Pharmacokinetic characterization of carnosol from rosemary (Salvia Rosmarinus) in male C57BL/6 mice and inhibition profile in human cytochrome P450 enzymes.

Rosemary (Salvia Rosmarinus) is a rich source of dietary diterpenes with carnosol as one of the major polyphenols used to standardize rosemary extracts approved as a food preservative, however, at present there is not any information on the murine pharmacokinetic profile of carnosol or its potential for drug interactions. The present study utilizes cell-free, cell-based, and animal-based experiments to define the pharmacokinetic profile of the food based phytochemical carnosol. Mice were administered carnosol (100 mg/kg body weight) by oral gavage and plasma levels were analyzed by LC-MS/MS to establish a detailed pharmacokinetic profile. The maximum plasma concentration exceeded 1 µM after a single administration. The results are significant as they offer insights on the potential for food-drug interactions between carnosol from rosemary and active pharmaceutical ingredients. Carnosol was observed to inhibit selected CYP450 enzymes and modulate metabolic enzymes and transporters in in vitro assays.

Taichunins E-T, Isopimarane Diterpenes and a 20-nor-Isopimarane, from Aspergillus taichungensis (IBT 19404): Structures and Inhibitory Effects on RANKL-Induced Formation of Multinuclear Osteoclasts.

Fifteen new isopimarane-type diterpenes, taichunins E-S (1-15), and a new 20-nor-isopimarane, taichunin T (16), together with four known compounds were isolated from Aspergillus taichungensis (IBT 19404). The structures of these new compounds were determined by NMR and mass spectroscopy, and their absolute configurations were analyzed by NOESY and TDDFT calculations of ECD spectra. Taichunins G, K, and N (3, 7, and 10) completely inhibited the receptor activator of nuclear factor-κB ligand (RANKL)-induced formation of multinuclear osteoclasts in RAW264 cells at 5 µM, with 3 showing 92% inhibition at a concentration of 0.2 µM.

Rubesanolides F and G: Two Novel Lactone-Type Norditerpenoids from Isodon rubescens.

A phytochemical investigation of the leaves of the medicinal plant Isodon rubescens led to the isolation of the two new degraded abietane lactone diterpenoids rubesanolides F (1) and G (2). Their structures were elucidated based on the analyses of the HRESIMS and 1D/2D NMR spectral data, and their absolute configurations were determined by ECD spectrum calculations and X-ray single crystal diffraction methods. Compounds 1 and 2, with a unique γ-lactone subgroup between C-8 and C-20, were found to form a carbonyl carbon at C-13 by removal of the isopropyl group in an abietane diterpene skeleton. Rubesanolide G (2) is a rare case of abietane that possesses a cis-fused configuration between rings B and C. The two isolates were evaluated for their biological activities against two cancer cell lines (A549 and HL60), three fungal strains (Candida alba, Aspergillus niger and Rhizopus nigricans) and three bacterial strains (Escherichia coli, Staphylococcus aureus and Bacillus subtilis).

Diterpenoids with Aromatase Inhibitory Activity from the Rhizomes of Kaempferia elegans.

Investigation of bioactive compounds from the rhizomes of Kaempferia elegans led to the isolation and characterization of ten new diterpenoids, namely, five 12,13-seco-diterpenoids named elegansins A-E (1-5) and five new abietanes, elegansols A-E (6-10), together with seven known diterpenoids (11-17). The structure elucidation of the new compounds was achieved by HRESIMS, NMR, and ECD spectroscopic analysis. Compounds (1-5) are the first examples of 12,13-seco-diterpenoid-type compounds representing a decalin fused dihydropyran skeleton. Plausible biosynthetic pathways for compounds 1-5 are proposed. Aromatase inhibitory activities of all compounds were evaluated, and abieta-8,11,13-trien-11-ol (16) was found to be the most potent aromatase inhibitor with an IC50 value of 3.7 µM.

(9ßH)- and 17-Nor-Pimaranes from Icacina oliviformis.

Eleven pimarane-type diterpenoids were isolated from the tubers of Icacina oliviformis, including three new compounds, icacinlactone M (9), icacinlactone H 2-O-ß-d-glucopyranoside (10), and icacinlactone N 3-O-ß-d-glucopyranoside (11), together with an artifact of acrenol (8). Among the known structures, icacinlactone A (2), icacinlactone B (3), icacinlactone H (4), 12-hydroxyicacinlactone A (5), 14α-methoxyhumirianthol (6), and annonalide (7) are reported from I. oliviformis for the first time, whereas icacinol (1) has previously been found in this plant. Icacinol, 14α-methoxyhumirianthol, and annonalide displayed moderate cytotoxic activity in a panel of human cancer cell lines.

Self-assembled natural small molecule diterpene acids with favorable anticancer activity and biosafety for synergistically enhanced antitumor chemotherapy.

Natural biocompatible materials such as self-assembled natural small molecule products (NSMP) with anticancer activity are of increasing interest for synergistic biomedical applications. Herein, we discovered and developed four new self-assembled tricyclic diterpene acids NSMP with favorable anticancer activity for synergistic and safe antitumor chemotherapy, including dehydroabietic acid, 15-hydroxy-dehydroabietic acid, abietic acid, and 12-hydroxyabietic acid. The self-assembled performance and mechanism of these four compounds with different morphologies were explored in detail by molecular dynamics simulation, and revealed the coplanarity and orderliness of molecular arrangements which are speculated to be responsible for the self-assembly into spheres or rods. The screened and optimized abietic acid (AA) was chosen to prepare the synergistic antitumor drug AA-PTX NPs by co-administration with paclitaxel through multiple hydrogen bonds. The resulting nanodrugs were internalized into cells through a lysosome acidification uptake pathway. The improved water-solubility, significantly enhanced in vitro cytotoxicity, and excellent biosafety, lead to a highly efficient and safe in vivo anticancer efficacy of 81.2% inhibition rate with only three doses. This work provides new insights to explore the self-assembly behavior of small molecules and broadens the types of self-assembled active NSMP, providing a promising perspective for the fabrication of active NSMP mediated medical agents for multiple synergistic therapies.

Nor-abietane Diterpenoids from Perovskia abrotanoides Roots with Anti-inflammatory Potential.

Fractionation of an EtOAc extract of the roots of Perovskia abrotanoides yielded 28 diterpenoids, including 12 new analogues, 1-12. The structures of these diterpenoids were established using comprehensive spectroscopic data analysis, including 1D and 2D NMR, high-resolution electrospray ionization mass spectrometry, electronic circular dichroism spectroscopy, and comparison with literature data. The extract and some of the tested compounds showed significant anti-inflammatory activity on J774A.1 macrophage cells stimulated with E. coli lipopolysaccharide. In particular, the tested compounds significantly inhibited the release of nitric oxide and the expression of related proinflammatory enzymes, such as inducible nitric oxide synthase.

The protective effect of tanshinone IIa on endothelial cells: a generalist among clinical therapeutics.

INTRODUCTION: Tanshinone IIa (TSA) has been approved to treat cardiovascular diseases by the China State Food and Drug Administration. TSA has exhibited a variety of pharmacological effects, including vasodilator, antioxidant, anti-inflammatory, and anti-tumor properties. Endothelial cells play an important physiological role in vascular homeostasis and control inflammation, coagulation, and thrombosis. Accumulating studies have shown that TSA can improve endothelial function through various pathways. AREAS COVERED: The PubMed database was reviewed for relevant papers published up to 2020. This review summarizes the current clinical and pharmaceutical studies to provide a systemic overview of the pharmacological and therapeutic effects of TSA on endothelial cells. EXPERT OPINION: TSA is a representative monomeric compound extracted from Danshen and it exhibits significant pharmacological and therapeutic properties to improve endothelial cell function, including alleviating oxidative stress, attenuating inflammatory injury, modulating ion channels and so on. TSA represents a spectrum of agents that are extracted from plants and can restore the endothelial function to establish the beneficial and harmless molecular therapeutics. This also suggests the possible detection of endothelial cells for very early diagnosis of diseases. In future, precise therapeutic methods will be developed to repair endothelial cells injury and recover endothelial dysfunction.

Isolation and characterization of ent-pimarane diterpenoids from Sigesbeckia pubescens.

Five new ent-pimarane diterpenoids ent-16-nor-2-oxopimar-8(14)-ene-15,19-dial (1), ent-16-nor-2α,19-dihydroxypimar-8-en-15-al (2), 3-O-acetyldarutigenol (3), 19-O-acetylkirenol (4), ent-16-nor-3ß,15-dihydroxypimar-8(14)-ene (5) were isolated and characterized from the ethanol extract of Sigesbeckia pubescens. Their structures were elucidated on the basis of spectroscopic analysis. The absolute configuration of C-15 in compounds 3 and 4 was assigned using Snatzke's method. All these compounds were assessed for their anti-inflammatory potential by measuring the inhibitory effects on NO production in LPS-induced RAW 264.7 macrophage cells and compound 4 showed significantly inhibitory activity with IC50 value of 5.9 µM.

Anti-Zika virus activity of several abietane-type ferruginol analogues.

Abietane diterpenoids are naturally occurring plant metabolites with a broad spectrum of biological effects including antibacterial, antileishmanial, antitumor, antioxidant, as well as antiinflammatory activities. Recently, we found that some analogues of natural ferruginol ( 2 ) actively inhibited dengue virus 2 (DENV-2) replication. Due to the similarity with DENV, we envisaged that abietane diterpenoids would also be active against Zika virus (ZIKV). Six selected semi-synthetic abietane derivatives of (+)-dehydroabietylamine ( 3 ) were tested. Cytotoxicity was determined by MTT assay in Vero cells. In vitro anti-ZIKV (clinical isolate, IMT17) activity was evaluated by plaque assay. Interestingly, these molecules showed potential as anti-ZIKV agents, with EC50 values ranging from 0.67 to 18.57 µM, and cytotoxicity (CC50 values) from 2.56 to 35.09 µM. The 18-Oxoferruginol (8) (EC50 = 2.60 µM, SI = 13.51) and 12-nitro-N-benzoyldehydroabietylamine (9) (EC50= 0.67 µM, SI = 3.82) were the most active compounds, followed by 12-hydroxy-N-tosyldehydroabietylamine ( 7 ) (EC50 = 3.58 µM, SI = 3.20) and 12-hydroxy-N,N-phthaloyldehydroabietylamine ( 5 ) (EC50 = 7.76 µM, SI = 1.23). To the best of our knowledge, this is the first report on anti-Zika virus properties of abietanes.

Tanshinone IIA exerts therapeutic effects by acting on endogenous stem cells in rats with liver cirrhosis.

BACKGROUND AND OBJECTIVE: Liver cirrhosis (LC), the major pathway for the progression and development of chronic liver disease, is an advanced stage of liver disease. It is the third most common chronic noncommunicable disease after cardiovascular diseases and malignant tumors. Tanshinone IIA (Tan), an extract of Salvia miltiorrhiza (S. miltiorrhiza), has been proven to promote the proliferation and differentiation of stem cells. Moreover, its protective effect in liver injury has received widespread attention. The present study investigated whether Tan plays a therapeutic role in LC by promoting endogenous stem cell proliferation and differentiation. MATERIALS AND METHODS: LC models were established by intraperitoneal injection of an olive oil solution containing 50 % carbon tetrachloride (CCL4) combined with 10 % alcohol in the drinking water. After successful model establishment, the animals were randomly divided into four groups and injected with physiological saline or low-, medium-, or high-dose (10, 20, or 40 mg/kg) Tan for seven consecutive days. The protective effect of Tan on LC was observed by western blotting, serological examination and histopathological staining. Furthermore, immunofluorescence double-labeling of 5-bromo-2-deoxyuridine (BrdU) and the liver cell markers albumin and CK-18 or the liver stem cell markers EPCAM and OV-6 was used to evaluate the proliferation and differentiation of endogenous liver stem cells. RESULTS: We confirmed successful establishment of the LC model by observing transaminase levels and hematoxylin-eosin (HE) and Masson staining of liver sections in CCL4-treated and healthy rats. After Tan treatment, HE and Masson staining of paraffin sections of liver tissue showed that Tan treatment significantly improved histological injury to the liver. Serological tests showed that albumin-bilirubin (ALBI) scores and models for end-stage liver disease (MELD) were lower. Immunofluorescence and immunohistochemical staining showed that the newly proliferated cells were colocalized with ALB, OV-6, EPCAM, and CK-18, indicating that new expression of these markers occurred after Tan injection. All results were most significant in the medium-dose treatment group. CONCLUSION: Tan can alleviate liver injury induced by CCL4 combined with alcohol in rats and plays a therapeutic role in LC by promoting the proliferation and differentiation of endogenous liver stem cells.

A new ent-abietane lactone from Glycosmis pentaphylla.

A new ent-abietane lactone, 3-oxojolkinolide A (1), together with 16 known compounds, helioscopinolide E (2), helioscopinolide A (3), 3-methyl-9H-carbazole (4), carbalexin (5), carbalexin B (6), glycaborinine (7), arborinine (8), 1H-indole-3-carbaldehyde (9), glycoamide A (10), glycoamide B (11), 2-(N-methyl-2-phenylacetamido)benzoic acid (12), 2-(methylamine)-methylbenzoate (13), fraxidin (14), scopoletin (15), (-)-syringaresinol (16) and ferulic acid (17) were isolated from Glycosmis pentaphylla. The structures of these compounds were elucidated using spectroscopic techniques such as NMR and MS. Among them, compounds 1-3, 9 and 12-17 were isolated from the genus Glycosmis for the first time.

Lophachinins A-E, abietane diterpenes from a Mongolian traditional herbal medicine Lophanthus chinensis.

Five new abietane diterpenes, lophachinins A-E (1-5), and eleven known related diterpenes were isolated from a Mongolian traditional herbal medicine, the aerial parts of Lophanthus chinensis (Lamiaceae). The structures of new diterpenes were assigned by spectroscopic analyses. Lophachinins A (1) and B (2) were abietane diterpene possessing an endoperoxy bridge at C-ring. In contrast, lophachinins C-E (3-5) had an abietane skeleton with an aromatized C-ring. The absolute configuration of 1 was elucidated by application of the modified Mosher's method, while those of 2, 3, and 5 were assigned by chemical conversions. The absolute configuration of lophachinin D (4) was deduced by ECD calculation. Anti-inflammatory activity of isolated diterpenes on microglial cells were evaluated.

Tanshinone IIA Ameliorates Progression of CAD Through Regulating Cardiac H9c2 Cells Proliferation and Apoptosis by miR-133a-3p/EGFR Axis.

BACKGROUND: Coronary artery disease (CAD) leads to the highest mortality worldwide, seriously threatening human health. Tanshinone IIA (Tan IIA), which could be extracted from Danshen, is applied in the treatment of cardiovascular and cerebrovascular diseases. MicroRNAs (miRNAs, miRs) play pivotal roles in cell proliferation and cell apoptosis of the cardiovascular system. The aim of the present study was to explore the role of Tan IIA in CAD in vitro and the underlying molecular mechanism. METHODS: Real-time polymerase chain reaction (RT-PCR) and Western blot were used for the detection of miRNA/mRNA and protein, respectively. Target genes of miR-133a-3p were searched in TargetScan, and the targeting relationship was verified by dual-luciferase reporter assay. Cell proliferation was determined using a Cell Counting Kit-8 (CCK-8) and EdU labeling. Cell apoptosis was detected by flow cytometry and TUNEL staining. RESULTS: In the present study, lower miR-133a-3p level and higher epidermal growth factor receptor (EGFR; the target of miR-133a-3p) level were found in H2O2-induced H9c2 cells. In addition, Tan IIA upregulated miR-133a-3p and downregulated EGFR expression. Moreover, Tan IIA promoted cell proliferation and suppressed apoptosis and enhanced G0/G1, which was reversed by miR-133a-3p inhibitor, while siRNA-EGFR abolished the effects induced by miR-133a-3p in H2O2-induced H9c2 cells. CONCLUSION: Tan IIA reversed H2O2-induced cell proliferation reduction, cell apoptosis induction, and G0/G1 arrest reduction in H9c2 cells by miR-133a-3p/EGFR axis. The findings suggested a potential molecular basis of Tan IIA in treating patients with CAD.

19-nor-pimaranes from Icacina trichantha.

Four new unusual 19-nor-pimarane-type diterpenes were isolated from the tuber of Icacina trichantha (Icacinaceae, Oliv.). The structures were elucidated based on spectroscopic and HRMS analysis. The absolute configurations were determined by electronic circular dichroism. All four compounds are structural analogues of icacinol and humirianthol, but do not demonstrate the same cytotoxic activity. A plausible biogenetic pathway is proposed.

Anti-Obesity Effects of Tanshinone I from Salvia miltiorrhiza Bunge in Mice Fed a High-Fat Diet through Inhibition of Early Adipogenesis.

Tanshinone I (Tan I) is a diterpenoid isolated from Salvia miltiorrhiza Bunge and exhibits antitumor effects in several cancers. However, the anti-obesity properties of Tan I remain unexplored. Here, we evaluated the anti-obesity effects of Tan I in high-fat-diet (HFD)-induced obese mice and investigated the underlying molecular mechanisms in 3T3-L1 cells. HFD-induced obese mice were orally administrated Tan I for eight weeks, and body weight, weight gain, hematoxylin and eosin staining and serum biological parameters were examined. The adipogenesis of 3T3-L1 preadipocytes was assessed using Oil Red O staining and measurement of intracellular triglyceride (TG) levels, and mitotic clonal expansion (MCE) and its related signal molecules were analyzed during early adipogenesis of 3T3-L1 cells. The administration of Tan I significantly reduced body weight, weight gain, and white adipocyte size, and improved obesity-induced serum levels of glucose, free fatty acid, total TG, and total cholesterol in vivo in HFD-induced obese mice. Furthermore, Tan I-administered mice demonstrated improvement of glucose metabolism and insulin sensitivity. Treatment with Tan I inhibited the adipogenesis of 3T3-L1 preadipocytes in vitro, with this inhibition mainly occurring at an early phase of adipogenesis through the attenuation of MCE via cell cycle arrest at the G1/S phase transition. Tan I inhibited the phosphorylation of p38, extracellular signal-regulated kinase (ERK), and Akt during the process of MCE, while it stimulated the phosphorylation of AMP-activated protein kinase. Furthermore, Tan I repressed the expression of CCAAT-enhancer-binding protein ß (C/EBPß), histone H3K9 demethylase JMJD2B, and subsequently cell cycle genes. Moreover, Tan I regulated the expression of early adipogenic transcription factors including GATAs and Kruppel-like factor family factors. These results indicate that Tan I prevents HFD-induced obesity via the inhibition of early adipogenesis, and thus improves glucose metabolism and insulin sensitivity. This suggests that Tan I possesses therapeutic potential for the treatment of obesity and obesity-related diseases.

Two New Abietane Diterpenoids from Selaginella moellendorffii Hieron.

Two new abietane diterpenoids, (3S,5R,10S)-3-hydroxy-12-O-demethyl-11-deoxy-19(4→3)-abeo-cryptojaponol, 12,19-dihydroxyabieta-8,11,13-trien-7-one, were isolated from Selaginella moellendorffii Hieron., together with one known abietane diterpenoid and four known tetracyclic triterpenoids. Their structures were characterized by their 1D- and 2D-NMR, ECD and mass spectral studies. All compounds were tested for their inhibitory effects on proliferation of three human cancer cells (human non-small-cell lung carcinoma cell lines A549 and human breast adenocarcinoma cell lines MDA-MB-231 and MCF-7) in vitro. Among them, three compounds displayed modest cytotoxic activities against the above three human cancer cell lines with IC50 values ranging from 16.28 to 40.67 µM.

Antibacterial and ATP Synthesis Modulating Compounds from Salvia tingitana.

A surface extract of the aerial parts of Salvia tingitana afforded a nor-sesterterpenoid (1) and eight new sesterterpenoids (2-̵9), along with five known sesterterpenoids, five labdane and one abietane diterpenoid, one sesquiterpenoid, and four flavonoids. The structures of the new compounds were established by 1D and 2D NMR spectroscopy, HRESIMS, and VCD data and Mosher's esters analysis. The antimicrobial activity of compounds was evaluated against 30 human pathogens including 27 clinical strains and three isolates of marine origin for their possible implications on human health. The methyl ester of salvileucolide (10), salvileucolide-6,23-lactone (11), sclareol (15), and manool (17) were the most active against Gram-positive bacteria. The compounds were also tested for the inhibition of ATP production in purified mammalian rod outer segments. Terpenoids 10, 11, 15, and 17 inhibited ATP production, while only 17 inhibited also ATP hydrolysis. Molecular modeling studies confirmed the capacity of 17 to interact with mammalian ATP synthase. A significant reduction of ATP production in the presence of 17 was observed in Enterococcus faecalis and E. faecium isolates.

Anti-Migratory and Pro-Apoptotic Properties of Parvifloron D on Triple-Negative Breast Cancer Cells.

Medicinal plants are important sources of new bioactive compounds with potential anticancer activity. Parvifloron D (ParvD) is an abietane diterpenoid, isolated in high amounts from Plectranthus ecklonii Benth. Previous reports have suggested potential therapeutic properties for ParvD. ParvD has shown pro-apoptotic and cytotoxic effects in leukemia and melanoma cell lines. However, to the best of our knowledge, there are no studies in triple-negative breast cancer (TNBC) models. TNBC is a breast cancer subtype characterized by an aggressive behavior with poor clinical outcomes and weak overall therapeutic responses to the current treatment options. This work aimed at evaluating the anticancer effect of ParvD in MDA-MB-231 cells, a model of human TNBC. To obtain sufficient amounts of purified ParvD the efficiency of several extraction methods was compared. ParvD (0.1-10 µM) decreased cell viability in a concentration-dependent manner. Treatment with ParvD (5 µM) significantly increased the percentage of apoptotic nuclei and exposure to 3 µM ParvD increased the sub-G1 population. Since altered cell adherence, migration, and invasion are determinant processes for the formation of metastases, the effect of ParvD on these cellular processes was tested. Although treatment with ParvD (1 µM) had no effect on cell-substrate attachment, ParvD (1 µM) significantly reduced cell chemotaxis and invasion. This is the first report describing the proapoptotic effect of ParvD in TNBC cells. Moreover, for the first time we have shown that ParvD reduces cell motility, unraveling potential anti-metastatic properties.

New cadinane sesquiterpenoids from Mikania micrantha.

Chemical investigation of the aerial parts of Mikania micrantha led to the isolation of eight sesquiterpenoids and ten diterpenoids, including five cadinane sesquiterpenoids (1-5), three bisabolene sesquiterpenoids (6 - 8), nine ent-kaurane diterpenoids (9-17), and an abietane diterpenoid (18). Among them, 1 - 3 are new and feature a rare lactone or furan ring derived from C-6 isopropyl group side chain. Compound 18 was isolated from genus Mikania for the first time, and was also the first example of abietane-type diterpenoids from this plant. Their structures were elucidated on the basis of extensive spectroscopic analyses (1D and 2D NMR, HRESIMS, and ECD). All compounds were examined for their inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 macrophage cells, and compound 18 exhibited pronounced inhibition on NO production (IC50 = 11.04 µM), being comparable to the positive control, quercetin (IC50 = 11.15 µM).