Cardenolide glycosides sensitize gefitinib-induced apoptosis in non-small cell lung cancer: inhibition of Na+/K+-ATPase serving as a switch-on mechanism.

The treatment of non-small cell lung cancer (NSCLC) is known as a significant level of unmet medical need in spite of the progress in targeted therapy and personalized therapy. Overexpression of the Na+/K+-ATPase contributes to NSCLC progression, suggesting its potentiality in antineoplastic approaches. Epi-reevesioside F, purified from Reevesia formosana, showed potent anti-NSCLC activity through inhibiting the Na+/K+-ATPase, leading to internalization of α1- and α3-subunits in Na+/K+-ATPase and suppression of Akt-independent mTOR-p70S6K-4EBP1 axis. Epi-reevesioside F caused a synergistic amplification of apoptosis induced by gefitinib but not cisplatin, docetaxel, etoposide, paclitaxel, or vinorelbine in both NCI-H460 and A549 cells. The synergism was validated by enhanced activation of the caspase cascade. Bax cleavage, tBid formation, and downregulation of Bcl-xL and Bcl-2 contributed to the synergistic apoptosis induced by the combination treatment of epi-reevesioside F and gefitinib. The increase of membrane DR4 and DR5 levels, intracellular Ca2+ concentrations, and active m-calpain expression were responsible for the caspase-8 activation and Bax cleavage. The increased α-tubulin acetylation and activation of MAPK (i.e., p38 MAPK, Erk, and JNK) depending on cell types contributed to the synergistic mechanism under combination treatment. These signaling pathways that converged on profound c-Myc downregulation led to synergistic apoptosis in NSCLC. In conclusion, the data suggest that epi-reevesioside F inhibits the Na+/K+-ATPase and displays potent anti-NSCLC activity. Epi-reevesioside F sensitizes gefitinib-induced apoptosis through multiple pathways that converge on c-Myc downregulation. The data support the inhibition of Na+/K+-ATPase as a switch-on mechanism to sensitize gefitinib-induced anti-NSCLC activity.

Anti-inflammatory butanolides and lignanoids from the root of Machilus zuihoensis var. mushaensis.

From the anti-inflammatory screening of Formosan Lauraceous plants, the methanolic extract of the root of Machilus zuihoensis var. mushaensis stood out for its potent inhibitory activity toward superoxide anion and elastase release in human neutrophils. Bioassay-guided fractionation of the root of M. zuihoensis var. mushaensis led to eight new compounds, including two butanolides (1-2), five lignanoids (3-7), and one sesquiterpenoid (8), along with 50 known compounds (9-58). Structures of these compounds were elucidated by NMR, UV, IR, CD, and MS analyses. Thirty-two isolates were evaluated for their anti-inflammatory activity. Among them, 9, 20, 27, 28, 30, 31, 35, and 40 exhibited significant superoxide anion generation inhibition selectively (IC50 value < 7.4 µM), 15 and 19 showed selective inhibition toward elastase release (IC50 value < 8.0 µM). Moreover, 3, 16, 21, and 22 simultaneously displayed superoxide anion generation and elastase release inhibition. It is worth mentioning that 21 and 22 showed more potent inhibitory activities (IC50 < 1.0 µM) on superoxide anion than the positive control, LY294002. Further quantitative HPLC analysis indicated the content of 21 and 22 were 0.90 and 3.04 mg/g (w/w) in the ethyl-acetate layer of the root of M. zuihoensis var. mushaensis, respectively. Altogether, M. zuihoensis var. mushaensis revealed a potential for developing the botanical new drug against inflammation-related disease.

Meso-Dihydroguaiaretic Acid Ameliorates Acute Respiratory Distress Syndrome through Inhibiting Neutrophilic Inflammation and Scavenging Free Radical.

The pathogenesis of acute respiratory distress syndrome (ARDS) is very complex. Patients with ARDS still suffer high mortality rates. Infiltration and activation of neutrophils in lungs are critical pathogenic factors in ARDS. In this study, we demonstrate that meso-dihydroguaiaretic acid (MDGA), a natural lignan, inhibits inflammatory responses in human neutrophils and ameliorates ARDS in mice. MDGA inhibited superoxide anion generation and elastase release in various G-protein coupled receptor agonists-induced human neutrophils. However, MDGA did not alter superoxide anion generation and elastase activity in cell-free systems. These results suggest that the anti-inflammatory effects of MDGA are mediated by regulating cellular signals in human neutrophils. In consistent with this, MDGA suppressed phosphorylation of extracellular signal-regulated kinase and c-Jun N-terminal kinase in activated human neutrophils. Moreover, MDGA inhibited CD11b expression and adhesion in activated human neutrophils. Interestingly, MDGA reduced reactive oxygen species (ROS) generation but not superoxide anion generation in protein kinase C (PKC) activator-induced human neutrophils, suggesting that MDGA may also have ROS scavenging ability. Indeed, MDGA showed strong free radical scavenging activity in cell-free assays. Significantly, MDGA suppressed PKC-induced neutrophil extracellular trap formation. Additionally, treatment of MDGA attenuated neutrophil infiltration and lung damage on lipopolysaccharide-induced ARDS in mice. In conclusion, our results demonstrate that MDGA has anti-neutrophilic inflammatory effects and free-radical scavenging activity. We also suggest that MDGA has potential to serve as a lead for developing new therapeutics to treat ARDS.

Antileukemic Natural Product Induced Both Apoptotic and Pyroptotic Programmed Cell Death and Differentiation Effect.

Acute myeloid leukemia (AML) is one of the most common forms of leukemia. Despite advances in the management of such malignancies and the progress of novel therapies, unmet medical needs still exist in AML because of several factors, including poor response to chemotherapy and high relapse rates. Ardisianone, a plant-derived natural component with an alkyl benzoquinone structure, induced apoptosis in leukemic HL-60 cells. The determination of dozens of apoptosis-related proteins showed that ardisianone upregulated death receptors and downregulated the inhibitor of apoptosis protein (IAPs). Western blotting showed that ardisianone induced a dramatic increase in tumor necrosis factor receptor 2 (TNFR2) protein expression. Ardisianone also induced downstream signaling by activating caspase-8 and -3 and degradation in Bid, a caspase-8 substrate. Furthermore, ardisianone induced degradation in DNA fragmentation factor 45 kDa (DFF45), a subunit of inhibitors of caspase-activated DNase (ICAD). Q-VD-OPh (a broad-spectrum caspase inhibitor) significantly diminished ardisianone-induced apoptosis, confirming the involvement of caspase-dependent apoptosis. Moreover, ardisianone induced pyroptosis. Using transmission electron microscopic examination and Western blot analysis, key markers including gasdermin D, high mobility group box1 (HMGB1), and caspase-1 and -5 were detected. Notably, ardisianone induced the differentiation of the remaining survival cells, which were characterized by an increase in the expression of CD11b and CD68, two markers of macrophages and monocytes. Wright-Giemsa staining also showed the differentiation of cells into monocyte and macrophage morphology. In conclusion, the data suggested that ardisianone induced the apoptosis and pyroptosis of leukemic cells through downregulation of IAPs and activation of caspase pathways that caused gasdermin D cleavage and DNA double-stranded breaks and ultimately led to programmed cell death. Ardisianone also induced the differentiation of leukemic cells into monocyte-like and macrophage-like cells. The data suggested the potential of ardisianone for further antileukemic development.

Chemical Constituent of ß-Glucuronidase Inhibitors from the Root of Neolitsea acuminatissima.

Neolitsea acuminatissima (Lauraceae) is an endemic plant in Taiwan. One new carboline alkaloid, demethoxydaibucarboline A (1), two new eudesmanolide-type sesquiterpenes, methyl-neolitacumone A (2), neolitacumone E (3), and twelve known compounds (4-15) were isolated from the root of Neolitsea acuminatissima. Their structures were elucidated by spectroscopic analysis. Glucuronidation represents a major metabolism process of detoxification for carcinogens in the liver. However, intestinal bacterial ß-Glucuronidase (ßG) has been considered pivotal to colorectal carcinogenesis. To develop specific bacterial-ßG inhibitors with no effect on human ßG, methanolic extract of roots of N. acuminatissima was selected to evaluate their anti-ßG activity. Among the isolates, demethoxydaibucarboline A (1) and quercetin (8) showed a strong bacterial ßG inhibitory effect with an inhibition ratio of about 80%. Methylneolitacumone A (2) and epicatechin (10) exhibited a moderate or weak inhibitory effect and the enzyme activity was less than 45% and 74%, respectively. These four compounds specifically inhibit bacterial ßG but not human ßG. Thus, they are expected to be used for the purpose of reducing chemotherapy-induced diarrhea (CID). The results suggest that the constituents of N. acuminatissima have the potential to be used as CID relief candidates. However, further investigation is required to determine their mechanisms of action.

Anti-Inflammatory and Antibacterial Activity Constituents from the Stem of Cinnamomum validinerve.

One new dibenzocycloheptene, validinol (1), and one butanolide firstly isolated from the natural source, validinolide (2), together with 17 known compounds were isolated from the stem of Cinnamomum validinerve. Among the isolates, lincomolide A (3), secosubamolide (7), and cinnamtannin B1 (19) exhibited potent inhibition on both superoxide anion generation (IC50 values of 2.98 ± 0.3 µM, 4.37 ± 0.38 µM, and 2.20 ± 0.3 µM, respectively) and elastase release (IC50 values of 3.96 ± 0.31 µM, 3.04 ± 0.23 µM, and 4.64 ± 0.71 µM, respectively) by human neutrophils. In addition, isophilippinolide A (6), secosubamolide (7), and cinnamtannin B1 (19) showed bacteriostatic effects against Propionibacterium acnes in in vitro study, with minimal inhibitory concentration (MIC) values at 16 µg/mL, 16 µg/mL, and 500 µg/mL, respectively. Further investigations using the in vivo ear P. acnes infection model showed that the intraperitoneal administration of the major component cinnamtannin B1 (19) reduced immune cell infiltration and pro-inflammatory cytokines TNF-α and IL-6 at the infection sites. The results demonstrated the potential of cinnamtannin B1 (19) for acne therapy. In summary, these results demonstrated the anti-inflammatory potentials of Formosan C. validinerve during bacterial infections.

Chemical Constituents with GNMT-Promoter-Enhancing and NRF2-Reduction Activities from Taiwan Agarwood Excoecaria formosana.

Hepatocellular carcinoma (HCC) is considered to be a silent killer, and was the fourth leading global cause of cancer deaths in 2018. For now, sorafenib is the only approved drug for advanced HCC treatment. The introduction of additional chemopreventive agents and/or adjuvant therapies may be helpful for the treatment of HCC. After screening 3000 methanolic extracts from the Formosan plant extract bank, Excoecaria formosana showed glycine N-methyltransferase (GNMT)-promoter-enhancing and nuclear factor erythroid 2-related factor 2 (NRF2)-suppressing activities. Further, the investigation of the whole plant of E. formosana led to the isolation of a new steroid, 7α-hydroperoxysitosterol-3-O-ß-d-(6-O-palmitoyl)glucopyranoside (1); two new coumarinolignans, excoecoumarin A (2) and excoecoumarin B (3); a new diterpene, excoeterpenol A (4); and 40 known compounds (5-44). Among them, Compounds 38 and 40-44 at a 100 µM concentration showed a 2.97 ± 0.27-, 3.17 ± 1.03-, 2.73 ± 0.23-, 2.63 ± 0.14-, 6.57 ± 0.13-, and 2.62 ± 0.05-fold increase in GNMT promoter activity, respectively. In addition, Compounds 40 and 43 could reduce NRF2 activity, a transcription factor associated with drug resistance, in Huh7 cells with relative activity of 33.1 ± 0.2% and 45.2 ± 2.5%. These results provided the basis for the utilization of Taiwan agarwood for the development of anti-HCC agents.

Anti-HIV tigliane diterpenoids from Reutealis trisperma.

Bioassay-guided fractionation of the n-butanol extract from the branches and leaves of Reutealis trisperma resulted in the isolation of six undescribed (crotignoids L ~ Q) together with two known (12-deoxyphorbol-13-hexadecanoate and 12-deoxyphorbol-13-myristate) tigliane diterpenoids. Their structures, especially the absolute configurations, were determined from extensive spectroscopic studies, including 2D NMR spectra, CD data analysis and electronic circular dichroism (ECD) calculations. All isolates were tested for anti-HIV activity against HL4-3 virus in MT4 cells. Except for crotignoid Q, the remaining seven tigliane diterpenoids exhibited potent anti-HIV activity with IC50 values ranging from 0.0023 to 4.03 µM.

Anti-inflammatory alkaloids from the root bark of Hernandia nymphaeifolia.

Four undescribed alkaloids, 7-ethoxy-6-methoxy-2-methylisoquinolin-1(2H)-one, 7,8-dihydroxy-6-methoxy-2-methylisoquinolin-1(2H)-one, N-formylhernagine, and 5,6-dihydroxy-N-methylphthalimide, were obtained from the root bark of Hernanadia nymphaeifolia, along with fourteen known compounds. The structures of these compounds were determined through spectroscopic and MS analyses. 7,8-Dihydroxy-6-methoxy-2-methylisoquinolin-1(2H)-one, N-formylhernagine, 5,6-dihydroxy-N-methylphthalimide, oxohernagine, hernandonine, and N-trans-feruloylmethoxytyramine inhibited the superoxide anion (O2-) production (IC50 values ≤ 6.23 µg/mL) by neutrophils stimulated with formyl-L-methionyl-L-leuckyl-L-phenyl-alanine/cytochalasin B (fMLP/CB). Furthermore, 7,8-dihydroxy-6-methoxy-2-methylisoquinolin-1(2H)-one, N-formylhernagine, 5,6-dihydroxy-N-methylphthalimide, oxohernagine, and N-trans-feruloylmethoxytyramine inhibited fMLP/CB-induced elastase release with IC50 values ≤ 7.41 µg/mL. In addition, 7,8-dihydroxy-6-methoxy-2-methylisoquinolin-1(2H)-one, N-formylhernagine, oxohernagine, and N-trans-feruloylmethoxytyramine showed potent inhibition with IC50 values ≤ 28.55 µM, against lipopolysaccharide (LPS)-induced nitric oxide (NO) generation.

Ascleposide, a natural cardenolide, induces anticancer signaling in human castration-resistant prostatic cancer through Na+ /K+ -ATPase internalization and tubulin acetylation.

BACKGROUND: Cardiac glycosides, which inhibit Na+ /K+ -ATPase, display inotropic effects for the treatment of congestive heart failure and cardiac arrhythmia. Recent studies have suggested signaling downstream of Na+ /K+ -ATPase action in the regulation of cell proliferation and apoptosis and have revealed the anticancer activity of cardiac glycosides. The study aims to characterize the anticancer potential of ascleposide, a natural cardenolide, and to uncover its primary target and underlying mechanism against human castration-resistant prostate cancer (CRPC). METHODS: Cell proliferation was examined in CRPC PC-3 and DU-145 cells using sulforhodamine B assay, carboxyfluorescein succinimidyl ester staining assay and clonogenic examination. Flow cytometric analysis was used to detect the distribution of cell cycle phase, mitochondrial membrane potential, intracellular Na+ and Ca2+ levels, and reactive oxygen species production. Protein expression was examined using Western blot analysis. Endocytosis of Na+ /K+ -ATPase was determined using confocal immunofluorescence microscopic examination. RESULTS: Ascleposide induced an increase of intracellular Na+ and a potent antiproliferative effect. It also induced a decrease of G1 phase distribution while an increase in both G2/M and apoptotic sub-G1 phases, and downregulated several cell cycle regulator proteins, including cyclins, Cdk, p21, and p27 Cip/Kip proteins, Rb and c-Myc. Ascleposide decreased the expression of antiapoptotic Bcl-2 members (eg, Bcl-2 and Mcl-1) but upregulated proapoptotic member (eg, Bak), leading to a significant loss of mitochondrial membrane potential and activation of both caspase-9 and caspase-3. Ascleposide also dramatically induced tubulin acetylation, leading to inhibition of the catalytic activity of Na+ /K+ -ATPase. Notably, extracellular high K+ (16 mM) significantly blunted ascleposide-mediated effects. Furthermore, ascleposide induced a p38 MAPK-dependent endocytosis of Na+ /K+ -ATPase and downregulated the protein expression of Na+ /K+ -ATPase α1 subunit. CONCLUSION: Ascleposide displays antiproliferative and apoptotic activities dependent on the inhibition of Na+ /K+ -ATPase pumping activity through p38 MAPK-mediated endocytosis of Na+ /K+ -ATPase and downregulation of α1 subunit, which in turn cause tubulin acetylation and cell cycle arrest. Cell apoptosis is ultimately triggered by the activation of caspase cascade attributed to mitochondrial damage through the downregulation of Bcl-2 and Mcl-1 protein expressions while upregulation of Bak protein levels. The data also suggest the potential of ascleposide in anti-CRPC development.

Cyclohexylamine, an active compound from Toddalia asiatica, contracts epididymal vas deferens via serotonergic receptors.

BACKGROUND: Toddalia asiatica of Rutaceae, a Taiwan folk medicine, is used as an analgesic and anti-inflammatory herb. Cyclohexylamine (CHA) is an active compound from T. asiatica. Previous reports indicate CHA contracts rat vas deferens. However, the contractile mechanism of CHA on rat vas deferens was not yet reported. The purpose of this study was to investigate the contractile mechanism of CHA on rat epididymal portion of vas deferens. METHODS: Male S.D. rats weighting between 200 g to 250 g were used. The epididymal portion of vas deferens was isolated and was added with various concentrations of serotonin, serotonin antagonists and CHA. RESULTS: Serotonin elicited dose-dependent (1 × 10-7M~1 × 10-4M) contractions on rat epididymal vas deferens, which were inhibited by pretreatment with ketanserin (1 × 10-8 M ~ 1 × 10-6 M), methysergide (1 × 10-5 M) and propranolol (1 × 10-4 M), respectively. CHA elicited dose-dependent (1 × 10-8M~1 × 10-4M) contractions on rat epididymal vas deferens. The contractions of CHA (1 × 10-4M) on epididymal vas deferens were enhanced by serotonin in a dose-dependent manner. Methysergide (1 × 10-7 ~1 × 10-5 M) did not affect the contractions evoked by CHA. However, the CHA elicited contraction was almost completely inhibited by ketanserin (1 × 10-5 M) and was enhanced by propranolol. The effect of propranolol at the concentration of 1 × 10-4 M on CHA was likely as CHA at high concentration alone. CONCLUSIONS: From the above results, the contraction evoked by CHA on the isolated rat epididymal vas deferens might be mediated by serotonergic receptors through 5-HT2A subtype.

Cinnamtannin B1 attenuates rosacea-like signs via inhibition of pro-inflammatory cytokine production and down-regulation of the MAPK pathway.

BACKGROUND: Rosacea is a common inflammatory disease of facial skin. Dysregulation of innate immunity with enhanced inflammation and increased abundance of LL-37 at the epidermal site is a characteristic feature of rosacea. Cinnamtannin B1 (CB1) is a condensed tannin with anti-inflammatory and anti-microbial activities. The aims of the study were to evaluate the potential of CB1 as a therapy for rosacea and to characterize the potential mechanisms of action. METHODS: We intraperitoneally administered 20 mg/kg CB1 once daily for 2 days into the LL-37-induced mouse model of rosacea. The effects of CB1 in vivo were evaluated by the observations of lesions, histology, immunohistochemistry, and the transcription and translation of pro-inflammatory cytokines and chemokines. Human keratinocyte HaCaT and monocyte THP-1 were used to characterize the effects of CB1 on LL-37-induced inflammation in vitro. The changes in pro-inflammatory chemokine interleukin-8 (IL-8) were quantitated by enzyme-linked immunosorbent assay (ELISA), and the expressions of genes involved were determined by Western blotting. RESULTS: CB1 attenuated local redness, inflammation, and neutrophil recruitment in the mouse model of rosacea in vivo. CB1 suppressed myeloperoxidase (MPO) and macrophage inflammatory protein 2 (MIP-2) production, a functional homolog of interleukin-8 (IL-8), at the lesions. In vitro experiments confirmed that CB1 reversed the LL-37-induced IL-8 production in human keratinocytes HaCaT and monocyte THP-1 cells. CB1 inhibited IL-8 production through downregulating the phosphorylation of extracellular signal-regulated kinase (ERK) in the mitogen-activated protein kinase (MAPK) pathway. CONCLUSION: CB1 attenuated LL-37-induced inflammation, specifically IL-8 production, through inhibiting the phosphorylation of ERK. CB1 has potential as a treatment for rosacea.

The cardenolides ouabain and reevesioside A promote FGF2 secretion and subsequent FGFR1 phosphorylation via converged ERK1/2 activation.

Na+/K+-ATPase α1 was reported to directly interact with and recruit FGF2 (fibroblast growth factor 2), a vital cell signaling protein implicated in angiogenesis, to the inner plasma membrane for subsequent secretion. Cardenolides, a class of cardiac glycosides, were reported to downregulate FGF2 secretion upon binding to Na+/K+-ATPase α1 in a cell system with ectopically expressed FGF2 and Na+/K+-ATPase α1. Herein, we disclose that the cardenolides ouabain and reevesioside A significantly enhance the secretion/release of FGF2 and the phosphorylation of FGFR1 (fibroblast growth factor receptor 1) in a time- and dose-dependent manner, in A549 carcinoma cells. A pharmacological approach was used to elucidate the pertinent upstream effectors. Only the ERK1/2 inhibitor U0126 but not the other inhibitors examined (including those inhibiting the unconventional secretion of FGF2) was able to reduce ouabain-induced FGF2 secretion and FGFR1 activation. ERK1/2 phosphorylation was increased upon ouabain treatment, a process found to be mediated through upstream effectors including ouabain-induced phosphorylated EGFR and a reduced MKP1 protein level. Therefore, at least two independent lines of upstream effectors are able to mediate ouabain-induced ERK1/2 phosphorylation and the subsequent FGF2 secretion and FGFR1 activation. These finding constitute unprecedent insights into the regulation of FGF2 secretion by cardenolides.

Avocado (Persea americana) fruit extract (2R,4R)-1,2,4-trihydroxyheptadec-16-yne inhibits dengue virus replication via upregulation of NF-κB-dependent induction of antiviral interferon responses.

Dengue virus (DENV) caused millions of infections around the world annually. Co-infection with different serotypes of DENV is associated with dengue hemorrhagic shock syndrome, leading to an estimate of 50% death rate. No approved therapies are currently available for the treatment of DENV infection. Hence, novel anti-DENV agents are urgently needed for medical therapy. Here we demonstrated that a natural product (2 R,4 R)-1,2,4-trihydroxyheptadec-16-yne (THHY), extracted from avocado (Persea americana) fruit, can inhibit DENV-2 replication in a concentration-dependent manner and efficiently suppresses replication of all DENV serotypes (1-4). We further reveal that the NF-κB-mediated interferon antiviral response contributes to the inhibitory effect of THHY on DENV replication. Using a DENV-infected ICR suckling mouse model, we found that THHY treatment caused an increased survival rate among mice infected with DENV. Collectively, these findings support THHY as a potential agent to control DENV infection.

2',3-dihydroxy-5-methoxybiphenyl suppresses fMLP-induced superoxide anion production and cathepsin G release by targeting the ß-subunit of G-protein in human neutrophils.

This study investigates the effect and the underlying mechanism of 2',3-dihydroxy-5-methoxybiphenyl (RIR-2), a lignan extracted from the roots of Rhaphiolepis indica (L.) Lindl. ex Ker var. tashiroi Hayata ex Matsum. & Hayata (Rosaceae), on N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP)-induced respiratory burst and cathepsin G in human neutrophils. Signaling pathways regulated by RIR-2 which modulated fMLP-induced respiratory burst were evaluated by an interaction between ß subunit of G-protein (Gß) with downstream signaling induced by fMLP and by immunoblotting analysis of the downstream targets of Gß-protein. RIR-2 inhibited fMLP-induced superoxide anion production (IC50:2.57 ±â€¯0.22 µM), cathepsin G release (IC50:18.72 ±â€¯3.76 µM) and migration in a concentration dependent manner. RIR-2 specifically suppresses fMLP-induced Src family kinases phosphorylation by inhibiting the interaction between Gß-protein with Src kinases without inhibiting Src kinases activities, therefore, RIR-2 attenuated the downstream targets of Src kinase, such as phosphorylation of Raf/ERK, AKT, P38, PLCγ2, PKC and translocation Tec, p47ph°x and P40ph°x from the cytosol to the inner leaflet of the plasma membrane. Furthermore, RIR-2 attenuated fMLP-induced intracellular calcium mobilization by inhibiting the interaction between Gß-protein with PLCß2. RIR-2 was not a competitive or allosteric antagonist of fMLP. On the contrary, phorbol 12-myristate 13-acetate (PMA)-induced phosphorylation of Src, AKT, P38, PKC and membrane localization of p47ph°x and P40ph°x remained unaffected. RIR-2 specifically modulates fMLP-mediated neutrophil superoxide anion production and cathepsin G release by inhibiting the interaction between Gß-protein with downstream signaling which subsequently interferes with the activation of intracellular calcium, PLCγ2, AKT, p38, PKC, ERK, p47ph°x and p40phox.

Immunomodulatory Effects of Taiwanese Neolitsea Species on Th1 and Th2 Functionality.

Neolitsea species, medicinal plants belonging to Lauraceae, contain rich alkaloids, steroids, sesquiterpenoids, and triterpenoids which possess antimicrobial, antioxidant, and anti-inflammatory bioactivities. However, species differences in the immunomodulatory effects and evidence pertaining to the effects of Neolitsea species on adaptive immunity are scarce. This study aimed to evaluate the immunomodulatory properties of ten Taiwanese Neolitsea plants on T helper (Th) cell functionality, especially Th1 and Th2. Most of the 29 crude extracts of Neolitsea were not toxic to splenocytes, except N. buisanensis roots. N. aciculata and N. villosa leaf extracts possessed differential immunomodulatory effects on Th1/Th2 balance. N. aciculata var. variabillima and N. hiiranensis leaf extracts attenuated both Th1 and Th2 cytokines while N. konishii dramatically suppressed IFN-γ production. As N. aciculata var. variabillima and N. konishii leaf extracts significantly attenuated Th1 functionality, we further evaluated their effects on CD4 cells under CD3/CD28 stimulation. N. aciculata var. variabillima significantly suppressed IFN-γ, IL-10, and IL-17, demonstrating the broad suppressive effects on T helper cells; N. konishii significantly suppressed IFN-γ and IL-10 production, while the production of IL-17 was not altered. Collectively, these data demonstrated that leaf extracts of Taiwanese Neolitsea species contain phytochemicals with potentials to be developed as selective immunomodulators.

Identification of anti-viral activity of the cardenolides, Na+/K+-ATPase inhibitors, against porcine transmissible gastroenteritis virus.

A series of naturally occurring cardenolides that exhibit potent anti-transmissible gastroenteritis virus (TGEV) activity in swine testicular (ST) cells has been identified. In an immunofluorescence assay, these cardenolides were found to diminish the expressions of TGEV nucleocapsid and spike protein, which was used as an indication for viral replication; block TGEV infection induced apoptosis and cytopathic effects; and impart the same trend of inhibitory activity against Na+/K+-ATPase as for anti-TGEV activity. The viral titer inhibition was found to take place in a dose-dependent manner. Knocking down expression of Na+/K+-ATPase, the cellular receptor of cardenolides, in ST cells was found to significantly impair the susceptibility of ST cells to TGEV infectivity. Thus, we have identified Na+/K+-ATPase as an anti-viral drug target and its antagonists, cardenolides, a novel class of anti- TGEV agents.

Secondary Metabolites of the Endophytic Fungus Lachnum abnorme from Ardisia cornudentata.

Fractionation of an EtOAc-soluble fraction of the solid fermentate of an endophytic fungus, Lachnum abnorme Mont. BCRC 09F0006, derived from the endemic plant, Ardisia cornudentata Mez. (Myrsinaceae), resulted in the isolation of three new chromones, lachnochromonins D-F (1-3), one novel compound, lachabnormic acid (4), along with nine known compounds (5-13). Their structures were elucidated by spectroscopic analyses. Alternariol-3,9-dimethyl ether (6) was given the correct data as well as 2D spectral analyses for the first time. This is the first report of the isolation of one unprecedented compound 4 from Lachnum genus, while all known compounds were also found for the first time from Lachnum. The effects of some isolates (3, 4, 7-9, 10, and 13) on the inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-activated RAW 264.7 murine macrophages were also evaluated. Several compounds exhibited weak inhibitory activity on lipopolysaccharide (LPS)-stimulated NO production in RAW 264.7 macrophages.

Cytotoxic cardenolides and sesquiterpenoids from the fruits of Reevesia formosana.

Bioassay-guided fractionation of the fruits of Reevesia formosana led to isolation of three cardenolides (reevesioside J, reevesioside K, and epi-reevesioside K), three sesquiterpenoids (reevesiterpenol C, reevesiterpenol D, and reevesiterpenol E), and two glycosides (reevesianin A and reevesianin B), along with 46 known compounds. Their structures were determined using spectroscopic techniques. In addition to the reported cytotoxic cardenolides, reevesioside J and strophanthidin exhibited moderate cytotoxicity against the cell lines MCF-7, NCI-H460, and HepG2, with IC50 values of 0.39 ± 0.06 µM and 1.06 ± 0.12 µM for MCF-7, 0.12 ± 0.01 µM and 0.29 ± 0.01 µM for NCI-H460, and 1.09 ± 0.02 µM and 1.72 ± 0.02 µM for HepG2, respectively. Reevesiterpenol E also exhibited the best selective cytotoxicity to the NCI-H460 cell line, with an IC50 value of 3.15 ± 0.22 µM.

Antiproliferation of Cryptocarya concinna-derived cryptocaryone against oral cancer cells involving apoptosis, oxidative stress, and DNA damage.

BACKGROUND: Cryptocarya-derived crude extracts and their compounds have been reported to have an antiproliferation effect on several types of cancers but their impact on oral cancer is less well understood. METHODS: We examined the cell proliferation effect and mechanism of C. concinna-derived cryptocaryone (CPC) on oral cancer cells in terms of cell viability, apoptosis, reactive oxygen species (ROS), mitochondrial depolarization, and DNA damage. RESULTS: We found that CPC dose-responsively reduced cell viability of two types of oral cancer cells (Ca9-22 and CAL 27) in MTS assay. The CPC-induced dose-responsive apoptosis effects on Ca9-22 cells were confirmed by flow cytometry-based sub-G1 accumulation, annexin V staining, and pancaspase analyses. For oral cancer Ca9-22 cells, CPC also induced oxidative stress responses in terms of ROS generation and mitochondrial depolarization. Moreover, γH2AX flow cytometry showed DNA damage in CPC-treated Ca9-22 cells. CPC-induced cell responses in terms of cell viability, apoptosis, oxidative stress, and DNA damage were rescued by N-acetylcysteine pretreatment, suggesting that oxidative stress plays an important role in CPC-induced death of oral cancer cells. CONCLUSIONS: CPC is a potential ROS-mediated natural product for anti-oral cancer therapy.