Antiinflammatory properties of the stem-bark of Anopyxis klaineana and its major constituent, methyl angolensate.

Anopyxis klaineana (Pierre) Engl. (Rhizophoraceae) is one of the reputed West African folkloric medicines that has never been investigated for its pharmacological effects or phytochemical constituents. In the present study, the antiinflammatory properties of the stem-bark extracts were evaluated using the carrageenan-induced paw oedema model in chicks. The petroleum ether, ethyl acetate and methanol extracts all showed a time and dose-dependent antiinflammatory effect over the 5-h observation period. Phytochemical analysis of the most active extract (methanol extract) yielded the principal constituent that was identified as methyl angolensate through extensive spectroscopic and X-ray analysis studies. Although slightly less potent (ED50 , 4.05 ± 0.0034 mg/kg, orally) than the positive control, diclofenac (ED50 , 2.49 ± 0.023, intraperitoneally n = 5), this first ever compound isolated from A. klaineana showed promising antiinflammatory activity that may account to some of the reported medicinal uses of the plant.

Evaluation of the Microbial Load and Heavy Metal Content of Two Polyherbal Antimalarial Products on the Ghanaian Market.

The use of herbal products has increased and become more popularized globally; however, limited studies coupled with questions related to the quality and safety of these herbal products have been raised. Herbal products with hope of their nontoxicity may play a role of alternative to overcome the problems of multi-drug resistant pathogens. Medicinal plants used as raw materials for production may have quality and safety issues due to proximity to wastewater application of fungicides and pesticides, which may be directly deposited superficially or absorbed by the plant system. Therefore, possible contamination of some Ghanaian herbal products cannot be ignored, as it may severely affect human life in the process of treatment. Aim. To evaluate the microbial load and the presence of toxic heavy metals in Mist Amen Fevermix and Edhec Malacure, two polyherbal products used in the treatment of uncomplicated malaria in Ghana. Methods. Thermo Elemental M5 Atomic Absorption Spectrophotometer (AAS) fitted with graphite furnace and an auto sampler was used to determine the heavy metal contents of the herbal products. The herbal samples were evaluated for the microbial load by using the appropriate culture media. Results and Analysis. Mist Amen Fevermix and Edhec Malacure complied with the safety limits evaluated for all different microbial counts and contamination. The following heavy metals were present in Mist Amen Fevermix and Edhec Malacure Mixture: Fe, Ni, K, Zn, Hg, Cu, Mn, Cr, Cd, Pb, Fe, Cu, K, and Na. Ni was below detectable limit in Edhec Malacure. Conclusion. Mist Amen Fevermix and Edhec Malacure may be assured of safety. The products contained heavy metals, but all were within acceptable limit established by the FAO/WHO. The levels of microbial contamination were below the maximum acceptable limit.

Leishmanicidal activity of the root bark of Erythrophleum Ivorense (Fabaceae) and identification of some of its compounds by ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-QTOF-MS/MS).

ETHNOPHARMACOLOGICAL RELEVANCE: Leishmaniasis is one of the neglected tropical disease caused by a protozoan of the genus Leishmania transmitted by sandflies. High cost and lack of oral formulation of existing drugs, rapid developments of resistance by the parasite coupled with serious side effects require new treatments to augment or replace currently available therapies. The major merits of herbal medicine seem to demonstrate perceived efficacy, low incidence of serious adverse effects and low cost. Erythrophleum plants possess beneficial biological properties and, as such, characterization of the bioactive components of these plants is imperative. Previous work has shown an overwhelming presence of cassaine alkaloids in these plants. However, amongst these plants, the African based specie (Erythrophleum ivorense) is the least studied. OBJECTIVE: In the current study, the in vitro anti-leishmanial activity of the crude extract, its fractions and isolated compounds were evaluated using direct counting assay of promastigotes of Leishmania donovani using amphotericin B as positive control. MATERIALS AND METHODS: The anti-leishmanial activity of E. ivorense extract was evaluated in vitro against the promastigote forms of Leishmania Donovani using a direct counting assay based on growth inhibition. Different crude extracts from ethyl acetate, pet-ether, and methanol as well as pure isolated compounds of E. ivorense: Erythroivorensin, Eriodictyol and Betulinic acid were screened. To know the possible components of the active methanolic extract, attempt was made to elucidate the extract using ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UHPLC-QTOF-MS/MS). RESULTS: This afforded a weak pet-ether fraction, a moderately active ethyl acetate fraction and a significantly active methanol fraction (IC50 = 2.97µg/mL) compared to Amphotericin B (IC50 = 2.40±0.67µg/mL). The novel diterpene erythroivorensin, betulinic acid and the flavanone Eriodictyol, from the ethyl acetate fraction, showed weak activity. UPLC-QTOF-MS/MS was used to identify the cassaine diterpenoids from the active methanol fraction. Here, 10 compounds of this type were putatively identified from the ethanol crude extract. CONCLUSION: The fragmentation mechanism of these metabolites is also proposed and are expected to serve as reference template for identification of these and related compounds in future. The presence of these compounds is an indication that they are an inherited and evolutionary component of plants belonging to the Erythrophleum genus. Our results further present another dimension where these compounds and their relative abundances can be used as chemo-taxonomical bio-markers of the genus. The present study also successfully demonstrated/re-affirmed the use of UPLC-QTOF-MS/MS as a robust technique for the characterization of natural products.

Mosquito larvicidal activity of Cassia tora seed extract and its key anthraquinones aurantio-obtusin and obtusin.

BACKGROUND: The edible and medicinal leguminous plant Cassia tora L. (Fabaceae) is known to possess insecticidal properties against a wide range of plant-feeding insects. However, the bioactivity of extracts of this plant and their constituents against vectors of medical importance has been largely unexplored. We investigated the mosquito larvicidal activity of the seed extract and its major anthraquinones against larvae of the African malaria vector Anopheles gambiae (s.s.). METHODS: Third-fourth instar larval mortality was observed after 24, 48, 72 and 96 h of exposure to varying doses of the extracts, and two anthraquinones isolates identified using liquid chromatography- quadrupole time of flight mass spectrometry (LC-QtoF-MS). The mosquito larval mortality was evaluated relative to the natural insecticide azadirachtin. RESULTS: Fractionation of the crude extract decreased mosquito larvicidal activity, however, larvicidal activity increased with increasing dose of the treatment and exposure time. The known anthraquinones aurantio-obtusin and obtusin were identified as key larvicidal compounds. Aurantio-obtusin and obtusin, exhibited similar toxicity to larvae of A. gambiae (s.s.) with LD50 values of 10 and 10.2 ppm, respectively. However, the two anthraquinones were four- and ~ six-fold less potent than that of the crude seed extract and azadirachtin, which had comparable LD50 values of 2.5 and 1.7 ppm, respectively. CONCLUSION: Both aurantio-obtusin and obtusin showed mosquito larvicidal activity which were comparable to their respective fractions although they were less potent relative to the crude extract and azadirachtin. Further studies need to be conducted on C. tora for its exploitation as a potential eco-friendly tool in mosquito larval source reduction.

Discovery of cahuitamycins as biofilm inhibitors derived from a convergent biosynthetic pathway.

Pathogenic microorganisms often have the ability to attach to a surface, building a complex matrix where they colonize to form a biofilm. This cellular superstructure can display increased resistance to antibiotics and cause serious, persistent health problems in humans. Here we describe a high-throughput in vitro screen to identify inhibitors of Acinetobacter baumannii biofilms using a library of natural product extracts derived from marine microbes. Analysis of extracts derived from Streptomyces gandocaensis results in the discovery of three peptidic metabolites (cahuitamycins A-C), with cahuitamycin C being the most effective inhibitor (IC50=14.5 µM). Biosynthesis of cahuitamycin C proceeds via a convergent biosynthetic pathway, with one of the steps apparently being catalysed by an unlinked gene encoding a 6-methylsalicylate synthase. Efforts to assess starter unit diversification through selective mutasynthesis lead to production of unnatural analogues cahuitamycins D and E of increased potency (IC50=8.4 and 10.5 µM).

Erythroivorensin: A novel anti-inflammatory diterpene from the root-bark of Erythrophleum ivorense (A Chev.).

The stem- and root-bark of Erythrophleum ivorense (A Chev., family, Fabaceae) are routinely employed in the West African traditional medicine to treat inflammation and a variety of other disease conditions. Although the chemistry and pharmacology of cassaine-type diterpene alkaloids isolated from the stem-bark of the plant are fairly established, the root-bark has not yet been investigated. In the present study, the crude aqueous-alcohol extract of the root-bark was demonstrated to display a time- and dose (30-300 mg/kg p.o.)-dependent anti-inflammatory effect in chicks. Comprehensive chromatographic analysis coupled with spectroscopic and X-ray study further allowed the assignment of one of the major anti-inflammatory constituents as a novel cassaine-type diterpene, erythroivorensin. The other major constituents were known anti-inflammatory compounds: a triterpene, betulinic acid and a flavonoid, eriodictyol. The dose (10-100mg/kg p.o.)-dependent anti-inflammatory effects of the three compounds were either comparable or more significant than the positive control, diclofenac.

A novel triterpene from the roots of Paullinia pinnata: 6α-(3'-methoxy-4'-hydroxybenzoyl)-lup-20(29)-ene-3-one.

Paullinia pinnata L. (Sapindaceae) is an endemic West African plant that is extensively used in traditional medicine to treat various diseases. Previous phytochemical analysis by various groups led to the isolation of several novel lupene-based triterpenene derivatives along with other classes of compounds. As part of our continued phytochemical studies on the roots of this plant, we have now identified yet another novel triterpene, 6a-(3'-methoxy-4'-hydroxybenzoyl)-lup-20(29)-ene-3-one. The identification of the compound through comprehensive spectroscopic studies is discussed.

Terpenoids in Buddleja: relevance to chemosystematics, chemical ecology and biological activity.

The terpenoids reported from Buddleja species are described. The antifungal activity of chloroform extracts of B. cordata and B. davidii stembark against the soil fungi Fusarium culmorum and Sordari fimicola is reported, with buddledin A shown to be the major compound responsible. The terpenoids present support the view that the Buddlejaceae should be classified in a taxon with Scrophulariaceae rather than Loganiaceae. Ecological aspects of the terpenoids are considered in relation to insects and soil fungi and the role of terpenoids in the chemical basis of the use of Buddleja in traditional medicine is also discussed, especially with regard to their anti-inflammatory properties.

In vitro evaluation of effects of two Ghanaian plants relevant to wound healing.

Commelina diffusa and Spathodea campanulata are used as wound-healing agents in Ashanti traditional medicine in Ghana. The methanol extracts of Commelina diffusa herb and Spathodea campanulata bark showed some level of antimicrobial activity with C. diffusa exhibiting selective antifungal activity against Trichophyton species. The extracts reduced the peroxidation of bovine brain extract with an IC(50) value of 1.39 mg/mL and 0.24 mg/mL, respectively. In addition the extracts also exhibited significant antioxidant activity by protecting MRC-5 cells from hydrogen peroxide induced oxidant injury at concentrations between 1 microg/mL and 10 microg/mL. The extracts showed no inhibition of NF-kappaB at 100 microg/mL. The antioxidant activities and antimicrobial activities suggest that the use of the plants in wound healing may be based on antioxidant and antiseptic effects of its constituents.