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

Application of heat-treated oyster shell powder to induce priming of Theobroma cocoa seedlings plant defense system against Phytophthora megakarya attack

Priming with natural compounds is an interesting alternative for sustainable agriculture to explore the molecular mechanisms associated with the management of diseases caused by soil borne pathogens. The aim of this work was to evaluate the effect of the soil amendment with bio-oyster shell on the stimulation of the cocoa plant defense systems against P. megakarya in the nursery. For this purpose, the potential of bio-oyster shell to stimulate cocoa plant defense mechanisms was evaluated by soil amendment at 1% W/W under greenhouse conditions. After soil amendment, agronomic growth parameters and soil parameters were analyzed. The degree of expression of phytoalexins and defense genes was carried out by UPLC-DAD- HRESI–MS (+) and qRT-PCR analyses, respectively. The results obtained show that soil treatment with these composites improves the sanitary quality of cocoa seedlings in controlled conditions through the stimulation of agronomic growth parameters such as plant height, number of leaves, leaf surface area, and fresh weight of shoot and root. The latter leads to an increase in soil pH by about 32 % as well as the improvement of the nutritional status of the soil by 90%. Moreover, bio-oyster shell soil amendment induces up-regulation of TcPer-1, TcGlu1, TcChiB, and TcMYBPA genes and accumulation of primed metabolites such as flavonols, brevifolin, and isoflavone compounds before and after infection. This stimulation based on biological substances make it possible to pre-immunize cocoa plants against pathogen attacks and would be a good candidate to improve the quality of cocoa seeds in Cameroon

Rothmanniamide and other constituents from the leaves of Rothmannia hispida (K.Schum.) fagerl. (Rubiaceae) and their chemophenetic significance

Wonkam AKN, Ngansop CAN, Wouamba SCN, et al. Rothmanniamide and other constituents from the leaves of Rothmannia hispida (K.Schum.) fagerl. (Rubiaceae) and their chemophenetic significance. Biochemical Systematics and Ecology. 2020;93: 104137.The chemical investigation of the CH2Cl2/MeOH (1:1) extract of the leaves of Rothmannia hispida (K. Schum.) Fagerl. (Rubiaceae) led to the isolation of a new ceramide rothmanniamide (1) and a naturally isolated alkyl cinnamate derivative n-heptadecyl-4-hydroxy-trans-cinnamate (2), along with fifteen known compounds including lupeol palmitate (3), lupeol (4), a mixture of uvaol (5) and erythrodiol (6), ursolic acid (7), 30-nor2 alpha,3 beta-dihydroxyurs-12-ene (8), hederagenin (9), stigmast-22-en-3-ol (10), a mixture of beta-sitosterol (11) and stigmasterol (12), stigmast-4,22-dien-3-ol (13), stigmasterol 3-O-beta-D-glucoside (14), triacontan-1-ol (15), kaempferol 3-O-beta-D-glucopyranoside (16) and D-mannitol (17). Their structures were elucidated with the help of MS and NMR data. Compounds 8, 10 and 15 were isolated for the first time from the Rubiaceae family. The crude extract and the isolates were assessed in vitro for their antileishmanial activity against Leishmania donovani 1 S (MHOM/SD/62/1 S) promastigotes and cytotoxicity on RAW 264.7 macrophage cells. Compounds 7 and 8 exhibited a highly potent antileishmanial activity with IC50 values of 0.88 and 1.75 mu g/mL, respectively, with good selectivity indexes (SI > 57). The chemophenetic significance of these compounds is also discussed

Chemical constituents of two Cameroonian medicinal plants: Sida rhombifolia L. and Sida acuta Burm. f. (Malvaceae) and their antiplasmodial activity

Kamdoum BC, Simo I, Wouamba SCN, et al. Chemical constituents of two Cameroonian medicinal plants: Sida rhombifolia L. and Sida acuta Burm. f. (Malvaceae) and their antiplasmodial activity. Natural product research. 2021.An extensive phytochemical investigation of the EtOH/H2O (7:3) extracts of Sida rhombifolia L. and Sida acuta Burm. f., yielded a previously undescribed ceramide named rhombifoliamide (1) and a xylitol dimer (2), naturally isolated here for the first time, as well as the thirteen known compounds viz, oleanolic acid (3), beta-amyrin glucoside (4), ursolic acid (5), beta-sitosterol glucoside (6), tiliroside (7), 1,6-dihydroxyxanthone (8), a mixture of stigmasterol (9) and beta-sitosterol (10), cryptolepine (11), 20-Hydroxyecdysone (12), (E)-suberenol (13), thamnosmonin (14) and xanthyletin (15). Their structures were elucidated by the analyses of their spectroscopic and spectrometric data (1D and 2D NMR, and HRESI-MS) and by comparison with the previously reported data. The crude extracts, fractions, and some isolated compounds were tested against chloroquine-sensitive (3D7) and chloroquine-resistant (Dd2) Plasmodium falciparum strains. All the tested samples demonstrated moderate and/or significant activities against 3D7 (IC50 values: 0.18-20.11g/mL) and Dd2 (IC50 values: 0.74-63.09g/mL)

Antibacterial and antishigellosis activity of Xylopia staudtii (engl. & diels), Annonaceae

Nguiam MP, Wouamba SCN, Longo F, et al. Antibacterial and antishigellosis activity of Xylopia staudtii (engl. & diels), Annonaceae. Journal of Ethnopharmacology. 2021: 114406.Ethnopharmacological relevance Xylopia staudtii is a medicinal plant which fruits are traditionally used in western Cameroon as a spice in the preparation of soups known for their abdominal cramp relieving properties. Often identified as Xylopia africana, its bark is used in the treatment of dysentery in Mont Cameroun localities. This plant could therefore contain active ingredients against intestinal pathogens, including Shigella spp, which are responsible of the deathly dysenteric diarrhoea. Aim of the study This study aims to assess the efficacy of the hydroethanolic extract from Xylopia staudtii bark in immunodepressed mice infected with Shigella flexneri. Materials and methods Qualitative detection of compounds in the crude extract was done using UPLC–DAD–(HR) ESI-MS analysis in an attempt to link the activity to the chemical composition. The MIC and the MBC of the extract was determined using broth dilution method. Shigellosis was induced by intraperitoneal administration of Shigella flexneri to immunodepressed mice pretreated with streptomycin. These infected mice were then treated with the extract (100, 200 and 400 mg/kg), and reference substances (ciprofloxacin and saline). During the 9 days of treatment, animal morphology, fecal pathology and deaths were recorded. At the end of the treatment period, blood and organs were collected from any surviving animals for hematological, biochemical and histopathological analyses. Results The extract was found to be significantly active, with a bactericidal effect against Shigella and a bacteriostatic effect against Escherichia coli. It was able to reduce and stop the faecal pathology caused by the infection in mice, as well as the rate of deaths which was brought to zero (0) in animal treated at 400 mg/kg. The bacteria load in faeces was reduced by 100% in animal treated at 400 mg/kg. Xylopia staudtii extract elicited anti-inflammatory properties by reducing MPO activity and Lcn2 intestinal level. It also prevents damages in the intestinal tissue and the shortening of colon which characterise Shigella infection. The serum level of ASAT, ALAT, bilirubin, urea and creatinine in animals treated with the extract was similar to those of normal animal used in the study. These activities of the plant may be due at least in part to the presence of ent-kauran type diterpens such as kaurenoic acid identified in the extract. Conclusion These findings support the usage of Xylopia staudtii as an antimicrobial against bacillary dysentery, making this plant a potential candidate for the formulation of an improved standardized traditional medicine

Secondary metabolites from Detarium microcarpum Guill. and Perr. (Fabaceae)

Fouatio Feudjou W, Mbock AM, Tedjon Sielinou V, et al. Secondary metabolites from Detarium microcarpum Guill. and Perr. (Fabaceae). Zeitschrift für Naturforschung C, Journal of Biosciences . 2022.The chemical investigation of the ethanol/water (7:3) extract of the roots of Detarium microcarpum (Fabaceae) led to the isolation of one new labdane diterpenoid, microcarpin (1) and one new ceramide derivative, microcarpamide (2), along with eight known secondary metabolites (3-10)including, 5-(carboxymethyl)-5,6,8a-trimethyl-3,4,4a,5,6,7,8,8a-octahydronaphthalene-1-carboxylic acid (3), microcarposide (4), rhinocerotinoic acid (5), 1,7-dihydroxy-6-methylxanthone (6), ursolic acid (7), 3beta,23-dihydroxylup-20(29)-en-28-oic acid (8), alphitolic acid (9), and stigmasterol glucoside (10). The structures of these compounds were elucidated based on their spectroscopic data. Although compounds 3 and 4 are known, their crystalline structures are reported here for the first time. These compounds were evaluated in vitro for their antisalmonella activity. The results obtained showed that, microcarpamide (2), microcarposide (4), and rhinocerotinoic acid (5) were moderately active against three salmonella strains: Salmonella typhi, Salmonella enteritidis and Salmonella typhimirium, with minimum inhibition concentration values of 76.7 and 153.5muM. © 2022 Walter de Gruyter GmbH, Berlin/Boston

In Vitro Assessment of the Cercaricidal Activity of Sida acuta Burm. F. and Sida rhombifolia Linn. (Malvaceae) Hydroethanolic Extracts, Cytotoxicity, and Phytochemical Studies

Membe Femoe U, Kadji Fassi JB, Boukeng Jatsa H, et al. In Vitro Assessment of the Cercaricidal Activity of Sida acuta Burm. F. and Sida rhombifolia Linn. (Malvaceae) Hydroethanolic Extracts, Cytotoxicity, and Phytochemical Studies. Evidence-based Complementary and Alternative Medicine. 2022;2022: 7281144.Despite the global efforts, schistosomiasis remains a public health problem in several tropical and subtropical countries. One of the major challenges in the fight against schistosomiasis is the interruption of the parasite life cycle. Here, we evaluated the anticercarial, cytotoxicity, and phytochemical profiles of Sida acuta (HESa) and Sida rhombifolia (HESr) hydroethanolic extracts (Malvaceae). Schistosoma mansoni cercaria was collected from fifteen Biomphalaria pfeifferi-infected snails. Twenty-five cercariae were incubated in duplicate with different concentrations (31.25-1,000mug/mL) of HESa or HESr. The cercaria viability was monitored at 30min time intervals for 150min, and the concentration-response curve of each plant extract was used to determine their respective lethal concentration 50 (LC50). Additionally, the cytotoxicity profile of each plant extract was evaluated on the Hepa 1-6cell line at a concentration range of 15.625-1,000g/mL using the WST-8 assay method and its inhibitory concentration 50 (IC50) was calculated. Moreover, phytochemical characterization of each plant extract was carried out by HPLC-MS. Both extracts exhibited cercaricidal activity in a time- and concentration-dependent manner. At 30min time point, HESa (LC50=28.41±3.5g/mL) was more effective than HESr (LC50=172.42±26.16g/mL) in killing S. mansoni cercariae. Regarding the cytotoxicity effect of both extracts, the IC50 of HESa (IC50=109.67g/mL) was lower than that of HESr (IC50=888.79g/mL). The selectivity index was 3.86 and 5.15 for HESa and HESr, respectively. Fifteen compounds were identified from HESa and HESr after HPLC-MS analysis. N-Feruloyltyramine, a polyphenol, and thamnosmonin, a coumarin, were identified in both extracts. HESa and HESr displayed cercaricidal activity and were not toxic on Hepa 1-6 cell line. Based on the selectivity index of these extracts, S. rhombifolia extract could be more effective on S. mansoni cercariae than S. acuta extract. This study could provide baseline information for further investigations aiming to develop plant-based alternative drugs against S. mansoni. Copyright © 2022 Ulrich Membe Femoe et al