Cyperenoic acid suppresses osteoclast differentiation and delays bone loss in a senile osteoporosis mouse model by inhibiting non-canonical NF-κB pathway

Cyperenoic acid is a terpenoid isolated from the root of a medicinal plant Croton crassifolius with a wide range of biological activities. In this study, the effects of cyperenoic acid on osteoclast differentiation were investigated both in vitro and in vivo using receptor activator of nuclear factor-κB ligand (RANKL)-induced bone marrow-derived osteoclasts and senescence-accelerated mouse prone 6 (SAMP6). Cyperenoic acid significantly suppressed RANKL-induced osteoclast differentiation at the concentrations with no apparent cytotoxicity. The half maximum inhibitory concentration (IC₅₀) for osteoclast differentiation was 36.69 μM ± 1.02. Cyperenoic acid treatment evidently reduced the expression of two key transcription factors in osteoclast differentiation, NFATc1 and c-Fos. Detailed signaling analysis revealed that cyperenoic acid did not affect MAPK pathways and canonical NF-κB pathway but impaired activation of p100/p52 in the non-canonical NF-κB pathway upon RANKL stimulation. Moreover, the expression of osteoclast-related genes, nfatc1, ctsk, irf8, acp5 and cfos were disrupted by cyperenoic acid treatment. The bone resorption activity by cyperenoic acid-treated osteoclasts were impaired. In a senile osteoporosis mouse model SAMP6, mice fed on diet supplemented with cyperenoic acid showed delay in bone loss, compared to the control. Taken together, plant-derived cyperenoic acid shows great potential as therapeutic agent for osteoporosis.

Effect of 20-Hydroxyecdysone on Proteolytic Regulation in Skeletal Muscle Atrophy

BACKGROUND/AIM

20-Hydroxyecdystone (20E) is an ecdysteroid hormone which controls molting and reproduction in arthropods. 20E also produces a variety of effects in vertebrates, including enhancing protein synthesis and skeletal muscle regeneration. The effect of 20E on disuse muscle atrophy has not been reported to date. This study examined the proteolytic regulation of 20E in tenotomized rat slow soleus and fast plantaris muscles.

MATERIALS AND METHODS

Male Wistar rats were randomly divided into three groups: sedentary control (CON), tenotomy without 20E treatment (TEN), and tenotomy with treatment of 5 mg/kg BW of 20E (TEN+20E). The TEN+20E group was administered 20E via subcutaneous injection to the right thigh for 7 days after tenotomy.

RESULTS

20E treatment tended to attenuate disuse muscle atrophy and reduced ubiquitination only in soleus muscle.

CONCLUSION

20E treatment alleviates skeletal muscle atrophy partially mediated by ubiquitinate pathway, dependent on the muscle phenotype.

6-Hydroxy-3-O-methyl-kaempferol 6-O-glucopyranoside potentiates the anti-proliferative effect of interferon α/β by promoting activation of the JAK/STAT signaling by inhibiting SOCS3 in hepatocellular carcinoma cells

Suppressor of cytokine signaling 3 (SOCS3) is a key negative regulator of type I interferon (IFN α/β) signaling. Inhibition of SOCS3 by small molecules may be a new strategy to enhance the efficacy of type I IFN and reduce its side effects. We established a cell-based screening assay using human hepatoma HepG2 cells stably transfected with a plasmid wherein the luciferase reporter activity was propelled by interferon α-stimulated response element (ISRE), which is a motif specifically recognized by type I IFN-induced activation of Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway. After screening our chemical library, 6-hydroxy-3-O-methyl-kaempferol 6-O-glucopyranoside (K6G) was identified to be a potent activator of type I IFN with EC₅₀ value of 3.33±0.04μM. K6G enhanced the phosphorylation of JAK1, Tyk2, and STAT1/2 but decreased the phosphorylation of STAT3. K6G also promoted endogenous IFN-α-regulated genes expression. More interestingly, K6G significantly decreased the expression of SOCS3 without affecting the expression of SOCS1. Furthermore, K6G enhanced the anti-proliferative effect of IFN-α on hepatocellular carcinoma (HCC) cells. These results suggested that K6G potentiated the inhibitory effect of IFN-α on HCC cell proliferation through activation of the JAK/STAT signaling pathway by inhibiting SOCS3 expression. K6G warrants further investigation as a novel therapeutic method to enhance the efficacy of IFN-α/β.

Characterization of synthetic ecdysteroid analogues as functional mimics of brassinosteroids in plant growth

Brassinosteroids (BRs) are plant steroidal hormones that play important roles in many stages of plant growth. Several plant species produce ecdysteroids, which are known as insect molting steroid hormones. In this study, we evaluated the biological activities of three hydroxysteroidal compounds, 20-hydroxyecdysone (ECD), 7,8-dihydro-8α-20-hydroxyecdysone (DHECD), and 7,8-dihydro-5α,8α-20-hydroxyecdysone (α-DHECD), and compared their activities with that of brassinolide (BL), the most potent BR. In rice, DHECD and α-DHECD enhanced the degree of lamina inclination, as do BRs. In Arabidopsis thaliana, DHECD and α-DHECD increased hypocotyl length in the wild-type, and also partially overcame the hypocotyl shortening in the wild-type caused by 0.3μM brassinazole, a specific BR biosynthesis inhibitor. DHECD and α-DHECD partially reduced dwarfism in the BR-biosynthesis-deficient mutant det2. Treatment with DHECD or α-DHECD downregulated the expression of the BR biosynthesis genes DWF4 and CPD, which are generally, suppressed by BR, and upregulated the expression of TCH4 and SAUR-AC1, which are generally promoted by BR. However, their regulated activities were less effective than BL. Moreover, the 10^-4M DHECD and α-DHECD induced the accumulation of dephosphorylated BIL1/BZR1 that enhanced BR signaling as a master transcription factor. In contrast, ECD did not affect rice lamina bending, Arabidopsis hypocotyl elongation, the expression levels of BR-related genes and BIL1/BZR1 phosphorylation status. Based on these results, we hypothesize that both DHECD and α-DHECD have functional activities similar to those of BR.

Selective Estrogen Receptor Modulator (SERM)-like Activities of Diarylheptanoid, a Phytoestrogen from Curcuma comosa, in Breast Cancer Cells, Pre-osteoblast Cells, and Rat Uterine Tissues

Diarylheptanoids from Curcuma comosa, of the Zingiberaceae family, exhibit diverse estrogenic activities. In this study we investigated the estrogenic activity of a major hydroxyl diarylheptanoid, 7-(3,4 -dihydroxyphenyl)-5-hydroxy-1-phenyl-(1E)-1-heptene (compound 092) isolated from C. comosa. The compound elicited different transcriptional activities of estrogen agonist at low concentrations (0.1-1 μM) and antagonist at high concentrations (10-50 μM) using luciferase reporter gene assay in HEK-293T cells. In human breast cancer (MCF-7) cells, compound 092 showed an anti-estrogenic activity by down-regulating ERα-signaling and suppressing estrogen-responsive genes, whereas it attenuated the uterotrophic effect of estrogen in immature ovariectomized rats. Of note, compound 092 promoted mouse pre-osteoblastic (MC3T3-E1) cell differentiation and the related bone markers, indicating its positive osteogenic effect. Our findings highlight a new, nonsteroidal, estrogen agonist/antagonist of catechol diarylheptanoid from C. comosa, which is scientific evidence supporting its potential as a dietary supplement to prevent bone loss with low risk of breast and uterine cancers in postmenopausal women.

A New Ajmaline-type Alkaloid from the Roots of Rauvolfia serpentina

A new ajmaline-type alkaloid, 21- O-methylisoajmaline (1), together with twenty-one known compounds, a mixture ofβ-sitosterol (2) and stigmasterol (3), reserpinine (4), tetrahydroalstonine (5), reserpine (6), venoterpine (7), yohimbine (8), 6'- O-(3,4,5-trimethoxybenzoyl)glomeratose A (9), isoajmaline (10), 3- epi-α-yohimbine (11), methyl 3,4,5-trimethoxy- trans-cinnamate (12), a mixture of β-sitosterol 3- O-β-D-glucopyranoside (13) and stigmasterol 3- O-β-D-glucopyranoside (14), rescidine (15), 7-deoxyloganic acid (16), ajmaline (17), suaveoline (18), (+)-tetraphyllicine (19), loganic acid (20), 3-hydroxysarpagine (21), and sarpagine (22), were isolated from the roots of Rauvolfia serpentina. Their structures were elucidated by spectroscopic data analysis and comparison with literature data. Compounds 11, 12 and 15 were for the first time identified from the genus Rauvolfia and 5, 7, 11, 12, 15, 18 and 22 were found from R. serpentina for the first time. Compound 11 showed moderate anticholinesterase activity with IC50 value of 15.58 μM, whereas 6 exhibited strong vasorelaxant activity with the EC50 value of 0.05 μM.

A New Ajmaline-type Alkaloid from the Roots of Rauvolfia serpentina

A new ajmaline-type alkaloid, 21-Ο-methylisoajmaline (1), together with twenty-one known compounds, a mixture of β-sitosterol (2) and stigmasterol (3), reserpinine (4); tetrahydroalstonine (5), reserpine (6), venoterpine (7), yohimbine (8), 6'-O-(3,4,5-trimethoxybenzoyl)glomeratose A (9), isoajmaline (10), 3-epi-α-yohimbine (11), methyl 3,4,5-trimethoxy-trans-cinnamate (12), a mixture of β-sitosterol 3-Ο-β-D-glucopyranoside (13) and stigmasterol 3-Ο-β-D- glucopyranoside (14), rescidine (15), 7-deoxyloganic acid (16), ajmaline (17), suaveoline (18), (+)-tetraphyllicine (19), loganic acid (20), 3-hydroxysarpagine (21), and sarpagine (22), were isolated from the roots of Rauvolla serpentina. Their structures were elucidated by spectroscopic data analysis and comparison with literature data. Compounds 11, 12 and 15 were for the first time identified from the genus Rauvolfla and 5, 7, 11, 12, 15, 18 and 22 were found from R. sepentina for the first time. Compound 11 showed moderate anticholinesterase activity with IC₅₀ value of 15.58 μM, whereas 6 exhibited strong vasorelaxant activity with the EC₅₀ value of 0.05 μM.

Isomahanine induces endoplasmic reticulum stress and simultaneously triggers p38 MAPK-mediated apoptosis and autophagy in multidrug-resistant human oral squamous cell carcinoma cells

Advanced oral squamous cell carcinoma (OSCC) is typically aggressive and closely correlated with disease recurrence and poor survival. Multidrug resistance (MDR) is the most critical problem leading to therapeutic failure. Investigation of novel anticancer candidates targeting multidrug-resistant OSCC cells may provide a basis for developing effective strategies for OSCC treatment. In the present study, we investigated the cytotoxic mechanism of a carbazole alkaloid, namely isomahanine, in a multidrug‑resistant OSCC cell line CLS-354/DX. We demonstrated that CLS-354/DX cells overexpressing multidrug resistance-associated protein 1 (MRP1) were resistant to anticancer drugs cisplatin and camptothecin. Isomahanine effectively induced cytotoxicity against CLS-354/DX cells regardless of resistance. Apoptosis as determined by FITC‑Annexin V/PI staining and western blot analysis of cleaved caspase-3 and cleaved poly(ADP‑ribose) polymerase (PARP) was significantly induced in a time-dependent manner upon isomahanine treatment. Isomahanine-induced caspase‑dependent apoptosis was determined using z-VAD‑fmk. The effects on autophagy in isomahanine-treated cells were investigated via conversion of LC3B and degradation of p62/SQSTM1 (p62). Isomahanine obviously induced autophagic flux as shown by an increase in punctate GFP-LC3B and the LC3B-II/LC3B-I ratio with a concomitant decrease in p62 levels. Autophagy inhibitors 3-methyladenine (3-MA) and chloroquine (CQ) protected isomahanine-induced cell death, indicating the activation of autophagic cell death. Endoplasmic reticulum (ER) stress and MAPK activation were examined to elucidate the mechanism underlying cell death. The expression levels of PERK, CHOP and phosphorylated MAPK (p38, ERK1/2 and JNK1/2) were upregulated following isomahanine treatment. We found that p38 MAPK inhibitor (SB203580) significantly attenuated isomahanine-induced apoptosis and autophagic flux and this prevented cell death. Collectively, the present study demonstrated that isomahanine was able to induce ER stress and trigger p38 MAPK-mediated apoptosis and autophagic cell death in multidrug-resistant OSCC cells. The potential cytotoxic action of isomahanine may provide the development of anticancer candidates for treating multidrug-resistant cancer.

Serum lipidomics analysis of ovariectomized rats under Curcuma comosa treatment

ETHNOPHARMACOLOGICAL RELEVANCE

Curcuma comosa Roxb. (C. comosa) or Wan Chak Motluk, Zingiberaceae family, has been used in Thai traditional medicine for the treatment of gynecological problems and inflammation.

AIM OF THE STUDY

This study aimed to investigate the therapeutic potential of C. comosa by determining the changes in the lipid profiles in the ovariectomized rats, as a model of estrogen-deficiency-induced hyperlipidemia, after treatment with different components of C. comosa using an untargeted lipidomics approach.

MATERIALS AND METHODS

Lipids were extracted from the serum of adult female rats subjected to a sham operation (SHAM; control), ovariectomy (OVX), or OVX with 12-week daily doses of estrogen (17β-estradiol; E₂), (3R)-1,7-diphenyl-(4E,6E)-4,6-heptadien-3-ol (DPHD; a phytoestrogen from C. comosa), powdered C. comosa rhizomes or its crude ethanol extract. They were then analyzed by liquid chromatography-mass spectrometry, characterized, and subjected to the orthogonal projections to latent structures discriminant analysis statistical model to identify tentative biomarkers.

RESULTS

Levels of five classes of lipids (ceramide, ceramide-1-phosphate, sphingomyelin, 1-O-alkenyl-lysophosphatidylethanolamine and lysophosphatidylethanolamine) were elevated in the OVX rats compared to those in the SHAM rats, while the monoacylglycerols and triacylglycerols were decreased. The E₂ treatment only reversed the levels of ceramides, whereas treatments with DPHD, C. comosa extract or powder returned the levels of all upregulated lipids back to those in the SHAM control rats.

CONCLUSIONS

The findings suggest the potential beneficial effects of C. comosa on preventing the increased ceramide levels in OVX rats, a possible cause of metabolic disturbance under estrogen deficiency. Overall, the results demonstrated the power of untargeted lipidomics in discovering disease-relevant biomarkers, as well as evaluating the effectiveness of treatment by C. comosa components (DPHD, extract or powder) as utilized in Thai traditional medicine, and also providing scientific support for its folklore use.

Cyanidin-3-glucoside attenuates angiotensin II-induced oxidative stress and inflammation in vascular endothelial cells

Angiotensin II (Ang II) causes oxidative stress and vascular inflammation, leading to vascular endothelial cell dysfunction, and is associated with the development of inflammatory cardiovascular diseases such as atherosclerosis. Therefore, interventions of oxidative stress and inflammation may contribute to the reduction of cardiovascular diseases. Cyanidin-3-glucoside (C3G) plays a role in the prevention of oxidative damage in several diseases. Here, we investigated the effect of C3G on Ang II-induced oxidative stress and vascular inflammation in human endothelial cells (EA.hy926). C3G dose-dependently suppressed the free radicals and inhibited the nuclear factor-kappa B (NF-κB) signaling pathway by protecting the degradation of inhibitor of kappa B-alpha (IκB-α), inhibiting the expression and translocation of NF-κB into the nucleus through the down-regulation of NF-κB p65 and reducing the expression of inducible nitric oxide synthase (iNOS). Pretreatment with C3G not only prohibited the NF-κB signaling pathway but also promoted the activity of the nuclear erythroid-related factor 2 (Nrf2) signaling pathway through the upregulation of endogenous antioxidant enzymes. Particularly, we observed that C3G significantly enhanced the production of superoxide dismutase (SOD) and induced the expression of heme oxygenase (HO-1). Our findings confirm that C3G can protect against vascular endothelial cell inflammation induced by AngII. C3G may represent a promising dietary supplement for the prevention of inflammation, thereby decreasing the risk for the development of atherosclerosis.

Emodin potentiates the antiproliferative effect of interferon α/β by activation of JAK/STAT pathway signaling through inhibition of the 26S proteasome

The 26S proteasome is a negative regulator of type I interferon (IFN-α/β) signaling. Inhibition of the 26S proteasome by small molecules may be a new strategy to enhance the efficacy of type I IFNs and reduce their side effects. Using cell-based screening assay for new 26S proteasome inhibitors, we found that emodin, a natural anthraquinone, was a potent inhibitor of the human 26S proteasome. Emodin preferably inhibited the caspase-like and chymotrypsin-like activities of the human 26S proteasome and increased the ubiquitination of endogenous proteins in cells. Computational modeling showed that emodin exhibited an orientation/conformation favorable to nucleophilic attack in the active pocket of the β1, β2, and β5 subunits of the 26S proteasome. Emodin increased phosphorylation of STAT1, decreased phosphorylation of STAT3 and increased endogenous gene expression stimulated by IFN-α. Emodin inhibited IFN-α-stimulated ubiquitination and degradation of type I interferon receptor 1 (IFNAR1). Emodin also sensitized the antiproliferative effect of IFN-α in HeLa cervical carcinoma cells and reduced tumor growth in Huh7 hepatocellular carcinoma-bearing mice. These results suggest that emodin potentiates the antiproliferative effect of IFN-α by activation of JAK/STAT pathway signaling through inhibition of 26S proteasome-stimulated IFNAR1 degradation. Therefore, emodin warrants further investigation as a new means to enhance the efficacy of IFN-α/β.

Effects of andrographolide on intrahepatic cholestasis induced by alpha-naphthylisothiocyanate in rats

Cholestasis is a cardinal manifestation of liver diseases but effective therapeutic approaches are limited. Therefore, alternative therapy for treating and preventing cholestatic liver diseases is necessary. Andrographolide, a promising anticancer drug derived from the medicinal plant Andrographis paniculata, has diverse pharmacological properties and multi-spectrum therapeutic applications. However, it is unknown whether andrographolide has a hepatoprotective effect on intrahepatic cholestasis. The aims of this study were to investigate the protective effect and possible mechanisms of andrographolide in a rat model of acute intrahepatic cholestasis induced by alpha-naphthylisothiocyanate (ANIT). Andrographolide was administered intragastrically for four consecutive days, with a single intraperitoneal injection of ANIT on the second day. Liver injury was evaluated biochemically and histologically together with hepatic gene and protein expression analysis. Rats pretreated with andrographolide prior to ANIT injection demonstrated lower levels of serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyltransferase, as well as bilirubin and bile acids as compared to rats treated with ANIT alone. Andrographolide also decreased the incidence and extent of periductular fibrosis and bile duct proliferation. Analysis of protein expression in livers from andrographolide-treated cholestatic rats revealed markedly decreased expression of alpha-smooth muscle actin and nuclear factor kappa-B (NF-κB). In conclusion, andrographolide has a potent protective property against ANIT-induced cholestatic liver injury. The mechanisms that underlie this protective effect are mediated through down-regulation of NF-κB expression and inhibition of hepatic stellate cell activation. These findings suggest that andrographolide could be a promising therapeutic option in prevention and slowing down the progression of cholestatic liver diseases.

Neuroprotective effects of cyanidin against Aβ-induced oxidative and ER stress in SK-N-SH cells

This study evaluated the mechanisms underlying the protective effect of cyanidin against Aβ_25-35-induced neuronal cell death in SK-N-SH cells. Aβ_25-35-induced neurotoxicity is characterized by a decrease in cell viability, inducing the expression of endoplasmic reticulum (ER) stress proteins; an increase in intracellular reactive oxygen species (ROS) production; and an increase in intracellular calcium release. Aβ_25-35 also induces neuronal toxicity through the disturbance of ER calcium levels. Pretreatment with cyanidin significantly attenuated the Aβ_25-35-induced loss of cell viability, reducing the expression of endoplasmic reticulum (ER) stress response proteins with regard to the down-regulation of the expression levels of 78 kDa glucose regulated protein (Grp78), phosphorylated forms of pancreatic ER elF2α kinase (PERK), eukaryotic initiation factor 2 α (eIF2α), and inositol-requiring enzyme 1 (IRE1), and the expression levels of X-box binding protein 1 (XBP-1), activating transcription factor 6 (ATF6), and CCAAT/enhancer binding protein homologous transcription factor (C/EBP) homologous protein (CHOP); decreased intracellular ROS production; decreased intracellular calcium release; and reduced down-regulation of the protein expression levels of calpain and cleaved caspase-12. This result suggests that cyanidin may be an alternative agent in preventing neurodegenerative diseases.

Synergistic effect of atorvastatin and cyanidin-3-glucoside against angiotensin II-mediated vascular smooth muscle cell proliferation and migration through MAPK and PI3K/Akt pathways

This study aimed to investigate the mechanism of cyanidin-3-glucoside (C3G) in synergy with atorvastatin, even when it is used in low concentrations. Human aortic smooth muscle cells (HASMCs) were used to verify the synergistic mechanism of atorvastatin and C3G against angiotensin II-induced proliferation and migration. BrdU incorporation assay was used to evaluate cell proliferation. Wound healing and Boyden chamber assays were used to investigate cell migration. The cell cycle was examined using flow cytometry. The results revealed that atorvastatin and C3G exhibit a synergistic effect in ameliorating HASMC proliferation and migration by enhancing cell cycle arrest. In addition, these effects also decreased mitogen-activated protein kinase (MAPK) activity by attenuating the expression of phospho-p38, phospho-extracellular signaling-regulated kinase 1/2, and phospho-c-Jun N-terminal kinase. Furthermore, the combination of atorvastatin and C3G modulated the PI3K/Akt pathway and upregulated p21Cip1, which was associated with decreases in cyclin D1 and phospho-retinoblastoma expressions. The synergistic effect of atorvastatin and C3G induced anti-proliferation and anti-migration through MAPK and PI3K/Akt pathways mediated by AT1R. These results suggest that the synergistic effect of atorvastatin and C3G may be an alternative therapy for atherosclerosis patients.