Anti-angiogenic effects of pterogynidine alkaloid isolated from Alchornea glandulosa

<p>Abstract</p> <p>Background</p> <p>Angiogenesis, a complex multistep process that comprehends proliferation, migration and anastomosis of endothelial cells (EC), has a major role in the development of pathologic conditions such as inflammatory diseases, tumor growth and metastasis. Brazilian flora, the most diverse in the world, is an interesting spot to prospect for new chemical leads, being an important source of new anticancer drugs. Plant-derived alkaloids have traditionally been of interest due to their pronounced physiological activities. We investigated the anti-angiogenic potential of the naturally occurring guanidine alkaloid pterogynidine (Pt) isolated from the Brazilian plant <it>Alchornea glandulosa</it>. The purpose of this study was to examine which features of the angiogenic process could be disturbed by Pt.</p> <p>Methods</p> <p>Human umbilical vein endothelial cells (HUVEC) were incubated with 8 μM Pt and cell viability, proliferation, apoptosis, invasion and capillary-like structures formation were addressed. Nuclear factor κB (NFκB), a transcription factor implicated in these processes, was also evaluated in HUVEC incubated with Pt. Quantifications were expressed as mean ± SD of five independent experiments and one-way analysis of variance (ANOVA) followed by the Dunnet test was used.</p> <p>Results</p> <p>A significant decrease in proliferation and invasion capacity and an effective increase in apoptosis as assessed by bromodeoxyuridine (BrdU), double-chamber and terminal transferase dUTP nick end labeling (TUNEL) assay, respectively, have been found. Pt also led to a drastic reduction in the number of capillary-like structures formation when HUVEC were cultured on growth factor reduced-Matrigel (GFR-Matrigel) coated plates. In addition, incubation of HUVEC with Pt resulted in reduced NFκB activity.</p> <p>Conclusion</p> <p>These findings emphasize the potential use of Pt against pathological situations where angiogenesis is stimulated as tumor development.</p

Liana communities exhibit different species composition, diversity and community structure across forest types in the Congo Basin

Lianas are poorly characterized for central African forests. We quantify variation in liana composition, diversity and community structure in different forest types in the Yangambi Man and Biosphere Reserve, Democratic Republic of Congo. These attributes of liana assemblages were examined in 12 1-ha plots, randomly demarcated within regrowth forest, old growth monodominant forest, old growth mixed forest and old growth edge forest. Using a combination of multivariate and univariate community analyses, we visualize the patterns of these liana assemblage attributes and/or test for their significant differences across forest types. The combined 12 1-ha area contains 2,638 lianas (>= 2 cm diameter) representing 105 species, 49 genera and 22 families. Liana species composition differed significantly across forest types. Taxonomic diversity was higher in old growth mixed forests compared to old growth monodominant and regrowth forests. Trait diversity was higher than expected in the regrowth forest as opposed to the rest of forest types. Similarly, the regrowth forest differed from the rest of forest types in the pattern of liana species ecological traits and diameter frequency distribution. The regrowth forest was also less densely populated in lianas and had lower liana total basal area than the rest of forest types. We speculate that the mechanism of liana competitive exclusion by dominant tree species is mainly responsible for the lower liana species diversity in monodominant compared to mixed forests. We attribute variation in liana community structure between regrowth and old growth forests mostly to short development time of size hierarchies

Studies on the antidiarrhoeal activity of Aegle marmelos unripe fruit: Validating its traditional usage

<p>Abstract</p> <p>Background</p> <p><it>Aegle marmelos </it>(L.) Correa has been widely used in indigenous systems of Indian medicine due to its various medicinal properties. However, despite its traditional usage as an anti-diarrhoeal there is limited information regarding its mode of action in infectious forms of diarrhoea. Hence, we evaluated the hot aqueous extract (decoction) of dried unripe fruit pulp of <it>A. marmelos </it>for its antimicrobial activity and effect on various aspects of pathogenicity of infectious diarrhoea.</p> <p>Methods</p> <p>The decoction was assessed for its antibacterial, antigiardial and antirotaviral activities. The effect of the decoction on adherence of enteropathogenic <it>Escherichia coli </it>and invasion of enteroinvasive <it>E. coli </it>and <it>Shigella flexneri </it>to HEp-2 cells were assessed as a measure of its effect on colonization. The effect of the decoction on production of <it>E. coli </it>heat labile toxin (LT) and cholera toxin (CT) and their binding to ganglioside monosialic acid receptor (GM1) were assessed by GM1-enzyme linked immuno sorbent assay whereas its effect on production and action of <it>E. coli </it>heat stable toxin (ST) was assessed by suckling mouse assay.</p> <p>Results</p> <p>The decoction showed cidal activity against <it>Giardia </it>and rotavirus whereas viability of none of the six bacterial strains tested was affected. It significantly reduced bacterial adherence to and invasion of HEp-2 cells. The extract also affected production of CT and binding of both LT and CT to GM1. However, it had no effect on ST.</p> <p>Conclusion</p> <p>The decoction of the unripe fruit pulp of <it>A. marmelos</it>, despite having limited antimicrobial activity, affected the bacterial colonization to gut epithelium and production and action of certain enterotoxins. These observations suggest the varied possible modes of action of <it>A. marmelos </it>in infectious forms of diarrhoea thereby validating its mention in the ancient Indian texts and continued use by local communities for the treatment of diarrhoeal diseases.</p

Anti-HIV-1 integrase potency of methylgallate from Alchornea cordifolia using in vitro and in silico approaches:

According to the 2018 report of the United Nations Programme on HIV/AIDS (UNAIDS), acquired immune deficiency syndrome (AIDS), a disease caused by the human immunodeficiency virus (HIV), remains a significant public health problem. The non-existence of a cure or effective vaccine for the disease and the associated emergence of resistant viral strains imply an urgent need for the discovery of novel anti-HIV drug candidates. The current study aimed to identify potential anti-retroviral compounds from Alchornea cordifolia

In vivo anti-inflammatory activity of Alchornea cordifolia (Schumach. & Thonn.) Müll. Arg. (Euphorbiaceae)

Alchornea cordifolia (Schumach. & Thonn.) Müll. Arg. (Euphorbiaceae) is a widely distributed plant in Africa. It is used in the traditional medicine of many African countries for the treatment of bacterial, fungal, parasitic and inflammatory disorders. Aqueous decoction and methanol leaf extracts were tested for their ability to reduce Croton oil-induced oedema in the mouse ear, after topical application. The methanol leaf extract dose-dependently inhibited the Croton oil-induced ear oedema in mice (ID(50)<500 microg/cm(2)). A bio-assay guided liquid-liquid fractionation of this methanol extract gave four active fractions: water insoluble (F1), hexane (F2), ethyl acetate (F3) and water (F4). The hexane fraction showed a very high activity (42% inhibition at 0.7 microg/cm(2)) as compared to the control. The other fractions were less active (F1: 56% at 506.2 microg/cm(2); F3: 57% at 289.3 microg/cm(2); F4: 32% for 203.8 microg/cm(2)) while indomethacin gave 49% of inhibition at 90 microg/cm(2). The activity of F1 and F3 may be at least in part explained by the presence of anti-inflammatory flavonoids (hyperoside and quercitrin, quercitrin being identified in the plant for the first time) while the activity was not correlated to the tannin contents. None of these compounds were detected in the most active F2 fraction. These results support the reported traditional use of this plant against topical inflammatory disorders

Anti-inflammatory compounds from leaves and root bark of Alchornea cordifolia (Schumach. & Thonn.) Müll. Arg.

Alchornea cordifolia is one of the most widely-used plants in traditional medicine throughout Africa, principally for inflammatory, antimicrobial and parasitic diseases. In continuation of our investigations on its anti-inflammatory activity, we fractionated the leaf and root bark extracts and isolated six compounds which exhibited significant topical anti-inflammatory activity in the mouse ear oedema model using croton oil at a dose of 90 microg/cm2. Daucosterol (2), acetyl aleuritolic acid (4), N1,N2-diisopentenyl guanidine (5) and N1,N2,N3-triisopentenyl guanidine (6) were shown to be more active than indomethacin, while beta-sitosterol (1) and di(2-ethylhexyl) phthalate (3) were less effective. This is the first report on the presence of compounds 1, 2, 3 and 4 in this plant and of the anti-inflammatory activity of 3, 5 and 6. These compounds may account, at least in part, for the use of A. cordifolia in folk medicine to treat inflammation

N1,N2,N3-trisisopentenyl guanidine and N1,N2-diisopentenyl guanidine, two cytotoxic alkaloids from Alchornea cordifolia (Schumach.& Thonn.) Mull. Arg. (Euphorbiaceae) root barks.

This paper describes the purification of two guanidine alkaloids: NI, N2-diisopentenyl guanidine (DIPG) 1 and NI,N2,N3-trilsopentenyl guanidine (TIPG) 2 from Alchornea cordifolia root bark and reports their cytotoxic properties on cancer (HeLa, Me]-5, J774) and non cancer (WI 38) cells. TIPG showed the highest cytotoxicity with IC50 values from 0.7 to 14.3 mu g/mL (2.6 to 54.3 mu M) on the four cell lines while DIPG was much less active: IC50 45.8 and 97.6 mu g/mL (234.8 and 500.5 mu M) on Mel-5 and HeLa and > 512.8 mu M on J774 and WI 38. The results indicate that the cytotoxicity notably decreased with the loss of one isopentenyl substituent