Oridonin enhances cytotoxic activity of natural killer cells against lung cancer

Rabdosia rubescens (Hemsl.) H. Hara: A potent anti-tumor herbal remedy - Botany, phytochemistry, and clinical applications and insights

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese herbal medicine has unique advantages as anti-cancer drugs and adjuvant therapies. Rabdosia rubescens (Hemsl.) H. Hara (R. rubescens) is a traditional medicinal plant known for its anti-inflammatory, antioxidant, antibacterial, anti-angiogenic and antitumor properties. The antitumor activity of R. rubescens is widely recognized among the folk communities in Henan Province, China.

AIM OF THE STUDY

This study reviews the botany, ethnopharmacology, phytochemistry, anti-tumor active ingredients, mechanisms, and clinical applications of R. rubescens, aiming to provide a comprehensive understanding for its use as an anti-cancer drug and adjuvant therapy.

MATERIALS AND METHODS

We systematically searched the literature in PubMed, Web of Science, and CNKI using the following keywords: "Rabdosia rubescens", "Isodon rubescens", "traditional application", "anti-tumor", "phytochemistry", "anti-tumor active compounds", "oridonin" and "clinical application". The search covered publications from 1997 to 2024. Inclusion criteria included original studies or reviews focusing on the anti-tumor properties of R. rubescens or its active components. Exclusion criteria included studies related to non-R. rubescens applications.

RESULTS

R. rubescens is a perennial herbaceous plant in the family Lamiaceae, mainly found in central and southern China. Historically, it has been used to treat conditions such as sore throat, cough, and excess phlegm. The plant contains various compounds, including diterpenes, triterpenes, steroids, flavonoids, phenolic acids, essential oils, amino acids, alkaloids, and polysaccharides, with diterpenes, triterpenes, flavonoids, and phenolic acids being the most active. This review identifies 50 compounds with anti-tumor properties, comprising 34 diterpenes, 2 triterpenes, 7 flavonoids, and 7 phenolic acids. Notably, besides oridonin and ponicidin, the ent-kaurane diterpenoids (20S)-11β,14β,20-trihydroxy-7α,20-epoxy-ent-kaur-16-en15-one and (20S)-11β,14β-dihydroxy-20-ethoxy7α,20-epoxy-ent-kaur-16-en-15-one demonstrate significant anti-tumor activity, attributed to their carbonyl group at C-15, hydroxyl group at C-1, and OEt group at C-20. Mechanistically, R. rubescens combats tumors by blocking the tumor cell cycle, promoting apoptosis, inhibiting cell migration and angiogenesis, inducing ferroptosis, reversing drug resistance, and enhancing radiosensitivity in tumor cells. Clinically, R. rubescens is available in various forms, including tablets, drops, syrups, capsules, and lozenges, and is primarily used for tonsillitis, pharyngitis, and stomatitis. According to the 2020 edition of the Pharmacopoeia of China, R. rubescens tablets are recognized as an adjuvant therapy for cancer. Clinical studies indicate that R. rubescens syrup, tablets, and thermal therapy can enhance cancer patient survival rates and lower tumor recurrence rates.

CONCLUSIONS

Given its traditional and modern uses, active anti-tumor components, and mechanisms, R. rubescens is a promising resource in traditional Chinese medicine for anti-tumor therapy. To realize its full potential, future research should explore additional active anti-tumor compounds beyond oridonin and ponicidin. For these key components, studies should focus on structural modifications to identify new active molecules and essential anti-tumor structures. Clinically, it is important to investigate how R. rubescens interacts with other Chinese herbs in anti-tumor formulations to enhance treatment efficacy and guide appropriate clinical use. Furthermore, future studies should undergo ethical review and include larger-scale randomized controlled trials to validate the efficacy of R. rubescens in treating tumors, thereby promoting its role as an anti-tumor traditional Chinese medicine.

Enhancing cancer therapy: advanced nanovehicle delivery systems for oridonin

Oridonin (ORI), an ent-kaurane diterpenoid derived from Rabdosia rubescens (Hemsl.) H.Hara, serves as the primary bioactive component of this plant. It demonstrates a broad spectrum of therapeutic activities, including moderate to potent anticancer properties, alongside anti-inflammatory, antibacterial, antifibrotic, immunomodulatory, and neuromodulatory effects, thus influencing diverse biological processes. However, its clinical potential is significantly constrained by poor aqueous solubility and limited bioavailability. In alignment with the approach of developing drug candidates from natural compounds, various strategies, such as structural modification and nanocarrier systems, have been employed to address these challenges. This review provides an overview of ORI-based nano-delivery systems, emphasizing their potential to improve the clinical applicability of oridonin in oncology. Although some progress has been made in advancing ORI nano-delivery research, it remains insufficient for clinical implementation, necessitating further investigation.

H2S-releasing oridonin derivatives with improved antitumor activity by inhibiting the PI3K/AKT pathway

Activating programmed cell death by delivering hydrogen sulfide (H2S) has emerged as a promising strategy for tumor therapy. Oridonin serves as a lead compound for drug development due to its unique scaffold and wide-ranging biological effects, especially its antitumor properties. Based on the previous structure-activity relationship studies, 33 novel 1-O/14-O H2S-releasing oridonin derivatives were synthesized. Particularly, 11a exhibited the most potent antiproliferative activity, effectively inhibiting colony formation, migration and invasion in both MCF-7 and MIA-PaCa-2 cells. It also inhibited the PI3K/AKT pathway to regulate the expression of Bax and Bcl-2, thereby initiating the Caspase cascade to activate mitochondrial mediated apoptosis. Furthermore, 11a suppressed tumor growth in breast cancer syngeneic models with no apparent toxicity.

Network Pharmacology and in vitro Experimental Verification on Intervention of Oridonin on Non-Small Cell Lung Cancer

OBJECTIVE

To explore the key target molecules and potential mechanisms of oridonin against non-small cell lung cancer (NSCLC).

METHODS

The target molecules of oridonin were retrieved from SEA, STITCH, SuperPred and TargetPred databases; target genes associated with the treatment of NSCLC were retrieved from GeneCards, DisGeNET and TTD databases. Then, the overlapping target molecules between the drug and the disease were identified. The protein-protein interaction (PPI) was constructed using the STRING database according to overlapping targets, and Cytoscape was used to screen for key targets. Molecular docking verification were performed using AutoDockTools and PyMOL software. Using the DAVID database, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted. The impact of oridonin on the proliferation and apoptosis of NSCLC cells was assessed using cell counting kit-8, cell proliferation EdU image kit, and Annexin V-FITC/PI apoptosis kit respectively. Moreover, real-time quantitative PCR and Western blot were used to verify the potential mechanisms.

RESULTS

Fifty-six target molecules and 12 key target molecules of oridonin involved in NSCLC treatment were identified, including tumor protein 53 (TP53), Caspase-3, signal transducer and activator of transcription 3 (STAT3), mitogen-activated protein kinase kinase 8 (MAPK8), and mammalian target of rapamycin (mTOR). Molecular docking showed that oridonin and its key target molecules bind spontaneously. GO and KEGG enrichment analyses revealed cancer, apoptosis, phosphoinositide-3 kinase/protein kinase B (PI3K/Akt), and other signaling pathways. In vitro experiments showed that oridonin inhibited the proliferation, induced apoptosis, downregulated the expression of Bcl-2 and Akt, and upregulated the expression of Caspase-3.

CONCLUSION

Oridonin can act on multiple targets and pathways to exert its inhibitory effects on NSCLC, and its mechanism may be related to upregulating the expression of Caspase-3 and downregulating the expressions of Akt and Bcl-2.

Induction of apoptosis by oridonin in nonfunctioning pituitary adenoma cells

Nonfunctioning pituitary adenoma (NFPA) is one of the major subtypes of pituitary adenomas (PA) and its primary treatment is surgical resection. However, normal surgery fails to remove lesions completely and there remains in lack of frontline treatment, so the development of new drugs for NFPA is no doubt urgent. Oridonin (ORI) has been reported to have antitumor effects on a variety of tumors, but whether it could exhibit the same effect on NFPA requires to be further investigated. The effects of ORI on pituitary-derived folliculostellate cell line (PDFS) cell viability, colony formation, proliferation ability, migration, and invasion were examined by Cell Counting Kit-8, colony formation assay, 5‑Ethynyl‑2'‑deoxyuridine proliferation assay, wound-healing assay, and Transwell assay. The differentially expressed genes in the control and ORI-treated groups were screened by transcriptome sequencing analysis and analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment. Cell cycle analysis was performed to detect changes in cell cycle. Annexin V-fluorescein isothiocyanate/propidium iodide staining was performed to detect apoptosis in ORI-treated cells. Western blot assay was performed to detect Bax, Bcl-2, and cleaved Caspase-3 protein expression. ORI inhibited PDFS cell viability and significantly suppressed cell proliferation, migration, and invasion. GO and KEGG results showed that ORI was associated with signaling pathways such as cell cycle and apoptosis in PDFS cells. In addition, ORI blocked cells in G2/M phase and induced apoptosis in PDFS cells. ORI can trigger cell cycle disruption and apoptosis collaboratively in PDFS cells, making it a promising and effective agent for NFPA therapy.

Designable Nanoadaptor for Enhanced Recognition of Natural Killer Cell to Tumor via Bio-orthogonal Click Reaction

Highly efficient recognition of cancer cells by immune cells is important for successful therapeutic-cell-based cancer immunotherapy. Herein, we present a facile NIR-II nanoadaptor [hyaluronic acid (HA)/dibenzocyclooctyne (DBCO)-Au:Ag2Te quantum dots (QDs)] for enhancing the tumor recognition and binding ability of natural killer (NK) cells via a bio-orthogonal click reaction in vivo. The Nanoadaptor possesses superior tumor-targeting capacity, facilitating the accumulation of the chemical receptor DBCO at the tumor sites. Subsequently, the enrichment of DBCO on tumor cell surfaces provides multivalent recognition sites for capturing pretreated azide engineered NK92 cells (NK92-N3) through an efficient click reaction, thereby significantly enhancing the therapeutical efficiency. The dynamic process of nanoadaptor-mediated recognition of NK cells to tumor cells could be vividly observed using multiplexed NIR-II fluorescence imaging in a mouse model of lung cancer. Such a nanoadaptor strategy can be extended to other therapeutic cellular systems and holds promise for future clinical applications.

Synthesis and Application of a pH-Responsive Functional Metal-Organic Framework: In Vitro Investigation for Delivery of Oridonin in Cancer Therapy

Oridonin (Ori) is a naturally existing diterpenoid substance that mainly exists in the Chinese medicinal plant Rabdosia rubescens. It was previously found to possess intriguing biological properties; however, the quick clearance from plasma and limited solubility in water restricts its use as a drug. Several metal-organic frameworks (MOFs), having big surfaces and large pores, have recently been considered promising drug transporters. The zeolitic imidazolate framework-8 (ZIF-8), a form of MOF consisting of 2-methylimidazole with zinc ions, is structurally stable under physiologically neutral conditions, while it can degrade at low pH values such as in tumor cells. Herein, a nanosized drug delivery system, Ori@ZIF-8, was successfully designed for encapsulating and transporting oridonin to the tumor site. The drug loading of the prepared Ori@ZIF-8 was 26.78%, and the particles' mean size was 240.5 nm. In vitro, the release of Ori@ZIF-8 exhibited acid sensitivity, with a slow release under neutral conditions and rapid release of the drug under weakly acidic conditions. According to the in vitro anti-tumor experiments, Ori@ZIF-8 produced higher cytotoxicity than free Ori and induced apoptosis in A549 cancer cells. In conclusion, Ori@ZIF-8 could be a potential pH-responsive carrier to accurately release more oridonins at the tumor site.

Oridonin from Rabdosia rubescens: An emerging potential in cancer therapy - A comprehensive review

Cancer incidences are rising each year. In 2020, approximately 20 million new cancer cases and 10 million cancer-related deaths were recorded. The World Health Organization (WHO) predicts that by 2024 the incidence of cancer will increase to 30.2 million individuals annually. Considering the invasive characteristics of its diagnostic procedures and therapeutic methods side effects, scientists are searching for different solutions, including using plant-derived bioactive compounds, that could reduce the probability of cancer occurrence and make its treatment more comfortable. In this regard, oridonin (ORI), an ent-kaurane diterpenoid, naturally found in the leaves of Rabdosia rubescens species, has been found to have antitumor, antiangiogenesis, antiasthmatic, antiinflammatory, and apoptosis induction properties. Extensive research has been performed on ORI to find various mechanisms involved in its anticancer activities. This review article provides an overview of ORI's effectiveness on murine and human cancer populations from 1976 to 2022 and provides insight into the future application of ORI in different cancer therapies.

Hawthorn Proanthocyanidin Extract Inhibits Colorectal Carcinoma Metastasis by Targeting the Epithelial-Mesenchymal Transition Process and Wnt/β-Catenin Signaling Pathway

Colorectal carcinoma (CRC) is a major global health concern, with cancer metastasis being the main cause of patient mortality, and current CRC treatments are challenged by drug resistance. Although natural compounds, especially in foods like hawthorn proanthocyanidin extract (HPOE), have good anticancer activity, their effects on CRC metastasis remain unknown. Therefore, our objective was to investigate the impact and potential mechanisms of HPOE on the movement and infiltration of cells in the HCT116 CRC cells. Firstly, scratch-healing experiments confirmed the anti-migratory and anti-invasive capabilities of HPOE. Then, network pharmacology identified 16 possible targets, including MMP-9. Subsequently, RT-qPCR and Western blotting experiments confirmed that HPOE downregulated epithelial-mesenchymal transition-related factors (N-cadherin and MMP-9) and inhibited Wnt/β-catenin pathway activation. Finally, these results were experimentally validated using the Wnt pathway activator Licl and inhibitor XAV939. It was confirmed that HPOE had a certain inhibitory effect on the activation of the Wnt signaling pathway caused by the activator Licl and could enhance the inhibitory effect of the inhibitor XAV939. Our findings provide a basis for developing functional foods or dietary supplements, especially positioning HPOE as a functional food raw material for adjuvant treatment of CRC, given its ability to inhibit metastasis through the Wnt/β-catenin pathway.

Oridonin-induced ferroptosis and apoptosis: a dual approach to suppress the growth of osteosarcoma cells

BACKGROUND

Osteosarcoma (OS) is one of the most common aggressive bone malignancy tumors in adolescents. With the application of new chemotherapy regimens, finding new and effective anti-OS drugs to coordinate program implementation is urgent for the patients of OS. Oridonin had been proved to mediate anti-tumor effect on OS cells, but its mechanism has not been fully elucidated.

METHODS

The effects of oridonin on the viability, clonal formation and migration of 143B and U2OS cells were detected by CCK-8, colony formation assays and wound-healing test. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was used to explore the mechanism of oridonin on OS. Western blot (WB), real-time quantitative PCR (qRT-PCR) were used to detect the expression levels of apoptosis and ferroptosis-relative proteins and genes. Annexin V-FITC apoptosis detection kit and flow cytometry examination were used to detect the level of apoptosis. Iron assay kit was used to evaluate the relative Fe2+ content. The levels of mitochondrial membrane potential and lipid peroxidation production was determined by mitochondrial membrane potential detection kit and ROS assay kit.

RESULTS

Oridonin could effectively inhibit the survival, clonal formation and metastasis of OS cells. The KEGG results indicated that oridonin is associated with the malignant phenotypic signaling pathways of proliferation, migration, and drug resistance in OS. Oridonin was capable of inhibiting expressions of BAX, cl-caspase3, SLC7A11, GPX4 and FTH1 proteins and mRNA, while promoting the expressions of Bcl-2 and ACSL4 in 143B and U2OS cells. Additionally, we found that oridonin could promote the accumulation of reactive oxygen species (ROS) and Fe2+ in OS cells, as well as reduce mitochondrial membrane potential, and these effects could be significantly reversed by the ferroptosis inhibitor ferrostatin-1 (Fer-1).

CONCLUSION

Oridonin can trigger apoptosis and ferroptosis collaboratively in OS cells, making it a promising and effective agent for OS therapy.

A review of natural products targeting tumor immune microenvironments for the treatment of lung cancer

Lung cancer (LC) produces some of the most malignant tumors in the world, with high morbidity and mortality. Tumor immune microenvironment (TIME), a component of the tumor microenvironment (TME), are critical in tumor development, immune escape, and drug resistance. The TIME is composed of various immune cells, immune cytokines, etc, which are important biological characteristics and determinants of tumor progression and outcomes. In this paper, we reviewed the recently published literature and discussed the potential uses of natural products in regulating TIME. We observed that a total of 37 natural compounds have been reported to exert anti-cancer effects by targeting the TIME. In different classes of natural products, terpenoids are the most frequently mentioned compounds. TAMs are one of the most investigated immune cells about therapies with natural products in TIME, with 9 natural products acting through it. 17 natural products exhibit anti-cancer properties in LC by modulating PD-1 and PD-L1 protein activity. These natural products have been extensively evaluated in animal and cellular LC models, but their clinical trials in LC patients are lacking. Based on the current review, we have revealed that the mechanisms of LC can be treated with natural products through TIME intervention, resulting in a new perspective and potential therapeutic drugs.