scholarly journals Spirostanol Saponins from Flowers of Allium Porrum and Related Compounds Indicating Cytotoxic Activity and Affecting Nitric Oxide Production Inhibitory Effect in Peritoneal Macrophages

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6533
Author(s):  
Juraj Harmatha ◽  
Miloš Buděšínský ◽  
Zdeněk Zídek ◽  
Eva Kmoníčková

Saponins, a diverse group of natural compounds, offer an interesting pool of derivatives with biomedical application. In this study, three structurally related spirostanol saponins were isolated and identified from the leek flowers of Allium porrum L. (garden leek). Two of them were identical with the already known leek plant constituents: aginoside (1) and 6-deoxyaginoside (2). The third one was identified as new component of A. porrum; however, it was found identical with yayoisaponin A (3) obtained earlier from a mutant of elephant garlic Allium ampeloprasun L. It is a derivative of the aginoside (1) with additional glucose in its glycosidic chain, identified by MS and NMR analysis as (2α, 3β, 6β, 25R)-2,6-dihydroxyspirostan-3-yl β-D-glucopyranosyl-(1 → 3)-β-D-glucopranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 3)]-β-D-glucopyranosyl]-(1 → 4)-β-D-galactopyranoside, previously reported also under the name alliporin. The leek native saponins were tested together with other known and structurally related saponins (tomatonin and digitonin) and with their related aglycones (agigenin and diosgenin) for in vitro cytotoxicity and for effects on NO production in mouse peritoneal cells. The highest inhibitory effects were exhibited by 6-deoxyaginoside. The obtained toxicity data, however, closely correlated with the suppression of NO production. Therefore, an unambiguous linking of obtained bioactivities of saponins with their expected immunobiological properties remained uncertain.

1989 ◽  
Vol 61 (02) ◽  
pp. 254-258 ◽  
Author(s):  
Margaret L Rand ◽  
Peter L Gross ◽  
Donna M Jakowec ◽  
Marian A Packham ◽  
J Fraser Mustard

SummaryEthanol, at physiologically tolerable concentrations, inhibits platelet responses to low concentrations of collagen or thrombin, but does not inhibit responses of washed rabbit platelets stimulated with high concentrations of ADP, collagen, or thrombin. However, when platelet responses to high concentrations of collagen or thrombin had been partially inhibited by prostacyclin (PGI2), ethanol had additional inhibitory effects on aggregation and secretion. These effects were also observed with aspirin- treated platelets stimulated with thrombin. Ethanol had no further inhibitory effect on aggregation of platelets stimulated with ADP, or the combination of ADP and epinephrine. Thus, the inhibitory effects of ethanol on platelet responses in the presence of PGI2 were very similar to its inhibitory effects in the absence of PGI2, when platelets were stimulated with lower concentrations of collagen or thrombin. Ethanol did not appear to exert its inhibitory effects by increasing cyclic AMP above basal levels and the additional inhibitory effects of ethanol in the presence of PGI2 did not appear to be brought about by further increases in platelet cyclic AMP levels.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Vicky Mody ◽  
Joanna Ho ◽  
Savannah Wills ◽  
Ahmed Mawri ◽  
Latasha Lawson ◽  
...  

AbstractEmerging outbreak of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is a major threat to public health. The morbidity is increasing due to lack of SARS-CoV-2 specific drugs. Herein, we have identified potential drugs that target the 3-chymotrypsin like protease (3CLpro), the main protease that is pivotal for the replication of SARS-CoV-2. Computational molecular modeling was used to screen 3987 FDA approved drugs, and 47 drugs were selected to study their inhibitory effects on SARS-CoV-2 specific 3CLpro enzyme in vitro. Our results indicate that boceprevir, ombitasvir, paritaprevir, tipranavir, ivermectin, and micafungin exhibited inhibitory effect towards 3CLpro enzymatic activity. The 100 ns molecular dynamics simulation studies showed that ivermectin may require homodimeric form of 3CLpro enzyme for its inhibitory activity. In summary, these molecules could be useful to develop highly specific therapeutically viable drugs to inhibit the SARS-CoV-2 replication either alone or in combination with drugs specific for other SARS-CoV-2 viral targets.


Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 493
Author(s):  
 Chung-Yu Chen ◽  
Chien-Rung Chen ◽  
Chiao-Nan Chen ◽  
Paulus S. Wang ◽  
Toby Mündel ◽  
...  

The purpose of this study is to evaluate the amphetamine effects on progesterone and estradiol production in rat granulosa cells and the underlying cellular regulatory mechanisms. Freshly dispersed rat granulosa cells were cultured with various test drugs in the presence of amphetamine, and the estradiol/progesterone production and the cytosolic cAMP level were measured. Additionally, the cytosolic-free Ca2+ concentrations ([Ca2+]i) were measured to examine the role of Ca2+ influx in the presence of amphetamine. Amphetamine in vitro inhibited both basal and porcine follicle-stimulating hormone-stimulated estradiol/progesterone release, and amphetamine significantly decreased steroidogenic enzyme activities. Adding 8-Bromo-cAMP did not recover the inhibitory effects of amphetamine on progesterone and estradiol release. H89 significantly decreased progesterone and estradiol basal release but failed to enhance a further amphetamine inhibitory effect. Amphetamine was capable of further suppressing the release of estradiol release under the presence of nifedipine. Pretreatment with the amphetamine for 2 h decreased the basal [Ca2+]i and prostaglandin F2α-stimulated increase of [Ca2+]i. Amphetamine inhibits progesterone and estradiol secretion in rat granulosa cells through a mechanism involving decreased PKA-downstream steroidogenic enzyme activity and L-type Ca2+ channels. Our current findings show that it is necessary to study the possibility of amphetamine perturbing reproduction in females.


Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1301
Author(s):  
Yun Xiong ◽  
Ken Ng ◽  
Pangzhen Zhang ◽  
Robyn Dorothy Warner ◽  
Shuibao Shen ◽  
...  

Diabetes is a global health challenge. Currently, an effective treatment for diabetes is to reduce the postprandial hyperglycaemia by inhibiting the carbohydrate hydrolysing enzymes in the digestive system. In this study, we investigated the in vitro α-glucosidase and α-amylase inhibitory effects of free and bound phenolic extracts, from the bran and kernel fractions of five sorghum grain genotypes. The results showed that the inhibitory effect of sorghum phenolic extracts depended on the phenolic concentration and composition. Sorghum with higher phenolic contents generally had higher inhibitory activity. Among the tested extracts, the brown sorghum (IS131C)-bran-free extract (BR-bran-free, half-maximal inhibitory concentration (IC50) = 18 ± 11 mg sorghum/mL) showed the strongest inhibition against α-glucosidase which was comparable to that of acarbose (IC50 = 1.39 ± 0.23 mg acarbose/mL). The red sorghum (Mr-Buster)-kernel-bound extract (RM-kernel-bound, IC50 = 160 ± 12 mg sorghum/mL) was the most potent in inhibiting α-amylase but was much weaker compared to acarbose (IC50 = 0.50 ± 0.03 mg acarbose/mL).


1966 ◽  
Vol 44 (4) ◽  
pp. 661-676 ◽  
Author(s):  
Robert P. Thompson

To demonstrate the phenomenon of homologous inhibition by clearly interpretable results in a readily reactive system, experiments were carried out to study the effect of chick whole eye extract on the development of the vesicular lens of the chick embryo in vitro. The heads of embryos of 11 through 13 somites were explanted onto nutrient medium diluted with varying amounts of the extract, and cultured for 30 hours. A total of 35 embryos exposed to concentrations of 1:1, 1:2, and 1:4 (extract to medium) showed complete inhibition of lens vesicle formation. Of a total of 53 embryos on concentrations of 1:8, 1:16, 1:32, and 1:64, more than 50% showed inhibition of vesicle formation. The inhibitory effect disappeared at a concentration of 1:128. Control material exposed to some equivalent concentrations of nutrient medium – saline mixtures showed inhibition of vesicle formation in only 15% of 33 embryos. Of a total of 27 control embryos exposed to ventricular muscle extract, approximately one-third showed inhibition of vesicle formation at concentrations of 1:8 and 1:16, with the inhibitory effect disappearing at 1:32. The implications of this result are discussed. Other factors and control experiments are described and their value is assessed.


2002 ◽  
Vol 11 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Vera L. Petricevich

The purpose of this study was to investigate the effects ofTityus serrulatusvenom (TSV) on murine peritoneal macrophages evaluated in terms of activation. The effects of crude TSV were analysed by detection of cytokines, oxygen intermediate metabolites (H2O2) and nitric oxide (NO) in supernatants of peritoneal macrophages. Several functional bioassays were employed including anin vitromodel for envenomating: cytotoxicity of TSV was assessed using the lyses percentage. Tumor necrosis factor (TNF) activity was assayed by measuring its cytotoxic activity on L-929 cells, and interleukin-6 (IL-6) and interferon-γ (IFN-γ) were assayed by enzyme-linked immunosorbent assay, whereas NO levels were detected by Griess colorimetric reactions in culture supernatant of macrophages incubated with TSV and subsequently exposed to either lipopolysaccharide or IFN-γ. Incubation of macrophages with TSV increased production of IL-6 and IFN-γ in a dose-dependent manner. TNF production was not detected in supernatants treated with TSV at any concentration. The increase in IL-6 secretion was not associated with concentration-dependent cytoxicity of TSV on these cells. These data suggest that the cytotoxicity does not appear to be the main cause of an increased cytokine production by these cells. Although NO is an important effector molecule in macrophage microbicidal activity, the inducing potential of the test compounds for its release was found to be very moderate, ranging from 125 to 800 mM. Interestingly, NO levels of peritoneal macrophages were increased after IFN-γ. Moreover, NO production had an apparent effect on macrophage activity. The results obtained here also shown that the TSV induces an important elevation in H2O2release. These results combined with NO production suggest that TSV possesses significant immunomodulatory activities capable of stimulating immune functionsin vitro.


Toxins ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 850
Author(s):  
Murilo Luiz Bazon ◽  
Luis Gustavo Romani Fernandes ◽  
Isabela Oliveira Sandrini Assugeni ◽  
Lucas Machado Pinto ◽  
Patrícia Ucelli Simioni ◽  
...  

The social wasp Polybia paulista (Hymenoptera, Vespidae) is highly aggressive, being responsible for many medical occurrences. One of the most allergenic components of this venom is Antigen 5 (Poly p 5). The possible modulation of the in vitro immune response induced by antigen 5 from P. paulista venom, expressed recombinantly (rPoly p 5), on BALB/c mice peritoneal macrophages, activated or not with LPS, was assessed. Here, we analyzed cell viability changes, expression of the phosphorylated form of p65 NF-κB subunit, nitric oxide (NO), proinflammatory cytokines production, and co-stimulatory molecules (CD80, CD86). The results suggest that rPoly p 5 does not affect NO production nor the expression of co-stimulatory molecules in mouse peritoneal macrophages. On the other hand, rPoly p 5 induced an increase in IL-1β production in non-activated macrophages and a reduction in the production of TNF-α and MCP-1 cytokines in activated macrophages. rPoly p 5 decreased the in vitro production of the phosphorylated p65 NF-κB subunit in non-activated macrophages. These findings suggest an essential role of this allergen in the polarization of functional M2 macrophage phenotypes, when analyzed in previously activated macrophages. Further investigations, mainly in in vivo studies, should be conducted to elucidate Polybia paulista Ag5 biological role in the macrophage functional profile modulation.


2000 ◽  
Vol 47 (1) ◽  
pp. 113-120 ◽  
Author(s):  
K Bielawski ◽  
A Galicka ◽  
A Bielawska ◽  
K Sredzińska

Pentamidine despite its rather high toxicity, is currently in clinical use. For development of new drugs of this type it is important to know the mechanism of their action. Two new amidines (I and II) and 4',6-diamidino-2-phenylindole (DAPI) were found in preliminary experiments to inhibit protein synthesis in vitro in the cell-free rat liver system. The three compounds differed in the precise mode of action. The inhibitory effect of I on the activity of the eukaryotic elongation factor eEF-2 and ribosomes seems to suggest that the binding site of eEF-2 on the ribosome was blocked by this compound. eEF-2 has been identified as the primary target of II and eEF-1 as the primary target of DAPI in the system studied.


2021 ◽  
pp. 122-137
Author(s):  
Chingju Lin ◽  
Fuu-Jen Tsai ◽  
Yuan-Man Hsu ◽  
Tsung-Jung Ho ◽  
Guo-Kai Wang ◽  
...  

Negative impacts of COVID-19 on human health and economic and social activities urge scientists to develop effective treatments. Baicalin is a natural flavonoid, extracted from a traditional medicinal plant, previously reported with anti-inflammatory activity. In this study, we used pharmacophore fitting and molecular docking to screen and determine docking patterns and the binding affinity of baicalin on 3 major targets of SARS-CoV-2 (3-chymotrypsin-like cysteine protease [3CLpro], papain-like protease [PLpro], and RNA-dependent RNA polymerase). The obtained data revealed that baicalin has high pharmacophore fitting on 3CLpro and predicted good binding affinity on PLpro. Moreover, using the enzymatic assay, we examined the inhibitory effect of baicalin in vitro on the screened enzymes. Baicalin also exhibits inhibitory effect on these proteases in vitro. Additionally, we performed pharmacophore-based screening of baicalin on human targets and conducted pathway analysis to explore the potential cytoprotective effects of baicalin in the host cell that may be beneficial for COVID-19 treatment. The result suggested that baicalin has multiple targets in human cell that may induce multiple pharmacological effects. The result of pathway analysis implied that these targets may be associated with baicalin-induced bioactivities that are involved with signals of pro-inflammation factors, such as cytokine and chemokine. Taken together with supportive data from the literature, the bioactivities of bailalin may be beneficial for COVID-19 treatment by reducing cytokine-induced acute inflammation. In conclusion, baicalin is potentially a good candidate for developing new therapeutic to treat COVID-19.


2021 ◽  
Vol 16 (10) ◽  
pp. 1934578X2110559
Author(s):  
Le Minh Ha ◽  
Ngo Thi Phuong ◽  
Nguyen Thi Thu Hien ◽  
Pham Thi Tam ◽  
Do Thi Thao ◽  
...  

In this study, we aimed at evaluating in vitro and in vivo anti-inflammatory activity of various extracts of the rhizomes of Globba pendula Roxb. Three extracts ( n-hexane, ethyl acetate, and water) were screened for their inhibitory effect on NO production by lipopolysaccharide-stimulated RAW 264.7 macrophages. The ethyl acetate extract of G. pendula rhizomes (EGP) showed a potential effect with an IC50 value of 32.45 µg/mL. For in vivo study, the ethyl acetate extract was further investigated for its anti-inflammatory effect using collagen antibody-induced arthritic mice (CAIA). The level of arthritis in experimental mice significantly reduced ( P < .05) after treatment with EGP at a dose of 500 mg/kg body weight (b.w.). This study also revealed that EGP is orally non-toxic. Ethyl p-methoxy cinamate was identified as the main constituent of EGP, which may result in its anti-inflammatory effect.


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