Staphylococcus aureus
infections are considered as seriously problematic for human health and necessitate the development of new medicines and innovative antimicrobial strategies. Plant secondary ...metabolites have already demonstrated their potential as antibacterials when used alone but also in combination with other antimicrobial agents to potentiate their activity. Triterpenoids are widely distributed in the plant kingdom and known to have many beneficial effects, including anti-inflammatory, immunomodulatory, anti-proliferative, antimycotic, or antimicrobial activity. The aim of this paper is to review the activity of pentacyclic triterpenoids belonging to the ursane, oleanane, or lupane groups against
Staphylococcus aureus
. We summarize their activity as anti-staphylococcal compounds but also as resistance modifying agents when combined with common antibiotics.
Objectives This review covers the compounds with antiplasmodial activity isolated from plants published from 2005 to the end of 2008, organized according to their phytochemical classes. Details are ...given for substances with IC50 values ≤ 11 μM.
Key findings Malaria is a major parasitic disease in many tropical and subtropical regions and is responsible for more than 1 million deaths each year in Africa. The rapid spread of resistance encourages the search for new active compounds. Nature and particularly plants used in traditional medicine are a potential source of new antimalarial drugs as they contain molecules with a great variety of structures and pharmacological activities.
Summary A large number of antimalarial compounds with a wide variety of structures have been isolated from plants and can play a role in the development of new antimalarial drugs. Ethnopharmacological approaches appear to be a promising way to find plant metabolites that could be used as templates for designing new derivatives with improved properties.
Cymbopogon species are largely used in folk medicine for the treatment of many diseases some of which related to parasitical diseases as fevers and headaches. As part of our research on antiparasitic ...essential oils from Beninese plants, we decided to evaluate the in vitro antiplasmodial and antitrypanosomal activities of essential oils of four Cymbopogon species used in traditional medicine as well as their cytotoxicity.
The essential oils of four Cymbopogon species Cymbopogon citratus (I), Cymbopogon giganteus (II), Cymbopogon nardus (III) and Cymbopogon schoenantus (IV) from Benin obtained by hydrodistillation were analysed by GC/MS and GC/FID and were tested in vitro against Trypanosoma brucei brucei and Plasmodium falciparum respectively for antitrypanosomal and antiplasmodial activities. Cytotoxicity was evaluated in vitro against Chinese Hamster Ovary (CHO) cells and the human non cancer fibroblast cell line (WI38) through MTT assay to evaluate the selectivity.
All tested oils showed a strong antitrypanosomal activity with a good selectivity. Sample II was the most active against Trypanosoma brucei brucei and could be considered as a good candidate. It was less active against Plasmodium falciparum. Samples II, III and IV had low or no cytotoxicity, but the essential oil of Cymbopogon citratus (I), was toxic against CHO cells and moderately toxic against WI38 cells and needs further toxicological studies. Sample I (29 compounds) was characterised by the presence as main constituents of geranial, neral, β-pinene and cis-geraniol; sample II (53 compounds) by trans-p-mentha-1(7),8-dien-2-ol, trans-carveol, trans-p-mentha-2,8-dienol, cis-p-mentha-2,8-dienol, cis-p-mentha-1(7),8-dien-2-ol, limonene, cis-carveol and cis-carvone; sample III (28 compounds) by β-citronellal, nerol, β-citronellol, elemol and limonene and sample IV (41 compounds) by piperitone, (+)-2-carene, limonene, elemol and β-eudesmol.
Our study shows that essential oils of Cymbopogon genus can be a good source of antitrypanosomal agents. This is the first report on the activity of these essential oils against Trypanosoma brucei brucei, Plasmodium falciparum and analysis of their cytotoxicity.
IC50 values on Trypanosoma brucei brucei (Tbb) of Cymbopogon (C.) essential oils and some of their components compared to suramine. Display omitted
is one of the pathogens causing cutaneous leishmaniasis which is associated with patient morbidity. In our researches for new safe and effective treatments, thirty-seven essential oils (EOs) ...extracted from Vietnamese plants were screened in vitro for the first time on
promastigotes at the maximum concentration of 50 nL/mL. Active EOs were also analyzed for cytotoxicity on mammalian cell lines (WI38, J774) and their selectivity indices (SI) were calculated. Their composition was determined by GC-MS and GC-FID. Our results indicated that EOs extracted from
,
,
and
, possessed a moderate anti-leishmanial activity, with IC
values of 2.92 ± 0.08, 3.34 ± 0.34, 8.49 ± 0.32 and 9.25 ± 0.64 nL/mL respectively. However, they also showed cytotoxicity with SI < 10. The most promising EO was extracted from
, displaying an IC
of 4.85 ± 1.65 nL/mL and SI > 10. It contained 86.5% eugenol, which was demonstrated to be effective on
with IC
of 2.57 ± 0.57 nL/mL and not toxic on mammalian cells, explaining the observed activity.
Volatiles metabolites from the liverwort
harvested in Corsica were investigated by chromatographic and spectroscopic methods. In addition to already reported constituents, three new compounds were ...isolated by preparative chromatography and their structures were elucidated by mass spectrometry (MS) and NMR experiments. Hence, an atypic aliphatic compound, named 1,2-dihydro-4,5-dehydronerolidol and two isomers, (E) and (Z), possessing an unusual humbertiane skeleton (called
-menth-1-en-3-2-methylbut-1-enyl-8-ol) are newly reported and fully characterized in this work. The in vitro antiprotozoal activity of essential oil and extract of
against
and
and cytotoxicity were determined. Essential oil and Et
O extract showed a moderate activity against
with IC
values: 2.03 and 5.18 μg/mL, respectively. It is noteworthy that only the essential oil showed a high selectivity (SI = 11.7). Diethyl oxide extract exhibited moderate anticancer (cancerous macrophage-like murine cells) activity and also cytotoxicity (human normal fibroblast) with IC
values: 1.25 and 2.96 μg/mL, respectively.
New anti-infective agents are urgently needed to fight microbial resistance. Methicillin-resistant
(MRSA) strains are particularly responsible for complicated pathologies that are difficult to treat ...due to their virulence and the formation of persistent biofilms forming a complex protecting shell. Parasitic infections caused by
and
are also of global concern, because of the mortality due to the low number of safe and effective treatments. Female inflorescences of hop produce specialized metabolites known for their antimicrobial effects but underexploited to fight against drug-resistant microorganisms. In this study, we assessed the antimicrobial potential of phenolic compounds against MRSA clinical isolates,
and
. By fractionation process, we purified the major prenylated chalcones and acylphloroglucinols, which were quantified by UHPLC-UV in different plant parts, showing their higher content in the active flowers extract. Their potent antibacterial action (MIC < 1 µg/mL for the most active compound) was demonstrated against MRSA strains, through kill curves, post-antibiotic effects, anti-biofilm assays and synergy studies with antibiotics. An antiparasitic activity was also shown for some purified compounds, particularly on
(IC
< 1 to 11 µg/mL). Their cytotoxic activity was assessed both on cancer and non-cancer human cell lines.
Summary
The bioactivity and phytochemical composition of a partially purified extract of açai (PPEA), concentrated in phenolic compounds (PC) and without the presence of macronutrients, were ...investigated. The major PC quantified by UHPLC‐DAD‐LTQ‐Orbitrap MS‐MS/MS in the PPEA are anthocyanins. In vitro, PPEA showed a cytostatic effect on the K‐562 lymphoid leukaemia at a concentration of 40 μg PC mL−1, with a GI50 equal to 1.08 μg PC mL−1. In vivo, the extract did not promote acute toxicity in mice in any of the doses tested. The extract displayed gastroprotective activity in rats treated orally with 16, 48 and 160 mg PC kg−1, with a significant decrease in the ulcerative lesion index, compared with the negative control. The lack of toxicity and the bioactivity of the PPEA show that this extract is beneficial to health and useful as a commercial food additive containing natural violet colourant, with pharmaceutical and functional potentials.
Partially purified extract of açai (PPEA), high in phenolic compounds presents antiproliferative and gastroprotective effects and does not present acute toxicity.
Bioactivity-guided fractionation of the ethyl acetate extract of the leaves of Poupartia borbonica led to the isolation of three new alkyl cyclohexenone derivatives 1-3, and named Poupartone A-C. The ...structures of the new compounds were elucidated by 1D and 2D NMR spectroscopic data analysis and MS, whereas calculated and experimental ECD spectra were used to define the absolute configurations. These compounds were active against 3D7 and W2 Plasmodium falciparum strains with IC
values between 0.55 and 1.81 μM. In vitro cytotoxicity against WI38 human fibroblasts and the human cervical cancer cell line HeLa (WST-1 assay) showed that these compounds were also cytotoxic, but no hemolytic activity was observed for the extract and pure compounds. An in vivo antimalarial assay was performed on the major cyclohexenone using P. berghei-infected mice at a dose of 15 mg/kg/day ip. The assay revealed growth inhibition of 59.1 and 69.5% at days 5 and 7 postinfection, respectively, although some toxicity was observed. Zebrafish larvae were used as a model to determine the type of toxicity, and the results showed cardiac toxicity. The methanol extract was also studied, and it displayed moderate antiplasmodial properties in vitro. This extract contained the known flavonoids, quercetin, 3'-O-hydroxysulfonylquercetin, quercitrin, and isoquercitrin as well as ellagic acid, which showed high to low activity against the 3D7 P. falciparum strain.
is used in Pakistani traditional medicine to treat inflammation-related disorders. Its anti-inflammatory potential was evaluated on hexane, dichloromethane, ethyl acetate, methanol, and aqueous ...extracts of whole plant on pro-inflammatory mediators in LPS-activated murine macrophage J774 cells at the non-cytotoxic concentration of 50 µg/mL. Ethyl acetate (ARE) and methanol (ARM) extracts significantly decreased mRNA levels of IL-6, TNF-α, MCP-1, COX-2, and iNOS. Furthermore, both extracts dose dependently decreased IL-6, TNF-α, and MCP-1 secretion. Forty-five compounds were putatively identified in ARE and ARM by dereplication (using HPLC-UV-HRMS
analysis and molecular networking), most of them are reported for the first time in
, as for example, nineteen phenolic derivatives. Rutin, kaempferol-3-
-rutinoside, chlorogenic acid, 3,5-di-
-caffeoylquinic acid,
-
-
-coumaroyl-tyramine, and
-
-feruloyl-tyramine were main constituents identified and quantified by HPLC-PDA in ARE and ARM. Furthermore, chlorogenic acid, tyramine derivatives, and the mixture of the six identified major compounds significantly decreased IL-6 secretion by LPS-activated J774 cells. The activity of
-
-
-coumaroyl-tyramine is shown here for the first time. Our results indicate that ARE, ARM and major constituents significantly inhibited the expression of pro-inflammatory mediators, which supports the use of this plant to treat inflammatory diseases.
Leishmaniasis is a neglected tropical disease that still infects thousands of people per year throughout the world. The occurrence of resistance against major treatments for this disease causes a ...healthcare burden in low-income countries. Eugenol is a phenylpropanoid that has shown in vitro antileishmanial activity against
(
) promastigotes with an IC
of 2.72 µg/mL and a high selectivity index. Its specific mechanism of action has yet to be studied. We prepared large unilamellar vesicles (LUVs), mimicking
membranes, and observed that eugenol induced an increase in membrane permeability and a decrease in membrane fluidity at concentrations much higher than IC
. The effect of eugenol was similar to the current therapeutic antibiotic, amphotericin B, although the latter was effective at lower concentrations than eugenol. However, unlike amphotericin B, eugenol also affected the permeability of LUVs without sterol. Its effect on the membrane fluidity of
showed that at high concentrations (≥22.5× IC
), eugenol increased membrane fluidity by 20-30%, while no effect was observed at lower concentrations. Furthermore, at concentrations below 10× IC
, a decrease in metabolic activity associated with the maintenance of membrane integrity revealed a leishmaniostatic effect after 24 h of incubation with
promastigotes. While acidocalcisomes distribution and abundance revealed by
vacuolar H
pyrophosphatase (TbVP1) immunolabeling was not modified by eugenol, a dose-dependent decrease of lipid droplets assessed by the Nile Red assay was observed. We hereby demonstrate that the antileishmanial activity of eugenol might not directly involve plasma membrane sterols such as ergosterol, but rather target the lipid storage of
.
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