Anti-Dengue Screening on Several Vietnamese Medicinal Plants: Experimental Evidences and Computational Analyses.

Worldwide, medicinal plants have been known for economic and geographical advantages, thus possibly holding potentiality against dengue hemorrhagic fever. The methanol/water extracts from different parts of fourteen Vietnam-based plant species were subjected for experimental screening on anti-dengue activity using baby hamster kidney cells (BHK21) and plaque reduction neutralisation test (PRNT). Firstly, the methanol/water extracts were tested against serotype dengue virus DENV-1. Seven out from nineteen extracts show the PRNT50 values less than 31.25 µg/mL. Four of the above extracts namely from Euphorbia hirta, Cordyline terminalis, Carica papaya, and Elaeagnus latifolia were chosen for testing against the serotype DENV-2. All of them exhibit good activity with the PRNT50 values less than 31.25 µg/ml, which were further fractionated to obtain hexane, ethyl acetate and butanol fractions. Anti-dengue virus activity of the fractions against four serotypes DENV-1, -2, -3 and -4 was evaluated. As results, the ethyl acetate fraction of Elaeagnus latifolia is highly active against all four serotype viruses. The structural formulae of its nine constituents were input for molecular docking simulation. The docking-based order for static inhibitability is 6-3L6P>7-3L6P>9-3L6P>2-3L6P>3-3L6P≈5-3L6P>9-3L6P>1-3L6P>8-3L6P; QSARIS-based analysis reveals the biocompatibility of the most promising ligands (4-7); ADMET-based analysis expects their pharmacological suitability. Exceptional finding on 2-3LKW hydrophilic interaction at Lys43 (with the associated Gibbs free energy of -10.3 kcal mol-1 ) raises an open explanation for inhibitory effects. The results encourage further investigations for more in-depth mechanisms and drug development, such as in vitro enzyme assays or in vitro clinical trials with natural substances from E. latifolia.

Antioxidant activity and α-glucosidase inhibitability of Distichochlamys citrea M.F. Newman rhizome fractionated extracts: in vitro and in silico screenings.

Distichochlamys citrea M.F. Newman (commonly known as "Black Ginger") is an endemic plant to Vietnam and has been extensively exploited by folk medication for treatments of infection-related diseases and diabetes. In this work, its rhizomes were subjected to fractionated extraction, phytochemical examination, evaluation of antioxidant effect by DDPH free radical neutralization, and inhibitory activity toward α-glucosidase. The compositional components were subjected to in silico screening, including density functional theory calculation, molecular docking simulation, physicochemical analysis, and pharmacokinetic regression. In the trials, EtOAc fraction is found as the bioactive part of most effectiveness, regarding both antioxidant effect (IC50 = 90.27 µg mL-1) and α-glucosidase inhibitory activity (IC50 = 115.75 µg mL-1). Chemical determination reveals there are 13 components of its composition. DFT-based calculations find no abnormal constraints in their structures. Docking-based simulation provides order of inhibitory effectiveness: 3-P53341 > 12-P53341 > 7-P53341 > 4-P53341 > 11-P53341 > 10-P53341. QSARIS-based investigations implicate their biocompatibility. ADMET-based regressions indicate that all candidates are generally safe for medicinal applications. The findings would contribute to the basis for further studies on the chemical compositions of Distichochlamys citrea and their biological activities. Supplementary Information: The online version contains supplementary material available at 10.1007/s11696-022-02273-2.

Antioxidant and Cell Proliferation Properties of the Vietnamese Traditional Medicinal Plant Peltophorum pterocarpum.

Peltophorum pterocarpum is regarded as one of the most important medicinal plants in the traditional medicine system of Vietnam. However, scientific evidence for the antioxidant effects against lipid peroxidation and the potential effects in cancer of this plant are lacking. In our experiments, 70% ethanolic extracts of P. pterocarpum leaves (LPP) and stem bark (SPP) were evaluated for their low-density lipoprotein (LDL) oxidation and cytotoxic activity against cancer cell lines. Both LPP and SPP inhibited Cu2+-mediated LDL by increasing the lag time of conjugated diene formation and inhibiting the generation of thiobarbituric acid reactive substances (TBARS) in a dose-dependent manner. In cancer cells, LPP and SPP triggered the most potent cytotoxic effects against human leukemia cells, CRF-SBA and HL-60, with half-maximal inhibitory concentration (IC50) values ranging from 118.5 to 157.2 µg/mL. SPP exhibited significant cytotoxicity against MIA PACA2, A549, and KG cell lines with IC50 values of 167.5, 244.1 and 255.0 µg/mL, respectively. Meanwhile, LPP showed cytotoxic activity against KG with an IC50 value of 228.1 µg/mL. SPP mediated cytotoxicity in HL-60 and CCRF-SBA cells through the activation of the apoptosis pathway, including the activation of caspases 3, and 9 and poly (ADP-ribose) polymerase (PARP). These results suggested that SPP may prevent the development and progression of atherosclerosis and leukemia in humans.

Morinlongosides A-C, Two New Naphthalene Glycoside and a New Iridoid Glycoside from the Roots of Morinda longissima.

Two new naphthalene glycosides, morinlongosides A and B (1, 2) and a new iridoid glycoside, morinlongoside C (3), together with four known ones, geniposidic acid (4), (3R)-3-O-[ß-D-xylopyranosyl-(1→6)-ß-D-glucopyranosyl]-l-octen-3-ol (5), lucidin-3-O-ß-primeveroside (6), and morindone-6-O-ß-gentiobioside (7), were isolated from the roots of Morinda longissima Y. Z. RUAN. The structures of all isolated compounds (1-7) were elucidated on the basis of spectroscopic data (high resolution (HR)-MS, one and two dimensional (1/2D)-NMR).

Anti-inflammatory activity of phenolic compounds from the whole plant of Scutellaria indica.

Six new phenolics, scutellariosides A-F (1-3, 5-6, and 8), together with six known compounds (4, 7, 9-12) were isolated from the whole plant of Scutellaria indica (Labiatae). The chemical structures of these compounds were determined by spectroscopic analyses including 2D NMR. Their anti-inflammatory activities were evaluated against LPS-induced NO production in macrophage RAW 264.7 cells. Among them, compounds 10-12 had inhibitory effects with IC50 values ranging from 7.2 to 27.8µM. Compound 12 reduced LPS-induced iNOS expression in a dose-dependent manner.

Cassaine diterpene alkaloids from Erythrophleum fordii and their anti-angiogenic effect.

Angiogenesis plays a critical role in embryonic development and various physiological processes. However, excessive angiogenesis is associated with several pathological conditions including cancer. Angiogenesis is closely related to tumor growth, invasion and metastasis, and is considered a prime target for anticancer therapy. In this study, two new mono cassaine diterpenoid amides (1, 5) and four known compounds (2-4, 6) were isolated from the bark of Erythrophleum fordii (Leguminosae). Their chemical structures were established mainly by 1D and 2D NMR techniques and mass spectrometry. The effects of isolates on endothelial tube formation on Matrigel were investigated. Among them, compound 3 was found to have the most potent inhibitory effect on the capillary-like structure formation of human umbilical vein endothelial cells (HUVECs).

In vitro apoptotic effect of cassaine-type diterpene amides from Erythrophleum fordii on PC-3 prostate cancer cells.

Cytotoxic activity-guided fractionation of Erythrophleum fordii led to the isolation of two new cassaine diterpenoid-diterpenoid amide dimers, erythrophlesins H-I (1, 2). Spectral data indicated that they consist of asymmetrical dimeric structure via an ester bond between two cassaine diterpenoids. MTT assay confirmed that compound 1, erythrophlesin H, had the strongest cytotoxic effect toward the human prostate cancer cell line, PC-3. The molecular mechanism by which this compound induced apoptosis cell in prostate cancer remains unknown. Erythrophlesin H induced apoptosis in a dose-dependent manner. Acridine orange and annexin V-FITC/PI double staining confirmed that erythrophlesin H effectively induces apoptosis in PC-3 cells.

Anti-inflammatory compounds from the aerial parts of Aceriphyllum rossii.

A new megastigmane glycoside, galloyl linarionoside A (1), together with 13 known compounds (2-14) were isolated from the aerial parts of Aceriphyllum rossii ENGLER. (Saxifragaceae). The chemical structures of the isolated compounds were established mainly by using nuclear magnetic resonance spectra, mass spectrometry, and modified Mosher's method. Among the isolates, compounds 4, 5, 6 and 7 showed potent inhibitory activity against the lipopolysaccharide-induced nitric oxide production in RAW264.7 macrophage cells with IC50 values of 12.5, 9.5, 10.5 and 9.3 µM, respectively. The anti-inflammatory effect of compound 7 was accompanied by dose-dependent decreases in the production of inducible nitric oxide synthase and cyclooxygenase-2 proteins not in the inhibitor kappa B (IκB)-dependent nuclear factor-kappa B activation.

Inhibitory effect on NO production of triterpenes from the fruiting bodies of Ganoderma lucidum.

Four new lanostane triterpenes, butyl lucidenate P (1), butyl lucidenate D(2) (2), butyl lucidenate E(2) (3) and butyl lucidenate Q (4) along with 11 known compounds (5-15) were isolated from the fruiting bodies of Ganoderma lucidum. Their chemical structures were established mainly by 1D and 2D NMR techniques and mass spectrometry. Their anti-inflammatory activity was evaluated against LPS-induced NO production in macrophage RAW 264.7 cells. Compounds 1, 3, 4, 9, 10 and 15 showed inhibitory potency with IC(50) values of 7.4, 6.4, 4.3, 9.4, 9.2 and 4.5 µM, respectively. Compounds 1, 3 and 15 dose-dependently reduced the LPS-induced iNOS expressions. Preincubation of cell with 1, 3 and 15 significantly suppressed LPS-induced expression of COX-2 protein.

Cytotoxic activity of new phenolic compounds from Vietnamese Caesalpinia sappan.

Two new phenolic compounds, caesalpiniaphenols G-H (1 and 2), were isolated from Vietnamese Caesalpinia sappan heartwood. The chemical structures were established mainly by extensive spectroscopic studies and chemical evidence. Compounds 1 and 2 showed potent inhibitory activity against HL-60 cancer cell lines with respective IC50 values of 16.7 and 22.5 µg/mL. Treating HL-60 cells with various concentrations of 1 resulted in growth inhibition and the induction of apoptosis.

Malabaricone C inhibits PDGF-induced proliferation and migration of aortic smooth muscle cells through induction of heme oxygenase-1.

Malabaricone C (Mal-C), isolated from nutmeg, is known to exert a variety of pharmacological activities. However, the effect of Mal-C on vascular smooth muscle cells (VSMCs) is unknown. This study examined the effect of Mal-C on proliferation and migration of primary rat aortic smooth muscle cells (RASMCs) as well as its underlying mechanisms. Treatment of RASMCs with Mal-C induced both protein and mRNA expression of heme oxygenase-1 (HO-1) in a dose- and time-dependent manner. Mal-C-mediated HO-1 induction was inhibited by treatment with actinomycin D or by cycloheximide. SB203580 (a p38 inhibitor), SP600125 (a JNK inhibitor), U0126 (a MEK inhibitor), and N-acetylcysteine (NAC, an antioxidant) did not suppress Mal-C-induced HO-1 expression. In contrast, LY294002 (a PI3K inhibitor) blocked Mal-C-induced HO-1 expression. Moreover, RASMCs treated with Mal-C exhibited activation of AKT in a dose- and time-dependent manner. Treatment of RASMCs with Mal-C increased nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2), which is a key regulator of HO-1 expression, and this translocation was also inhibited by LY294002. Consistent with the notion that HO-1 has protective effects against VSMCs, Mal-C remarkably inhibited platelet-derived growth factor (PDGF)-induced proliferation and migration of RASMCs. However, inhibition of HO-1 significantly attenuated the inhibitory effects of Mal-C on PDGF-induced proliferation and migration of RASMCs. Taken together, these findings suggest that Mal-C could suppress PDGF-induced proliferation and migration of RASMCs through Nrf2 activation and subsequent HO-1 induction via the PI3K/AKT pathway, and may be a potential HO-1 inducer for preventing or treating vascular diseases.

Compounds from the heartwood of Caesalpinia sappan and their anti-inflammatory activity.

Two new phenolics, (3S,4R)-3,7,2',3'-tetrahydroxy-3,4-dihydro-9H-indeno[6,5-c]chromene (caesalpiniaphenol E, 1), and (3R,4S)-3,7-dihydroxy-3-(3'-methoxy-4'-hydroxyphenyl)-4-methoxychroman (caesalpiniaphenol F, 2), together with eleven known compounds (3-13), were isolated from the heartwood of Caesalpinia sappan. Their chemical structures were established mainly by 1D and 2D NMR techniques and mass spectrometry. Their anti-inflammatory activity was evaluated against LPS-induced NO production in macrophage RAW264.7 cells. Among them, compounds 10 and 13 showed strong inhibitory activities toward the LPS-induced NO production in macrophage RAW264.7 cells, with IC(50) values of 12.5 and 8.1 µm, respectively. In addition, compounds 10 and 13 inhibited the inductions of iNOS mRNA in dose-dependent manners, indicating that these compounds attenuated the synthesis of these transcripts at the transcriptional level.

Phenolic compounds from Caesalpinia sappan heartwood and their anti-inflammatory activity.

Four new phenolic compounds, caesalpiniaphenols A-D (1-4), together with eight known compounds were isolated from Caesalpinia sappan heartwood. The chemical structures were established mainly by NMR, MS, ECD, and Mosher's method. Compounds 4, 5, and 7 showed weak inhibitory activity against the LPS-induced NO production in macrophage RAW264.7 cells with IC(50) values of 12.2, 3.5, and 5.7 µM, respectively.

Cycloartane-type triterpene glycosides from the rhizomes of Cimicifuga heracleifolia and their anticomplementary activity.

Seven known triterpene glycosides, 23-O-acetylshengmanol 3-O-α-L-arabinopyranoside (1), 23-O-acetylshengmanol 3-O-ß-D-xylopyranoside (2), 24-epi-24-O-acetylhydroshengmanol 3-O-ß-D-xylopyranoside (3), cimiaceroside B (4), (23R,24S)-cimigenol 3-O-ß-D-xylopyranoside (5), (23R,24R)-25-O-acetylcimigenol 3-O-ß-D-xylopyranoside (6) and (23R,24S)-25-O-anhydrocimigenol 3-O-ß-D-xylopyranoside (7) were isolated from the rhizomes of Cimicifuga heracleifolia. Their chemical structures were determined on the basis of spectroscopic analyses including 2D NMR. All isolates were investigated for their inhibitory effects on the classical pathway of the complement system. Among them, compound 6 showed strong inhibitory activity with an IC50 value of 7.7 µM while compound 3 was moderately active with an IC50 value of 195.6 µM.

Inhibitory effect on NO production of phenolic compounds from Myristica fragrans.

Three new phenolics: ((7S)-8'-(benzo[3',4']dioxol-1'-yl)-7-hydroxypropyl)benzene-2,4-diol (1), ((7S)-8'-(4'-hydroxy-3'-methoxyphenyl)-7-hydroxypropyl)benzene-2,4-diol (2) and ((8R,8'S)-7-(4-hydroxy-3-methoxyphenyl)-8'-methylbutan-8-yl)-3'-methoxybenzene-4',5'-diol (3), along with four known compounds (4-7) were isolated from the seeds of Myristica fragrans. Their chemical structures were established mainly by 1D and 2D NMR techniques and mass spectrometry. Their anti-inflammatory activity was evaluated against LPS-induced NO production in macrophage RAW264.7 cells.

Alkaloids from Chelidonium majus and their inhibitory effects on LPS-induced NO production in RAW264.7 cells.

A new alkaloid, methyl 2'-(7,8-dihydrosanguinarine-8-yl)acetate (1), together with six known alkaloids, stylopine (2), protopine (3), norchelidonine (4), chelidonine (5), berberine (6), and 8-hydroxydihydrosanguinarine (7), were isolated from Chelidonium majus. Their chemical structures were primarily established using 1D and 2D NMR techniques and mass spectrometry. The anti-inflammatory activity of the isolates was examined for their inhibitory effects on LPS-induced NO production in macrophage RAW264.7 cells. Among them, compounds 5 and 7 showed strong inhibitory activities toward the LPS-induced NO production in macrophage RAW264.7 cells with IC(50) values of 7.3 and 4.5 µM, respectively. In addition, compounds 5 and 7 inhibited the inductions of COX-2 and iNOS mRNA in dose-dependent manners, indicating that these compounds attenuated the syntheses of these transcripts at the transcriptional level.

Two new lignans from the roots of Pulsatilla koreana.

Two new lignans, (2 R,3 R)-2 ß-(4''-hydroxy-3''-methoxybenzyl)-3 α-(4'-hydroxy-3'-methoxybenzyl)-γ-butyrolactone 2-O-( ß-D-glucopyranoside) (1) and (1 S,2 R,3 S)-dimethyl-1,2,3,4-tetrahydro-3,6,7-trihydroxy-1-(3',4'-dihydroxyphenyl)naphthalene-2,3-dicarboxylate (2) together with nine known compounds (3-11) were isolated from the ethyl acetate fraction of the roots of Pulsatilla koreana. Their chemical structures were established based on physicochemical and spectroscopic data analyses. All isolates were investigated for their inhibition effects against the classical pathway of the complement system. Among them, compound 6 showed significant inhibitory activity with an IC (50) value of 75.9 µM, compounds 8 and 9 had moderate effects with IC (50) values of 182.2 and 166.5 µM, respectively.

Labdane-type diterpenoids from Leonurus heterophyllus and their cholinesterase inhibitory activity.

In the course of screening plants used in natural medicines as memory enhancers, a 70% ethanol extract of the aerial parts of Leonurus heterophyllus showed significant AChE inhibitory activity. Bioassay-guided fractionation and repeated column chromatography led to the isolation of a new labdane-type diterpenoids (1), named leoheteronin F, and six known compounds (2-7). The chemical structures of isolated compounds were elucidated based on extensive 1D and 2D NMR spectroscopic data. The isolates 1-7 were investigated in vitro for their anticholinesterase activity using mouse cortex AChE enzyme. Leoheteronin A (5) and leopersin G (7), which possess a 15,16-epoxy group at the side chain, were found to be potent in the inhibition of AChE.

Ergosta-7,22-diene-2ß,3α,9α-triol from the fruit bodies of Ganoderma lucidum induces apoptosis in human myelocytic HL-60 cells.

Ganoderma lucidum is known as a medicinal mushroom used in traditional medicine. In our study, the cytotoxic activities of 17 compounds (1-17) isolated from the fruiting bodies of G. lucidum were investigated. Among them, ergosta-7,22-diene-2ß,3α,9α-triol (EGDT) induced apoptosis in HL-60 human premyelocytic leukemia cells. EGDT activated the apoptotic process, including DNA fragmentation and caspase-3 activity. In immunoblotting analysis, treatment with EGDT resulted in the cleavage of procaspase-3 and poly(ADP-ribose) polymerase (PARP) into active forms. In the in vivo study, the administration (i.p.) of EGDT to Lewis lung carcinoma (LLC)-inoculated mice evidenced a significant inhibition of tumor growth. These results indicate that EGDT was one of the apoptotic constituents of G. lucidum, and might be an antitumor agent.

Flavonoid glycosides from Chromolaena odorata leaves and their in vitro cytotoxic activity.

Two new flavonoid glycosides, (1, 2), and eleven known compounds, (3-13), were isolated from from a 70% EtOH extract of the leaves of Chromolaena odorata (Asteraceae). Their structures were elucidated by 1D and 2D NMR spectroscopic interpretation as well as by chemical studies. The newly isolated compounds were tested in vitro for their cytotoxic activities against the LLC and HL-60 cancer cell lines. Compound 1 showed cytotoxicity against LLC and HL-60 cancer cell lines with IC(50) values of 28.2 and 11.6 µM, respectively. Compound 2 exhibited significant cytotoxic activity in the inhibition of HL-60 cancer cell lines with IC(50) value of 10.8 µM.