Multiple pro-apoptotic targets of abietane diterpenoids from Salvia species

Structurally diverse abietane diterpenoids from the whole plants of Salvia przewalskii Maxim. With anti-inflammatory activity

Using bioactivity guidance, eight previously undescribed abietane diterpenoids (1-8), were isolated from the whole plants of Salvia przewalskii Maxim. along with seven known analogues (9-15). Their structures were elucidated by extensive spectroscopic analyses, quantum chemical calculations, and single crystal X-ray diffraction. Among them, compound 1, an abietane diterpenoid bearing unique C-20 m-cymen-8-ol monoterpenoid moiety, was the first example of the adduct between a monocyclic monoterpenoid and an abietane diterpenoid connected by ester bond within the Salvia genus. The plausible biosynthetic pathways of 1-8 were proposed. All isolates were tested for their inhibitory activity towards the LPS-induced NO production in RAW 264.7 cells. Compounds 3, 5, 6 and 9 significantly inhibited nitric oxide (NO) production in RAW264.7 cells, which also could suppress the release of pro-inflammatory factors (TNF-α, IL-1β and IL-6). The key structure-activity relationships of these abietane-type diterpenes for anti-inflammatory effects have been summarized.

Design, Synthesis, and Biological Evaluation of Novel Urea-Containing Carnosic Acid Derivatives with Anticancer Activity

A series of novel carnosic acid 1 derivatives incorporating urea moieties at the C-20 position was synthesized and evaluated for their antiproliferative activity against the HCT116 colorectal cancer cell line. Most derivatives demonstrated enhanced antiproliferative activity compared to that of carnosic acid 1. The most promising derivatives were tested in other colorectal cancer cell lines (SW480, SW620, and Caco-2), melanoma (A375), and pancreatic cancer (MiaPaca-2). Derivative 14 consistently demonstrated the highest activity across all tested cancer cell lines, showing selectivity for cancer cells over normal cells. Further investigation of the mechanism of action in SW480 cells revealed that compound 14 induced cell cycle arrest at the G0/G1 phase by downregulating CDK4 and CDK6. Molecular docking studies revealed that compound 14 established several interactions with key residues in the active site of CDK6. Additionally, compound 14 also reduced ROS production. In summary, our results strongly indicate that compound 14 has potential as a lead compound in the development of innovative anticancer drugs.

Abietane-Type Diterpenoids: Insights into Structural Diversity and Therapeutic Potential

The abietane-type diterpenoids are among the most significant diterpene subsets found in hundreds of plant species belonging to various families. Among which, the members of the genus Salvia and Euphorbia are rich in abietane diterpenoids. Because of the chemical diversity and notable bioactivities, such as anticancer, antiinflammatory, antimicrobial, and antioxidant activities, they are attractive. Herein, recent advances in the isolation and characterization of abietanes from natural sources, as well as their biological activities, from 2015 up to 2024 are reviewed. During this time, over 300 abietanes with diverse structures have been discovered.

Anticancer diterpenes of African natural products: Mechanistic pathways and preclinical developments

BACKGROUND

The African continent is home to five biodiversity hotspots, boasting an immense wealth of medicinal flora, fungi and marine life. Diterpenes extracted from such natural products have compelling cytotoxic activities that warrant further exploration for the drug market, particularly in cancer therapy, where mortality rates remain elevated worldwide.

PURPOSE

To demonstrate the potential of African natural products on the global stage for cancer therapy development and provide an in-depth analysis of the current literature on the activity of cancer cytotoxic diterpenes from African natural sources (to our knowledge, the first of its kind); not only to reveal the most promising candidates for clinical development, but to demonstrate the importance of preserving the threatened ecosystems of Africa.

METHODS

A comprehensive search by means of the PRISMA strategy was conducted using electronic databases, namely Web of Science, PubMed, Google Scholar and ScienceDirect. The search terms employed were 'diterpene & mechanism & cancer' and 'diterpene & clinical & cancer'. The selection process involved assessing titles in English, Portuguese and Spanish, adhering to predefined eligibility criteria. The timeframe for inclusion spanned from 2010 to 2023, resulting in 218 relevant papers. Chemical structures were visualized using ChemDraw 21.0, PubChem was utilized to search for CID numbers.

RESULTS

Despite being one of the richest biodiverse zones in the world, African natural products are proportionally underreported compared to Asian countries or otherwise. The diterpenes andrographolide (Andrographis paniculata), forskolin (Coleus forskohlii), ent-kauranes from Isodon spp., euphosorophane A (Euphorbia sororia), cafestol & kahweol (Coffea spp.), macrocylic jolkinol D derivatives (Euphorbia piscatoria) and cyathane erinacine A (Hericium erinaceus) illustrated the most encouraging data for further cancer therapy exploration and development.

CONCLUSIONS

Diterpenes from African natural products have the potential to be economically significant active pharmaceutical and medicinal ingredients, specifically focussed on anticancer therapeutics.

Cytotoxic abietane diterpenoids from Salvia leriifolia Benth

The Phytochemical profiling of the root extract of Salvia leriifolia, an endemic plant of Iran, was investigated and 16 abietane diterpenes were isolated, and three were original compounds. 1D and 2D NMR and HRMS performed structural elucidation. The absolute configuration of the previously unreported compounds was determined by circular dichroism (ECD). The cytotoxicity of the isolated compounds was investigated against AGS, MIA PaCa-2, HeLa, and MCF-7 cell lines by the MTT assay. The known diterpene pisiferal possesses high cytotoxicity against all investigated cell lines at a concentration between 9.3 ± 0.6 and 14.38 ± 1.4 μM.

Effect of Modified Levopimaric Acid Diene Adducts on Mitochondrial and Liposome Membranes

This paper demonstrates the membranotropic effect of modified levopimaric acid diene adducts on liver mitochondria and lecithin liposomes. We found that the derivatives dose-dependently reduced the efficiency of oxidative phosphorylation of mitochondria due to inhibition of the activity of complexes III and IV of the respiratory chain and protonophore action. This was accompanied by a decrease in the membrane potential in the case of organelle energization both by glutamate/malate (complex I substrates) and succinate (complex II substrate). Compounds 1 and 2 reduced the generation of H2O2 by mitochondria, while compound 3 exhibited a pronounced antioxidant effect on glutamate/malate-driven respiration and, on the other hand, caused ROS overproduction when organelles are energized with succinate. All tested compounds exhibited surface-active properties, reducing the fluidity of mitochondrial membranes and contributing to nonspecific permeabilization of the lipid bilayer of mitochondrial membranes and swelling of the organelles. Modified levopimaric acid diene adducts also induced nonspecific permeabilization of unilamellar lecithin liposomes, which confirmed their membranotropic properties. We discuss the mechanisms of action of the tested compounds on the mitochondrial OXPHOS system and the state of the lipid bilayer of membranes, as well as the prospects for the use of new modified levopimaric acid diene adducts in medicine.

White Sage (Salvia apiana)-a Ritual and Medicinal Plant of the Chaparral: Plant Characteristics in Comparison with Other Salvia Species

Salvia apiana, commonly known as white sage, is an aromatic evergreen subshrub of the chaparral, commonly found in coastal plains in California and Baja California. It has been traditionally used by the Chumash people as a ritual and medicinal plant and used as a calmative, a diuretic, and a remedy for the common cold. However, until recently, relatively little has been known about the composition and biological activity of white sage. Phytochemical studies on S. apiana revealed the presence of substantial amounts of essential oil, accompanied by a variety of triterpenes, C23 terpenoids, diterpenes, and flavonoids. Extracts of the plant have been shown to exhibit antioxidative, antimicrobial, and cytotoxic effects. The influence of white sage constituents on the nervous system, including GABA, opioid, and cannabinoid receptors, has also been documented. The review aimed to compile information on the taxonomy, botany, chemical composition, and biological activities of S. apiana. White sage was compared with other representatives of the genus in terms of chemical composition. The differences and similarities between S. apiana and other sage species were noted and discussed in the context of their therapeutic applications. Reports on ethnomedicinal uses of white sage were confronted with reports on chemistry, bioactivity, and bioavailability of S. apiana constituents. Finally, a critical assessment of the available data was made and perspectives for the use of white sage preparations in modern phytomedicine were discussed.

Characterization of undescribed melanoma inhibitors from Euphorbia mauritanica L. cultivated in Egypt targeting BRAFV600E and MEK 1 kinases via in-silico study and ADME prediction

Three undescribed diterpenes including two ent-abietanes, euphomauritanol A, and euphomauritanol B, and one jatrophane, euphomauritanophane A, in addition to eight previously described metabolites were isolated from the MeOH-CH₂Cl₂ (1:1) extract of the Euphorbia mauritanica. The chemical structures of isolates were established based on the spectroscopic means including FT-IR, HRMS, 1D and 2D NMR. The absolute stereochemistry of the undescribed diterpenes was deduced by experimental and calculated TDDFT-electronic circular dichroism (ECD). The anti-proliferative effects of the isolated diterpenes were evaluated against B16-BL6, Hep G2, and Caco-2. The euphomauritanol A, euphomauritanol B, and euphomauritanophane A significantly inhibited the growth of murine melanoma B16-BL6 cell lines with IC₅₀ 10.28, 20.22, and 38.81 μM, respectively with no responses against the other cells. These activities were rationalized by molecular docking of the active compounds in BRAF^V600E and MEK1 active sites. Moreover, the in-silico pharmacokinetics predictions by Swiss ADME revealed that the active compounds possessed favorable oral bioavailability and drug-likeness properties.

In vitro biological potential of the essential oil of some aromatic species used in Iranian traditional medicine

The goal of this study is to evaluate the chemical compounds, the anti-bacterial/fungal activity, and the cytotoxicity of the essential oil of three species of lamiaceae in Iran. After the extraction of the essential oil implementing the hydrodistillation method, the analysis and identification of the compounds were carried out with a chromatograph coupled with a mass spectrometer. For the evaluation of the anti-bacterial/fungal activity of the essential oils, the measurement of the diameter of inhibition halo, the minimum inhibitory concentration (MIC), bactericidal and fungicidal concentrations (MBC/MFC) were utilized; and for the evaluation of the cytotoxic activity of the essential oils, the 3-(4,5-dimethylthiazolyl)-2,5-diphenyltetrazolium bromide (MTT) method was used. The results show that the dominant compounds in the Perovskia abrotanoides Kar essential oil were camphor (21.68%), 1,8-cineole (14.26%), and α-pinene (7.23%); moreover, the dominant compounds in the Salvia reuteriana Boiss. Essential oil were benzyl benzoate (27.10%), linalool (13.27%), and sclareol (7.75%); in addition, the dominant compounds in the Ziziphora clinopodioides subsp. rigida (Boiss.) Rech.f. were cyclofenchene (25.29%), pulegone (14.14%), and menthol (7.70%). The largest halo diameter of inhibition halo (~ 22 mm) was against Streptococcus pyogenes and the strongest inhibiting and killing activity was against Candida albicans (MIC and MFC = 125 μg/mL) shown by the S. reuteriana essential oil which, respectively, matched the control antibiotics rifampin and nystatin. The analysis of the MTT test results showed that the Z. clinopodioides subsp. rigida essential oil (with IC50 value of ~ 144.2500) had the strongest cytotoxic activity against human ovarian cancer cells (OVCAR-3). On the whole, the results show that the essential oil of the Lamiaceae family plants is a source for various compounds with potential biological activities which can serve as a possible alternative to produce herbal medicine which are effective on some microorganisms and cancer cell lines.

Isoprenylated Flavonoids as Cav3.1 Low Voltage-Gated Ca2+ Channel Inhibitors from Salvia digitaloides

Saldigones A-C (1, 3, 4), three new isoprenylated flavonoids with diverse flavanone, pterocarpan, and isoflavanone architectures, were characterized from the roots of Salvia digitaloides, together with a known isoprenylated flavanone (2). Notably, it's the first report of isoprenylated flavonoids from Salvia species. The structures of these isolates were elucidated by extensive spectroscopic analysis. All of the compounds were evaluated for their activities on Cav3.1 low voltage-gated Ca2+ channel (LVGCC), of which 2 strongly and dose-dependently inhibited Cav3.1 peak current.

Vanillin downregulates NNMT and attenuates NNMT‑related resistance to 5‑fluorouracil via ROS‑induced cell apoptosis in colorectal cancer cells

Chemoresistance is the main cause of poor prognosis in colorectal cancer (CRC). Nicotinamide N-methyltransferase (NNMT) is a metabolic enzyme that is upregulated in various tumor types. It has been reported that NNMT inhibits apoptosis and enhances resistance to 5-fluorouracil (5-Fu) via inhibition of the apoptosis signal regulating kinase 1 (ASK1)-p38 MAPK pathway in CRC cells. A natural product library was screened, and it was found that vanillin, also known as 4-hydroxy-3-methoxybenzaldehyde, a plant secondary metabolite found in several essential plant oils, mainly Vanilla planifolia, Vanilla tahitensis, and Vanilla pompon, may be a promising anticancer compound targeted to NNMT. The aim of the present study was to explore the effect of vanillin on promoting apoptosis and attenuating NNMT-induced resistance to 5-Fu in CRC. Lentiviral vectors of short hairpin RNA and small interfering RNA were transfected into HT-29 cells to construct NNMT-knockdown HT-29 cell lines. Vectors containing an open reading frame of NNMT were stably transfected into SW480 cells to induce NNMT overexpression in SW480 cell lines. Vanillin was found to inhibit the mRNA and protein expression levels of NNMT following the inhibition of NNMT activity in HT-29 cell lines. Vanillin was able to reverse NNMT-induced increased cell proliferation, decreased cell apoptosis and resistance to 5-Fu by inhibiting NNMT expression. Furthermore, it increased cell apoptosis by activating the ASK1-p38 MAPK pathway, which could be inhibited by NNMT. In addition, vanillin increased cell apoptosis by promoting mitochondrial damage and reactive oxygen species. In vivo, the combination of vanillin with 5-Fu yielded a notable synergy in inhibiting tumor growth and inducing apoptosis. Considering that vanillin is an important flavor and aromatic component used in foods worldwide, vanillin is deemed to be a promising anticancer candidate by inhibiting NNMT and may attenuate NNMT-induced resistance to 5-Fu in human CRC therapy with few side effects.

Laurus nobilis, Salvia sclarea and Salvia officinalis Essential Oils and Hydrolates: Evaluation of Liquid and Vapor Phase Chemical Composition and Biological Activities

Laurus nobilis, Salvia officinalis and Salvia sclarea essential oils (EOs) and hydrolates (HYs) were investigated to define their chemical compositions and biological properties. Gas-chromatography/Mass-spectrometry (GC/MS) and Headspace-GC/MS (HS-GC/MS) techniques were used to characterize the liquid and vapor phase chemical composition of EOs and HYs. 1,8-Cineole (42.2%, 33.5%) and α-pinene (16.7%, 39.0%) were the main compounds of L. nobilis EO; 1,8-cineole (30.3%, 48.4%) and camphor (17.1%, 8.7%) were for S. officinalis EO; linalyl acetate (62.6%, 30.1%) and linalool (11.1%, 28.9%) were for S. sclarea EO for the liquid and vapor phase, respectively. Chemical profile of HYs was characterized by 1,8-cineole (65.1%, 61.4%) as a main constituent of L. nobilis and S. officinalis HYs, while linalool (89.5%) was the main constituent of S. sclarea HY. The antioxidant activity of EOs and HYs was carried out by DPPH and ABTS assays and antimicrobial properties were also investigated by microdilution and the disc diffusion method for liquid and vapor phase against five different bacterial strains such as Escherichia coli ATCC 25922, Pseudomonas fluorescens ATCC 13525 and Acinetobacter bohemicus DSM 102855 among Gram-negative and Bacillus cereus ATCC 10876 and Kocuria marina DSM 16420 among Gram-positive. L. nobilis and S. officinalis EOs demonstrated considerable antibacterial activity, while S. sclarea EO proved to be less effective. Agar diffusion method and vapor phase test showed the EOs activity with the biggest halo inhibition diameters against A. bohemicus and B. cereus. A remarkably high antioxidant activity was determined for L. nobilis showing low EC₅₀ values and also for S. sclarea; good EO results were obtained in both of the used assays. S. officinalis EC₅₀ values were slightly higher to which corresponds to a lower antioxidant activity. Concerning the HYs, the EC₅₀ values for L. nobilis, S. officinalis and S. sclarea were remarkably high corresponding to an extremely low antioxidant activity, as also obtained by expressing the values in Trolox equivalent antioxidant capacity (TEAC).

Manool, a diterpene from Salvia officinalis, exerts preventive effects on chromosomal damage and preneoplastic lesions

The present study aimed to evaluate the effect of the manool diterpene on genomic integrity. For this purpose, we evaluated the influence of manool on genotoxicity induced by mutagens with different mechanisms of action, as well as on colon carcinogenesis. The results showed that manool (0.5 and 1.0 µg/ml) significantly reduced the frequency of micronuclei induced by doxorubicin (DXR) and hydrogen peroxide in V79 cells but did not influence genotoxicity induced by etoposide. Mice receiving manool (1.25 mg/kg) exhibited a significant reduction (79.5%) in DXR-induced chromosomal damage. The higher doses of manool (5.0 and 20 mg/kg) did not influence the genotoxicity induced by DXR. The anticarcinogenic effect of manool (0.3125, 1.25 and 5.0 mg/kg) was also observed against preneoplastic lesions chemically induced in rat colon. A gradual increase in manool doses did not cause a proportional reduction of preneoplastic lesions, thus demonstrating the absence of a dose-response relationship. The analysis of serum biochemical indicators revealed the absence of hepatotoxicity and nephrotoxicity of treatments. To explore the chemopreventive mechanisms of manool via anti-inflammatory pathways, we evaluated its effect on nitric oxide (NO) production and on the expression of the NF-kB gene. At the highest concentration tested (4 μg/ml), manool significantly increased NO production when compared to the negative control. On the other hand, in the prophylactic treatment model, manool (0.5 and 1.0 μg/ml) was able to significantly reduce NO levels produced by macrophages stimulated with lipopolysaccharide. Analysis of NF-kB in hepatic and renal tissues of mice treated with manool and DXR revealed that the mutagen was unable to stimulate expression of the gene. In conclusion, manool possesses antigenotoxic and anticarcinogenic effects and its anti-inflammatory potential might be related, at least in part, to its chemopreventive activity.

The Potential Anticancer Activity of Phytoconstituents against Gastric Cancer-A Review on In Vitro, In Vivo, and Clinical Studies

Gastric cancer belongs to the heterogeneous malignancies and, according to the World Health Organization, it is the fifth most commonly diagnosed cancer in men. The aim of this review is to provide an overview on the role of natural products of plant origin in the therapy of gastric cancer and to present the potentially active metabolites which can be used in the natural therapeutical strategies as the support to the conventional treatment. Many of the naturally spread secondary metabolites have been proved to exhibit chemopreventive properties when tested on the cell lines or in vivo. This manuscript aims to discuss the pharmacological significance of both the total extracts and the single isolated metabolites in the stomach cancer prevention and to focus on their mechanisms of action. A wide variety of plant-derived anticancer metabolites from different groups presented in the manuscript that include polyphenols, terpenes, alkaloids, or sulphur-containing compounds, underlines the multidirectional nature of natural products.

Boosting the Synthesis of Pharmaceutically Active Abietane Diterpenes in S. sclarea Hairy Roots by Engineering the GGPPS and CPPS Genes

Abietane diterpenoids (ADs), synthesized in the roots of different Salvia species, such as aethiopinone, 1-oxoaethiopinone, salvipisone, and ferruginol, have a variety of known biological activities. We have shown that aethiopinone has promising cytotoxic activity against several human tumor cell lines, including the breast adenocarcinoma MCF7, HeLa, epithelial carcinoma, prostate adenocarcinoma PC3, and human melanoma A375. The low content of these compounds in natural sources, and the limited possibility to synthesize them chemically at low cost, prompted us to optimize the production of abietane diterpenoids by targeting genes of the methylerythritol phosphate (MEP) pathway, from which they are derived. Here, we report our current and ongoing efforts to boost the metabolic flux towards this interesting class of compounds in Salvia sclarea hairy roots (HRs). Silencing the gene encoding the ent-copalyl-diphosphate synthase gene (entCPPS), acting at the lateral geranylgeranyl pyrophosphate (GGPP) competitive gibberellin route, enhanced the content of aethiopinone and other ADs in S. sclarea HRs, indicating indirectly that the GGPP pool is a metabolic constraint to the accumulation of ADs. This was confirmed by overexpressing the GGPPS gene (geranyl-geranyl diphosphate synthase) which triggered also a significant 8-fold increase of abietane diterpene content above the basal constitutive level, with a major boosting effect on aethiopinone accumulation in S. sclarea HRs. A significant accumulation of aethiopinone and other AD compounds was also achieved by overexpressing the CPPS gene (copalyl diphosphate synthase) pointing to this biosynthetic step as another potential metabolic target for optimizing the biosynthesis of this class of compounds. However, by co-expressing of GGPPS and CPPS genes, albeit significant, the increase of abietane diterpenoids was less effective than that obtained by overexpressing the two genes individually. Taken together, the results presented here add novel and instrumental knowledge to a rational design of a hairy root-based platform to yield reliable amounts of aethiopinone and other ADs for a deeper understanding of their molecular pharmacological targets and potential future commercialization.

Spirodesertols A and B, two highly modified spirocyclic diterpenoids with an unprecedented 6-isopropyl-3H-spiro[benzofuran-2,1′-cyclohexane] motif from Salvia deserta

Two highly modified spirocyclic diterpenoids with an unprecedented 6-isopropyl-3H-spiro[benzofuran-2,1′-cyclohexane] motif and four new icetexane diterpenoids were isolated from Salvia deserta. 1 showed more potent cytotoxicity than cis-platin.

Pro-apoptoticeffect of diterpenoids from Fokienia hodginsii on acute myeloid leukemia cells

Previously, we isolated four known diterpenoids, trans-communic acid (1), 13-oxo-15,16-dinor-labda-8(17), 11E-diene-19-oic acid (2), 3β-hydroxytotarol (3), and totarolone (4) from Fokienia hodginsii leaves. Further study demonstrated the antiproliferative activity of all four compounds in acute myeloid leukemia (OCI-AML) cells due to impaired cell cycle progression. Interestingly, 3β-hydroxytotarol (3) had very powerful bioactivity at low concentrations (5 µg/mL).

Characterization of Phenolic Compounds and Antiproliferative Effects of Salvia pomifera and Salvia fruticosa Extracts

The phenolic compounds of methanolic extracts of Salvia pomifera and Salvia fruticosa were identified by liquid chromatography tandem mass spectrometry. Carnosic acid and its metabolite carnosol were the most abundant terpene phenolic compounds of S. fruticosa, while they were completely absent in S. pomifera. The main terpene phenolic constituent of S. pomifera was 12-O-methylcarnosic acid and its mass/mass fragmentation pathway was explained. The detailed mechanism of carnosic acid oxidation to carnosol was suggested. The effects of Salvia extracts and/or carnosic acid, the main diterpene phenolic component of S. fruticosa, on the proliferation and cell cycle of two melanoma cell lines (A375, Mel JuSo) and human fibroblast cell line (HFF) were investigated by MTT assay, PI-exclusion assay and flow cytometry cell cycle analysis. Extract of S. fruticosa more efficiently than S. pomifera extract reduced the proliferation of the human melanoma cells. Carnosic acid showed the most significant effect. The first evidence that carnosic acid affects microtubule dynamics and arrests the cell cycle in the G2/M phase was provided. Collectively, our results demonstrate that these two Salvia species are plants of medicinal interest with perspective for further investigation. Carnosic acid could be the compound responsible for the biological activities of S. fruticosa extracts.

Salvia lachnostachys Benth has antitumor and chemopreventive effects against solid Ehrlich carcinoma

Salvia lachnostachys is an herbaceous plant with anti-inflammatory, analgesic and cytotoxic properties. This study investigated the antitumor effect of an ethanolic extract of Salvia lachnostachys leaves (EES) in a solid Ehrlich carcinoma model. Ehrlich cells were inoculated subcutaneously in the right pelvic member (2 × 10⁶ cells) in female Swiss mice. The animals were treated with vehicle (10 mL kg^-1, p.o.), EES (30 and 100 mg kg^-1, p.o.), or methotrexate (2.5 mg kg^-1, i.p.) for 21 days (early treatment) or 14 days (late treatment) after tumor inoculation, or 10 days before tumor inoculation and continued for 21 days after tumor inoculation (chemopreventive treatment). The acute toxicity test was performed according OECD guidelines Late treatment with EES had no antitumor effect. Early treatment with 100 mg kg^-1 EES prevented tumor development, increased tumor necrosis factor-α (TNF-α) levels and decreased tumor superoxide dismutase (SOD) activity, interleukin-10 (IL-10) levels and Cyclin D1 expression, and tumor cell necrosis was observed. Chemopreventive treatment with EES for 10 and 31 days prevented tumor development in the same manner. EES treatment for 31 days decreased hepatic and tumor SOD activity, tumor IL-10 levels and Cyclin D1 expression, and increased tumor reduced glutathione, N-acetylglucosaminidase, reactive oxygen species, lipid peroxidation, TNF-α levels and Nrf2 expression. No toxicity was observed in the acute toxicity assay. In conclusion, EES had an antitumor effect by inhibiting Cyclin D1 expression and increasing inflammation with early and chemopreventive treatment. Modulation of the antioxidant system also contribute for the antitumor effects of EES.

Ferruginol Diterpenoid Selectively Inhibits Human Thyroid Cancer Growth by Inducing Mitochondrial Dependent Apoptosis, Endogenous Reactive Oxygen Species (ROS) Production, Mitochondrial Membrane Potential Loss and Suppression of Mitogen-Activated Protein Kinase (MAPK) and PI3K/AKT Signaling Pathways

Background

Thyroid cancer causes considerable mortality and morbidity across the globe. Owing to the unavailability of biomarkers and the adverse effects of existing drugs, there is an urgent need to develop efficient chemotherapy for the treatment of thyroid cancers. Plants have served as exceptional source of drugs for the treatment of lethal diseases. The purpose of this study was to evaluate the anticancer effects of ferruginol against thyroid cancer cells.

Material/Methods

We monitored the cell proliferation rate using 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was detected using 4′,6-diamidino-2-phenylindole (DAPI), acridine orange/ethidium bromide (AO/EB), and annexin V/propidium iodide (PI) staining. Reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) levels were examined by fluorescence microscopy. Protein expressed was examined by western blotting.

Results

We found that ferruginol exerted potent antiproliferative action against thyroid cancer cells, and an IC₅₀ of 12 μM was observed for ferruginol against the MDA-T32 cell line. The toxic effects of ferruginol were less pronounced against normal cells. The anticancer effects of ferruginol were likely due to the induction of apoptosis which was also associated with upregulation of Bax and downregulation of Bcl-2. Ferruginol also caused ROS mediated alterations in the MMP of MDA-T32 cells. In MDA-T32 cells, ferruginol might also block the MAPK and PI3K/AKT signaling pathway, which is believed to be an important therapeutic target of anticancer drugs.

Conclusions

In conclusion, in view of the results of this study, it might be suggested that ferruginol might serve as an essential lead molecule for the treatment of thyroid cancer provided further in-depth studies especially studying ferruginol toxicological as well as in vivo studies are needed.

Structure-Based Classification and Anti-Cancer Effects of Plant Metabolites

A variety of malignant cancers affect the global human population. Although a wide variety of approaches to cancer treatment have been studied and used clinically (surgery, radiotherapy, chemotherapy, and immunotherapy), the toxic side effects of cancer therapies have a negative impact on patients and impede progress in conquering cancer. Plant metabolites are emerging as new leads for anti-cancer drug development. This review summarizes these plant metabolites with regard to their structures and the types of cancer against which they show activity, organized by the organ or tissues in which each cancer forms. This information will be helpful for understanding the current state of knowledge of the anti-cancer effects of various plant metabolites against major types of cancer for the further development of novel anti-cancer drugs.

Activation of ER Stress-Dependent miR-216b Has a Critical Role in Salviamiltiorrhiza Ethanol-Extract-Induced Apoptosis in U266 and U937 Cells

Although Salviamiltiorrhiza has been reported to have anti-cancer mechanisms, such as caspase activation, cell cycle arrest, an anti-angiogenesis effect, and Bcl-2 family regulation, its underlying mechanism of endoplasmic reticulum (ER) stress-mediated apoptosis has never been demonstrated. Thus, in this current study, ER stress-related apoptosis via miR-216b of the ethanol extract of Salviamiltiorrhiza (SM) is elucidated for the first time. SM treatment inhibited the viability of U266 and U937 cells in a concentration-dependent manner. However, SM-exposed Raw264.7 cells were intact compared to U266 or U937 cells. Treatment with SM significantly elevated the generation of reactive oxygen species (ROS). The anti-proliferative effect of SM was reversed by pretreatment with the ROS scavenger, N-acetyl-l-cysteine (NAC), compared to cells treated only with SM. Also, SM treatment increased the ER stress by elevation of phosphorylated activating transcription factor 4 (p-ATF4), phosphorylated eukaryotic Initiation Factor 2 (p-eIF2), and phosphorylated protein kinase RNA-like endoplasmic reticulum kinase (p-PERK) expression. Caspase-3 and Poly (ADP-ribose) polymerase (PARP) were cleaved and CCAAT-enhancer-binding protein homologous protein (CHOP) was activated by SM treatment. PARP cleavage and CHOP activation were attenuated by NAC pretreatment. Furthermore, SM increased the tumor suppressor, miR-216b, and suppressed its target, c-Jun. miR-216b inhibitor attenuated the apoptotic effect of SM. Taken together, SM treatment induced apoptosis through regulation of miR-216b and ROS/ER stress pathways. SM could be a potential drug for treatment of multiple myeloma and myeloid leukemia.

Euphorbia lunulata extract acts on multidrug resistant gastric cancer cells to inhibit cell proliferation, migration and invasion, arrest cell cycle progression, and induce apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

The milky sap or the aboveground part of the plant Euphorbia lunulata has long been used by Chinese people to treat noncancerous growths and cancerous ailments but the specific mode of action and the action mechanism remain to be elucidated.

AIM OF THE STUDY

To investigate the effects of Euphorbia lunulata extract on cell proliferation, migration, invasion, cell cycle progression, and apoptosis of multidrug resistant human gastric cancer cells; To study the mechanism of apoptosis induction by Euphorbia lunulata extract in multidrug resistant human gastric cancer cells.

MATERIALS AND METHODS

The aboveground part of fresh Euphorbia lunulata plant was extracted first with ethanol and then with n-hexane. The aseptic extract at varying concentrations was used to treat the multidrug resistant human gastric cancer SGC7901/ADR cells. After treatment, the inhibition of cell proliferation was examined by MTT assay. The inhibitions of cell migration and invasion were detected by Transwell method. The alteration of cell cycle progression was studied by flow cytometry. The morphological changes of cell nuclei were observed with fluorescence microscopy following Hoechst 33258 staining and the apoptotic indexes were calculated. The activation of caspase enzymes was analyzed by spectrophotometry. The sub-cellular distribution of cytochrome complex and the expression of Bax and Bcl-2 proteins were determined by Western blot.

RESULTS

The proliferation, migration, and invasion of SGC7901/ADR cells were significantly inhibited by Euphorbia lunulata extract, which showed time- and dose-dependent manners. Cell cycle was arrested in G2/M phase. Significant apoptotic morphological changes were observed in the nuclei of the treated cells, and apoptotic indexes were increased significantly; these changes were diminished when Z-VAD-FMK, a caspase inhibitor, was also presented. The activities of caspase-3, caspase-8, and caspase-9 were increased. The sub-cellular distribution of cytochrome complex was altered----reduced in the mitochondria and increased in the cytoplasm. The expression of Bax was upregulated, while that of Bcl-2 was downregulated.

CONCLUSION

Euphorbia lunulata extract inhibited the proliferation, migration, and invasion of SGC7901/ADR cells, arrested cell cycle progression, and induced cell apoptosis; the mechanism of apoptosis induction involved both the extrinsic and the intrinsic pathways.

Structure, Absolute Configuration, and Antiproliferative Activity of Abietane and Icetexane Diterpenoids from Salvia ballotiflora

From the aerial parts of Salvia ballotiflora, eleven diterpenoids were isolated; among them, four icetexanes and one abietane (1-5) are reported for the first time. Their structures were established by spectroscopic means, mainly ¹H- and 13C-NMR, including 1D and 2D homo- and hetero-nuclear experiments. Most of the isolated diterpenoids were tested for their antiproliferative, anti-inflammatory, and radical scavenging activities using the sulforhodamine B assay on six cancer cell lines, the TPA-induced ear edema test in mice, and the reduction of the DPPH assay, respectively. Some diterpenoids showed anti-proliferative activity, these being icetexanes 6 and 3, which were the most active with IC50 (μM) = 0.27 ± 0.08 and 1.40 ± 0.03, respectively, for U251 (human glioblastoma) and IC50 (μM) = 0.0.46 ± 0.05 and 0.82 ± 0.06 for SKLU-1 (human lung adenocarcinoma), when compared with adriamycin (IC50 (μM) = 0.08 ± 0.003 and 0.05 ± 0.003, as the positive control), respectively. Compounds 3 and 10 showed significant reduction of the induced ear edema of 37.4 ± 2.8 and 25.4 ± 3.0% (at 1.0 μmol/ear), respectively. Compound 4 was the sole active diterpenoid in the antioxidant assay (IC50 = 98. 4 ± 3.3), using α-tocopherol as the positive control (IC50 (μM) = 31.7 ± 1.04). The diterpenoid profile found is of chemotaxonomic relevance and reinforces the evolutionary link of S. ballotiflora with other members of the section Tomentellae.

Chemical constituents from the roots of Tripterygium wilfordii and their cytotoxic activity

In our ongoing search for bioactive constituents, a new sesquiterpene polyol ester, named triptersinine U (1), together with five known triterpenes (2-6) and seven sesquiterpene pyridine alkaloids (7-13), were isolated from the roots of Tripterygium wilfordii Hook. f. Their chemical structures were elucidated using extensive spectroscopic analyses, including 1D and 2D NMR, and HRESIMS, as well as comparison with previously reported data. Cytotoxic activities of all compounds 1-13 were evaluated against six human tumor cell lines (HepG2, Hep3B, Bcap37, U251, MCF-7 and A549) using the MTT in vitro assay. The results showed that triterpenes exhibited moderate cytotoxic activities toward the tested cell lines.

Assessment of antioxidant, antitumor and pro-apoptotic effects of Salvia fruticosa Mill. subsp. thomasii (Lacaita) Brullo, Guglielmo, Pavone & Terrasi (Lamiaceae)

The aim of the present study was to investigate the in vitro antioxidant and antitumor effects of Salvia fruticosa Mill subsp. thomasii (Lacaita) Brullo, Guglielmo, Pavone & Terrasi (Lamiaceae). The aerial parts were extracted by maceration with methanol. This extract was partitioned with methanol and n-hexane. Luteolin, luteolin 7-O-glucoside, rutin and salvigenin were isolated from the methanol-soluble fraction. n-Hexane fraction showed viridiflorol, β-pinene, 1,8-cineole, as main components. The methanol-soluble fraction exerted antitumor activity against human breast cancer (MCF-7 and MDA-MB-231) and human colorectal carcinoma (RKO and Caco-2) cells. TUNEL test revealed that S. fruticosa subsp. thomasii leads to cells death by apoptosis, with low cytotoxic effects on non-tumoral 3T3-L1 cells. Moreover, it exerted the highest protection of lipid peroxidation and reduced the oxidative stress induced by menadione treatment in 3T3-L1 murine fibroblasts. S. fruticosa subsp. thomasii bioactivity could promote its use not only as food but also in nutraceutical/pharmaceutical industries.

Tanshinone Suppresses Arecoline-Induced Epithelial-Mesenchymal Transition in Oral Submucous Fibrosis by Epigenetically Reactivating the p53 Pathway

Oral submucous fibrosis (OSF) induced by chewing of the areca nut has been considered to be a precancerous lesion with a high probability of developing oral squamous cell carcinoma. Tanshinone (TSN) is the main component extracted from Salvia miltiorrhiza, a traditional Chinese medicine, which was found to have diverse pharmacological effects, such as anti-inflammatory and antitumor. In the current study, we aimed to identify the inhibitory effects and the underlying mechanism of TSN on OSF progress. We found that treatment with TSN inhibited the arecoline-mediated proliferation of primary human oral mucosal fibroblasts and reversed the promotive effects of arecoline on the EMT process. By RNA deep sequencing, we screened two possible targets for TSN: LSD1 and p53. We confirmed that p53 is much lower in OSF than in normal mucous tissues. In addition, p53 and its downstream molecules were decreased by arecoline treatment in oral mucosal fibroblasts, which was reversed by treatment with TSN in a dose-dependent manner. Our results also revealed that arecoline stimulation resulted in hypermethylation of the promoter of TP53 and subsequent downregulation of p53 levels, which was reversed by TSN. Furthermore, we identified that LSD1 could epigenetically activate TP53 by recruiting H3K27me1 and H3K4m2 to its promoter. Our findings provide new insights into the mechanism by which TSN influences arecoline-induced OSF and rationale for the development of clinical intervention strategies for OSF and even oral squamous cell carcinoma.

Antiproliferative effects of extracts from Salvia officinalis L. and Saliva miltiorrhiza Bunge on hepatocellular carcinoma cells

Salvia species have been used as valuable medicinal and herbal plant in many countries. Salvia officinalis L. and Salvia miltiorrhiza Bunge are widely used in traditional medicine for a long time. In the present study, cytotoxicity of ethanol and acetone extracts prepared from leaves and roots of two Salvia species was investigated using hepatocellular carcinoma cells (HepG2) and normal human liver cells (WRL-68). The cytotoxicity and anti-proliferative abilities of the extracts were evaluated by measuring cell viability (MTS assay), lactate dehydrogenase (LDH) leakage, the cellular ATP level, morphological changes using an inverted microscope, and apoptosis using flow cytometry. The results indicated that ethanol and acetone extracts of leaves and roots of S. officinalis (SO-L-E, SO-L-A, SO-R-E and SO-R-A, respectively) and ethanol and acetone extracts of roots of S. miltiorrhiza (SM-R-E and SM-R-A, respectively) significantly inhibited the proliferation of HepG2 cells in a time- and dose-dependent manner when the concentration was less than 150μg/mL. The cytotoxity of SO-L-E, SO-R-E and SO-R-A were significantly less in WRL-68 when compared to HepG2 cells in vitro. The increase of LDH leakage, decrease of ATP and the changes in morphology of HepG2 cells further confirmed the cytotoxic effect of these extracts to HepG2 cells. Furthermore, SO-L-E, SO-L-A, SO-R-E ethanol extract of leaves of S. miltiorrhiza (SM-L-E) and SM-R-E were able to induce apoptosis in HepG2 cells. This study shows the potential of the extracts to be used in the prevention and/or treatment of liver cancer or as ingredients in functional foods and provides scientific support for development and utilization of S. officinalis and S. miltiorrhiza, especially the roots of S. officinalis.

Abietane and nor-abitane diterpenoids from the roots of Salvia rhytidea

Background

The genus Salvia is a rich source of structurally diverse terpenoids. Different species of the Salvia have been used in folk medicine of Iran and therefore attracted the attention of researchers for exploring their chemical constituents. In a project directed at structurally interesting bioactive metabolites from Iranian Lamiaceae, we studied Salvia rhytidea.

Results

Fractionation of the petroleum ether extract of the root of S. rhytidea led to the isolation of a new 20-nor-abietane diterpenoid (1), together with seven known compounds, comprising five abietane diterpenoids (2–6), and two rearranged abietanes (7, 8). Their structures were established by a combination of 1D and 2D NMR.

Conclusions

Our results showed that the root of S. rhytidea could be considered as a new and rich source of different types of abietane and rearranged abietane diterpenoids.

Radix Astragali and Tanshinone Help Carboplatin Inhibit B16 Tumor Cell Growth

Background:

Excessive UV radiation causes increased melanoma incidence. Postoperation chemotherapy will destroy lymphocytes and compromise immune response. Immunodepression is also detected in patients with cancers. Previous studies suggested that polysaccharide–protein complexes manifested immunomodulatory and antitumor activities. Radix Astragali (RA) extract is a product of polysaccharide–protein complexes, which has been used in the treatment of a variety of diseases because of its low toxicity to the host. Tanshinone (TA) is a derivative of phenanthrenequinone isolated from Danshen, which is suggested to inhibit tumor growth by inducing apoptosis in tumor cells. Carboplatin (CA) is a commonly used chemotherapeutic drug in melanoma treatment. Therefore, we hypothesized that the combination of RA and TA will help CA better inhibit the B16 cell growth.

Purpose:

The study will test that the efficacy of growth inhibition of tumor cell produced by CA + RA + TA is better than CA + RA or CA + TA.

Methods:

The B16 tumor cells were injected to Swiss-Hauschka (ICR) mice subcutaneously. Twenty-four hours later, mice received CA intraperitoneally, CA + RA (RA were administered gastrically at the dosage of 10 g/kg body weight), CA + TA (TA were administered gastrically at the dosage of 0.5 g/kg body weight), or no treatment (model group). Tumor weight, volume, latency, incidence, the percentage of CD4+ and CD8+ in spleen, and natural killer (NK), and cytotoxic lymphocyte (CTL) activities were measured and compared among different groups.

Results:

Compared with mice treated with CA + RA, CA + TA, or CA alone, the mice treated with CA + RA + TA showed (1) significantly smaller tumor weight and tumor volume; (2) significantly longer tumor latency; (3) significantly lower tumor incidence; and (4) significantly increased percentage of CD4+ and CD8+ in spleen and increased activities of NK and CTL.

Conclusion:

Combination of RA and TA can help CA produce more effective inhibition on B16 cell growth.

Pharmacological perspectives from Brazilian Salvia officinalis (Lamiaceae): antioxidant, and antitumor in mammalian cells

ABSTRACT Salvia officinalis (Lamiaceae) has been used in south of Brazil as a diary homemade, in food condiment and tea-beverage used for the treatment of several disorders. The objective of this study was to characterize chemical compounds in the hydroalcoholic (ExtHS) and aqueous (ExtAS) extract from Salvia officinalis (L.) by gas chromatography-mass spectrometry (GC-MS) and by high-resolution electrospray ionization mass spectrometry (ESI-QTOF MS/MS), evaluate in vitro ability to scavenge the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+), catalase (CAT-like) and superoxide dismutase (SOD-like) activity, moreover cytotoxic by MTT assay, alterations on cell morphology by giemsa and apoptotic-induced mechanism for annexin V/propidium iodide. Chemical identification sage extracts revealed the presence of acids and phenolic compounds. In vitro antioxidant analysis for both extracts indicated promising activities. The cytotoxic assays using tumor (Hep-2, HeLa, A-549, HT-29 and A-375) and in non-tumor (HEK-293 and MRC-5), showed selectivity for tumor cell lines. Immunocytochemistry presenting a majority of tumor cells at late stages of the apoptotic process and necrosis. Given the results presented here, Brazilian Salvia officinalis (L.) used as condiment and tea, may protect the body against some disease, in particularly those where oxidative stress is involved, like neurodegenerative disorders, inflammation and cancer.

Synthesis, antiproliferative and antifungal activities of 1,2,3-triazole-substituted carnosic Acid and carnosol derivatives

Abietane diterpenes exhibit an array of interesting biological activities, which have generated significant interest among the pharmacological community. Starting from the abietane diterpenes carnosic acid and carnosol, twenty four new triazole derivatives were synthesized using click chemistry. The compounds differ in the length of the linker and the substituent on the triazole moiety. The compounds were assessed as antiproliferative and antifungal agents. The antiproliferative activity was determined on normal lung fibroblasts (MRC-5), gastric epithelial adenocarcinoma (AGS), lung cancer (SK-MES-1) and bladder carcinoma (J82) cells while the antifungal activity was assessed against Candida albicans ATCC 10231 and Cryptococcus neoformans ATCC 32264. The carnosic acid γ-lactone derivatives 1–3 were the most active antiproliferative compounds of the series, with IC₅₀ values in the range of 43.4–46.9 μM and 39.2–48.9 μM for MRC-5 and AGS cells, respectively. Regarding antifungal activity, C. neoformans was the most sensitive fungus, with nine compounds inhibiting more than 50% of its fungal growth at concentrations ≤250 µg∙mL⁻¹. Compound 22, possessing a p-Br-benzyl substituent on the triazole ring, showed the best activity (91% growth inhibition) at 250 µg∙mL⁻¹ In turn, six compounds inhibited 50% C. albicans growth at concentrations lower than 250 µg∙mL⁻¹.