Inhibiting Angiogenesis by Anti-Cancer Saponins: From Phytochemistry to Cellular Signaling Pathways

Evaluation of the antiproliferative, cytotoxic and phytochemical properties of Zimbabwean medicinal plants used in cancer treatment

BACKGROUND

Cancer cases have been on the rise globally and several treatment strategies have been developed but mortality rates remain high. Zimbabwe, like many other countries, has also experienced a surge in cancer cases. In Zimbabwe, medicinal plants have been widely used to treat cancer for centuries. However, there has been limited research on the effectiveness, safety, and chemical composition of these plants. The current study assessed antiproliferative, cytotoxic and phytochemical properties of selected Zimbabwean medicinal plants.

METHOD

Cytotoxic activity of Agelenthus pungu, Carissa edulis, Dombeya rotundifolia, Flacourtia indica, Lannea discolor, Leonotis ocymifolia, Leucas martinicensis, Plicosepalus kalachariensis, Pseudolachnostylis maproneifolia, Solanum incanum, Strychnos cocculoides, Strychnos spinosa and Viscum verrucosum extracts were evaluated on normal murine peritoneal cells and sheep erythrocytes while antiproliferative activity was assessed on Jurkat T and HL60 cell lines. Cell viability was determined using the trypan blue exclusion and sulforhodamine B assay. Additionally, the effect of reduced glutathione on cytotoxic extracts was examined. The phytochemicals of the methanolic extracts were qualitatively determined using standard methods.

RESULTS

Agelenthus pungu, Carissa edulis, Flacourtia indica, Strychnos cocculoides, Strychnos spinosa and Viscum verrucosum were cytotoxic to normal murine peritoneal cells. Flacourtia indica and Viscum verruscosum caused haemolysis of sheep erythrocytes at a concentration of 250 µg/mL for both plant extracts and 125 µg/mL for Viscum verrucosum. Cell viability increased on addition of 25 µg/mL of reduced glutathione to the extracts considered the most cytotoxic extracts, Agelenthus pungu and Viscum verrucosum. Agelenthus pungu, Carissa edulis, Leonotis ocymifolia, Leucas martinicensis and Viscum verrucosum significantly inhibited Jurkat T and HL60 cell proliferation. Viscum verrucosum was the most potent with the lowest half-maximum inhibitory concentration (IC50) values of 33 and 34 µg/mL on Jurkat T and HL60 cell lines respectively. The most dominant phytochemical classes were alkaloids, flavonoids and saponins.

CONCLUSION

This study demonstrates that Agelenthus pungu, Carissa edulis, Leonotis ocymifolia, Leucas martinicensis and Viscum verrucosum have antiproliferative activity against Jurkat T and HL60 cell lines. Viscum verrucosum was the most potent. These findings emphasise the importance of medicinal plants as well as their potential use as sources of novel compounds in anticancer drug discovery.

Natural sapogenins as potential inhibitors of aquaporins for targeted cancer therapy: computational insights into binding and inhibition mechanism

Aquaporins (AQPs) are membrane proteins that facilitate the transport of water and other small molecules across biological membranes. AQPs are involved in various physiological processes and pathological conditions, including cancer, making them as potential targets for anticancer therapy. However, the development of selective and effective inhibitors of AQPs remains a challenge. In this study, we explored the possibility of using natural sapogenins, a class of plant-derived aglycones of saponins with diverse biological activities, as potential inhibitors of AQPs. We performed molecular docking, dynamics simulation and binding energy calculation to investigate the binding and inhibition mechanism of 19 sapogenins against 13 AQPs (AQP0-AQP13) that are overexpressed in various cancers. Our results showed that out of 19 sapogenins, 8 (Diosgenin, Gitogenin, Tigogenin, Ruscogenin, Yamogenin, Hecogenin, Sarsasapogenin and Smilagenin) exhibited acceptable drug-like characteristics. These sapogenin also exhibited favourable binding affinities in the range of -7.6 to -13.4 kcal/mol, and interactions within the AQP binding sites. Furthermore, MD simulations provided insights into stability and dynamics of the sapogenin-AQP complexes. Most of the fluctuations in binding pocket were observed for AQP0-Gitogenin and AQP4-Diosgenin. However, remaining protein-ligand complex showed stable root mean square deviation (RMSD) plots, strong hydrogen bonding interactions, stable solvent-accessible surface area (SASA) values and minimum distance to the receptor. These observations suggest that natural sapogenin hold promise as novel inhibitors of AQPs, offering a basis for the development of innovative therapeutic agents for cancer treatment. However, further validation of the identified compounds through experiments is essential for translating these findings into therapeutic applications.

Rice bran as a potent ingredient: unveiling its potential for value-added applications

Rice bran production significantly contributes to global environmental deterioration, yet its potential remains underutilized. This review discusses the nutritional composition, bioactive compounds, health benefits, limitations, and potential application of rice bran in both food and non-food sectors. While minor variations exist between pigmented and non-pigmented rice bran, the former is abundant in phytochemicals, which offer therapeutic benefits. The primary limitations hindering rice bran's food application include rancidity, toxic heavy metals, and antinutrients. Effective stabilization is crucial to extend rice bran's shelf life. Despite these challenges, rice bran holds significant potential for value-added products. Hence, its rich composition and diverse applications underscore its importance as a valuable resource for sustainable production practices.

Immunomodulatory Effects of Selected Non-Nutritive Bioactive Compounds and Their Role in Optimal Nutrition

The contemporary approach to nutrition increasingly considers the role of non-nutritive bioactive compounds in modulating the immune system and maintaining health. This article provides up-to-date insight into the immunomodulatory effects of selected bioactive compounds, including micro- and macronutrients, vitamins, as well as other health-promoting substances, such as omega-3 fatty acids, probiotics, prebiotics, postbiotics (including butyric acid and sodium butyrate), coenzyme Q10, lipoic acid, and plant-derived components such as phenolic acids, flavonoids, coumarins, alkaloids, polyacetylenes, saponins, carotenoids, and terpenoids. Micro- and macronutrients, such as zinc, selenium, magnesium, and iron, play a pivotal role in regulating the immune response and protecting against oxidative stress. Vitamins, especially vitamins C, D, E, and B, are vital for the optimal functioning of the immune system as they facilitate the production of cytokines, the differentiation of immunological cells, and the neutralization of free radicals, among other functions. Omega-3 fatty acids exhibit strong anti-inflammatory effects and enhance immune cell function. Probiotics, prebiotics, and postbiotics modulate the intestinal microbiota, thereby promoting the integrity of the intestinal barrier and communication between the microbiota and the immune system. Coenzyme Q10, renowned for its antioxidant attributes, participates in the protection of cells from oxidative stress and promotes energy processes essential for immune function. Sodium butyrate and lipoic acid exhibit anti-inflammatory effects and facilitate the regeneration of the intestinal epithelium, which is crucial for the maintenance of immune homeostasis. This article emphasizes the necessity of an integrative approach to optimal nutrition that considers not only nutritional but also non-nutritional bioactive compounds to provide adequate support for immune function. Without them, the immune system will never function properly, because it has been adapted to this in the course of evolution. The data presented in this article may serve as a foundation for further research into the potential applications of bioactive components in the prevention and treatment of diseases associated with immune dysfunction.

Phytosome-Enhanced Secondary Metabolites for Improved Anticancer Efficacy: Mechanisms and Bioavailability Review

Purpose

Phytosome technology, an advanced lipid-based delivery system, offers a promising solution for enhancing the bioavailability and therapeutic efficacy of secondary metabolites, particularly in cancer treatment. These metabolites, such as flavonoids, terpenoids, and alkaloids, possess significant anticancer potential but are often limited by poor solubility and low absorption. This review aims to investigate how phytosome encapsulation improves the pharmacokinetic profiles and anticancer effectiveness of these bioactive compounds.

Patients and Methods

This comprehensive review is based on an analysis of recent literature retrieved from PubMed, Scopus, and ScienceDirect databases. It focuses on findings from preclinical and in vitro studies that examine the pharmacokinetic enhancements provided by phytosome technology when applied to secondary metabolites.

Results

Phytosome-encapsulated secondary metabolites exhibit significantly improved solubility, absorption, distribution, and cellular uptake compared to non-encapsulated forms. This enhanced bioavailability facilitates more effective inhibition of cancer pathways, including NF-κB and PI3K/AKT, leading to increased anticancer efficacy in preclinical models.

Conclusion

Phytosome technology has demonstrated its potential to overcome bioavailability challenges, resulting in safer and more effective therapeutic options for cancer treatment. This review highlights the potential of phytosome-based formulations as a novel approach to anticancer therapy, supporting further development in preclinical, in vitro, and potential clinical applications.

Nature's arsenal unleashed: Senegalia modesta derived thymol halts cancer progression by suppressing proangiogenic genes

Inhibiting angiogenesis with plant-derived bioactive compounds can inhibit tumour progression. Antiangiogenic potential of Senegalia modesta was analysed by preparing and analysing ethanolic extracts of S.modesta by GC-MS and HPLC to identify bioactive components. In-vivo blood vessel formation assays in mice and chorioallantoic membrane assays (CAM) in eggs were employed to assess the antiangiogenic effects. qPCR was performed to elucidate mRNA expression of proangiogenic genes in MDA-MB-231 cells after exposure to S.modesta and thymol. Molecular docking analysis highlighted the interaction of thymol with VEGF receptors. S.modesta treatment significantly delayed wound healing in mice compared to control group. GC-MS and HPLC analyses thymol as a bioactive compound in S.modesta extract. CAM assay indicated reduced angiogenesis in thymol-treated groups, further confirmed by downregulation of proangiogenic genes. Molecular docking of thymol with VEGFR1/VEGFR2 revealed strong binding affinity, suggesting thymol-mediated receptor blocking. Thymol exhibits antiangiogenic potential and may serve as a promising therapeutic agent against cancer.

Decoding the power of saponins in ferroptosis regulation and disease intervention: a review

OBJECTIVES

This review endeavors to elucidate the complex interplay underlying diseases associated with ferroptosis and to delineate the multifaceted mechanisms by which triterpenoid and steroidal saponins modulate this form of cell death.

METHODS

A meticulous examination of the literature was undertaken, drawing from an array of databases including Web of Science, PubMed, and Wiley Library, with a focus on the keywords "ferroptosis," "saponin," "cancer," "inflammation," "natural products," and "signaling pathways."

KEY FINDINGS

Ferroptosis represents a distinctive mode of cell death that holds considerable promise for the development of innovative therapeutic strategies targeting a wide range of diseases, especially cancer and inflammatory disorders. This review reveals the nuanced interactions between saponins and critical signaling pathways, including system Xc--GSH-GPX4, Nrf2, p53, and mTOR. These interactions highlight the dual capacity of saponins to modulate ferroptosis, thereby offering fresh perspectives for therapeutic intervention.

CONCLUSIONS

The insights garnered from this review significantly advance our comprehension of the dynamic relationship between saponins and ferroptosis. By shedding light on these mechanisms, this work sets the stage for leveraging these insights in the creation of pioneering approaches to disease treatment, marking a significant stride in the evolution of therapeutic modalities.

Regulation of bone homeostasis by traditional Chinese medicine active scaffolds and enhancement for the osteoporosis bone regeneration

ETHNOPHARMACOLOGICAL RELEVANCE

The active ingredients of traditional Chinese medicine (TCM), such as naringin (NG), Eucommiol, isopsoralen, icariin, Astragalus polysaccharides, and chondroitin sulfate, contained in Drynariae Rhizoma, Eucommiae Cortex, Psoralea corylifolia, Herba Epimedii, Astragalus radix and deer antler, are considered promising candidates for enhancing the healing of osteoporotic defects due to their outstanding bone homeostasis regulating properties. They are commonly used to activate bone repair scaffolds.

AIM OF THE REVIEW

Bone repair scaffolds are inadequate to meet the demands of osteoporotic defect healing due to the lack of regulation of bone homeostasis. Therefore, selecting bone scaffolds activated with TCM to improve the therapeutic effect of repairing osteoporotic bone defects.

MATERIALS AND METHODS

To gather information on bone scaffold activated by traditional Chinese medicine, we conducted a thorough search of several scientific databases, including Google Scholar, Web of Science, Scifinder, Baidu Scholar, PubMed, and China National Knowledge Infrastructure (CNKI).

RESULTS

This review discusses the mechanism of TCM active ingredients in regulating bone homeostasis, including stimulating bone formation and inhibiting bone resorption process and the healing mechanism of traditional bone repair scaffolds activated by them for osteoporotic defect healing.

CONCLUSION

In general, the introduction of TCM active ingredients provides a novel therapeutic approach for modulating bone homeostasis and facilitating osteoporotic defect healing, and also offers a new strategy for design of other unconventional bone defect healing materials.

Genome-wide methylation, transcriptome and characteristic metabolites reveal the balance between diosgenin and brassinosteroids in Dioscorea zingiberensis

Diosgenin (DG) is a bioactive metabolite isolated from Dioscorea species, renowned for its medicinal properties. Brassinosteroids (BRs) are a class of crucial plant steroidal hormones. Cholesterol and campesterol are important intermediates of DG and BR biosynthesis, respectively. DG and BRs are structurally similar components; however, the regulatory network and metabolic interplays have not been fully elucidated. In an effort to decode these complex networks, we conducted a comprehensive study integrating genome-wide methylation, transcriptome and characteristic metabolite data from Dioscorea zingiberensis. Leveraging these data, we were able to construct a comprehensive regulatory network linking DG and BRs. Mass spectrometry results enabled us to clarify the alterations in cholesterol, campesterol, diosgenin, and castasterone (one of the major active BRs). The DG content decreased by 27.72% at 6 h after brassinolide treatment, whereas the content increased by 85.34% at 6 h after brassinazole treatment. Moreover, we pinpointed DG/BR-related genes, such as CASs, CYP90s, and B3-ARFs, implicated in the metabolic pathways of DG and BRs. Moreover, CASs and CYP90s exhibit hypomethylation, which is closely related to their high transcription. These findings provide robust evidence for the homeostasis between DG and BRs. In conclusion, our research revealed the existence of a balance between DG and BRs in D. zingiberensis. Furthermore, our work not only provides new insights into the relationship between the two pathways but also offers a fresh perspective on the functions of secondary metabolites.

Plant-Based Oil-in-Water Food Emulsions: Exploring the Influence of Different Formulations on Their Physicochemical Properties

The global focus on incorporating natural ingredients into the diet for health improvement encompasses ω-3 polyunsaturated fatty acids (PUFAs) derived from plant sources, such as flaxseed oil. ω-3 PUFAs are susceptible to oxidation, but oil-in-water (O/W) emulsions can serve to protect PUFAs from this phenomenon. This study aimed to create O/W emulsions using flaxseed oil and either soy lecithin or Quillaja saponins, thickened with modified starch, while assessing their physical properties (oil droplet size, ζ-potential, and rheology) and physical stability. Emulsions with different oil concentrations (25% and 30% w/w) and oil-to-surfactant ratio (5:1 and 10:1) were fabricated using high-pressure homogenization (800 bar, five cycles). Moreover, emulsions were thickened with modified starch and their rheological properties were measured. The physical stability of all emulsions was assessed over a 7-day storage period using the TSI (Turbiscan Stability Index). Saponin-stabilized emulsions exhibited smaller droplet diameters (0.11-0.19 µm) compared to lecithin (0.40-1.30 µm), and an increase in surfactant concentration led to a reduction in droplet diameter. Both surfactants generated droplets with a high negative charge (-63 to -72 mV), but lecithin-stabilized emulsions showed greater negative charge, resulting in more intense electrostatic repulsion. Saponin-stabilized emulsions showed higher apparent viscosity (3.9-11.6 mPa·s) when compared to lecithin-stabilized ones (1.19-4.36 mPa·s). The addition of starch significantly increased the apparent viscosity of saponin-stabilized emulsions, rising from 11.6 mPa s to 2117 mPa s. Emulsions stabilized by saponin exhibited higher stability than those stabilized by lecithin. This study confirms that plant-based ingredients, particularly saponins and lecithin, effectively produce stable O/W emulsions with flaxseed oil, offering opportunities for creating natural ingredient-based food emulsions.

Natural products targeting the MAPK-signaling pathway in cancer: overview

PURPOSE

This article summarizes natural products that target the MAPK-signaling pathway in cancer therapy. The classification, chemical structures, and anti-cancer mechanisms of these natural products are elucidated, and comprehensive information is provided on their potential use in cancer therapy.

METHODS

Using the PubMed database, we searched for keywords, including "tumor", "cancer", "natural product", "phytochemistry", "plant chemical components", and "MAPK-signaling pathway". We also screened for compounds with well-defined structures that targeting the MAPK-signaling pathway and have anti-cancer effects. We used Kingdraw software and Adobe Photoshop software to draw the chemical compound structural diagrams.

RESULTS

A total of 131 papers were searched, from which 85 compounds with well-defined structures were selected. These compounds have clear mechanisms for targeting cancer treatment and are mainly related to the MAPK-signaling pathway. Examples include eupatilin, carvacrol, oridonin, sophoridine, diosgenin, and juglone. These chemical components are classified as flavonoids, phenols, terpenoids, alkaloids, steroidal saponins, and quinones.

CONCLUSIONS

Certain MAPK pathway inhibitors have been used for clinical treatment. However, the clinical feedback has not been promising because of genomic instability, drug resistance, and side effects. Natural products have few side effects, good medicinal efficacy, a wide range of sources, individual heterogeneity of biological activity, and are capable of treating disease from multiple targets. These characteristics make natural products promising drugs for cancer treatment.

Steroidal Saponins: Naturally Occurring Compounds as Inhibitors of the Hallmarks of Cancer

Cancer is a global health burden responsible for an exponentially growing number of incidences and mortalities, regardless of the significant advances in its treatment. The identification of the hallmarks of cancer is a major milestone in understanding the mechanisms that drive cancer initiation, development, and progression. In the past, the hallmarks of cancer have been targeted to effectively treat various types of cancers. These conventional cancer drugs have shown significant therapeutic efficacy but continue to impose unfavorable side effects on patients. Naturally derived compounds are being tested in the search for alternative anti-cancer drugs. Steroidal saponins are a group of naturally occurring compounds that primarily exist as secondary metabolites in plant species. Recent studies have suggested that steroidal saponins possess significant anti-cancer capabilities. This review aims to summarize the recent findings on steroidal saponins as inhibitors of the hallmarks of cancer and covers key studies published between the years 2014 and 2024. It is reported that steroidal saponins effectively inhibit the hallmarks of cancer, but poor bioavailability and insufficient preclinical studies limit their utilization.