Erythrina Abyssinica Research Articles

Medicinal plants used by traditional medicine practitioners for the treatment of HIV/AIDS and related conditions in Uganda

Introduction and objectives In Uganda, there are over one million people with HIV/AIDS. When advanced, this disease is characterized by life-threatening opportunistic infections. As the formal health sector struggles to confront this epidemic, new medicines from traditional sources are needed to complement control efforts. This study was conducted to document herbal medicines used in the treatment of HIV/AIDS and related opportunistic infections, and to document the existing knowledge, attitudes and practices related to HIV/AIDS recognition, control and treatment in Sembabule, Kamuli, Kabale and Gulu districts in Uganda. Methods In this study, 25 traditional medicine practitioners (TMPs) were interviewed using structured questionnaires. Results The TMPs could recognize important signs and symptoms of HIV/AIDS and its associated opportunistic infections. The majority of practitioners treated patients who were already receiving allopathic medicines including antiretroviral drugs (ARVs) prescribed by allopathic practitioners. There were 103 species of medicinal plants identified in this survey. Priority plants identified include Aloe spp., Erythrina abyssinica, Sarcocephalus latifolius, Psorospermum febrifugum, Mangifera indica and Warburgia salutaris. There was low consensus among TMPs on the plants used. Decoctions of multiple plant species were commonly used except in Gulu where mono-preparations were common. Plant parts frequently used were leaves (33%), stem bark (23%) and root bark (18%). About 80% of preparations were administered orally in variable doses over varied time periods. The TMP had insufficient knowledge about packaging and preservation techniques. Conclusions Numerous medicinal plants for treatment of HIV/AIDS patients were identified in the four districts surveyed and the role of these plants in the management of opportunistic infections warrants further investigation as these plants may have a role in Uganda's public health approach to HIV/AIDS control.

AMP-Activated Protein Kinase (AMPK) Activation by Benzofurans and Coumestans Isolated from Erythrina abyssinica

AMP-activated protein kinase (AMPK) has been proposed as a therapeutic target for the treatment of metabolic syndrome including obesity and type-2 diabetes. The bioassay-guided fractionation of an EtOAc-soluble extract of the stem bark of Erythrina abyssinica led to the isolation of a new coumestan, erythribyssin N (1), and two new benzofurans, erythribyssin F (2) and erythribyssin H (3), along with five known compounds (4-8). When tested for their stimulatory effects on AMPK activity at a concentration of 10 muM, compounds 4 and 5 showed potent activation, while compounds 1, 2, and 7 had moderate effects. These results suggest that benzofurans and coumestans may be new lead compounds for regulating the AMPK enzyme.

Prenylated pterocarpans as bacterial neuraminidase inhibitors

During the course of a neuraminidase inhibitor screening program on natural products, four new (6, 8, 11, and 12) and eleven known (1–5, 7, 9–10, and 13–15) pterocarpan derivatives were isolated as active principles from the EtOAc extract of the stem bark of Erythrina abyssinica. Their structures were identified by spectroscopic data analyses. All isolates exhibited significant inhibitory effects on the neuraminidases from Clostridium perfringens and Vibrio cholerae with IC50 values ranging from 1.32 to 77.10μM and 0.35 to 77.73μM, respectively. The isolates (1–3, 5–8, 10, and 13–15), which possessed noncompetitive inhibition modes in kinetic studies, showed stronger activity against C. perfringens neuraminidase (IC50 1.32–19.82μM) than quercetin (IC50 25.34μM), which was used as the positive control. In contrast, compounds 4 and 9 behaved as competitive inhibitors and were displayed less effective (IC50 26.39–33.55μM). Furthermore, calopocarpine, as a neuraminidase inhibitor, produced a decrease of V. cholerae adhesion to the host cell. Overall, these results suggest that neuraminidase inhibitors can be used in the development of new treatments to combat infectious diseases.

New Prenylated Flavanones fromErythrina abyssinicawith Protein Tyrosine Phosphatase 1B (PTP1B) Inhibitory Activity

As the insulin and leptin signaling pathway can be regulated by PTP1B, it has been suggested that compounds that reduce PTP1B activity or expression levels can be used for treating type 2 diabetes and obesity. In the course of our screening efforts on new PTP1B inhibitors, six new flavanones ( 1- 6) with dihydrofuran moiety and two known flavanones ( 7 and 8) were isolated from the stem bark of Erythrina abyssinica (Leguminosae). Their structures were elucidated on the basis of spectroscopic (including UV, CD, MS, 1D, and 2D NMR) and physicochemical analyses. With the exception of 3 and 5, the compounds inhibited PTP1B activity in an IN VITRO assay with IC (50) values ranging from 15.2 +/- 1.2 to 19.6 +/- 2.3 microM, whereas RK-682 as a positive control displayed an IC (50) value of 4.7 +/- 0.5 microM.

Cytotoxic and PTP1B inhibitory activities from Erythrina abyssinica

Bioassay-guided fractionation of the EtOAc extract of the stem bark of Erythrina abyssinica (Leguminosae) resulted in the isolation of three new ( 1– 3), along with 12 known ( 4– 15) pterocarpan derivatives. Their chemical structures were determined by physicochemical and spectroscopic data analysis (IR, UV, [ α ] D , CD, 1D and 2D NMR, and MS data). All the isolates were evaluated for their inhibitory effects on protein tyrosine phosphatase-1B (PTP1B), as well as their growth inhibition on MCF7, tamoxifen-resistant MCF7 (MCF7/TAMR), adriamycin-resistant MCF7 (MCF7/ADR) and MDA-MB-231 breast cancer cell lines. Compounds which exhibited PTP1B inhibitory activity (IC 50 values ranging from 4.2 ± 0.2 to 19.3 ± 0.3 μM) showed strong cytotoxic activity (IC 50 values from 5.6 ± 0.7 to 28.0 ± 0.2 μM). Our data suggested that pterocarpans could be considered as new anticancer materials by PTP1B inhibition.

8-Methoxyneorautenol and radical scavenging flavonoids from Erythrina abyssinica

A new pterocarpan (named 8-methoxyneorautenol) was isolated from the acetone extract of the root bark of Erythrina abyssinica . In addition, the known isoflavonoid derivatives eryvarin L, erycristagallin and shinpterocarpin were identified for the first time from the roots of this plant. The structures were determined on the basis of spectroscopic evidence. The new compound showed selective antimicrobial activity against Trichophyton mentagrophytes . The acetone extract of the root bark of E. abyssinica showed radical scavenging activity towards 2,2-diphenyl-1-picrylhydrazyl radical (DPPH). The pterocarpenes, 3-hydroxy-9-methoxy-10-(3,3- dimethylallyl)pterocarpene and erycristagallin, were the most active constituents of the roots of this plant and showing dose-dependent activities similar to that of the standard quercetin.

Screening of some kenyan medicinal plants for antibacterial activity

Eleven medicinal plants used by traditional healers in Machakos and Kitui District were screened, namely: Ajuga remota Benth, Aloe secundiflora Engl, Amaranthus hybridus L, Cassia didymobotrya Fes, Croton macrostachyus Del, Entada leptostachya Harms, Erythrina abyssinica DC, Harrisonia abyssinica Oliv, Schkuhria pinnata O. Ktze, Terminalia kilimandscharica Engl and Ziziphus abyssinica Hochst for potential antibacterial activity against four medically important bacterial strains, namely: Bacillus cereus ATCC 11778, Escherichia coli ATCC 25922, Micrococcus lutea ATCC 9341 and Pseudomonas aeruginosa ATCC 27853. The antibacterial activity of methanol extracts was determined as the minimum inhibitory concentration (MIC). The plant extracts were more active against Gram-positive (G+) than Gram-negative (G-) bacteria. The positive controls were streptomycin and benzylpenicillin for G- and G+ bacteria, respectively, both had a significant MIC at <1 mg/mL. The most susceptible bacteria were B. cereus, followed by M. lutea, while the most resistant bacteria were Ps. aeruginosa, followed by E. coli. The present study supports the use of these plants by the herbalists in the management of bacterial ailments. H. abyssinica and T. kilimandscharica showed the best antibacterial activity; hence these plants can be further subjected to phytochemical and pharmacological evaluation.

Flavanones from the stem bark of Erythrina abyssinica

Twelve new flavanones bearing a 2,2-dimethylpyrano ring were isolated from a MeOH extract of the stem bark of Erythrina abyssinica. Their structures were determined on the basis of spectroscopic (UV, CD, 1D and 2D NMR, HRMS) and physico-chemical analyses. Compounds 1, 3, 5, 6, 8, and 9 exhibited inhibitory effects on the enzyme activity of PTP1B in an in vitro assay with IC 50 values ranging from 13.9 ± 2.1 to 19.0 ± 1.8 μM. These results suggest that prenyl and methoxy groups on the B ring contribute to the inhibitory activity of flavanones against PTP1B.

New prenylated flavanones from stem bark of Erythrina abyssinica

In the course of investigation on Protein Tyrosine Phosphatase 1B (PTP1B) inhibitors from nature, we found that an EtOAc extract of the stem bark of Erythrina abyssinica greatly inhibited PTP1B activity in an in vitro assay [1]. Further bioactivity-guided fractionation of this fraction led to the isolation of twelve new flavanones (1–12) bearing a 2,2-dimethylpyran ring, named abyssinoflavone VIII–XIX. Their structures were determined on the basis of spectroscopic (UV, CD, 1D and 2D NMR, HR-MS) and physicochemical analyses. Compounds 1, 3, 5, 6, 8, and 9 exhibited inhibitory effect on PTP1B activity with IC50 values ranging from 13.9±2.1 to 19.0±1.8µM. This result suggests that prenyl and methoxy groups on B ring are responsible for the inhibitory activity of flavanones against PTP1B.

Four New Chalcones from Erythrina abyssinica

Four new chalcones 1 - 4, named abyssinones A - D, were isolated from the stem bark of the plant Erythrina abyssinica and their structures were elucidated on the basis of spectroscopic analyses. The compounds 1, 3, and 4 were found to exhibit moderate cytotoxic activity against the human colorectal cancer cell line (Caco2) with IC (50) values of 13.3, 15.1, and 11.1 microM, respectively.

Isoprenylated Flavonoids from the Stem Bark of Erythrina abyssinica

Three new prenylated flavanones, abyssinoflavanones V, VI, and VII (1-3), together with eight known flavanones (4-11) and two chalcones (12-13), were isolated from the stem bark of Erythrina abyssinica. Their structures were elucidated on the basis of spectroscopic and physicochemical analyses. All the isolates, with the exception of 1 and 8, strongly inhibited PTP1B activity in an in vitro assay with IC50 values ranging from 14.2 +/- 1.7 to 26.7 +/- 1.2 microM.

Radical Scavenging-Flavonoids from Erythrina abyssinica

Phytochemical analysis of twigs and roots of Erythrina abyssinica, a traditionally used medicinal plant, gave a new radical scavenging flavanone, 7,3′,4′-trihydroxy-5′-prenylflavanone (abyssinone VII; 1), along with twenty-one known compounds, whose radical scavenging and antimicrobial activities were also assessed.

Anti-plasmodial flavonoids from the stem bark of Erythrina abyssinica

The ethyl acetate extract of the stem bark of Erythrina abyssinica showed anti-plasmodial activity against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC50 values of 7.9±1.1 and 5.3±0.7 μg/ml, respectively. From this extract, a new chalcone, 2′,3,4,4′-tetrahydroxy-5-prenylchalcone (trivial name 5-prenylbutein) and a new flavanone, 4′,7-dihydroxy-3′-methoxy-5′-prenylflavanone (trivial name, 5-deoxyabyssinin II) along with known flavonoids have been isolated as the anti-plasmodial principles. The structures were determined on the basis of spectroscopic evidence.

Minor Flavanones from Erythrina abyssinica

Four new prenylated flavanones, abyssinone-V 4'-methyl ether (1) and abyssinoflavanones IV (2), V (3), and VI (4), have been isolated as minor flavanones from the African medicinal plant, Erythrina abyssinica, together with a known flavanone, sigmoidin D. The structure elucidation of compounds 1-4 by spectroscopic studies is described.

Wheat growth as influenced by application of agroforestry-tree prunings in Ethiopian highlands

The response of wheat (Triticum aestivum cv. ‘Enkoy’) to application of leaf prunings of nine agroforestry-tree species was investigated in a field trial and a six-week pot trial. The tree species were Grevillea robusta, Erythrina abyssinica, Gliricidia sepium, Albizia schimperiana, Acacia nilotica, Acacia polyacantha, Leucaena leucocephala, Leucaena pallida and Entada abyssinica. L. leucocephala, L. pallida, G. sepium and Entada abyssinica proved to be good pruning sources in the pot trial. G. robusta, A. polyacantha, A. nilotica and E. abyssinica had adverse effects on wheat seedlings with increased pruning loads probably due to immobilization processes or allelopathic effects. N and lignin content, C/N ratio, lignin/N ratio, phenolics/N ratio and (phenolics + lignin)/N ratio of the pruning material were all significantly correlated with shoot dry matter production of the wheat seedlings. With the exception of Entada abyssinica, which performed well under field conditions, a similar ranking as in the pot trial was established in the field experiment, but at harvest differences were not as pronounced as in the pot trial. Gliricidia treated wheat produced by far the highest grain yield with 248 g/m2.

Nitrogen Mineralization Pattern of Agroforestry Tree Leaves under Tropical Highland Conditions

AbstractLeaves of nine agroforestry tree species (Grevillea robusta, Erythrina abyssinica, Gliricidia sepium, Albizia schimperiana. Acacia nilotica. Acacia polyacantha, Leu‐caena leucocephala, Leucaena pallida and Entada abys‐sinica) were compared in a glasshouse incubation experiment under natural temperature conditions to relate the observed nitrogen mineralization pattern to quality factors of the mulch material such as N, lignin, phenolic and tannin content and C/N ratio, lignin/N ratio, phenolic/N ratio and (lignin ‐I‐ phenolics)/N ratio. Separation of the plant material into leaflets and petioles/rachis or into leaves and petioles with subsequent chemical analyses revealed large differences in the quality of the material not only between species but also amongst plant parts within the same species. Erythrina abyssinica, G. sepium, L. leucocephala and L. pallida had a rapid nitrogen release especially during the early sampling dates and were superior compared with mulch treatments of G. robusta, A. polyacantha, and Entada abyssinica. Immobilization processes started around 5 weeks after incubation and continued up to the end of the experiment, 9 weeks after incubation. N and lignin content, C/N ratio, lignin/N ratio, phenolics/N ratio and (phenolics + lignin)/N ratio were all significantly correlated with mineralized nitrogen after 3 weeks but their influence in driving the mineralization pattern decreased with incubation time.

Plant Nutrient Supply from Nine Agroforestry Tree Species to Wheat (Triticum aestivum) Analysed by Vector Diagnosis

AbstractSix‐week‐old wheat seedlings (Triticum aestivum) grown in pots with an alfisol soil with vertic properties and mulched at a rate equivalent to 10 t ha−1 with leaf prunings of Grevillea robusta, Erythrina abyssinica, Gliricidia sepium, Albizia schimperiana. Acacia nilotica. Acacia polyacantha, Leucaena leucocephala, Leucaena pallida and Entada abyssinica were used to diagnose nutrient contributions by these tree species. A control treatment of 20kg P+ 30kg N ha−1 was chosen as the reference treatment for the vector analysis applied to the mulch effects. Nitrogen was found to be the most important nutrient in seedlings mulched with L. pallida, L. leucocephala, Erythrina abyssinica and to a lesser extent A. schimperiana. Other nutrients of these mulches were also in the deficiency zone but with shorter vectors and therefore with lower impact. Since all these mulches showed increased values for shoot dry weight, nutrient concentration and nutrient uptake they have still reserves for further plant growth and appear therefore to be good mulch sources for annual crops. In contrast, wheat seedlings treated with A. polyacantha and Entada abyssinica had at least some vectors in the toxic zone due to an excess of nutrients while Grevillea treated plants showed a typical toxicity response with large vectors for all nutrients in between the toxic and the antagonistic zone. Allelopathic compounds might also have been involved.

Development of utility and location indices for classifying agroforestry species: the case of Rwanda

In a study of farmer knowledge and experimentation of trees and tree cultivation, two categories of farmer consultants were identified, tree experts (n = 44) and control farmers (n = 70), via a two stage process of ‘knowledge’ ranking and community interviews conducted in three communes in southern Rwanda in 1992. A detailed inventory of tree species was conducted revealing two key characteristics for on-farm trees: multiple utility and high locational flexibility. In order to logically organize the species inventory, two indices, a utility index (UI) and a locational flexibility index (LFI), were developed. The two indices were calculated for each species and then plotted as the axes on a bivariate grid. While few species had both high utility and flexibility indices, the majority that did were indigenous species long used in agroforestry systems (e.g., Euphorbia tirucalli, Vernonia amygdalina, Erythrina abyssinica, etc.). A few naturalized exotics introduced in the 1930s (e.g., Grevillea robusta, Eucalyptus camaldulensis, E. saligna, E. maideni, Cupressus lusitanica and Persea gratissima) were also appreciated for their multiple utility and locational flexibility. Farm sizes varied, averaging 1.27 ha among tree experts and 0.18 ha in the control group. The mean number of species cultivated was significantly higher on tree expert farms (P < 0.01). However, tree density was much lower on tree expert farms (731 trees · ha−1) than on control farms (1,689 trees · ha−1). Competitive species were found primarily on larger farms, whereas smaller farms were associated with species of greater UI and LFI. Farmers demonstrated deliberate and rational choices about which trees to plant in accordance with each species utility and flexibility in relation to land availability.

Kaempferol 3-O-(2-O-ß-D-Glucopyranosyl-6-O-a-L-Rhamnopyranosyl-ß-D-Glucopyranoside) from the African Plant Erythrina abyssinica

The flavonol, 3- O -(2- O-s -D-glucopyranosyl-6- O-a -L-rhamnopyranosyl- s -D-glucopyranoside), was isolated from Erythrina abyssinica Lamarck, an African plant widely used as folk remedies against malaria and syphilis. The structure was established on the basis of homo- and heteronuclear two-dimensional nuclear magnetic resonance techniques.

Structural Elucidation of New Flavanones Isolated from Erythrina abyssinica

Three new prenylated flavanones, abyssinin I (1), II (2), and III (3), have been isolated from the African medicinal plant Erythrina abyssinica, together with six known flavanones. The structural elucidation of 1−3 by spectroscopic studies is described.