Ionizing radiation­induced modification of nialamide as an anti­inflammatory agent against lipopolysaccharide­induced RAW 264.7 and DH82 cells.

Nialamide is a non-selective monoamine oxidase inhibitor that was widely used as an antidepressant. However, it has been prohibited for decades in the depressive medicine market due to the adverse hepatotoxic side effects. The re-use of drugs that have been withdrawn from the market represents a promising approach for the development of novel incrementally modified drugs and, in this context, ionizing radiation can serve as a powerful tool for producing new drug candidates. The present study exposed nialamide to γ radiation at 50 kGy to obtain the novel cyclized benzylamide, nialaminosin (compound 2), along with five known compounds, 3-amino-N-benzylpropanamide (compound 3), 3-methoxy-N-benzylpropanamide (compound 4), 3-hydroxy-N-benzylpropanamide (HBPA; compound 5), N-benzylpropanamide (compound 6) and isonicotinamide (compound 7). Among the isolated compounds, HBPA was established to inhibit the lipopolysaccharide-induced overproduction of pro-inflammatory mediators, including nitric oxide (NO) and prostaglandin E2 and cytokines including TNF-α, IL-6 and IL-10, without causing cytotoxicity to both RAW 264.7 and DH82 cells. Furthermore, HBPA was found to reduce the protein expression of inducible NO synthase and cyclooxygenase-2 in macrophages and compared with nialamide, it was established to have more potent radical scavenging activity. The present study therefore suggested the application of HBPA for the improvement of anti-inflammatory properties using ionizing radiation technology on the withdrawn drug nialamide.

Potent inhibition of human tyrosinase inhibitor by verproside from the whole plant of Pseudolysimachion rotundum var. subintegrum.

Affinity-based ultrafiltration-mass spectrometry coupled with ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry was utilised for the structural identification of direct tyrosinase ligands from a crude Pseudolysimachion rotundum var. subintegrum extract. False positives were recognised by introducing time-dependent inhibition in the control for comparison. The P. rotundum extract contained nine main metabolites in the UPLC-QTOF-MS chromatogram. However, four metabolites were reduced after incubation with tyrosinase, indicating that these metabolites were bound to tyrosinase. The IC50 values of verproside (1) were 31.2 µM and 197.3 µM for mTyr and hTyr, respectively. Verproside showed 5.6-fold higher efficacy than that of its positive control (kojic acid in hTyr). The most potent tyrosinase inhibitor, verproside, features a 3,4-dihydroxybenzoic acid moiety on the iridoid glycoside and inhibits tyrosinase in a time-dependent and competitive manner. Among these three compounds, verproside is bound to the active site pocket with a docking energy of -6.9 kcal/mol and four hydrogen bonding interactions with HIS61 and HIS85.

Novel aminopyridazine derivative of minaprine modified by radiolysis presents potent anti-inflammatory effects in LPS-stimulated RAW 264.7 and DH82 macrophage cells.

Radiation molecularly transforms naturally occurring products by inducing the methoxylation, hydroxylation, and alkylation of parent compounds, thereby affecting the anti-inflammatory capacities of those compounds. Minaprine (1) modified by ionizing radiation generated the novel hydroxymethylation hydropyridazine (2), and its chemical structure was determined based on NMR and HRESIMS spectra. Compared to the original minaprine, the novel generated product showed a highly enhanced anti-inflammatory capacity inhibited nitric oxide (NO) and prostaglandin E2 (PGE2) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 and DH82 macrophage cells. In addition, minaprinol (2) effectively inhibited cyclooxygenase-2 (COX-2) and inducible NO synthase (iNOS) at the protein level and pro-inflammatory cytokine (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-10) production in macrophages.

Cold Plasma Treatment Increases Bioactive Metabolites in Oat (Avena sativa L.) Sprouts and Enhances In Vitro Osteogenic Activity of their Extracts.

Cold plasma treatment has been studied to enhance the germination, growth, and bioactive phytochemical production in crops. Here, we aimed to investigate the effects of cold plasma treatment on the growth, bioactive metabolite production, and protein expression related to the physiological and osteogenic activities of oat sprouts. Oat seeds were soaked for 12 h, and then exposed to plasma for 6 min/day for 3 days after sowing. Plasma exposure did not significantly change the growth of oat sprouts; however, increased the content of bioactive metabolites. A single exposure for 6 min on the first day (T-1) increased the content of free amino acids (39.4%), γ-aminobutyric acid (53%), and avenacoside B (23%) compared to the control. Hexacosanol content was the highest in T-3 (6 min exposure on each day for 3 days), 28% higher than that in the control. Oat sprout extracts induced the phosphorylation of adenosine 5'-monophosphate-activated protein kinase and osteoblast differentiation was enhanced by increasing the alkaline phosphatase (ALP) activity; all these effects were induced by plasma treatment. Avenacoside B content was positively correlated with ALP activity (r = 0.911, p < 0.1). These results suggest that plasma treatment has the potential to improve the value of oat sprouts and that it may be used in food fortification to enhance nutritional value for promoting human health.

Comparative Analysis of Policosanols Related to Growth Times from the Seedlings of Various Korean Oat (Avena sativa L.) Cultivars and Screening for Adenosine 5'-Monophosphate-Activated Protein Kinase (AMPK) Activation.

The objectives of this research were to evaluate the policosanol profiles and adenosine-5'-monophosphate-activated protein kinase (AMPK) properties in the seedlings of Korean oat (Avena sativa L.) cultivars at different growth times. Nine policosanols in the silylated hexane extracts were detected using GC-MS and their contents showed considerable differences; specifically, hexacosanol (6) exhibited the highest composition, constituting 88-91% of the total average content. Moreover, the average hexacosanol (6) contents showed remarkable variations of 337.8 (5 days) → 416.8 (7 days) → 458.9 (9 days) → 490.0 (11 days) → 479.2 (13 days) → 427.0 mg/100 g (15 days). The seedlings collected at 11 days showed the highest average policosanol content (541.7 mg/100 g), with the lowest content being 383.4 mg/100 g after 5 days. Interestingly, policosanols from oat seedlings grown for 11 days induced the most prevalent phenotype of AMPK activation in HepG2 cells, indicating that policosanols are an excellent AMPK activator.

Changes in metabolites with harvest times of seedlings of various Korean oat (Avena sativa L.) cultivars and their neuraminidase inhibitory effects.

Oats and their seeds, stems, and leaves are approved for use as safe food ingredients. Oat seedlings are environmentally friendly and are becoming increasingly popular as they provide several health benefits. We used the UPLC-CAD to quantitatively analyze isolated compounds (1-11) between 15 cultivars of oat seedlings and their harvest time. Maximum average amount of total contents of isolated compounds was observed after the harvest time of 5 days (4711.3 mg/100 g), while the minimum was observed after the harvest time of 7 days (4184.8 mg/100 g). We demonstrated that all isolated compounds (1-11) showed neuraminidase inhibitory effects, with 6 and 7 being the most active with IC50 values of 3.7 and 20.5 µM, respectively. High content of compounds 6 and 7 was observed (2306.6 mg/100 g) in the Dahan cultivar at 9 days, indicating potential good cultivars with a high content of active compounds and neuraminidase inhibition activity.

Lutonarin from Barley Seedlings Inhibits the Lipopolysacchride-Stimulated Inflammatory Response of RAW 264.7 Macrophages by Suppressing Nuclear Factor-κB Signaling.

Extracts from barley seedlings (BS) have known antioxidant and anti-inflammatory activities. The flavonoid lutonarin (LN) is a component of BS extract and has several known bioactivities. Here, we evaluated LN anti-inflammatory efficacy against lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Lutonarin was isolated from BS by methanol extraction and characterized by ultra-performance liquid chromatography and quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS). Lutonarin did not reduce the viability or enhance the apoptosis rate of RAW 264.7 macrophages at concentrations up to 150 µM. Concentrations within 20-60 µM dose-dependently suppressed the LPS-induced expression, phosphorylation, and nuclear translocation of the inflammatory transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Furthermore, LN suppressed the LPS-induced upregulation of proinflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α and of the inflammatory enzyme cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Lutonarin may be a safe and effective therapeutic agent for alleviation of pathological inflammation.

Antioxidative Effects of Chrysoeriol via Activation of the Nrf2 Signaling Pathway and Modulation of Mitochondrial Function.

Retinal pigment epithelium (RPE) cell dysfunction caused by excessive oxidative damage is partly involved in age-related macular degeneration, which is among the leading causes of visual impairment in elderly people. Here, we investigated the protective role of chrysoeriol against hydrogen peroxide (H2O2)-induced oxidative stress in RPE cells. The cellular viability, reactive oxygen species (ROS) generation, and mitochondrial function of retinal ARPE-19 cells were monitored under oxidative stress or pre-treatment with chrysoeriol. The expression levels of mitochondrial-related genes and associated transcription factors were assessed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Moreover, the protein expression of antioxidant signal molecules was characterized by Western blot analysis. Chrysoeriol significantly increased cell viability, reduced ROS generation, and increased the occurrence of antioxidant molecules in H2O2-treated ARPE-19 cells. Additionally, mitochondrial dysfunction caused by H2O2-induced oxidative stress was also considerably diminished by chrysoeriol treatment, which reduced the mitochondrial membrane potential (MMP) and upregulated mitochondrial-associated genes and proteins. Chrysoeriol also markedly enhanced key transcription factors (Nrf2) and antioxidant-associated genes (particularly HO-1 and NQO-1). Therefore, our study confirms the protective effect of chrysoeriol against H2O2-induced oxidative stress in RPE cells, thus confirming that it may prevent mitochondrial dysfunction by upregulating antioxidant-related molecules.

Two new secondary metabolites isolated from Avena sativa L. (Oat) seedlings and their effects on osteoblast differentiation.

Seedlings of natural crops are valuable sources of pharmacologically active phytochemicals. In this study, we aimed to identify new active secondary metabolites in Avena sativa L. (oat) seedlings. Two new compounds, avenafuranol (1) and diosgenoside (2), along with eight known compounds (3-10) were isolated from the A. sativa L. seedlings. Their chemical structures were elucidated via 1D and 2D NMR spectroscopy, high-resolution ESIMS, IR spectroscopy, optical rotation analysis, and comparisons with the reported literature. The effect of each isolated compound on alkaline phosphatase (ALP) activity for osteoblast differentiation induced by bone morphogenetic protein-2 (BMP-2) was investigated using the C2C12 immortal mouse myoblast cell line. Compounds 1, 4, 6, 8, and 9 induced dose-dependent increases in ALP expression relative to ALP expression in cells treated with only BMP-2, and no cytotoxicity was observed. These results suggest that A. sativa L. seedlings are a natural source of compounds that may be useful for preventing bone disorders.

Policosanol profiles and adenosine 5'-monophosphate-activated protein kinase (AMPK) activation potential of Korean wheat seedling extracts according to cultivar and growth time.

Policosanols is a health promoting aliphatic alcohol known as lipid-lowing agent. To enable maximising the functional properties of wheat, this research investigates the policosanol profiles and adenosine 5'-monophosphate-activated protein kinase (AMPK) activation potential of Korean wheat seedlings according to cultivars and growth times. GC-MS revealed six policosanols that differed markedly in content between 17 cultivars, especially, octacosanol (8) showed the most predominant component (49-83%), varying significantly in average concentrations with growth times as 361.4 (3 days) â†’ 613.0 (6 days) â†’ 203.1 (9 days) â†’ 196.5 (12 days) â†’ 50.9 mg/100 g (19 days). The highest average policosanol (738.7 mg/100 g) exhibited after 6 days, while the lowest was 104.4 mg/100 g on 19 days. Moreover, the wheat cultivars including Shinmichal 1, Anbaek, Namhae, and Joah at 6 days may be recommended as potential sources because of high policosanols (921.7-990.6 mg/100 g). Western blot analysis revealed markedly higher AMPK activation in cells treated with the hexane extracts (150-370% at 100 µg/ml) and octacosanol (8) possessed potent AMPK activator (control; 100 â†’ 280% at 200 µg/ml). It is confirmed that the AMPK activation by wheat seedlings are positively related to the highest policosanol content at the 6 days of growth time, independent of the cultivar. Our results may be contributed to enhance the wheat value regarding development of new cultivars and functional foods.

Anti-melanin deposition activity and active constituents of Jatropha multifida stems.

Jatropha multifida is a medicinal plant that belongs to the Euphorbiaceae family. Our investigation revealed that the chloroform extract of J. multifida stems showed anti-melanin deposition activity against α-melanocyte stimulating hormone (α-MSH)- and 3-isobutyl-1-methylxanthine (IBMX)-induced melanogenesis in the mouse melanoma cell line (B16-F10). Further fractionation and purification of the major constituents led to the isolation of two coumarins (1 and 2) and seven known lignoids (3-9). All isolated compounds exhibited anti-melanin deposition activities against the mouse melanoma cell line (B16-F10) with IC50 values ranging from 37.5 to 560.1 µM, without any cytotoxicity even at high concentrations, except for 8. Further mechanistic studies suggested that 9 downregulated tyrosinase mRNA expression, while the anti-melanin deposition activities of 4 and 8 appeared to be unrelated to tyrosinase inhibition and the downregulated expression of the key melanogenesis-associated mRNAs. These results suggested that J. multifida could possess potent skin whitening ingredients.

Viral protein R inhibitors from Swertia chirata of Myanmar.

Viral protein R (Vpr) is a small, basic accessory protein (14 kDa) that is well conserved in Human immunodeficiency virus-1 (HIV-1), HIV-2, and simian immunodeficiency virus (SIV). Numerous investigations over the past 2 decades have suggested that Vpr would be an attractive target for HIV disease treatment. Small molecules, including fumagillin, damnacanthal, quercetin, vipirinin, isopimarane diterpenoids, picrasane quassinoids, iridoids, and bis-iridoid glycosides, have been reported as potent Vpr inhibitors. These compounds may not only represent HIV drug seeds, but also could be new target compounds for biochemical synthesis such as current synthetic biology and enzyme bioengineering approaches, due to their anti-Vpr activities. In our investigations of different types of compounds with Vpr inhibitory activity, we found that the CHCl3 soluble, crude extract of the whole Swertia chirata plant inhibited the expression of Vpr in Hela cells harboring the TREx plasmid encoding full-length Vpr (TREx-HeLa-Vpr cells). The purification and isolation of the active CHCl3 soluble portion afforded six secondary metabolites, including four xanthone derivatives, decussatine (1), methylswertianin (2), 1-hydroxy-3,5-dimethoxyxanthone (3), and bellidifolin (4), and two triterpenoids, oleanolic acid (5) and 12-hydroxyoleanolic lactone (6). The evaluation of the anti-Vpr activities of 1, 2, and 4-6 against TREx-HeLa-Vpr cells revealed that 4 and 5 are potent Vpr inhibitors with an effective dose of 10 µM, and are chemically and structurally distinct from previously reported inhibitors.

Lignans with melanogenesis effects from Premna serratifolia wood.

Three new lignoids, premnan A (1), premnan B (2), and tauntangyiol C (3), were isolated from Premna serratifolia wood, a traditional cosmetic plant in Myanmar, together with a new lignoid, premnan C (4) assumed to be an artifact, one natural new lignoid (5), and three known lignoids (6-8). The structures of the new compounds 1-4 were elucidated based on 1D and 2D NMR, IR spectroscopy, and HRESIMS. The absolute configurations of 1-4 were also determined by optical rotation, circular dichroism (CD) data analyses, and comparisons with the reported literature. All isolated compounds were tested for their melanogenesis activities against the B16-F10 mouse melanoma cell line. Compounds 1 and 4 showed melanogenesis enhancing activities of 31% and 50%, respectively, at a 50 µM concentration. Compounds 2, 3, and 6 increased melanin production by 67%, 30%, and 45%, respectively, at a 100 µM concentration, without any cytotoxicity.

Two new pyrrolo-2-aminoimidazoles from a Myanmarese marine sponge, Clathria prolifera.

Marine organisms such as marine sponges and soft corals are valuable sources of pharmacologically active secondary metabolites. In our ongoing research on the discovery of new secondary metabolites from marine organisms, two new pyrrolo-2-aminoimidazoles, clathriroles A (1) and B (2), were isolated from the water-soluble portion prepared from the methanol and acetone (2:1) extract of the marine sponge, Clathria prolifera, collected in Myanmar. The chemical structures of the isolated compounds were determined using extensive spectroscopic techniques, including NMR, HRESIMS, IR, and optical rotation, and comparisons with the reported literature. The spectroscopic analyses of 1 and 2 suggested that 1 is an enantiomer of antifungal N-methylmanzacidin C isolated from the marine sponge Axinella brevistyla, whereas 2 is a diastereomer of manzacidin D at C-11 isolated from the marine sponge Astrosclera willeyana. To the best of our knowledge, this is the first report of the isolation of the pyrrolo-2-aminoimidazole compounds from C. prolifera. Furthermore, in contrast to the potency of N-methylmanzacidin C against Saccharomyces cerevisiae, the antifungal assay revealed that 1 and 2 lack any activity against this strain. Thus, these observations may suggest that the absolute configurations at both C-9 and C-11 play an important role in controlling the antifungal activity of this type of compound.

Tetrahydrofuran lignans: Melanogenesis inhibitors from Premna integrifolia wood collected in Myanmar.

Two new tetrahydrofuran lignans, taungtangyiols A (1) and B (2), and eight known furofuran lignans (3-10), were isolated from the chloroform extract of Premna integrifolia wood collected in Myanmar. Their structures were elucidated by extensive spectroscopic techniques. The X-ray crystal structure of 1 clearly indicated its relative configuration. Taungtangyiols A (1) and B (2) inhibited the deposition of melanin in B16F10 mouse melanoma cells, with IC50 values of 50.7 and 40.9 µM, respectively, without notable cytotoxicity. An SAR study demonstrated that the furofuran and dioxymethylene moieties of the lignans play a vital role in inhibiting melanogenesis.

Syntheses of benzophenone-xanthone hybrid polyketides and their antibacterial activities.

Muchimangins are benzophenone-xanthone hybrid polyketides produced by Securidaca longepedunculata. However, their biological activities have not been fully investigated, since they are minor constituents in this plant. To evaluate the possibility of muchimangins as antibacterial agent candidates, five muchimangin analogs were synthesized from 2,4,5-trimethoxydiphenyl methanol and the corresponding xanthones, by utilizing p-toluenesulfonic acid monohydrate for the Brønsted acid-catalysis. The antibacterial assays against Gram-positive bacteria, Staphylococcus aureus and Bacillus subtilis, and Gram-negative bacteria, Klebsiella pneumoniae and Escherichia coli, revealed that the muchimangin analogs (±)-1,3,6,8-tetrahydroxy-4-(phenyl-(2',4',5'-trimethoxyphenyl)methyl)-xanthone (1), (±)-1,3,6-trihydroxy-4-(phenyl-(2',4',5'-trimethoxyphenyl)methyl)-xanthone (2), and (±)-1,3-dihydroxy-4-(phenyl-(2',4',5'-trimethoxyphenyl)methyl)-xanthone (3) showed significant activities against S. aureus, with MIC values of 10.0, 10.0, and 25.0µM, respectively. Analogs (±)-1 and (±)-2 also exhibited antibacterial activities against B. subtilis, with MIC values of 50.0 and 12.5µM, respectively. Furthermore, (+)-3 enhanced the antibacterial activity against S. aureus, with a MIC value of 10µM.

Anti-influenza virus activity of extracts from the stems of Jatropha multifida Linn. collected in Myanmar.

BACKGROUND: To contribute to the development of novel anti-influenza drugs, we investigated the anti-influenza activity of crude extracts from 118 medicinal plants collected in Myanmar. We discovered that extract from the stems of Jatropha multifida Linn. showed anti-influenza activity. J. multifida has been used in traditional medicine for the treatment of various diseases, and the stem has been reported to possess antimicrobial, antimalarial, and antitumor activities. However, the anti-influenza activity of this extract has not yet been investigated. METHODS: We prepared water (H2O), ethyl acetate (EtOAc), n-hexane (Hex), and chloroform (CHCl3) extracts from the stems of J. multifida collected in Myanmar, and examined the survival of Madin-Darby canine kidney (MDCK) cells infected with the influenza A (H1N1) virus, and the inhibitory effects of these crude extracts on influenza A viral infection and growth in MDCK cells. RESULTS: The H2O extracts from the stems of J. multifida promoted the survival of MDCK cells infected with the influenza A H1N1 virus. The EtOAc and CHCl3 extracts resulted in similar, but weaker, effects. The H2O, EtOAc, and CHCl3 extracts from the stems of J. multifida inhibited influenza A virus H1N1 infection; the H2O extract possessed the strongest inhibitory effect on influenza infection in MDCK cells. The EtOAc, Hex, and CHCl3 extracts all inhibited the growth of influenza A H1N1 virus, and the CHCl3 extract demonstrated the strongest activity in MDCK cells. CONCLUSION: The H2O or CHCl3 extracts from the stems of J. multifida collected in Myanmar demonstrated the strongest inhibition of influenza A H1N1 viral infection or growth in MDCK cells, respectively. These results indicated that the stems of J. multifida could be regarded as an anti-influenza herbal medicine as well as a potential crude drug source for the development of anti-influenza compounds.

Piscroside C, a novel iridoid glycoside isolated from Pseudolysimachion rotundum var. subinegrum suppresses airway inflammation induced by cigarette smoke.

ETHNOPHARMACOLOGICAL RELEVANCE: Pseudolysimachion rotundum var. subintegrum (Speedwell, Plantaginaceae) is used as a traditional herbal medicine for treating bronchitis, cough and asthma in Korea, China, Russia, and Europe. AIM OF THE STUDY: In this study, we investigated the protective effects of the novel iridoid glycoside, piscroside C (compound 1) isolated from the methanolic extract of P. rotundum var. subintegrum against inflammatory responses using a cigarette smoke induced chronic obstructive pulmonary disease (COPD) and TNF-α-stimulated human airway epithelial NCI-H292 cells. MATERIALS AND METHODS: The novel iridoid glycoside piscroside C was isolated from the methanolic extract of P. rotundum var. subintegrum. The chemical structure was established by NMR, HRESIMS, and optical rotation. In in vivo experiment, the mice received 1h of cigarette smoke for 3 days. Piscroside C was administered to mice by oral gavage 1h before cigarette smoke exposure for 3 days. In in vitro experiment, we evaluated the effect of piscroside C on proinflammatory mediators in H292 cells stimulated with TNF-α. RESULTS: Piscroside C significantly reduced the neutrophil influx, reactive oxygen species production, IL-6, TNF-α, and elastase activity in bronchoalveolar lavage fluid in COPD animals. In addition, piscroside C attenuated NF-κB and IκB phosphorylation, leading to reduced recruitment of inflammatory cells into the lung tissue. Consistent with the results of in vivo experiment, piscroside C significantly inhibited the expression of inflammatory cytokines (IL-6, IL-8 and IL-1ß) by inhibiting NF-κB activation, as resulting decrease in the phosphorylation of IKKß, IκBα and TAK1 in TNF-α-stimulated H292 cells. CONCLUSION: These findings indicate that piscroside C effectively inhibits inflammatory responses, which is an important process in the development of COPD through suppression of IKK/NF-κB activation. Our study suggest that piscroside C might represent a useful therapeutic for the treatment of inflammatory airway disease.