis as an inhibitor of mitochondrial biogenesis through targeting PGC-1α.

Natural products as glycolytic inhibitors for cervical cancer treatment: A comprehensive review

Cervical cancer, a prevalent gynaecological malignancy, presents challenges in late-stage treatment efficacy. Aerobic glycolysis, a prominent metabolic trait in cervical cancer, emerges as a promising target for novel drug discovery. Natural products, originating from traditional medicine, represent a significant therapeutic avenue and primary source for new drug development. This review explores the regulatory mechanisms of glycolysis in cervical cancer and summarises natural compounds that inhibit aerobic glycolysis as a therapeutic strategy. The glycolytic phenotype in cervical cancer is regulated by classical molecules such as HIF-1, HPV virulence factors and specificity protein 1, which facilitate the Warburg effect in cervical cancer. Various natural products, such as artemisinin, shikonin and kaempferol, exert inhibitory effects by downregulating key glycolytic enzymes through signalling pathways such as PI3K/AKT/HIF-1α and JAK2/STAT3. Despite challenges related to drug metabolism and toxicity, these natural compounds provide novel insights and promising avenues for cervical cancer treatment.

Pharmacological Significance of Boraginaceae with Special Insights into Shikonin and Its Potential in the Food Industry

Shikonin is a naphthoquinone pigment present in the hairy roots of the plant species from the Boraginaceae family. The compound has been well investigated for its highly efficient medicinal, antioxidant, and antimicrobial properties. Various extraction methodologies have been employed to maximise yield while minimising waste production of shikonin and its derivatives. Despite substantial research on shikonin and Boraginaceae plants, a research gap persists in the food industry and extraction technologies. This review addresses crucial aspects of shikonin deserving of further exploration. It begins by elucidating the attributes of the Boraginaceae plants and their medicinal traits in folklore. It proceeds to focus on the roots of the plant and its medicinal properties, followed by extraction procedures explored in the last fifteen years, emphasising the novel technologies that have been chosen to improve the yield extract while minimising extraction times. Furthermore, this review briefly outlines studies employing cell culture techniques to enhance in vitro shikonin production. Lastly, attention is directed towards research in the food industry, particularly on shikonin-loaded biodegradable films and the antioxidant activity of shikonin. This review concludes by summarising the future potential in food science and prominent research gaps in this field.

Shikonin enhances chemosensitivity of oral cancer through β-catenin pathway

OBJECTIVES

This study concentrates on exploring the synergistic effect of shikonin on cisplatin against oral cancer.

METHODS

To analyze the IC50 value of shikonin, gradient concentrations of shikonin were added to the oral cancer cell culture medium. After the cisplatin-resistant cell line was established, the effects of cisplatin and shikonin on the survival rate, proliferation, apoptosis and related pathway protein expression of common/drug-resistant oral cancer cells were compared through MTT, clone formation, flow cytometry, and Western blot experiments. β-catenin, which had the most significant expression changes, was overexpressed and silenced, and used to design a reverse validation.

RESULTS

Shikonin inhibited the viability of oral cancer cells. Although cisplatin killed some cancer cells, its effect on drug-resistant cancer cells was significantly reduced. The addition of shikonin enhanced the sensitivity of drug-resistant cells to cisplatin. Shikonin regulated key proteins in cell proliferation and apoptosis-related pathways. Among them, shikonin generated the most evident inhibitory effect on β-catenin. Therefore, β-catenin overexpression plasmid/siβ-catenin was transfected into the cells. Silenced β-catenin was found to reinforce the damaging effect of cisplatin on cancer cells, and overexpressed β-catenin reversed the effect of shikonin.

CONCLUSION

By down-regulating β-catenin expression, shikonin improves the sensitivity of drug-resistant oral cancer cells to cisplatin.

Preparation, in vitro anti-tumour activity and in vivo pharmacokinetics of RGD-decorated liposomes loaded with shikonin

Shikonin (SHK) has been evidenced to possess effects against various cancer cells. However, poor aqueous solubility and high toxicity restrict its application. In the study, RGD-decorated liposomes loaded with SHK (RGD-Lipo-SHK) were prepared via thin-film hydration method. Characterization and cellular uptake of liposomes was evaluated. Cytotoxicity of blank liposomes and different SHK formulations was measured against breast cancer cells (MDA-MB-231, MCF-7, and MCF-10A). Anti-tumour effects and pharmacokinetic parameters of different SHK formulations were appraised in tumour spheroids and in rat model, respectively. Liposomes displayed a particle size of less than 127 nm with a polydispersity index about 0.21. The encapsulation efficiency was about 91% for SHK, and drug leakage rate of liposomes was less than 6%. RGD-Lipo-SHK showed superior cellular internalization in the αvβ3-positive MDA-MB-231 cells. Blank liposomes had no cytotoxicity to MDA-MB-231 and MCF-7 cells. Howbeit, different SHK formulations obviously inhibited proliferation of MCF-10A cells, especially free SHK. Meanwhile, RGD-Lipo-SHK significantly inhibited growth inhibition of tumour spheroids. The pharmacokinetics study indicated that the peak concentration, area under plasma concentration-time curves, half-life, and mean residence time of RGD-Lipo-SHK distinctly increased compared with those of free SHK. Altogether, these results demonstrated RGD-Lipo-SHK could reduce cytotoxicity, strengthen the antitumor-targeted effect, and prolong circulation time, which provides a foundation for further in vivo experimentations.

An in silico approach to investigate the theranostic potential of coumarin-derived self-immolative luminescent probes

Till date the challenge exists in the treatments of cancer for various reasons. Most importantly, the available diagnostics are expensive with research gap for enhancing the cancer detection sensitivity. Herein, a series of coumarin-derived fluorescent theranostic probes are reported that can serve as potent anticancer agents as well as in the detection of cancer cells. The potential of these probes to efficiently block one of the well-known cancer drug targets NADPH quinone oxidoreductase-1 (NQO1) is evaluated through various pharmacokinetic methods including absorption, distribution, metabolism and excretion (ADME) properties evaluation, PASS (prediction of activity spectra for substance) algorithm along with molecular docking and dynamic simulations. Further the luminescent properties of these molecules were evaluated by investigating their electronic properties in the ground and excited states with the help of density functional theory methods. Results indicate that the proposed molecules can potentially block the NADPH (reduced form of nicotinamide adenine dinucleotide) binding site of NQO1, thereby inhibiting the activity of the enzyme to ultimately disrupt the metabolism of cancer cells.

Co-cultures from Plants and Cyanobacteria: A New Way for Production Systems in Agriculture and Bioprocess Engineering

Due to the global increase in the world population, it is not possible to ensure a sufficient food supply without additional nitrogen input into the soil. About 30-50% of agricultural yields are due to the use of chemical fertilizers in modern times. However, overfertilization threatens biodiversity, such as nitrogen-loving, fast-growing species overgrow others. The production of artificial fertilizers produces nitrogen oxides, which act as greenhouse gases. In addition, overfertilization of fields also releases ammonia, which damages surface waters through acidification and eutrophication. Diazotrophic cyanobacteria, which usually form a natural, stable biofilm, can fix nitrogen from the atmosphere and release it into the environment. Thus, they could provide an alternative to artificial fertilizers. In addition to this, biofilms stabilize soils and thus protect against soil erosion and desiccation. This chapter deals with the potential of cyanobacteria as the use of natural fertilizer is described. Possible partners such as plants and callus cells and the advantages of artificial co-cultivation will be discussed later. In addition, different cultivation systems for studying artificial co-cultures will be presented. Finally, the potential of artificial co-cultures in the agar industry will be discussed.

Shikonin potentiates skin wound healing in Sprague-Dawley rats by stimulating fibroblast and endothelial cell proliferation and angiogenesis

BACKGROUND

Shikonin, a major component of Lithospermum erythrorhizon, exerts anti-inflammatory and antibacterial effects and expedites wound healing. This study aims to evaluate the anti-inflammatory and antioxidant activities of shikonin in a Sprague-Dawley rat model and cell models using fibroblast and endothelial cells.

METHODS

The impact of shikonin on the activity of endothelial cells and fibroblasts was examined by cell counting kit 8 and wound-healing assays. A diabetic rat model was constructed, followed by wound creation for treatment with shikonin. Hematoxylin-eosin staining was used to assess pathological changes, and Masson's trichrome method to detect collagen deposition. Immunohistochemistry using antibodies against proliferating cell nuclear antigen and CD31 was conducted to detect proliferation and vascular density. Enzyme-linked immunosorbent assay and immunohistochemistry were carried out to assess pro-inflammatory and anti-inflammatory factor concentrations. Western blot and immunofluorescence were implemented to analyze oxidative stress-related protein expression.

RESULTS

Shikonin induced the activity of both fibroblasts and endothelial cells. Shikonin treatment contributed to facilitated wound healing and higher healing rates in rats. It also resulted in faster lesion debulking in tissues, reduced inflammatory infiltration, increased collagen deposition, and enhanced angiogenesis. Detection of markers at the wounds showed that shikonin accelerated cell proliferation, enhanced tissue remodeling, and inhibited oxidative stress.

CONCLUSION

Shikonin stimulates the proliferation and migration of fibroblasts and endothelial cells to promote angiogenesis and tissue remodeling, resulting in faster wound healing.

Local administration of shikonin improved the overall survival in orthotopic murine glioblastoma models with temozolomide resistance

BACKGROUND

Glioblastoma is a type of intracranial malignancy. Shikonin, a Chinese traditional medicine, has been shown to have anti-tumor efficacy toward human glioblastoma cells in vitro. However, shikonin cannot easily cross the blood-brain barrier. To address this issue, we evaluated the anti-tumor effects of direct intracranial infusion of shikonin in in vivo orthotopic syngeneic murine glioblastoma models using C57BL/6 mice.

MATERIALS AND METHODS

The cytotoxic effects of shikonin against murine glioblastoma cells, SB28 and CT-2A, were reported resistance to temozolomide, were evaluated using an allophycocyanin-conjugated annexin V and propidium iodide assay with flow cytometry. Impedance-based real-time cell analysis (RTCA) was used to analyze the inhibitory effects of shikonin on growth and proliferation. To evaluate the anti-tumor activity of shikonin in vivo, we used orthotopic syngeneic murine glioblastoma models with SB28 and CT-2A cells.

RESULTS

In flow cytometry-based cytotoxic assays, shikonin induced apoptosis. RTCA indicated that shikonin decreased the cell index of murine glioblastoma cells, SB28 and CT-2A, in a dose-dependent manner (p < 0.0001 for both cell lines), while temozolomide did not (p = 0.91 and 0.82, respectively). In murine glioblastoma models, SB28 and CT-2A, direct intracranial infusion of shikonin, as a local chemotherapy, improved the overall survival of mice in a dose-dependent manner compared with control groups (p < 0.0001 and p = 0.02, respectively). While temozolomide did not (p = 0.48 and 0.52, respectively).

CONCLUSIONS

The direct intracranial infusion of shikonin has potential as a local therapy for patients with glioblastoma.

Recent advances in shikonin for the treatment of immune-related diseases: Anti-inflammatory and immunomodulatory mechanisms

Shikonin, the primary active compound found in the rhizome of the traditional Chinese medicinal herb known as "ZiCao", exhibits a diverse range of pharmacological effects. This drug has a wide range of uses, including as an anti-inflammatory, antioxidant, and anti-cancer agent. It is also effective in promoting wound healing and treating autoimmune diseases such as multiple sclerosis, diabetes, asthma, systemic lupus erythematosus, inflammatory bowel disease, psoriasis, and rheumatoid arthritis. Although shikonin has a wide range of applications, its mechanisms are still not fully understood. This review article provides a comprehensive overview of the recent advancements in the use of shikonin for the treatment of immune-related diseases. The article also delves into the anti-inflammatory and immunoregulatory mechanisms of shikonin and offers insights into the inflammation and immunopathogenesis of related diseases. Overall, this article serves as a valuable resource for researchers and clinicians working in this field. These findings not only provide significant new information on the effects and mechanisms of shikonin but also establish a foundation for the development of clinical applications in treating autoimmune diseases.

The extraction and anti-inflammatory screening of Onosma glomeratum Y. L. Liu

"Zicao" has a long medicinal history and has a variety of pharmacological activities. As the main resource of "zicao" in Tibet, Onosma glomeratum Y. L. Liu (tuan hua dian zi cao), usually used for treating pneumonia in Tibet, has not been reported deeply. In order to determine the main anti-inflammatory active ingredients of Onosma glomeratum Y. L. Liu, in this study, the extracts enriched in naphthoquinones and polysaccharides were optimized prepared form Onosma glomeratum Y. L. Liu by ultrasonic extraction, and reflux extraction, respectively, with Box-Behnken design effect surface method. And their anti-inflammatory abilities were screened on LPS induced A549 cells model, for figuring out the anti-inflammatory active ingredients from Onosma glomeratum Y. L. Liu.The extract enriched naphthoquinone was obtained under following condition: extract with 85% ethanol in a liquid to material ratio of 1:40 g/mL at 30 °C for 30 minutes using ultrasound, leading to the extraction rate of total naphthoquinone as 0.98 ± 0.017%; the extract enriched polysaccharides was prepared as follows: extract 82 minutes at 100 °C with distilled water in a liquid to material ratio of 1:50 g/mL, with extraction rate of polysaccharide as 7.07 ± 0.02%.On the LPS-induced A549 cell model, the polysaccharide extract from Onosma glomeratum Y. L. Liu showed better anti-inflammatory effects than the naphthoquinone extract, indicating the extract enriched in polysaccharides is the anti-inflammatory extract of Onosma glomeratum Y. L. Liu, which could serve as a potential anti-inflammatory extract in medical and food industries in the future.

Natural Plant-Derived Compounds in Food and Cosmetics: A Paradigm of Shikonin and Its Derivatives

Shikonin and its derivatives are the natural naphthoquinone compounds produced in the roots of the Boraginaceae family. These red pigments have been used for a long time in coloring silk, as food colorants, and in the Chinese traditional system of medicines The resurgence of public interest in natural and plant-based products has led to this category of compounds being in high demand due to their wide range of biological activities including antioxidant, antitumor, antifungal, anti-inflammatory ones. Different researchers worldwide have reported various applications of shikonin derivatives in the area of pharmacology. Nevertheless, the use of these compounds in the food and cosmetics fields needs to be explored more in order to make them available for commercial utilization in various food industries as a packaging material and to enhance their shelf life without any side effects. Similarly, the antioxidant properties and skin whitening effects of these bioactive molecules may be used successfully in various cosmetic formulations. The present review delves into the updated knowledge on the various properties of shikonin derivatives in relation to food and cosmetics. The pharmacological effects of these bioactive compounds are also highlighted. Based on various studies, it can be concluded that these natural bioactive molecules have potential to be used in different sectors, including functional food, food additives, skin, health care, and to cure various diseases. Further research is required for the sustainable production of these compounds with minimum disturbances to the environment and in order to make them available in the market at an economic price. Simultaneous studies utilizing recent techniques in computational biology, bioinformatics, molecular docking, and artificial intelligence in laboratory and clinical trials would further help in making these potential candidates promising alternative natural bioactive therapeutics with multiple uses.

Portrayal of NLRP3 Inflammasome in Atherosclerosis: Current Knowledge and Therapeutic Targets

We are witnessing the globalization of a specific type of arteriosclerosis with rising prevalence, incidence and an overall cardiovascular disease burden. Currently, atherosclerosis increasingly affects the younger generation as compared to previous decades. While early preventive medicine has seen improvements, research advances in laboratory and clinical investigation promise to provide us with novel diagnosis tools. Given the physio-pathological complexity and epigenetic patterns of atherosclerosis and the discovery of new molecules involved, the therapeutic field of atherosclerosis has room for substantial growth. Thus, the scientific community is currently investigating the role of nucleotide-binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, a crucial component of the innate immune system in different inflammatory disorders. NLRP3 is activated by distinct factors and numerous cellular and molecular events which trigger NLRP3 inflammasome assembly with subsequent cleavage of pro-interleukin (IL)-1β and pro-IL-18 pathways via caspase-1 activation, eliciting endothelial dysfunction, promotion of oxidative stress and the inflammation process of atherosclerosis. In this review, we introduce the basic cellular and molecular mechanisms of NLRP3 inflammasome activation and its role in atherosclerosis. We also emphasize its promising therapeutic pharmaceutical potential.

Monomeric compounds from traditional Chinese medicine: New hopes for drug discovery in pulmonary fibrosis

Pulmonary fibrosis (PF) is a chronic and irreversible pulmonary disease, and can lead to decreased lung function, respiratory failure and even death. The pathogenesis research and treatment strategy of PF significantly lag behind the medical progress and clinical needs. The treatment of this disease remains a thorny clinical problem, and the effective therapeutic drugs are still limited. Monomeric compounds from traditional Chinese medicine own various biological activities and high safety. They play a broad part in treating diseases and is also a candidate drug for preventing and treating PF. In this paper, we reviewed the mechanism of action and potential value of various anti-PF monomeric compounds from traditional Chinese medicine. These monomeric compounds can attenuate inflammatory response, oxidative stress, epithelial mesenchymal transformation and other processes of lung through many signaling pathways, and inhibit the activation and differentiation of fibroblasts, thus contributing to the treatment of PF. This review can provide new ideas for the development of anti-PF drugs in high efficiency with low toxicity.

Shikonin potentiates therapeutic efficacy of oxaliplatin through reactive oxygen species-mediated intrinsic apoptosis and endoplasmic reticulum stress in oxaliplatin-resistant colorectal cancer cells

Oxaliplatin (OXA) has been recognized as a third-generation platinum-based chemotherapeutic agent with stellar therapeutic efficacy in managing colorectal cancer (CRC). Nevertheless, resistance to OXA in CRC patients hinders its effectiveness. Shikonin (SHI), a natural naphthoquinone derived from Arnebia euchroma (Royle) Johnst., features a broad pharmacological profile and minimal toxicities. To assess the synergism of SHI and OXA towards OXA-resistant CRC cells (HCT116^R ), we employed in vitro and in vivo pharmacological assays. Our experiments provided evidence that SHI, either alone or in combination with OXA, considerably reduced cell proliferation, triggered apoptosis, and induced the generation of reactive oxygen species (ROS) in HCT116^R cells. Furthermore, the combination of SHI and OXA dramatically curbed the extent of HCT116^R -initiated xenograft growth in mouse models. Bioinformatics, western blot, and ROS assays highlighted that the mechanisms of SHI against OXA-resistant CRC cells may involve the induction of cellular responses to chemical stress, intrinsic apoptosis, as well as endoplasmic reticulum stress pathways mediated by ROS. Notably, the synergism of SHI+OXA was partially abrogated by an ROS inhibitor N-acetyl cysteine. Our findings imply the potential of SHI to boost the sensitivity of OXA to CRC, offering promising benefits for clinical strategies to combat OXA resistance.

Unveiling the Potentiality of Shikonin Derivatives Inhibiting SARS-CoV-2 Main Protease by Molecular Dynamic Simulation Studies

Shikonin, a phytochemical present in the roots of Lithospermum erythrorhizon, is well-known for its broad-spectrum activity against cancer, oxidative stress, inflammation, viruses, and anti-COVID-19 agents. A recent report based on a crystallographic study revealed a distinct conformation of shikonin binding to the SARS-CoV-2 main protease (M^pro), suggesting the possibility of designing potential inhibitors based on shikonin derivatives. The present study aimed to identify potential shikonin derivatives targeting the M^pro of COVID-19 by using molecular docking and molecular dynamics simulations. A total of 20 shikonin derivatives were screened, of which few derivatives showed higher binding affinity than shikonin. Following the MM-GBSA binding energy calculations using the docked structures, four derivatives were retained with the highest binding energy and subjected to molecular dynamics simulation. Molecular dynamics simulation studies suggested that alpha-methyl-n-butyl shikonin, beta-hydroxyisovaleryl shikonin, and lithospermidin-B interacted with two conserved residues, His41 and Cys145, through multiple bonding in the catalytic sites. This suggests that these residues may effectively suppress SARS-CoV-2 progression by inhibiting M^pro. Taken together, the present in silico study concluded that shikonin derivatives may play an influential role in M^pro inhibition.

Shikonin as a WT1 Inhibitor Promotes Promyeloid Leukemia Cell Differentiation

This study aims to observe the differentiating effect of shikonin on Wilms' tumor 1 (WT1)-positive HL-60 cells and investigate the fate of the differentiated leukemia cells. WT1 overexpression unaffected cell viability but promoted resistance to H₂O₂-induced DNA injury and cell apoptosis. The binding of shikonin to the WT1 protein was confirmed by molecular docking and drug affinity reaction target stability (DARTS). Shikonin at the non-cytotoxic concentration could decrease the WT1 protein and simultaneously reduced the CD34 protein and increased the CD11b protein in a dose-dependent manner in normal HL-60 cells but not in WT1-overexpressed HL-60 cells. Shikonin unaffected HL-60 cell viability in 48 h. However, it lasted for 10 days; could attenuate cell proliferation, mitochondrial membrane potential (MMP), and self-renewal; prevent the cell cycle; promote cell apoptosis. In a mouse leukemia model, shikonin could decrease the WT1 protein to prevent leukemia development in a dose-dependent manner. In this study, we also confirmed preliminarily the protein-protein interactions between WT1 and CD34 in molecular docking and CO-IP assay. Our results suggest that: 1. shikonin can down-regulate the WT1 protein level for leukemia differentiation therapy, and 2. the interaction between WT1 and CD34 proteins may be responsible for granulocyte/monocyte immaturity in HL-60 cells.

Experimental and clinical trial investigations of phyto-extracts, phyto-chemicals and phyto-formulations against oral lichen planus: A systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

Bio-assay guided phytoextracts and derived phytoconstituents reported having multipotent biological activities and nearly 60-80% of the global population still using natural regimens as an alternative therapeutic source. This study focused on the ethnopharmacological and experimental evidence of natural remedies that are effective in treating oral lichen planus (OLP), a chronic T-cell mediated autoimmune disease that is associated with oral cancer transmission.

AIM OF THE REVIEW

A number of studies have shown that antioxidants and antiinflammatory phytoextracts and phyto-constituents are effective against OLP. In this systematic review, we summarize the details of experimentally assessed ancient Traditional Chinese Medicine (TCM), Indian Ayurveda or Ayurvedic Medicine, and Japanese Kampo Medicine (JKM) regimens (crude extracts, individual phytochemicals, and phyto-formulations) that reduce oral lesion, severity index and pain associated with OLP based on studies conducted in vivo, in vitro, and in randomized controlled trials (RCTs).

MATERIALS AND METHODS

Experimental, clinical and RCT investigation reports were gathered and presented according to PRISMA-2020 format. Briefly, the information was obtained from PubMed, ScienceDirect, Wiley journal library, Scopus, Google Scholar with ClinicalTrials.gov (a clinical trial registry database operated by the National Library of Medicine in the United States). Further, individual phytochemical structures were verified from PubChem and ChemSpider databases and visualized by ChemDraw 18.0 software.

RESULTS

We summarized 11 crude phytoextracts, 7 individual phytochemicals, 9 crude formulations, 8 specific TCM and JKM herbal cocktails, and 6 RCTs/patents corroborated by multiple in vitro, in vivo and enzyme assay methods. Briefly, plants and their family name, used plant parts, reported phytochemicals and their chemical structure, treatment doses, and duration of each experiment were presented more concisely and scientifically.

CONCLUSION

Documentation of evidence-based natural ethnomedicines or remedies could be useful for promoting them as potential, cost-effective and less toxic alternatives or as complementary to commonly prescribed steroids towards the control of OLP.

Screening and characterization estrogen receptor ligands from Arnebia euchroma (Royle) Johnst. via affinity ultrafiltration LC-MS and molecular docking

Arnebiae Radix (dried root of Arnebia euchroma (Royle) Johnst.) is a traditional Chinese medicine (TCM) used to treat macular eruptions, measles, sore throat, carbuncles, burns, skin ulcers, and inflammations. The Arnebiae Radix extract can exert anti-breast cancer effects through various mechanisms of action. This study aimed to rapidly screen potential estrogen receptor (estrogen receptor α and estrogen receptor β) ligands from the Arnebiae Radix extract. In this study, an analytical method based on affinity ultrafiltration coupled with UHPLC-Q-Exactive Orbitrap mass spectrometry was established for rapidly screening and identifying estrogen receptor ligands. Then, bindings of the components to the active site of estrogen receptor (estrogen receptor α and estrogen receptor β) were investigated via molecular docking. Moreover, surface plasmon resonance (SPR) experiments with six compounds were performed to verify the affinity. As a result, a total of 21 ligands were screened from Arnebiae Radix using affinity ultrafiltration. Among them, 14 and 10 compounds from Arnebiae Radix showed affinity with estrogen receptor α and estrogen receptor β, respectively. All of those ligands could have a good affinity for the multiple amino acid residues of the estrogen receptor based on molecular docking. In addition, six compounds display the great affinity by SPR. The method established in the study could be used to rapidly screen estrogen receptor ligands in Traditional Chinese medicine. The results demonstrated that the affinity ultrafiltration-UHPLC-Q-Exactive Orbitrap mass spectrometry method not only aids in the interpretation of the potential bioactive components and possible mechanisms of action of Arnebiae Radix but also provides a further effective basis for the quality control of this valuable herb medicine.

Shikonin Functionalized Packaging Film for Monitoring the Freshness of Shrimp

A shikonin embedded smart and active food packaging film was produced using a binary mixture of gelatin and cellulose nanofiber (CNF). Shikonin is an alcohol-soluble natural pigment extracted from Lithospermum erythrorhizon root. The fabricated film showed good pH-responsive color changes and volatile gas sensing properties. Moreover, the film exhibited excellent antioxidant and antibacterial activity against foodborne pathogens. The shikonin incorporated gelatin/CNF-based film showed excellent UV-light barrier properties (>95%) and high tensile strength (>80 MPa), which is useful for food packaging. The hydrodynamic properties of the film were also slightly changed in the presence of shikonin, but the thermal stability and water vapor permeability remained unaffected. Thus, the inclusion of shikonin in the gelatin/CNF-based film improves not only the physical properties but also the functional properties. The film’s color indicator properties also clearly show shrimp’s freshness and spoilage during storage for 48 h. The shikonin-based functional film is expected to be a promising tool for multi-purpose smart and active food packaging applications.

Effects of Alkanna bracteosa extract on the expression level of HSP90α and HER2 genes in human gastric cancer cell line

Gastric cancer was classified as the third most deadly cancer among all other cancer types. The HSP90 and HER2 genes play essential roles in the stability and function of high-expression proteins that cause malignancy. The aim of this research was to investigate the influence of the alcoholic Alkanna bracteosa extract on the expression of HSP90α and HER2 genes in AGS cell line. Therefore, the methanolic extraction was isolated from aerial parts of the plant and AGS and HuGu cell lines were analyzed using 102.4–0.05 mg ml⁻¹ dose concentrations in serial dilution; to measure the cell toxicity by MTT assay. Furthermore, real-time PCR analysis measured the expression level of HSP90α and HER2 genes using the IC50 dose concentrations. Quantification of apoptosis was analyzed by Annexin/PI kit in flow cytometry and DNA fragmentation tests. The results of MTT assay represented the IC50 dose concentration of 0.8 and 3.2 mg ml⁻¹ for AGS and HuGu respectively. The rate of HER2 gene expression was significantly decreased in AGS cells treated with 0.8 mg ml⁻¹ dose concentration compared to control. The exposure of AGS treated cells with 0.8 mg ml⁻¹ dose concentration after 24 h represented 24.3% apoptosis and 13.3% necrosis. The agarose gel represented the DNA fragmentation pattern of apoptosis. This study demonstrated the significant differences between the cell viability rate, gene expression level, and apoptosis of the Alkanna bracteosa extract on AGS cells. These results demonstrated the first report of which the Alkanna braceteosa would be an effective candidate for possible treatment of Gastric cancer.

ROS-triggered cycle amplification effect: A prodrug activation nanoamplifier for tumor-specific therapy

Selective in situ activation of prodrugs or generation of bioactive drugs is an important approach to reducing the side effects of chemotherapy. Herein, a tailored ROS-activable prodrug nanomedicine (Cu-SK@DTC-PPB) was developed as the prodrug activation nanoamplifier for highly selective antitumor therapy. Cu-SK@DTC-PPB was rationally constructed by the diethyldithiocarbamate (DTC) prodrug DTC-PPB and the nanoscale coordinated framework Cu-SK based on copper and the ROS generator shikonin (SK). Cu²⁺, SK and DTC were kept in the inactive state in the fabricated Cu-SK@DTC-PPB. In the presence of ROS within tumors, DTC-PPB can be activated to release less cytotoxic DTC, which can rapidly chelate Cu²⁺ from the Cu-SK framework to synthesize highly cytotoxic Cu(DTC)₂ and induce SK to release in a cascade. The released SK can generate ROS to increase the intracellular ROS level, further activating DTC-PPB to release more DTC. That is, Cu-SK@DTC-PPB can undergo a self-amplifying positive feedback loop to induce numerous bioactive Cu(DTC)₂ formation and SK release triggered by a small amount of ROS within the tumor microenvironment, which endows the transformation of "less toxic-to-high toxic" and thus significantly improve its selectivity towards tumors. Therefore, this study provides a new strategy of prodrug activation for tumor therapy with high efficiency and low toxicity. STATEMENT OF SIGNIFICANCE: Owing to the striking difference in ROS level between cancer cells and normal cells, ROS-responsive prodrugs are regarded as a promising approach for tumor-specific therapy. However, the stability and responsiveness of prodrugs are hard to balance. Preferable sensitivity may cause premature activation while favorable stability may lead to incomplete prodrug activation and insufficient active drug release. This study provides a tailored ROS-responsive prodrug activation nanoamplifier with favorable stability and effective prodrug activation capacity. The nanoamplifier can undergo a self-amplifying positive feedback loop to achieve numerous bioactive drugs generation in situ under ROS triggers within the tumor microenvironment, showing the enhanced antitumor therapeutic effect. Thus, this study provides a new strategy for prodrug activation and tumor-specific therapy.

Survival and clinicopathological significance of PYCR1 expression in cancer: A meta-analysis

Background

Proline metabolism is closely related to the occurrence and development of cancer. Δ1-Pyrroline-5-carboxylate reductase (PYCR) is the last enzyme in proline biosynthesis. As one of the enzyme types, PYCR1 takes part in the whole process of the growth, invasion, and drug resistance of cancer cells. This study investigated PYCR1 expressions in cancers together with their relationship to clinical prognosis.

Methods

A thorough database search was performed in PubMed, EMBASE, and Cochrane Library. RevMan5.3 software was used for the statistical analysis.

Results

Eight articles were selected, and 728 cancer patients were enrolled. The cancer types include lung, stomach, pancreatic ductal adenocarcinoma, hepatocellular carcinoma, and renal cell carcinoma. The meta-analysis results showed that the expression of PYCR1 was higher in the clinical stage III–IV group than that in the clinical stage I–II group (OR = 1.67, 95%CI: 1.03–2.71), higher in the lymph node metastasis group than in the non-lymph node metastasis group (OR = 1.57, 95%CI: 1.06–2.33), and higher in the distant metastasis group than in the non-distant metastasis group (OR = 3.46, 95%CI: 1.64–7.29). However, there was no statistical difference in PYCR1 expression between different tumor sizes (OR = 1.50, 95%CI: 0.89–2.53) and degrees of differentiation (OR = 0.82, 95%CI: 0.54–1.24).

Conclusion

PYCR1 had a high expression in various cancers and was associated with cancer volume and metastasis. The higher the PYCR1 expression was, the poorer the cancer prognosis was. The molecular events and biological processes mediated by PYCR1 might be the underlying mechanisms of metastasis.

A Discovery Strategy for Active Compounds of Chinese Medicine Based on the Prediction Model of Compound-Disease Relationship

An accurate characterization of diseases and compounds is the key to predicting the compound-disease relationship (CDR). However, due to the difficulty of a comprehensive description of CDR, the accuracy of traditional drug development models for large-scale CDR prediction is usually unsatisfactory. In order to solve this problem, we propose a new method that integrates the molecular descriptors of compounds and the symptom descriptors of diseases to build a CDR two-dimensional matrix to predict candidate active compounds. The Matlab software draws grayscale images of CDRs, which are used as a benchmark dataset for training convolutional neural network (CNN) models. The trained model is used to predict candidate antitumor active compounds. Among the AlexNet and GoogLeNet models, we selected the GoogLeNet model for the prediction of active compounds in Chinese medicine, and its Acc, Sen, Pre, F-measure, MCC, and AUC are 0.960, 0.956, 0.965, 0.960, 0.920, and 0.964, respectively. In the prediction results of compounds, 1624 candidate CDRs were found in 124 Chinese medicines. Among them, we obtained 31 features of candidate antitumor active compounds. This method provides new insights for the discovery of candidate active compounds in Chinese medicine.

Shikonin inhibits the proliferation of cervical cancer cells via FAK/AKT/GSK3β signalling

Cervical cancer is one of the most lethal malignancies of the female reproductive system. Shikonin, a naphthoquinone pigment extracted from the traditional medicinal herb, Lithospermum erythrorhizon, has been demonstrated to exert significant inhibitory effects on a variety of tumours in vitro and in vivo. In the present study, the effects of shikonin on cervical cancer and the underlying mechanisms were investigated. The effects of shikonin on the viability on HeLa and SiHa cervical cancer cells was examined using cell counting kit (CCK-8) and colony formation assays. Immunofluorescence assay was performed to detect the levels of the proliferation-related protein, Ki67. Western blot analysis was utilized to measure the phosphorylated and total expression levels of proteins, including focal adhesion kinase (FAK), AKT, and glycogen synthase kinase 3β (GSK3β). Cell migration was determined by using wound healing assay. Metastasis-associated 1 (MTA1), TGFβ1 and VEGF mRNA expression levels were determined using reverse transcription-quantitative PCR. It was demonstrated that, shikonin inhibited cervical cancer cell proliferation and migration. The data of the present study revealed that shikonin inhibited the proliferation of HeLa and SiHa cells in a concentration- and time-dependent manner. Mechanistically, shikonin blocked the proliferation of cervical cancer cells by downregulating the phosphorylation of FAK, AKT and GSK3β induced by EGF. In addition, shikonin significantly suppressed cell migration and reduced the expression of migration-related proteins, including MTA1, TGFβ1 and VEGF. On the whole, the present study demonstrates that shikonin may exert an inhibitory effect on the cervical cancer cell proliferation and migration through the FAK/AKT/GSK3β signaling pathway. These findings suggest that shikonin may function as a potential therapeutic drug for the treatment of cervical cancer.

Review of Shikonin and Derivatives: Isolation, Chemistry, Biosynthesis, Pharmacology and Toxicology

Shikonin and its derivatives, isolated from traditional medicinal plant species of the genus Lithospermum, Alkanna, Arnebia, Anchusa, Onosma, and Echium belonging to the Boraginaceae family, have numerous applications in foods, cosmetics, and textiles. Shikonin, a potent bioactive red pigment, has been used in traditional medicinal systems to cure various ailments and is well known for its diverse pharmacological potential such as anticancer, antithrombotic, neuroprotective, antidiabetic, antiviral, anti-inflammatory, anti-gonadotropic, antioxidants, antimicrobial and insecticidal. Herein, updated research on the natural sources, pharmacology, toxicity studies, and various patents filed worldwide related to shikonin and approaches to shikonin’s biogenic and chemical synthesis are reviewed. Furthermore, recent studies to establish reliable production systems to meet market demand, functional identification, and future clinical development of shikonin and its derivatives against various diseases are presented.

The NLRP3 Inflammasome Pathway: A Review of Mechanisms and Inhibitors for the Treatment of Inflammatory Diseases

The NLRP3 inflammasome is a multiprotein complex that plays a pivotal role in regulating the innate immune system and inflammatory signaling. Upon activation by PAMPs and DAMPs, NLRP3 oligomerizes and activates caspase-1 which initiates the processing and release of pro-inflammatory cytokines IL-1β and IL-18. NLRP3 is the most extensively studied inflammasome to date due to its array of activators and aberrant activation in several inflammatory diseases. Studies using small molecules and biologics targeting the NLRP3 inflammasome pathway have shown positive outcomes in treating various disease pathologies by blocking chronic inflammation. In this review, we discuss the recent advances in understanding the NLRP3 mechanism, its role in disease pathology, and provide a broad review of therapeutics discovered to target the NLRP3 pathway and their challenges.

Phylogenomics and Genetic Diversity of Arnebiae Radix and Its Allies (Arnebia, Boraginaceae) in China

Arnebiae Radix is a traditional medicine with pleiotropic properties that has been used for several 100 years. There are five species of Arnebia in China, and the two species Arnebia euchroma and Arnebia guttata are the source plants of Arnebiae Radix according to the Chinese Pharmacopoeia. Molecular markers that permit species identification and facilitate studies of the genetic diversity and divergence of the wild populations of these two source plants have not yet been developed. Here, we sequenced the chloroplast genomes of 56 samples of five Arnebia species using genome skimming methods. The Arnebia chloroplast genomes exhibited quadripartite structures with lengths from 149,539 and 152,040 bp. Three variable markers (rps16-trnQ, ndhF-rpl32, and ycf1b) were identified, and these markers exhibited more variable sites than universal chloroplast markers. The phylogenetic relationships among the five Arnebia species were completely resolved using the whole chloroplast genome sequences. Arnebia arose during the Oligocene and diversified in the middle Miocene; this coincided with two geological events during the late Oligocene and early Miocene: warming and the progressive uplift of Tianshan and the Himalayas. Our analyses revealed that A. euchroma and A. guttata have high levels of genetic diversity and comprise two and three subclades, respectively. The two clades of A. euchroma exhibited significant genetic differences and diverged at 10.18 Ma in the middle Miocene. Three clades of A. guttata diverged in the Pleistocene. The results provided new insight into evolutionary history of Arnebia species and promoted the conservation and exploitation of A. euchroma and A. guttata.

Shikonin induces apoptosis and autophagy via downregulation of pyrroline-5-carboxylate reductase1 in hepatocellular carcinoma cells

Shikonin(SK) is a natural small molecule naphthoquinone compound, which has anti-cancer activity in various human malignant tumors. Pyrroline-5-carboxylate reductase 1(PYCR1) is involved in tumorigenesis and regulates various cellular processes, including growth, invasion, migration, and apoptosis. However, the effect of SK and PYCR1 on apoptosis and autophagy in hepatocellular carcinoma are unclear. Our goal is to determine the internal molecular mechanism of the interaction between SK and PYCR1 and its role in the occurrence and development of liver cancer. The CCK8 assay, wound healing assay, and transwell assays show that SK and siPYCR1(gene silence PYCR1) inhibited the malignant phenotype of HCC cells, including cell viability, colony formation, migration, and invasion, respectively. The flow cytometry assays and immunofluorescence show that SK and siPYCR1 activated apoptosis and autophagy, respectively. SK induces apoptosis and autophagy in a dose-dependent manner. In addition, HCC cells were transfected with small interference fragment PYCR1 siRNA to construct siPYCR1 and SK single treatment group and co-treatment group to verify the interaction between SK and PYCR1. The Western blot identified that PI3K/Akt/mTOR signal pathway protein expression was significantly downregulated in HCC cells treated with SK and siPYCR1 together. Collectively, SK may induce apoptosis and autophagy by reducing the expression of PYCR1 and suppressing PI3K/Akt/mTOR. Thus, SK may be a promising antineoplastic drug in Hepatocellular carcinoma (HCC). SK downregulating PYCR1 might supply a theoretical foundation for the potential therapeutic application in hepatocellular carcinoma.

Chemical screen identifies shikonin as a broad DNA damage response inhibitor that enhances chemotherapy through inhibiting ATM and ATR

DNA damage response (DDR) is a highly conserved genome surveillance mechanism that preserves cell viability in the presence of chemotherapeutic drugs. Hence, small molecules that inhibit DDR are expected to enhance the anti-cancer effect of chemotherapy. Through a recent chemical library screen, we identified shikonin as an inhibitor that strongly suppressed DDR activated by various chemotherapeutic drugs in cancer cell lines derived from different origins. Mechanistically, shikonin inhibited the activation of ataxia telangiectasia mutated (ATM), and to a lesser degree ATM and RAD3-related (ATR), two master upstream regulators of the DDR signal, through inducing degradation of ATM and ATR-interacting protein (ATRIP), an obligate associating protein of ATR, respectively. As a result of DDR inhibition, shikonin enhanced the anti-cancer effect of chemotherapeutic drugs in both cell cultures and in mouse models. While degradation of ATRIP is proteasome dependent, that of ATM depends on caspase- and lysosome-, but not proteasome. Overexpression of ATM significantly mitigated DDR inhibition and cell death induced by shikonin and chemotherapeutic drugs. These novel findings reveal shikonin as a pan DDR inhibitor and identify ATM as a primary factor in determining the chemo sensitizing effect of shikonin. Our data may facilitate the development of shikonin and its derivatives as potential chemotherapy sensitizers through inducing ATM degradation.

Integrative analysis of the shikonin metabolic network identifies new gene connections and reveals evolutionary insight into shikonin biosynthesis

Plant specialized 1,4-naphthoquinones present a remarkable case of convergent evolution. Species across multiple discrete orders of vascular plants produce diverse 1,4-naphthoquinones via one of several pathways using different metabolic precursors. Evolution of these pathways was preceded by events of metabolic innovation and many appear to share connections with biosynthesis of photosynthetic or respiratory quinones. Here, we sought to shed light on the metabolic connections linking shikonin biosynthesis with its precursor pathways and on the origins of shiknoin metabolic genes. Downregulation of Lithospermum erythrorhizon geranyl diphosphate synthase (LeGPPS), recently shown to have been recruited from a cytoplasmic farnesyl diphosphate synthase (FPPS), resulted in reduced shikonin production and a decrease in expression of mevalonic acid and phenylpropanoid pathway genes. Next, we used LeGPPS and other known shikonin pathway genes to build a coexpression network model for identifying new gene connections to shikonin metabolism. Integrative in silico analyses of network genes revealed candidates for biochemical steps in the shikonin pathway arising from Boraginales-specific gene family expansion. Multiple genes in the shikonin coexpression network were also discovered to have originated from duplication of ubiquinone pathway genes. Taken together, our study provides evidence for transcriptional crosstalk between shikonin biosynthesis and its precursor pathways, identifies several shikonin pathway gene candidates and their evolutionary histories, and establishes additional evolutionary links between shikonin and ubiquinone metabolism. Moreover, we demonstrate that global coexpression analysis using limited transcriptomic data obtained from targeted experiments is effective for identifying gene connections within a defined metabolic network.

Therapeutic Effects of Shikonin on Skin Diseases: A Review

Shikonin is one of the primary active components extracted from the dried root ofZicao (Lithospermum erythrorhizon, Onosma paniculata, or Arnebia euchroma), a traditional Chinese herbal medicine. Shikonin is known to not only exert anti-proliferative, anti-inflammatory, and anti-angiogenic activities, but also play a crucial role in triggering the production of reactive oxygen species, suppressing the release of exosomes, and inducing apoptosis. Increasing evidence suggests that shikonin has a protective effect against skin diseases, including psoriasis, melanoma, and hypertrophic scars. In order to evaluate the application potential of shikonin in the treatment of skin diseases, this review is the first of its kind to provide comprehensive and up-to-date information regarding the uses of shikonin and its derivatives on skin diseases and its underlying mechanisms. In this review, we have focused on the signaling pathways and cellular targets involved in the anti-dermatosis effects of shikonin to bridge the gaps in the literature, thereby providing scientific support for the research and development of new drugs from a traditional medicinal plant.

Shikonin induced Apoptosis Mediated by Endoplasmic Reticulum Stress in Colorectal Cancer Cells

Shikonin is a naphthoquinone pigment isolated from the root of Lithospermum erythrorhizon, which has displayed potent anti-tumor properties. However, the effects of shikonin in colorectal cancer cells have not been yet fully investigated. In this study, we demonstrated that shikonin significantly inhibited the activity of colorectal cancer cells in a time- and dose-dependent manner. The flow cytometry and western blot results indicated that shikonin induced cell apoptosis by down-regulating BCL-2 and activating caspase-3/9 and the cleavage of PARP. The expression of BiP and the PERK/elF2α/ATF4/CHOP and IRE1α /JNK signaling pathways were upregulated after shikonin treatment. The pre-treatment with N-acetyl cysteine significantly reduced the cytotoxicity of shikonin. Taken together, shikonin could inhibit proliferation of the colorectal cancer cell through the activation of ROS mediated-ER stress. The in vivo results showed that shikonin effectively inhibited tumor growth in the HCT-116 and HCT-15 xenograft models. In conclusion, shikonin inhibited the proliferation of colorectal cancer cells in vitro and in vivo and warrants future investigation.

Shikonin, a naphthalene ingredient: Therapeutic actions, pharmacokinetics, toxicology, clinical trials and pharmaceutical researches

BACKGROUND

Shikonin is one of the major phytochemical components of Lithospermum erythrorhizon (Purple Cromwell), which is a type of medicinal herb broadly utilized in traditional Chinese medicine. It is well established that shikonin possesses remarkable therapeutic actions on various diseases, with the underlying mechanisms, pharmacokinetics and toxicological effects elusive. Also, the clinical trial and pharmaceutical study of shikonin remain to be comprehensively delineated.

PURPOSE

The present review aimed to systematically summarize the updated knowledge regarding the therapeutic actions, pharmacokinetics, toxicological effects, clinical trial and pharmaceutical study of shikonin.

METHODS

The information contained in this review article were retrieved from some authoritative databases including Web of Science, PubMed, Google scholar, Chinese National Knowledge Infrastructure (CNKI), Wanfang Database and so on, till August 2021.

RESULTS

Shikonin exerts multiple therapeutic efficacies, such as anti-inflammation, anti-cancer, cardiovascular protection, anti-microbiomes, analgesia, anti-obesity, brain protection, and so on, mainly by regulating the NF-κB, PI3K/Akt/MAPKs, Akt/mTOR, TGF-β, GSK3β, TLR4/Akt signaling pathways, NLRP3 inflammasome, reactive oxygen stress, Bax/Bcl-2, etc. In terms of pharmacokinetics, shikonin has an unfavorable oral bioavailability, 64.6% of the binding rate of plasma protein, and enhances some metabolic enzymes, particularly including cytochrome P450. In regard to the toxicological effects, shikonin may potentially cause nephrotoxicity and skin allergy. The above pharmacodynamics and pharmacokinetics of shikonin have been validated by few clinical trials. In addition, pharmaceutical innovation of shikonin with novel drug delivery system such as nanoparticles, liposomes, microemulsions, nanogel, cyclodextrin complexes, micelles and polymers are beneficial to the development of shikonin-based drugs.

CONCLUSIONS

Shikonin is a promising phytochemical for drug candidates. Extensive and intensive explorations on shikonin are warranted to expedite the utilization of shikonin-based drugs in the clinical setting.

Anti-cancer Research on Arnebiae Radix-derived Naphthoquinone in Recent Five Years

BACKGROUND

In recent years, many naphthoquinone compounds with anticancer activity have been identified in Arnebiae Radix, and some of them have the potential to be developed into anticancer drugs.

OBJECTIVE

This article aimed to provide a comprehensive overview of the anticancer effects of naphthoquinone compounds through a detailed review of literature and Chinese patents, and discuss their potential to be developed as anticancer drugs for clinical application.

METHODS

Research papers were collected through the databases of PubMed, Cnki and SciDirect using keyword searches "naphthoquinone compounds" and "anticancer". The keywords of "shikonin" and "shikonin derivatives" were also used in PubMed, Cnki and SciDirect databases to collect research articles. The Chinese patents were collected using the Cnki patent database.

RESULTS

Naphthoquinone compounds have been found to possess anti-cancer activity, and their modes of action are associated with inducing apoptosis, inhibiting cancer cell proliferation, promoting autophagy in cancer cells, anti-cancer angiogenesis and inhibition of cell adhesion, invasion and metastasis, inhibiting glycolysis and inhibiting DNA topoisomerase activity.

CONCLUSION

Most of the naphthoquinone compounds show effective anti-cancer activity in vitro. The structure modification of naphthoquinone aims to develop anti-cancer drugs with high efficacy and low toxicity.

Shikonin Induced Program Cell Death through Generation of Reactive Oxygen Species in Renal Cancer Cells

Shikonin mitigated tumor cell proliferation by elevating reactive oxygen species (ROS) levels. Herein, we investigated the effects of shikonin on renal cancer cell (RCC) cell proliferation. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated that shikonin dose-dependently reduced the proliferation of Caki-1 and ACHN cells. Shikonin remarkably triggered necrosis and apoptosis in Caki-1 and ACHN cells in proportion to its concentration. Moreover, necrostatin-1 recovered cell viability in the presence of shikonin. Elevated ROS levels and mitochondrial dysfunction were also found in shikonin treatment groups. Pretreatment with N-acetyl cysteine remarkably mitigated shikonin-induced cell death and ROS generation. Western blot analysis revealed that shikonin reduced pro-PARP, pro-caspase-3, and Bcl-2 expression and increased cleavage PARP expression. Enhanced autophagy was also found in the shikonin-treated group as evidenced by acridine orange staining. Moreover, light chain 3B (LC3B)-II accumulation and enhanced p62 expression indicated that autophagy occurred in the shikonin-treated group. LC3B knockdown considerably recovered cell viability in the presence of shikonin. Shikonin treatment elevated p38 activity in a dose-dependent manner. In conclusion, our results revealed that shikonin triggered programmed cell death via the elevation of ROS level and p38 activity in different types of RCC cells. These findings suggested that shikonin may be a potential anti-RCC agent.

A Focused Review of Synthetic Applications of Lawesson's Reagent in Organic Synthesis

Lawesson's reagent (LR) is a well-known classic example of a compound with unique construction and unusual chemical behavior, with a wide range of applications in synthetic organic chemistry. Its main functions were rounded for the thionation of various carbonyl groups in the early days, with exemplary results. However, the role of Lawesson's reagent in synthesis has changed drastically, and now its use can help the chemistry community to understand innovative ideas. These include constructing biologically valuable heterocycles, coupling reactions, and the thionation of natural compounds. The ease of availability and the convenient usage of LR as a thionating agent made us compile a review on the new diverse applications on some common functional groups, such as ketones, esters, amides, alcohols, and carboxylic acids, with biological applications. Since the applications of LR are now diverse, we have also included some new classes of heterocycles such as thiazepines, phosphine sulfides, thiophenes, and organothiophosphorus compounds. Thionation of some biologically essential steroids and terpenoids has also been compiled. This review discusses the recent insights into and synthetic applications of this famous reagent from 2009 to January 2021.

Shikonin Inhibits Non-Small-Cell Lung Cancer H1299 Cell Growth through Survivin Signaling Pathway

Overexpressed survivin is associated with worse survival of several types of human tumors. In this study, the antitumor activity of shikonin in non-small-cell lung cancer (NSCLC) by regulating survivin pathway was investigated. Results showed that shikonin inhibited the NSCLC H1299 cell proliferation in a dose-dependent manner. Moreover, shikonin fits well with survivin by molecular docking. Shikonin also inhibited the mRNA expression and protein level of survivin in H1299 cells. Shikonin arrested H1299 cell cycle at the G0/G1 phase by regulating CDK/cyclin family members. In addition, shikonin regulated the expression of X-linked inhibitor of apoptosis- (XIAP-) mediated caspases 3 and 9, thus leading to the damage of mitochondrial membrane potential and induction of H1299 cell apoptosis. Overall, shikonin inhibited H1299 cell growth by inducing apoptosis and blocking the cell cycle. The underlying mechanism involves targeting survivin, which subsequently regulates the protein expression of XIAP/caspase 3/9, CDK2/4, and cyclin E/D1. Thus, shikonin, a survivin inhibitor, is a promising therapeutic strategy in NSCLC treatment.

Shikonin suppresses the epithelial-to-mesenchymal transition by downregulating NHE1 in bladder cancer cells

Shikonin (SK) is the major bioactive component extracted from the roots of Lithospermum erythrorhizon with anticancer activity. SK could inhibit the epithelial-to-mesenchymal transition (EMT) of cancer cells. However, the underlying mechanism is elusive. In the present study, the inhibitory activities of SK on proliferation, invasion and migration were examined in bladder cancer (BC) cells. SK potently decreased the viabilities of BC cells but showed less cytotoxicity to normal bladder epithelial cells. Moreover, SK reversed the EMT, suppressed the migration and invasion of BC cells. Intriguingly, NHE1, the major proton efflux pump, was dramatically down-regulated by SK. The EMT-inhibitory effect of SK was mediated by NHE1 down-regulation, as NHE1-overexpress alleviated while Cariporide (NHE1 inhibitor) enhanced this effect. Further, enforced alkalinization of intracellular pH (pHi) reversed the EMT-inhibitory effect of SK, indicating a key role of acidic pHi in this process. Finally, elevated NHE1 expression was observed in human bladder cancer tissues. Collectively, this research reveals a supportive effect of NHE1 and alkaline pHi on EMT. SK can suppress EMT through inhibiting NHE1 and hence inducing an acidic pHi.

Phenolic Compounds of Rumex roseus L. Extracts and Their Effect as Antioxidant and Cytotoxic Activities

Rumex roseus L. (R. roseus) is acknowledged as an aromatic plant. For its excellent biological properties, it was used as a traditional medicine. The aim of the present study is to evaluate the chemical components and their effect as the biological activities of Tunisian extracts of R. roseus. Consecutive extractions by cold maceration of the aerial part with solvents of increasing polarity (cyclohexane (CYH), dichloromethane (DCM), and methanol (MeOH)) were performed, and the different chemical groups (phenolics, flavonoids, tannins, anthocyanins, etc.) were identified. In addition, the volatile compounds of the obtained extracts were identified before and after derivatization. Moreover, their antioxidant and anticancer activities were evaluated. The analysis of HPLC-DAD revealed the identification of 18 components from organic extracts, among them are, for example, chlorogenic acid and shikonin, while GC-MS analysis allowed the detection of 34 volatile compounds. Some of those compounds were identified for the first time in plant extracts such as pyrazolo[3,4-d] pyrimidine-3,4(2H,5H)-dione (1); L-proline (16); 2-amino-3-hydroxybutanoic acid (19); L-(-)-arabitol (23); D-(-)-fructopyranose (25); and D-(+)-talopyranose (27). DPPH tests revealed that the most important antioxidant activity was found in the methanolic extract with 75.2% inhibition at 50 mg/L and that the highest cytotoxic activity against HCT-116 and MCF-7 was recorded in the dichloromethane extract with 62.1 and 80.0% inhibition at 50 mg/L, respectively. The biological activities were fully correlated with the chemical composition of the different extracts. So, we can suggest that R. roseus is a source of bioactive molecules that could be considered potential alternatives for use in dietary supplements for the prevention or treatment of diseases.

Shikonin attenuates rheumatoid arthritis by targeting SOCS1/JAK/STAT signaling pathway of fibroblast like synoviocytes

Background

Rheumatoid arthritis is a progressive and systemic autoimmune disease seriously compromises human health. Fibroblast like synoviocytes are the major effectors of proliferation and inflammation in rheumatoid arthritis synovial tissue. Shikonin has anti-inflammatory and immunomodulatory activities. But, its role on synovitis of rheumatoid arthritis is unknown.

Methods

The DBA/1 male mice were randomly divided into the following three groups (n = 6): (1) the normal control group of mice, (2) the CIA (collagen-induced arthritis) group in which mice suffered from arthritis induced by collagen, (3) the SKN (shikonin) group of mice which got arthritis and given intragastrically with shikonin 4 mg/kg per day continuously for 20 days,(4) the MTX (methotrexate) group of mice which got arthritis and orally administration with shikonin 0.5  mg/kg once two days continuously for 20 days. The therapeutic effect of shikonin on collagen induced arthritis mice was tested by arthritis incidence rate, arthritis score and inflammatory joint histopathology. The invasion, adhesion and migration of fibroblast like synoviocytes induced by tumor necrosis factor-α were applied to measure the anti-synovitis role of shikonin. The effect of shikonin on expression of interleukin-6, interleukin-1β and tumor necrosis factor-α was measured by enzyme linked immunosorbent assay. The interaction between shikonin and suppressor of cytokine signaling 1 was verified by molecular docking. The signaling pathways activated by shikonin were measured by western blot.

Results

Shikonin decreased the arthritis score and arthritis incidence, and inhibited inflammation of inflamed joints in collagen induced arthritis mice. And shikonin reduced the number of vimentin⁺cells in collagen induced arthritis mice inflamed joints. Meanwhile, shikonin suppressed tumor necrosis factor-α-induced invasion, adhesion and migration of fibroblast like synoviocytes and reduced the expression of interleukin-6, interleukin-1β and tumor necrosis factor-α. And we found that shikonin targeted suppressor of cytokine signaling 1. More interestingly, shikonin blocked the phosphorylation of Janus kinase 1/signal transducer andactivator of transcription 1/signal transducer andactivator of transcription 6 in synovial tissues and in fibroblast like synoviocytes.

Conclusion

Shikonin represents a promising new anti-rheumatoid arthritis drug candidate that has anti-synovitis effect in collagen induced arthritis mice and inhibits tumor necrosis factor-α-induced fibroblast like synoviocytes by targeting suppressor of cytokine signaling 1/ Janus kinase/signal transducer andactivator of transcription signaling pathway. These findings demonstrate that shikonin has anti-synovitis effect and has great potential to be a new drug for the treatment of rheumatoid arthritis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-021-00510-6.

Phytochemical Composition, Antioxidant, Antiacetylcholinesterase, and Cytotoxic Activities of Rumex crispus L

Rumex crispus L. (R. crispus) is regarded as an aromatic plant. It was used for its excellent biological properties in traditional medicine. The aerial part was extracted successively by maceration with three solvents increasing polarity (cyclohexane (CYH), dichloromethane (DCM), and methanol (MeOH)) to evaluate their chemical compositions and biological activities. The extracts were rich in phenolic compounds (13.0 to 249.8 mg GAE/g of dry weight (dw)). The MeOH extract has presented remarkable IC₅₀ = 6.2 μg/mL for anti-DPPH and 31.6 μg/mL for anti-AChE. However, the DCM extract has the highest cytotoxic activity against the two cancer cells (HCT-116 and MCF-7) (69.2 and 77.2% inhibition at 50 μg/mL, respectively). Interestingly, GC-MS analysis enabled to identify three new compounds in R. crispus extracts, such as L-(−)-arabitol (5), D-(−) fructopyranose (7) detected only in MeOH extract, and 2, 5-dihydroxyacetophenone (3) detected in all extracts. For HPLC chromatograms, cardamonin (8), 5-hydroxy-3′-methoxyflavone (17), and 3′-hydroxy-b-naphthoflavone (18) showed the highest concentrations of 74.0, 55.5, and 50.4 mg/g of dw, respectively, among others who are identified. Some phenolic compounds were identified and quantified by HPLC in more than one organic extract, such as 4′, 5-dihydroxy-7-methoxyflavone (13), 4′, 5-dihydroxy-7-methoxyflavone (14), 5-hydroxy-3′-methoxyflavone (17), and 3′-hydroxy-b-naphthoflavone (18), were found for the first time in the R. crispus extracts. Our results showed that the biological activities of this plant might be linked to their phenolic compounds and that the polar extracts could be considered as new natural supplements to be used in food and pharmaceuticals.

Shikonin inhibits the Warburg effect, cell proliferation, invasion and migration by downregulating PFKFB2 expression in lung cancer

Lung cancer is one of the most lethal diseases and therefore poses a significant threat to human health. The Warburg effect, which is the observation that cancer cells predominately produce energy through glycolysis, even under aerobic conditions, is a hallmark of cancer. 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 2 (PFKFB) is an important regulator of glycolysis. Shikonin is a Traditional Chinese herbal medicine, which has been reported to exert antitumor effects. The present study aimed to investigate the anticancer activity of shikonin in lung cancer. Cell Counting Kit-8 (CCK-8) and colony formation assays were used to analyze proliferation in A549 and H446 cells. Wound healing and Transwell assays were used to measure migration and invasion in A549 and H446 cells. Cell apoptosis was analyzed using flow cytometry. Lactate levels, glucose uptake and cellular ATP levels were measured using their corresponding commercial kits. Western blotting was performed to analyze the protein expression levels of key enzymes involved in aerobic glucose metabolism. Reverse transcription-quantitative PCR was used to analyze the mRNA expression levels of PFKFB2. The results of the present study revealed that PFKFB2 expression levels were significantly upregulated in NSCLC tissues. Shikonin treatment decreased the proliferation, migration, invasion, glucose uptake, lactate levels, ATP levels and PFKFB2 expression levels and increased apoptosis in lung cancer cells in a dose-dependent manner. The overexpression of PFKFB2 increased the proliferation, migration, glucose uptake, lactate levels and ATP levels in lung cancer cells, while the knockdown of PFKFB2 expression exerted the opposite effects. Moreover, there were no significant differences in lung cancer cell migration, apoptosis, glucose uptake, lactate levels and ATP levels between cells with knocked down PFKFB2 expression or treated with shikonin and the knockdown of PFKFB2 in cells treated with shikonin. In conclusion, the results of the present study revealed that shikonin inhibited the Warburg effect and exerted antitumor activity in lung cancer cells, which was associated with the downregulation of PFKFB2 expression.