Potential of essential oils from four Cameroonian aromatic plants used in integrated protection of stored products programs: Presentation

The efficacy of essential oils extracted from fruits of Piper capense and Xylopia parviflora, and roots of Echinops giganteus and Mondia whitei were evaluated against Acanthoscelides obtectus and fungi isolated from bean seeds in laboratory conditions in Cameroon. The essential oils were extracted by water-distillation and their chemical composition identified by Gas Chromatography-Flame Ionization Detection (GC-FID) and Gas Chromatography- Mass Spectrometry (GC-MS). Toxicity assays of essential oils against A. obtectus were carried out by fumigation in which insect pests were exposed fumes of the essential oils, and mortality recorded after 6, 12, and 24 hours. Additionally, the toxicity by contact of the essential oils was evaluated through coating grains with essential oils or impregnating the essential oils onto the filter paper, allowing the insects to physically get in contact with the essential oil, and assessing weevil mortality recorded after 1, 2, 3, and 4 days. The essential oils from P. capense and X. parviflora consisted mainly of hydrocarbon monoterpenes (56.5% and 50.0% respectively), whereas the essential oils from E. giganteus was mostly constituted of sesquiterpenes (94.3%) in which the tricyclic compounds are more abundant. A major compound identified in the essential oil from M. whitei was 2-hydroxy- 4-methoxy-benzaldehyde (81%). The essential oil from X. parviflora was the most effective as contact and fumigant against A. obtectus, causing 100% mortality within 1 day at low lethal concentrations. On the other hand, the essential oil from M. whitei exhibited the best anti-fungal activity. These essential oils could play an important role in pest protection of stored beans and reduce the risks associated with use of synthetic insecticides especially in low income small holder farming systems.The efficacy of essential oils extracted from fruits of Piper capense and Xylopia parviflora, and roots of Echinops giganteus and Mondia whitei were evaluated against Acanthoscelides obtectus and fungi isolated from bean seeds in laboratory conditions in Cameroon. The essential oils were extracted by water-distillation and their chemical composition identified by Gas Chromatography-Flame Ionization Detection (GC-FID) and Gas Chromatography- Mass Spectrometry (GC-MS). Toxicity assays of essential oils against A. obtectus were carried out by fumigation in which insect pests were exposed fumes of the essential oils, and mortality recorded after 6, 12, and 24 hours. Additionally, the toxicity by contact of the essential oils was evaluated through coating grains with essential oils or impregnating the essential oils onto the filter paper, allowing the insects to physically get in contact with the essential oil, and assessing weevil mortality recorded after 1, 2, 3, and 4 days. The essential oils from P. capense and X. parviflora consisted mainly of hydrocarbon monoterpenes (56.5% and 50.0% respectively), whereas the essential oils from E. giganteus was mostly constituted of sesquiterpenes (94.3%) in which the tricyclic compounds are more abundant. A major compound identified in the essential oil from M. whitei was 2-hydroxy- 4-methoxy-benzaldehyde (81%). The essential oil from X. parviflora was the most effective as contact and fumigant against A. obtectus, causing 100% mortality within 1 day at low lethal concentrations. On the other hand, the essential oil from M. whitei exhibited the best anti-fungal activity. These essential oils could play an important role in pest protection of stored beans and reduce the risks associated with use of synthetic insecticides especially in low income small holder farming systems

Antioxidant Activities and Chemical Constituents of Extracts from Cordyline fruticosa (L.) A. Chev. (Agavaceae) and Eriobotrya japonica (Thunb) Lindl, (Rosaceae)

Background and Objective: Cordyline fruticosa (Agavaceae) and Eriobotrya japonica (Rosaceae) are two medicinal plants used for the treatment of various diseases such as infections of mammary glands, sore throat and neck pain for the first plant, diabetes, cough, ulcers, protection against oxidative stress and cognitive deficits for the latter. The present study was designed to evaluate the antioxidant activity of the different extracts of these two plants as well as to isolate and identify their chemical constituents. Materials and Methods: The plant extract was prepared by maceration in methanol, compounds were isolated from EtOAc and n-BuOH extracts of the two plants using column chromatography and their structures were determined by means of NMR and MS analysis as well as in comparison with published data. Antioxidant tests (DPPH, ferric reduction antioxidant power and anti-hemolytic) were performed over the MeOH, EtOAc and n-BuOH extracts of the plants. Results: The antioxidant-guided phytochemical investigation of the MeOH extracts of the two plants led to the isolation of twelve compounds identified as: Farrerol 1, quercetin helichrysoside 2, apigenin 8-C-β-D-glucopyranoside 3, isoquercitrin 4 and rutin 5 from C. fruticosa, β-sitosterol 6, catechin 7, oleanolic acid 8, lyoniresinol 9, cinchonain IIb 10, lyoniresinol 2-a-O-β-D-xylopyranoside 11 and β-sitosterol-3-O-β-D-glucopyranoside 12 from E. japonica. Amongst the isolated compounds, the most important antioxidant ones were identified as helichrysoside and rutin from C. fruticosa, catechin, cinchonain IIb, lyoniresinol 2-a-O-β-D-xylopyranoside from E. japonica with EC50 of 8.73, 9.91, 4.11, 3.14 and 10.61 μg mL–1, respectively. Conclusion: Based on the obtained results, it can be concluded that the high ability to scavenge free radicals, reducing power of Fe3+ and hemolysis activity exerted by extracts of C. fruticosa and E. japonica were due to their high content of phenolic compounds, thus the structure-activity relationships of the isolated flavonoids were discussed. The results of this study suggest that the extracts from these two plants could serve as potential source of antioxidant compound

In Vivo Anti-Inflammatory Effect of a New Steroidal Saponin, Mannioside A, and Its Derivatives Isolated from Dracaena mannii

A new steroidal saponin, mannioside A (1), was isolated from the stem bark of Dracaena mannii, together with the known pennogenin (2), pennogenin-3-O-β-D-glucopyranoside (3) and pennogenin-3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→3)]-β-D-glucopyranoside (4). Their structures were determined using 1D-and 2D-NMR spectroscopy and mass spectrometry. Compounds 1 and 3 significantly inhibited carrageenan-induced paw edema in the rat; compound 4 was moderately active whereas 2 showed very weak activity

Insecticidal effects of the powdery formulation based on clay and essential oil from the leaves of Clausena anisata (Willd.) J. D. Hook ex. Benth. (Rutaceae) against Acanthoscelides obtectus (Say) (Coleoptera: Bruchidae)

The bioefficacies of essential oil and aromatized clay powder based on the mixture of clay and essential oil extracted from Clausena anisata were evaluated for their insecticidal activities and their effects on progeny production of Acanthoscelides obtectus. Contact toxicity assayed by coating on bean grains showed that these chemicals caused significant mortality of the test insect. Beetle mortality was dose dependant and after 2-day exposure the aromatized clay powder was more toxic (LD50 = 0.069 mu l/g grain) than the pure essential oil (LD50 = 0.081 mu l/g grain). There was, however, a highly significant loss of toxicity after 24 and 36 h following treatment with essential oil and aromatized powder, respectively. Both aromatized clay powder and pure essential oil considerably reduced the F-1 progeny insect production. The essential oil evoked moderated repellent action and high fumigant toxicity (LC50 = 0.093 mu l/cm(3)) against adults of A. obtectus. These results suggest that the clay powder could be used to stabilize the essential oil to increase its efficacy for use as an alternative to synthetic insecticides

Furan derivatives from Lannea kerstingii

Tameko JEM, Chouna JR, Nkeng-Efouet-Alango P, Tapondjou LA, Sewald N. Furan derivatives from Lannea kerstingii. Phytochemistry Letters. 2017;20:282-284.Two new furan derivatives, lannefuran A (1) and lannefuran B (2) were isolated from the stem bark extract of Lannea kerstingii Engl. & K. Krause together with five known compounds, namely: taraxerol, stigmast-4-en-3-one, monoglyceride of hexacosanoic acid, beta-sitosterol and its glucoside. Their structures were determined by means of 1D and 2D NMR, IR, and HR-EI-MS spectra and comparison with the data of known analogues reported in the literature. Lannefuran A (1) exhibited very low antiplasmodial activity against Plasmodium falciparum 3D7

Cytotoxic and antimicrobial activities of phytoconstituents of the stem bark extract of Psychotria djumaensis

Phytochemical investigation of the stem bark extract of Psychotria djumaensis led to the isolation of ten known pentacyclic triterpenoids among which one lupane-, three oleanane-,  and six ursane-types. The structures of the isolated compounds were established by means of spectroscopic methods and by comparison with previously reported data. The isolated compounds were tested against five strains of bacteria, and the cytotoxicity against the human cervix carcinoma KB-3-1 cell was evaluated. The isolates exhibited weak antibacterial activity against the five strains. The cytotoxic activity exhibited by 3β,19α-dihydroxyurs-12-en-28-oic acid (5) (IC50 5.9 µM) was about three times more significant than that of the reference [(+) griseofulvin, IC50 17-21 µM]

Assessing implementation modalities of mHealth intervention on pregnant women in Dschang health district, West region of Cameroon

INTRODUCTION : Every 90 seconds, a woman dies of complications related to pregnancy and childbirth, resulting in more than 340,000 maternal deaths a year. Antenatal care (ANC) and postnatal care (PNC) are significant determinants of maternal health and, particularly, safe motherhood. Antenatal care is an important predictor of safe delivery and provides health information and services that can improve the health of women and infants. mHealth broadly encompasses the use of mobile telecommunication and multimedia technologies as they are integrated within increasingly mobile and wireless health care delivery systems. This study aimed at assessing the acceptable implementation modalities of mHealth intervention on pregnant Women in Dschang health district, West Region of Cameroon.ng ba. METHODS : This was a cross sectional descriptive study in the Dschang health district, West region of Cameroon. Key informants were all pregnant women from 18 years and above and a total of 372 pregnant women were included. This study was carried out from March to July 2017. RESULTS : Majority of the women, that is, 252(67.74%) were married, 117(31.45%) declaredtheir status as being single, while 3(0.81%) were devorced. Out of the 335 women that declared wanting an mHealth intervention, 41.79% of this number preferred SMS texts in the afternoon, 111(33.13%) in the evening, 46(13.73%) anytime and 38(11.34%) in the morning hours. A total of 83.33% women confirmed using telephone services. CONLUSION : This study reveals that cell phones would be the acceptable medium of providing pregnancy and postpartum support to women in the Dschang health district. This is justified by the fact that a vast majority of women interviewed had access to a cell phone and referred to it as their desired and accepted means of communication.http://www.panafrican-med-journal.comam2019School of Health Systems and Public Health (SHSPH

GC-MS/FID analysis, antibacterial activity and modes of action of essential oils from three Aframomum species found in Cameroon against foodborne pathogenic bacteria

Background: The current study examined the chemical profile and in vitro antibacterial activity of essential oils (EOs) extracted from Aframomum danielli (leaves and seeds), Aframomum chlamydentum (leaves), and Aframomum melegueta (leaves) against foodborne pathogenic bacteria. Methods: The hydro-distillation technique using a Clevenger-type apparatus was used to extract EOs, whereas the Gas  Chromatography-Mass Spectrometry (GC-MS) and GC coupled to Flame Ionization Detector (GC-FID) allowed the chemical  characterization of oil constituents. The broth micro-dilution method was applied for the determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Besides, some modes of action were studied on the cell membrane integrity and biofilm formation of Salmonella typhi. Results: The major compounds identified from EOs of A. danielli seeds were eucalyptol (48.707%), limonene (11.368%), beta pinene (10.342-10.335%), and alpha terpineol (8.785-9.049%), whereas EOs from A. danielli leaves were dominated by sabinene (42.87%), beta pinene, (11.22%), caryophyllene (7.84%), terpinen-4-ol (5.68%), linalool (3.48%) and gamma terpinene (2.02%). Major volatile markers from EOs of A. chlamydentum leaves comprised beta pinene (49.72%), caryophyllene (10.62%), alpha pinene (6.21%) and linalool (2.96%), while those of EOs from A. melegueta included beta pinene (37.15%), caryophyllene (17.64%), caryophyllene oxide (8.72%) and alpha pinene (8.26%). This study is the first to report on the chemical constituents of EOs from A. chlamydentum. Test oils displayed significant antibacterial activity with the MIC ranging from 0.0625 to 0.5% (v/v). EOs from A. melegueta (leaves) appeared to be the most active, acting against all tested bacteria. All EOs identified displayed bactericidal effects against Citrobacter freundii, a bacterium known to cause a broad range of infections associated with a higher rate of in-hospital mortality. The EOs from A. melegueta may act through perturbation of cell membrane integrity and permeability as well as the inhibition of bacterial biofilm formation. Conclusion: Our findings suggest the possible application of essential oils in agricultural food products for the control of bacterial diseases

Elemane‐Type Sesquiterpene, Acetonide Derived Polyacetylene and Other Constituents from the Whole Plant of (Schweinf. ex Oliv. & Hiern) H.Rob. and Their Chemophenetic Significance

Tafouo Tsakou A, Laure Ndontsa B, Carly Nono Nono E, et al. Elemane‐Type Sesquiterpene, Acetonide Derived Polyacetylene and Other Constituents from the Whole Plant of (Schweinf. ex Oliv. & Hiern) H.Rob. and Their Chemophenetic Significance. Chemistry & Biodiversity. 2023;20: e202200196.The chemical investigation of the methanol extract of the whole plant of Gymnanthemum theophrastifolium (Schweinf. ex Oliv. & Hiern) H.Rob. (Asteraceae) led to the isolation of a new elemane-type sesquiterpene (1), a new acetonide derived polyacetylene (2) and a naturally occurring compound (3) from the plant kingdom along with sixteen known compounds (4–19). Their structures were elucidated by extensive NMR and MS analysis. This is the first report on the chemical constituents of G. theophrastifolium. Furthermore, compounds 12, 13, and 14 are reported for the first time from the family Asteraceae, while compound 9 is reported for the first time from the genus Gymnanthemum. Thus, the present results provide valuable insights to the chemophenetic knowledge of G. theophrastifolium, which is also discussed in this work

23-Hydroxyursolic Acid Isolated from the Stem Bark of <i>Cussonia bancoensis</i> Induces Apoptosis through Fas/Caspase-8-Dependent Pathway in HL-60 Human Promyelocytic Leukemia Cells

The natural product 23-hydroxyursolic acid (23-HUA) is a derivative of ursolic acid, which is known to induce cancer cell apoptosis. However, apoptotic effects and mechanisms of 23-HUA have not been well characterized yet. Herein, we investigated the molecular mechanisms of 23-HUA-induced apoptosis in HL-60 human promyelocytic leukemia cells. 23-HUA-treated HL-60 cells showed apoptotic features including internucleosomal DNA condensation and fragmentation as well as externalization of phosphatidylserine residues. 23-HUA induced a series of mitochondrial events including disruption of mitochondrial membrane potential (&#916;&#936;m), cytochrome c and Smac/DIABLO release and loss of balance between pro-apoptotic and anti-apoptotic Bcl-2 proteins in HL-60 cells. In addition, 23-HUA activated caspase-8, caspase-9 and caspase-3. Pretreatment with a broad caspase inhibitor (z-VAD-fmk), a caspase-3 inhibitor (z-DEVD-fmk), and a caspase-8 inhibitor (z-IETD-fmk) significantly attenuated 23-HUA-induced DNA fragmentation. After 23-HUA-induced apoptosis, proteins expression levels of FasL, Fas and FADD constituting the death-inducing signaling complex (DISC) were upregulated in HL-60 cells. Moreover, transfection with Fas or FADD siRNA significantly blocked 23-HUA-induced DNA fragmentation and caspases activation. Taken together, these findings indicate that 23-HUA induces apoptosis in HL-60 human promyelocytic leukemia cells through formation of DISC and caspase-8 activation leading to loss of &#916;&#936;m and caspase-3 activation