In Cameroon, infectious diseases are amongst the most commonly notified diseases and largest cause of mortality. Many plants are used locally in traditional medicine for their treatment. The aim of the present review is to summarize currently available evidence and knowledge concerning Cameroonian plants used to treat bacterial and fungal infections, and the efficacy of plant-derived extracts and compounds. The traditional uses of plants in the treatment of infectious diseases have been collected and tabulated. The antimicrobial activity of the extracts and the chemical constituents of most of these plants are summarized in this report. Plants used traditionally in Cameroonian medicine, with laboratory work on any part or products, have been documented. Numerous extracts and compounds have been tested for antimycobacterial, antibacterial and antifungal efficacy and some of them were significantly active. Most of the bioactive compounds isolated were phenolics and alkaloids. In conclusion, many plant species are used in traditional medicine in Cameroon to treat infectious diseases, and several interesting openings have originated for further inquiry following IN VITRO antimicrobial activity evaluation. However, much work is still to be done to standardize methods and cut-off points for describing the antimicrobial activity, and on the study of the mechanisms of action.

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Potential of Cameroonian plants and derived products against microbial infections: a review.

Pharmacogenomics of Cameroonian traditional herbal medicine for cancer therapy.

Synthesis, structure-activity relationship analysis and kinetics study of reductive derivatives of flavonoids as Helicobacter pylori urease inhibitors.

Introduction Continuous efforts from scientists of diverse fields are necessary not only to better understand the mechanism by which multidrug resistant (MDR) cancer cells occur, but also to boost the discovery of new cytotoxic compounds. This work was designed to assess the cytotoxicity and the mechanism of action of flavonoids abyssinone IV (1), atalantoflavone (3) and neocyclomorusin (6) and isoflavonoids sigmoidin I (2), sophorapterocarpan A (4), bidwillon A (5) and 6α-hydroxyphaseollidin (7) isolated from Erythrina sigmoidea against nine drug sensitive and multidrug resistant (MDR) cancer cell lines. Methods The resazurin reduction assay was used to evaluate the cytotoxicity of the studied compounds whilst caspase-Glo assay was used to detect the activation of caspases enzymes by 1, 2, 4 and 7. Cell cycle, mitochondrial membrane potential and levels of reactive oxygen species were all analyzed via flow cytometry. Results The pterocarpan isoflavonoid 7 displayed the best antiproliferative activity with the IC50 values below 10 μM obtained on the nine tested cancer cell lines. The IC50 values below 50 μM were also recorded with compounds 1, 2 and 4 against the nine cancer cell lines whilst 3, 5 and 6 showed selective activities. The IC50 values varied from 14.43 μM (against MDA-MB-231-pcDNA cells) to 20.65 μM [towards HCT116 (p53
 +/+) cells] for compound 1, from 4.24 μM (towards CCRF-CEM cells) to 30.98 μM (towards MDA-MB-231-BCRP cells) for 2, from 3.73 μM (towards CCRF-CEM cells) to 14.81 μM (against U87MG.ΔEGFR cells) for 4, from 3.36 μM (towards CCRF-CEM cells) to 6.44 μM (against HepG2 cells) for 7, and from 0.20 μM (against CCRF-CEM cells) and 195.12 μM (against CEM/ADR5000 cells) for the positive control drug, doxorubicin. Compared to their corresponding sensitive cell lines, collateral sensitivity was observed with HCT116 (p53
 −/−) to 1, 2, 4, 5, and 7 and with U87MG.ΔEGFR to 1 to 6. Compound 7 induced apoptosis in CCRF-CEM cells mediated by the activation of caspases 3/7, 8 and 9 and breakdown of MMP and increase in ROS production, whereas the apoptotic process induced by 1, 2 and 4 was mediated by the loss of MMP as well as increase in ROS production. Conclusions Compounds from Erythrina sigmoidea and mostly 6α-hydroxyphaseollidin are potential antiproliferative natural products that deserve more investigations to develop novel anticancer drugs against sensitive and otherwise drug-resistant phenotypes.

Cytotoxic flavonoids and isoflavonoids from Erythrina sigmoidea towards multi-factorial drug resistant cancer cells.

Antimicrobial and antioxidant activity and chemical characterisation of Erythrina stricta Roxb. (Fabaceae).

The dichloromethane-methanol (1:1) soluble part of Calopogonium mucunoides (Fabaceae) resulted in the isolation of 10 isoflavones (4'-O-methylalpinumisoflavone, 4'-O-methylderrone, alpinumisoflavone, daidzeine, Calopogonium isoflavone A, atalantoflavone, 2',4',5',7-tetramethoxyisoflavone, 7-O-methylcuneantin, cabreuvin and 7-O-methylpseudobaptigenin) and a rotenoid (6a,12a-dehydroxydegueline). Among these, daidzeine, 7-O-methylcuneantin, atalantoflavone and 6a, 12a-dehydroxydegueline have been isolated for the first time from C. mucunoides while remaining are already reported from this source. Structures of all the isolated constituents were elucidated with the aid of NMR spectroscopic and mass spectrometric techniques. Among all the isolated constituents, nine were evaluated for their urease inhibitory potential. However, six were found potent. These include 4'-O-methylderrone, daidzeine, atalantoflavone, 2',4',5',7-tetramethoxyisoflavone, 7-O-methylcuneantin and 6a, 12a-dehydroxydegueline.

https://www.tandfonline.com/doi/pdf/10.3109/14756366.2012.719025

Urease inhibitory isoflavonoids from different parts of Calopogonium mucunoides (Fabaceae).

Three new compounds, 15-acetoxy-12-hydroxy-16-methyl-labda-8(17),13 E-diene ( 1), ENT-labda-8(17),13-dien-15,16-olid-19-oic acid methyl ester ( 2), and 12-hydroxy-labda-8(17),13-dien-15,16-olide ( 3), together with two known compounds, 19-acetoxy- ENT-labda-8(17),13-dien-15,16-olide ( 4), and 16-acetoxy-12,15-epoxy-15 s-hydroxy-labda-8(17),13(16)-diene ( 5) were isolated from the stem bark of TURRAEANTHUS MANNII (Meliaceae). The structures of compounds 1 - 3 were elucidated by analysis of the spectroscopic data. The crude methanol extract and compound 5 exhibited weak antibacterial and antifungal activity.

Diterpenoids from Turraeanthus mannii.

A new bis-isoflavone derivative, named amphiisoflavone (1), was isolated from the roots of Amphimas pterocarpoides, together with three known isoflavones, namely 8-methoxyisoformononetin (2), 6-methoxyisoformononetin (3) and isoformononetin (4). Chemical transformations carried out on compound 3 led to two new derivatives, 4´-acetoxy-6,7-dimethylisoflavone (3a) and 4´-O-prenyl- 6,7-dimethylisoflavone (3p), along with a known compound, 4´,6,7-trimethoxyisoflavone (3m). The structures of all compounds were elucidated from spectroscopic evidence, in particular by 1D and 2D NMR spectroscopic methods. These compounds were evaluated for their antioxidant properties and for their antimicrobial activities against a wide range of bacteria and fungi. Graphical Abstract Antimicrobial and Antioxidant Isoflavonoid Derivatives from the Roots of Amphimas pterocarpoides

Antimicrobial and Antioxidant Isoflavonoid Derivatives from the Roots of Amphimas pterocarpoides

From the dichloromethane–methanol (1:1) extract of the seeds of Turraeanthus mannii (Meliaceae), a new bis-labdane diterpenoid, namely (–)-15′,16′-dihydroxy-15(12′),15′(16′)-diolide-bislabda-8(17),8′(17′),12-trien-16-al, trivially named ent-turrealabdane (1), has been isolated together with six already known secondary metabolites: scopoletin, isoscopoletin, 6-hydroxy-7,8-dimethoxycoumarin, 3-methylhydantoin, β-sitosterol, and β-sitosterol 3-O-β-D-glucopyranoside. Esterification of ent-turrealabdane (1) using benzoyl chloride yielded a dibenzoyl derivative 2. The structures of these compounds were established by spectroscopic analysis including 1D and 2D NMR experiments in combination with MS.

Valerie Tedjon Sielinou

Papers

Urease inhibitory isoflavonoids from different parts of Calopogonium mucunoides (Fabaceae).

Diterpenoids from Turraeanthus mannii.

Antimicrobial and Antioxidant Isoflavonoid Derivatives from the Roots of Amphimas pterocarpoides

A New bis-Labdane and Other Secondary Metabolites from Turraeanthus mannii

Antimicrobial and Antioxidant Isoflavonoid Derivatives from the Roots of Amphimas pterocarpoides.