Essential Oil’s Chemical Composition and Pharmacological Properties

Essential oil, sent by nature, is a complex mixture of volatile secondary metabolites. Its composition varies along with many parameters that can lead to misunderstanding of its wonderful pharmacological property. In fact, from post-harvest treatment to the compound’s identification through extraction approaches, the original chemotype of essential oils can be misdescribed. The pharmacological potentials of these oils are well known in the traditional system since time immemorial. Nowadays, some chemotypes of these oils had shown the effect against WHO’s top 10 killer diseases. But the misuses of these essential oils are in part due to the lack of robust and easy analysis strategy that can allow the quality of the essential oils

Fungicide Tolerance and Effect of Environmental Conditions on Growth of Trichoderma spp. with Antagonistic Activity Against Sclerotinia sclerotiorum Causing White Mold of Common Bean (Phaseolus vulgaris)

The present study was conducted to evaluate in vitro compatibility of commonly used agrochemicals as well as the effect of temperature, pH and salt on the growth of six Trichoderma spp. with antagonistic activity against S. sclerotiorum responsible for white mold of common bean. The results revealed that in dual culture, the mycelial growth inhibition of S. sclerotiorum ranged from 83.4 to 87.4 %25. The highest inhibition (87.4 %25) was obtained with isolate T. erinaceum It-58, while the lowest inhibition (83.4 %25) was caused by T. koningiopsis It-21. Except T. asperellum It-13, antagonistic fungi were able to fully colonized pathogen in five days reaching class I antagonism according to Bell scale. The maximum inhibition percentage of volatile (54.07 %25) and non-volatile compounds (68.89 %25) on pathogen was respectively caused by T. asperellum It-13 and T. harzianum P-11. Fungicides affect the growth of Trichoderma differently. No growth was observed while testing compatibility of T. asperellum It-13 and T. erinaceum It-58 with Mancozeb as well as T. asperellum It-13 and T. afroharzianum P-8 with Methyl thiophanate illustrating the absence of compatibility. The excellent growth rate of Trichoderma was found at temperature range of 25ndash%253B30˚C and pH range 4.5-5.5. Apart from T. asperellum It-13, all the isolates were able to grow at NaCl concentrations up to 1000 micro%253BM and were identified as superior salt-tolerant isolates

Phytochemical analysis and antifungal property of Mallotus oppositifolius (Geiseler) Müll.Arg. (Euphorbiaceae)

The emergence of resistant fungi to available drugs highlights the need for new antifungal drugs. The present study aimed to evaluate the antifungal activity of the isolated compounds, fractions and crude extract from the leaf of Mallotus oppositifolius (Geiseler) Müll. Arg. Three pure compounds labelled 1-3 were isolated from the methylene chloride / methanol (1/1) extract of the leaf of this plant using chromatography techniques. These compounds were identified using analytical spectroscopic methods as betulinic acid (1), quercetine (2) and quercitin (3). The crude extract, fractions and compounds were tested against pathogenic yeasts (Candida albicans, Candida glabrata, Candida krusei) and dermatophytes (Trichophyton rubrum, Trichophyton soudanense, Microsporum audouinii, Microsporum langeronii) using agar well diffusion and dilution methods. The safety of the crude extract was studied on Wistar rats according to the WHO guidelines. The minimal inhibitory concentration (MIC) values ranged from 48 to 781 μg/ml against yeasts for crude extract and fractions, and 1.86 to 25000 μg/ml against dermatophytes for pure compounds, fractions and crude extract. The antifungal activity of pure compounds was not determined against yeasts. The crude extract of leaf was found to be safe in rat at up to 12 g/kg. The results achieved supported the traditional use of Mallotus oppositifolius leaf for the treatment of fungal infections.Keywords: Mallotus oppositifolius, antifungal activity, safety, phytochemical screening

Anti-yeast activity of extracts and fractions from Uvariodendron calophyllum (Annonaceae)

The resistance to available antifungals highlights the urgent need for innovative drugs to treat yeasts infections. This study aimed at evaluating the activity of extracts and fractions from Uvariodendron calophyllum against pathogenic yeasts. The ethanolic and aqueous extracts obtained by maceration were liquidliquid- partitioned using organic solvents and screened against isolates of Candida albicans, Candida glabrata, Candida parapsilosis, Cryptococcus neoformans and Candida albicans reference strains NR-29445, NR-29444, NR-29451, and NR-29450 from BEI Resources using the broth micro-dilution method. Time kill kinetic, inhibition of germ-tube, filamentation and chlamydosporulation, and biofilm formation were assessed using the best sub-fraction. Overall, the most interesting sub-fraction (FS: 237–253) showed an MIC value of 0.0625 mg/mL with cidal effect against C. albicans NR-29450 and NR-29445 at 0.25 mg/mL after 12-16 hours and 24 hours respectively. Moderate inhibitory effects were observed at 0.25 mg/mL against germ-tube formation, filamentation and chlamydosporulation of all C. albicans strains. Also, very moderate inhibition of biofilm formation by C. albicans NR-29450 at 0.25 mg/mL was obtained. The results obtained support U. calophyllum as a potential source of compounds with anti-yeast activity. Further studies will confirm its potential as source of anti-yeast drugs.© 2015 International Formulae Group. All rights reserved.Keywords: Uvariodendron calophyllum, anti-yeasts activity, time kill kinetics, biofil

Antimycobacterial activity of selected medicinal plants extracts from Cameroon

New drugs are highly needed to control mycobacterial infections. This study aimed at screening ethnobotanically selected plants extracted using organic solvents for their antimycobacterial activity. In vitro assays were performed on Mycobacterium smegmatis, Mycobacterium avium, Mycobacterium bovis Bacille Calmette Guerin (BCG), Mycobacterium tuberculosis and Mycobacterium ulcerans using the Resazurin Microtiter Assay. Cytotoxicity was assessed on Human lung fibroblast cells (MRC5) and bone marrow-derived macrophages (BMDM) using the MTS tetrazolium assay. The most promising extract from Annickia chlorantha stem bark (ACsbI) was tested for intracellular antimycobacterial activity against M. smegmatis using infected BMDM. Sixty crude extracts, 19 fractions, and 2 purified compounds were obtained from 19 Cameroonian medicinal plants. Results showed that crude extracts mainly inhibited BCG, while interface fractions from A. chlorantha stem bark (ACsbI) and stem (ACstI) displayed the strongest activity against M. ulcerans, with Minimal Inhibitory Concentrations (MIC) of 1.95 and 7.81 µg/ml respectively. Two compounds purified from Sorindeia juglandifolia fruits (SJfr 3.6 and SJfr 4.5) showed activity against BCG and M. ulcerans at 3.9 µg/ml and 62.5 µg/ml respectively. Finally, ACsbI showed no toxicity against MRC5 cells and BMDM and inhibited the growth of intracellular M. smegmatis. The results achieved in this investigation support the traditional to use of these plants and the need to investigate them in deeper details to be able to find alternatives for the existing antimycobacterial drugs

Biosynthesis of Silver Nanoparticles Using Bersama engleriana Fruits Extracts and Their Potential Inhibitory Effect on Resistant Bacteria

The absence of novel, safe, and effective bactericide is an urgent concern worldwide and remains a challenge in scientific communities. The unique proprieties of silver nanoparticles (SNPs) synthesized from plant extracts make them a suitable candidate to overcome these limitations. Herein, we synthesized SNPs from Bersama engleriana fruit (BEfr) extracts and determined their potential antibacterial activity and mode of action. SNPs were synthesized from BEfr methanolic fruit extracts at 25 and 70 ◦C, and the antibacterial effectiveness of SNPs against bacterial strains was investigated. The surface plasmon resonance peaked at 430.18 and 434.08 nm, respectively, for SNPs synthesized at 25 and 70 ◦C, confirming SNPs synthesis. BEfr-SNPs had minimum inhibitory concentrations (MIC) range of 0.234 to >50 µg/mL, which was 30-fold greater than extract alone (MIC of 500 µg/mL). BEfrSNPs-25 ◦C was potent against six bacterial strains (S. aureus, S. enterica, MRS. aureus, K. pneumonia, and S. pyogenes), with MIC range of 0.339 to 6.25 µg/mL. The mode of action of BEfr-SNPs-25 ◦C was achieved by an MRSA bacteria strain outer membrane and DNA nucleotide linkage. These results suggest that our synthesized SNPs, especially BEfr-SNPs-25 ◦C, demonstrated an enhanced antibacterial effect and could be potential candidates for bacterial infection treatment

Antiplasmodial volatile extracts from Cleistopholis patens Engler & Diels and Uvariastrum pierreanum Engl. (Engl. & Diels) (Annonaceae) growing in Cameroon

In a search for alternative treatment for malaria, plant-derived essential oils extracted from the stem barks and leaves of Cleistopholis patens and Uvariastrum pierreanum (Annonaceae) were evaluated in vitro for antiplasmodial activity against the W2 strain of Plasmodium falciparum. The oils were obtained from 500 g each of stem barks and leaves, respectively, by hydrodistillation, using a Clevenger-type apparatus with the following yields: 0.23% and 0.19% for C. patens and 0.1% and 0.3% for U. pierreanum (w/w relative to dried material weight). Analysis of 10% (v/v) oil in hexane by gas chromatography and mass spectrometry identified only terpenoids in the oils, with over 81% sesquiterpene hydrocarbons in C. patens extracts and U. pierreanum stem bark oil, while the leaf oil from the latter species was found to contain a majority of monoterpenes. For C. patens, the major components were α-copaene, δ-cadinene, and germacrene D for the stem bark oil and β-caryophyllene, germacrene D, and germacrene B for the leaf oil. The stem bark oil of U. pierreanum was found to contain mainly β-bisabolene and α-bisabolol, while α- and β-pinenes were more abundant in the leaf extract. Concentrations of oils obtained by diluting 1-mg/mL stock solutions were tested against P. falciparum in culture. The oils were active, with IC50 values of 9.19 and 15.19 μg/mL for the stem bark and leaf oils, respectively, of C. patens and 6.08 and 13.96 μg/mL, respectively, for those from U. pierreanum. These results indicate that essential oils may offer a promising alternative for the development of new antimalarials

In vitro antiplasmodial activity-directed investigation and UPLC–MS fingerprint of promising extracts and fractions from Terminalia ivorensis A. Chev. and Terminalia brownii Fresen.

Please read abstract in the article.The Grand Challenges Africa programme is supported by the African Academy of Sciences (AAS), Bill & Melinda Gates Foundation (BMGF), Medicines for Malaria Venture (MMV), and Drug Discovery and Development Centre of University of Cape Town (H3D).https://www.elsevier.com/locate/jethpharm2023-07-09hj2023Chemistr

Inhibitors of Farnesyl Diphosphate Synthase and Squalene Synthase: Potential Source for Anti-<i>Trypanosomatidae</i> Drug Discovery

Trypanosomatids are mainly responsible for leishmaniasis, sleeping sickness, and Chagas disease, which are the most challenging among the neglected tropical diseases due to the problem of drug resistance. Although problems of target deconvolution and polypharmacology are encountered, a target-based approach is a rational method for screening drug candidates targeting a biomolecule that causes infections. The present study aims to summarize the latest information regarding potential inhibitors of squalene synthase and farnesyl phosphate synthase with anti-Trypanosomatidae activity. The information was obtained by referencing textbooks and major scientific databases from their inception until April 2023. Based on in vitro experiments, more than seventy compounds were reported to inhibit squalene synthase and farnesyl diphosphate synthase. Among these compounds, more than 30 were found to be active in vitro against Trypanosomatidae, inferring that these compounds can be used as scaffolds to develop new drugs against trypanosomatid-related infections. Overall, natural and synthetic products can inhibit enzymes that are crucial for the survival and virulence of trypanosomatids. Moreover, in vitro experiments have confirmed the activity of more than half of these inhibitors using cell-based assays. Nevertheless, additional studies on the cytotoxicity, pharmacokinetics, and lead optimization of potent anti-Trypanosomatid compounds should be investigated