Antiproliferative and Pro-Apoptotic Effect of Uvaol in Human Hepatocarcinoma HepG2 Cells by Affecting G0/G1 Cell Cycle Arrest, ROS Production and AKT/PI3K Signaling Pathway

Sanguinarine induces apoptosis in osteosarcoma by attenuating the binding of STAT3 to the single-stranded DNA-binding protein 1 (SSBP1) promoter region

BACKGROUND AND PURPOSE

Osteosarcoma, a primary malignant bone tumour prevalent among adolescents and young adults, remains a considerable challenge despite protracted progress made in enhancing patient survival rates over the last 40 years. Consequently, the development of novel therapeutic approaches for osteosarcoma is imperative. Sanguinarine (SNG), a compound with demonstrated potent anticancer properties against various malignancies, presents a promising avenue for exploration. Nevertheless, the intricate molecular mechanisms underpinning SNG's actions in osteosarcoma remain elusive, necessitating further elucidation.

EXPERIMENTAL APPROACH

Single-stranded DNA-binding protein 1 (SSBP1) was screened out by differential proteomic analysis. Apoptosis, cell cycle, reactive oxygen species (ROS) and mitochondrial changes were assessed via flow cytometry. Western blotting and quantitative real-time reverse transcription PCR (qRT-PCR) were used to determine protein and gene levels. The antitumour mechanism of SNG was explored at a molecular level using chromatin immunoprecipitation (ChIP) and dual luciferase reporter plasmids.

KEY RESULTS

Our investigation revealed that SNG exerted an up-regulated effect on SSBP1, disrupting mitochondrial function and inducing apoptosis. In-depth analysis uncovered a mechanism whereby SNG hindered the JAK/signal transducer and activator of transcription 3 (STAT3) signalling pathway, relieved the inhibitory effect of STAT3 on SSBP1 transcription, and inhibited the downstream PI3K/Akt/mTOR signalling axis, ultimately activating apoptosis.

CONCLUSIONS AND IMPLICATIONS

The study delved further into elucidating the anticancer mechanism of SNG in osteosarcoma. Notably, we unravelled the previously undisclosed apoptotic potential of SSBP1 in osteosarcoma cells. This finding holds substantial promise in advancing the development of novel anticancer drugs and identification of therapeutic targets.

Regulation of Tumor Apoptosis of Poriae cutis-Derived Lanostane Triterpenes by AKT/PI3K and MAPK Signaling Pathways In Vitro

Poria cocos is traditionally used as both food and medicine. Triterpenoids in Poria cocos have a wide range of pharmacological activities, such as diuretic, sedative and tonic properties. In this study, the anti-tumor activities of poricoic acid A (PAA) and poricoic acid B (PAB), purified by high-speed counter-current chromatography, as well as their mechanisms and signaling pathways, were investigated using a HepG2 cell model. After treatment with PAA and PAB on HepG2 cells, the apoptosis was obviously increased (p < 0.05), and the cell cycle arrested in the G2/M phase. Studies showed that PAA and PAB can also inhibit the occurrence and development of tumor cells by stimulating the generation of ROS in tumor cells and inhibiting tumor migration and invasion. Combined Polymerase Chain Reaction and computer simulation of molecular docking were employed to explore the mechanism of tumor proliferation inhibition by PAA and PAB. By interfering with phosphatidylinositol-3-kinase/protein kinase B, Mitogen-activated protein kinases and p53 signaling pathways; and further affecting the expression of downstream caspases; matrix metalloproteinase family, cyclin-dependent kinase -cyclin, Intercellular adhesion molecules-1, Vascular Cell Adhesion Molecule-1 and Cyclooxygenase -2, may be responsible for their anti-tumor activity. Overall, the results suggested that PAA and PAB induced apoptosis, halted the cell cycle, and inhibited tumor migration and invasion through multi-pathway interactions, which may serve as a potential therapeutic agent against cancer.

Multidirectional Effects of Terpenoids from Sorbus intermedia (EHRH.) PERS Fruits in Cellular Model of Benign Prostate Hyperplasia

Benign prostatic hyperplasia (BPH) is a common urological disease affecting aging men. Its pathogenesis is regarded as complex and multifactorial, with sex hormones and inflammation as key contributory factors. In the current study, we investigated the anti-BPH potential of terpenoids present in the fruits of Sorbus intermedia (EHRH.) PERS. Not only the effects on testosterone-stimulated normal prostate epithelial PNT2 cells, namely suppression of 5-α-reductase activity, PSA secretion, and cell proliferation, were determined but also the inhibitory activity on heat-induced protein denaturation, hyaluronidase, as well as IL-6, TNF-α, and NO release in LPS-treated macrophages. Sorbus terpenoids significantly inhibited 5-α-reductase activity and reduced PSA secretion in PNT2 cells, reversing the stimulatory effect of testosterone. PNT2 cell proliferation was also found to be attenuated. Subsequently, all compounds reduced the release of pro-inflammatory mediators in RAW 264.7 cells. In addition, ursolic acid (UA) and its aldehyde (UAL) were the most potent hyaluronidase inhibitors of all compounds, with IC₅₀ values of 225.75 µg/mL and 369.77 µg/mL, respectively. For better understanding and interpretation of the overall effect of Sorbus terpenoids on different aspects of BPH pathogenesis and development, cluster analysis was applied.

Fractionation and Characterization of Triterpenoids from Vaccinium vitis-idaea L. Cuticular Waxes and Their Potential as Anticancer Agents

Fruit and leaf cuticular waxes are valuable source materials for the isolation of triterpenoids that can be applied as natural antioxidants and anticancer agents. The present study aimed at the semi-preparative fractionation of triterpenoids from cuticular wax extracts of Vaccinium vitis-idaea L. (lingonberry) leaves and fruits and the evaluation of their cytotoxic potential. Qualitative and quantitative characterization of obtained extracts and triterpenoid fractions was performed using HPLC-PDA method, followed by complementary analysis by GC-MS. For each fraction, cytotoxic activities towards the human colon adenocarcinoma cell line (HT-29), malignant melanoma cell line (IGR39), clear renal carcinoma cell line (CaKi-1), and normal endothelial cells (EC) were determined using MTT assay. Furthermore, the effect of the most promising samples on cancer spheroid growth and viability was examined. This study allowed us to confirm that particular triterpenoid mixtures from lingonberry waxes may possess stronger cytotoxic activities than crude unpurified extracts. Fractions containing triterpenoid acids plus fernenol, complexes of oleanolic:ursolic acids, and erythrodiol:uvaol were found to be the most potent therapeutic candidates in the management of cancer diseases. The specificity of cuticular wax extracts of lingonberry leaves and fruits, leading to different purity and anticancer potential of obtained counterpart fractions, was also enclosed. These findings contribute to the profitable utilization of lingonberry cuticular waxes and provide considerable insights into the anticancer effects of particular triterpenoids and pharmacological interactions.

The Impact of Oxidative Stress and AKT Pathway on Cancer Cell Functions and Its Application to Natural Products

Oxidative stress and AKT serine-threonine kinase (AKT) are responsible for regulating several cell functions of cancer cells. Several natural products modulate both oxidative stress and AKT for anticancer effects. However, the impact of natural product-modulating oxidative stress and AKT on cell functions lacks systemic understanding. Notably, the contribution of regulating cell functions by AKT downstream effectors is not yet well integrated. This review explores the role of oxidative stress and AKT pathway (AKT/AKT effectors) on ten cell functions, including apoptosis, autophagy, endoplasmic reticulum stress, mitochondrial morphogenesis, ferroptosis, necroptosis, DNA damage response, senescence, migration, and cell-cycle progression. The impact of oxidative stress and AKT are connected to these cell functions through cell function mediators. Moreover, the AKT effectors related to cell functions are integrated. Based on this rationale, natural products with the modulating abilities for oxidative stress and AKT pathway exhibit the potential to regulate these cell functions, but some were rarely reported, particularly for AKT effectors. This review sheds light on understanding the roles of oxidative stress and AKT pathway in regulating cell functions, providing future directions for natural products in cancer treatment.

Involvement of the PI3K/AKT Intracellular Signaling Pathway in the AntiCancer Activity of Hydroxytyrosol, a Polyphenol from Olea europaea, in Hematological Cells and Implication of HSP60 Levels in Its Anti-Inflammatory Activity

Hydroxytyrosol (HT), the main representative of polyphenols of olive oil, has been described as one of the most powerful natural antioxidants, also showing anti-inflammatory, antimicrobial, cardioprotective and anticancer activity in different type of cancers, but has been little studied in hematological neoplasms. The objective of this work was to evaluate the anticancer potential of HT in acute human leukemia T cells (Jurkat and HL60) and the anti-inflammatory potential in murine macrophages (Raw264.7). For this, cytotoxicity tests were performed for HT, showing IC₅₀ values, at 24 h, for Jurkat, HL60 and Raw264.7 cells, of 27.3 µg·mL⁻¹, 109.8 µg·mL⁻¹ and 45.7 µg·mL⁻¹, respectively. At the same time, HT caused cell arrest in G₀/G₁ phase in both Jurkat and HL60 cells by increasing G₀/G₁ phase and significantly decreasing S phase. Apoptosis and cell cycle assays revealed an antiproliferative effect of HT, decreasing the percentage of dividing cells and increasing apoptosis. Furthermore, HT inhibited the PI3K signaling pathway and, consequently, the MAPK pathway was activated. Inflammation tests revealed that HT acts as an anti-inflammatory agent, reducing NO levels in Raw264.7 cells previously stimulated by lipopolysaccharide (LPS). These processes were confirmed by the changes in the expression of the main markers of inflammation and cancer. In conclusion, HT has an anticancer and anti-inflammatory effect in the cell lines studied, which were Raw264.7, Jurkat, and HL60, and could be used as a natural drug in the treatment of liquid cancers, leukemias, myelomas and lymphomas.

Wound healing, anti-inflammatory and anti-melanogenic activities of ursane-type triterpenes from Semialarium mexicanum (Miers) Mennega

ETHNO-PHARMACOLOGICAL RELEVANCE

The bark of Semialarium mexicanum commonly known as 'Cancerina' is used as an infusion in Central America and Mexico to treat various wound infections, as well as skin and vaginal ulcers.

AIM OF THE STUDY

This study aimed to determine the wound healing, anti-inflammatory and anti-melanogenic activities of the aqueous extract of Semialarium mexicanum and to identify the compounds related to these activities.

MATERIALS AND METHODS

A bio-guided isolation of the active compounds of Semialarium mexicanum was carried out, selecting the sub-extracts and fractions depending on their wound healing, anti-inflammatory and anti-melanogenic activities in the RAW 264.7, NIH/3T3 and B16-F10 cells.

RESULTS

Three compounds were obtained and characterised by nuclear magnetic resonance and mass spectrometry. These compounds are (3β)-3-Hydroxy-urs-12-en-28-oic acid (1), (3β)-Urs-12-ene-3,28-diol (2) and (2α, 19α)-2,19-Dihydroxy-3-oxo-urs-12-en-28-oic acid (3). Regarding the anti-inflammatory activity, the three compounds inhibited the production of NF-κB and NO, however, compound 3 was the most active with IC₅₀ values of 8.15-8.19 μM and 8.94-9.14 μM, respectively, in all cell lines. The anti-melanogenic activity of these compounds was evaluated by the inhibition of tyrosinase and melanin in the B16-F10 cell line. The three compounds showed anti-melanogenic activity, however, compound 3 was the most active with an IC₅₀ of 8.03 μM for the inhibition of tyrosinase production, and an IC₅₀ of 8.53 μM for the inhibition of melanin production. Finally, concerning the wound healing activity, the three compounds presented proliferative activity in all the tested cell lines, however, compound 3 showed higher cell proliferation percentages than compounds 1 and 2 (88.89-89.60% compared to 64.92-65.71% and 71.53-71.99%, respectively).

CONCLUSION

The wound healing, anti-inflammatory and anti-melanogenic activity of the aqueous extract of Semialarium mexicanum was tested and analysed in the present study, after having isolated three ursane-type triterpenes.

In Vitro Antioxidant and Anticancer Properties of Various E. senegalensis Extracts

Although Erythrina senegalensis is a plant widely used in traditional medicine in sub-Saharan Africa, its biological properties have been poorly investigated to date. We first characterized by conventional reactions the composition of several stem bark extracts and evaluated in acellular and cellular assays their pro- or antioxidant properties supported by their high phenolic and flavonoid content, particularly with the methanolic extract. The pro- or antioxidant effects observed did not correlate with their IC₅₀ concentrations against five cancer cell lines determined by MTT assay. Indeed, the CH₂Cl₂ extract and its ethyl acetate (EtOAc) subfraction appeared more potent although they harbored lower pro- or antioxidant effects. Nevertheless, at equipotent concentration, both extracts induced ER- and mitochondria-derived vacuoles observed by fluorescent microscopy that further led to non-apoptotic cell death. LC coupled to high resolution MS investigations have been performed to identify chemical compounds of the extracts. These investigations highlighted the presence of compounds formerly isolated from E. senegalensis including senegalensein that could be retrieved only in the EtOAc subfraction but also thirteen other compounds, such as 16:3-Glc-stigmasterol and hexadecanoic acid, whose anticancer properties have been previously reported. Nineteen other compounds remain to be identified. In conclusion, E. senegalensis appeared rich in compounds with antioxidant and anticancer properties, supporting its use in traditional practice and its status as a species of interest for further investigations in anticancer drug research.

Nutraceutical Role of Polyphenols and Triterpenes Present in the Extracts of Fruits and Leaves of Olea europaea as Antioxidants, Anti-Infectives and Anticancer Agents on Healthy Growth

There is currently a worldwide consensus and recognition of the undoubted health benefits of the so-called Mediterranean diet, with its intake being associated with a lower risk of mortality. The most important characteristics of this type of diet are based on the consumption of significant amounts of fruit, vegetables, legumes, and nuts, which provide, in addition to some active ingredients, fiber and a proportion of vegetable protein, together with extra virgin olive oil (EVOO) as the main sources of vegetable fat. Fish and meat from poultry and other small farm animals are the main sources of protein. One of the main components, as already mentioned, is EVOO, which is rich in monounsaturated fatty acids and to a lesser extent in polyunsaturated fatty acids. The intake of this type of nutrient also provides an important set of phytochemicals whose health potential is widely spread and agreed upon. These phytochemicals include significant amounts of anthocyanins, stilbenes, flavonoids, phenolic acids, and terpenes of varying complexities. Therefore, the inclusion in the diet of this type of molecules, with a proven healthy effect, provides an unquestionable preventive and/or curative activity on an important group of pathologies related to cardiovascular, infectious, and cancerous diseases, as well as those related to the metabolic syndrome. The aim of this review is therefore to shed light on the nutraceutical role of two of the main phytochemicals present in Olea europaea fruit and leaf extracts, polyphenols, and triterpenes, on healthy animal growth. Their immunomodulatory, anti-infective, antioxidant, anti-aging, and anti-carcinogenic capabilities show them to be potential nutraceuticals, providing healthy growth.

Effects of Erythrodiol on the Antioxidant Response and Proteome of HepG2 Cells

Erythrodiol (EO) is a pentacyclic triterpenic alcohol found in olive tree leaves and olive oil, and it has important effects on the health properties and quality of olive oil. In this study, we characterized the cytotoxic effects of EO on human hepatocarcinoma (HepG2) cells by studying changes in cell viability, reactive oxygen species (ROS) production, antioxidant defense systems, and the proteome. The results reveal that EO markedly decreased HepG2 cell viability without changing ROS levels. The concentrations of glutathione and NADPH were significantly reduced, with selective changes in the activity of several antioxidant enzymes: glutathione peroxidase, glutathione reductase, glucose 6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase. Proteomic data reveal that EO led to the complete elimination or decreased abundance of 41 and 3 proteins, respectively, and the abundance of 29 proteins increased. The results of functional enrichment analysis show that important metabolic processes and the nuclear transport of mature mRNA were impaired, whereas AMP biosynthesis and cell cycle G2/M phase transition were induced. The transcription factors and miRNAs involved in this response were also identified. These potent antiproliferative effects make EO a good candidate for the further analysis of its hepatic antitumor effects in in vivo studies.

Uvaol Prevents Group B Streptococcus-Induced Trophoblast Cells Inflammation and Possible Endothelial Dysfunction

Group B Streptococcus (GBS) infection during pregnancy is involved in maternal sepsis, chorioamnionitis, prematurity, fetal infection, neonatal sepsis, and neurodevelopmental alterations. The GBS-induced chorioamnionitis leads to a plethora of immune and trophoblast cells alterations that could influence endothelial cells to respond differently to angiogenic mediators and alter placental vascular structure and function in pregnant women. In this context, preventive measures are needed to reduce such dysfunctions. As such, we evaluated the effects of a non-lethal exposure to inactivated GBS on trophoblast cells and chorionic villi explants, and if the treatment with uvaol would mitigate these effects. The concentration of 10⁶ CFU of GBS was chosen since it was unable to reduce the HTR-8/SVneo cell line nor term chorionic villi explant viability. Raman spectroscopy of trophoblast cells showed significant alterations in their biochemical signature, mostly reverted by uvaol. GBS exposure increased HTR-8/SVneo cells IL-1β and IFN-γ production, phagocytosis, oxidative stress, and decreased trophoblast cell migration. The Ea.hy926 endothelial cell line produced angiopoietin-2, CXCL-8, EGF, FGF-b, IL-6, PlGF, sPECAM-1, and VEGF in culture. When co-cultured in invasion assay with HTR-8/SVneo trophoblast cells, the co-culture had increased production of angiopoietin-2, CXCL-8, FGF-b, and VEGF, while reduced sPECAM-1 and IL-6. GBS exposure led to increased CXCL-8 and IL-6 production, both prevented by uvaol. Chorionic villi explants followed the same patterns of production when exposed to GBS and response to uvaol treatment as well. These findings demonstrate that, even a non-lethal concentration of GBS causes placental inflammation and oxidative stress, reduces trophoblast invasion of endothelial cells, and increases CXCL-8 and IL-6, key factors that participate in vascular dysregulation observed in several diseases. Furthermore, uvaol treatment prevented most of the GBS-provoked changes. Hence, uvaol could prevent the harmful effects of GBS infection for both the mother and the fetus.

Advances in Research on Chemical Constituents and Their Biological Activities of the Genus Actinidia

Kiwi, a fruit from plants of the genus Actinidia, is one of the famous fruits with thousand years of edible history. In the past twenty years, a great deal of research has been done on the chemical constituents of the Actinidia species. A large number of secondary metabolites including triterpenoids, flavonoids, phenols, etc. have been identified from differents parts of Actinidia plants, which exhibited significant in vitro and in vivo pharmacological activities including anticancer, anti-inflammatory, neuroprotective, anti-oxidative, anti-bacterial, and anti-diabetic activities. In order to fully understand the chemical components and biological activities of Actinidia plants, and to improve their further research, development and utilization, this review summarizes the compounds extracted from different parts of Actinidia plants since 1959 to 2020, classifies the types of constituents, reports on the pharmacological activities of relative compounds and medicinal potentials.

Sterols and Triterpene Diols in Virgin Olive Oil: A Comprehensive Review on Their Properties and Significance, with a Special Emphasis on the Influence of Variety and Ripening Degree

Olive oil is considered one of the most valuable vegetable oils and is highly appreciated by consumers for its specific and distinguishable taste and aroma, as well as its nutritional value. Sterols and triterpene diols are important carriers of bioactive properties of olive oil and are responsible for some of the beneficial effects of its consumption on human health, such as lowering serum LDL-cholesterol levels and significantly reducing the risk of cardiovascular diseases. The concentration of total sterols and the proportions of particular sterols and triterpene diols are among the parameters used to verify and prove the authenticity of olive oil in accordance with the EU and other countries’ regulations. Finally, their composition has been shown to have high discrimination potential for ensuring traceability with respect to variety, geographical origin, harvest date, and other factors. For these reasons, the research on sterols and triterpene diols in olive oil is an ever-growing field of scientific interest with great practical importance. This review focuses on all the important aspects of sterols and triterpene diols in olive oil, from their chemical structure, biosynthesis, occurrence and role in plants, health benefits, and their use in official controls of olive oil purity and authenticity, to a conclusive survey on the recent findings about the effects of different factors of influence on their content and composition, with a detailed comparative analysis of studies that investigated the effects of the two most important factors, variety and ripening degree.

Betulinic Acid Modulates the Expression of HSPA and Activates Apoptosis in Two Cell Lines of Human Colorectal Cancer

Betulinic acid (BA) is a pentacyclic triterpene usually isolated from botanical sources. Numerous studies have reported the inhibitory effect of BA against human colorectal cancer cells (CRC). However, its effect on the expression of the molecular chaperone HSPA is unclear. The aim of this research is to investigate the anti-cancer activities of BA purified from Piper retrofractum and study its effect on the expression of HSPA in colorectal cancer HCT116 and SW480 cells. The viability of both cancer cells was reduced after they were treated with an increasing dosage of BA. Flow cytometry assay revealed that levels of cell apoptosis significantly increased after incubation with BA in both cancer cells. Pro-apoptotic markers including Bax, cleaved-caspase-3 and cleaved-caspase-9 were increased while anti-apoptotic marker Bcl-2 was decreased after BA treatment. Western blot also showed that the expression of HSPA fluctuated upon BA treatment, whereby HSPA was increased at lower BA concentrations while at higher BA concentrations HSPA expression was decreased. Preliminary molecular docking assay showed that BA can bind to the nucleotide binding domain of the HSP70 at its ADP-bound state of the HSP70. Although further research is needed to comprehend the BA-HSPA interaction, our findings indicate that BA can be considered as potential candidate for the development of new treatment for colorectal cancer.

Uvaol Improves the Functioning of Fibroblasts and Endothelial Cells and Accelerates the Healing of Cutaneous Wounds in Mice

Uvaol is a natural pentacyclic triterpene that is widely found in olives and virgin olive oil, exerting various pharmacological properties. However, information remains limited about how it affects fibroblasts and endothelial cells in events associated with wound healing. Here, we report the effect of uvaol in the in vitro and in vivo healing process. We show the positive effects of uvaol on migration of fibroblasts and endothelial cells in the scratch assay. Protein synthesis of fibronectin and laminin (but not collagen type I) was improved in uvaol-treated fibroblasts. In comparison, tube formation by endothelial cells was enhanced after uvaol treatment. Mechanistically, the effects of uvaol on cell migration involved the PKA and p38-MAPK signaling pathway in endothelial cells but not in fibroblasts. Thus, the uvaol-induced migratory response was dependent on the PKA pathway. Finally, topical treatment with uvaol caused wounds to close faster than in the control treatment using experimental cutaneous wounds model in mice. In conclusion, uvaol positively affects the behavior of fibroblasts and endothelial cells, potentially promoting cutaneous healing.