In vitro antiviral, antioxidant and in vivo antipyretic activity of three South Africa medicinal plants crude extracts / Actividad antiviral, antioxidante y antipirética in vivo de tres extractos crudos de plantas medicinales de Sudáfrica

This study investigated anti-viral, antioxidant activity and anti-pyretic of crude extract from Artemisia afra, Artemisia absinthium and Pittiosporum viridflorum leaves. The crude extracts were prepared by maceration using aqueous, methanol and dichloromethane respectively. Antiviral studies were evaluated with influenza virus using Fluorescence based - Neuraminidase inhibitors. Antioxidant activities determined with DPPH, Nitric oxide, hydroxyl and super oxide anion radicals' Anti-pyretic activities were evaluated using rats with yeast induced pyrexia. Total phenol, flavonoids, and pro-anthocyanin contents of the plants samples were evaluated using standard protocols. The crude extracts exhibited neuraminidase inhibitory activity against the influenza virus at different thresholds. Artemisia absinthiumaqueous extract showed the best activity against A/Sydney/5/97. Whereas Artemisia afra methanol crude extract displayed highest antioxidant potential against the tested antioxidant parameters. All the crude extracts significantly reversed yeast induced pyrexia in rats, similar to paracetamol. Thus, they could serve as natural remedy for respiratory diseases such as Influenza.

Este estudio investigó la actividad antiviral, antioxidante y antipirética del extracto crudo de hojas de Artemisia afra, Artemisia absinthium y Pittiosporum viridflorum. Los extractos crudos se prepararon mediante maceración utilizando metanol acuoso y diclorometano respectivamente. Los estudios antivirales se evaluaron con el virus de la influenza utilizando inhibidores de neuraminidasa basados en fluorescencia. Actividades antioxidantes determinadas con DPPH, radicales aniónicos de óxido nítrico, hidroxilo y superóxido. Las actividades antipiréticas se evaluaron utilizando ratas con pirexia inducida por levaduras. El contenido total de fenol, flavonoides y proantocianina de las muestras de plantas se evaluó utilizando protocolos estándar. Los extractos crudos mostraron actividad inhibidora de neuraminidasa contra el virus de la influenza en diferentes umbrales. El extracto acuoso de Artemisia absinthium mostró la mejor actividad contra A/Sydney/5/97. Mientras que el extracto crudo de Artemisia aframetanol mostró el mayor potencial antioxidante contra los parámetros antioxidantes probados. Todos los extractos crudos revirtieron significativamente la pirexia inducida por levaduras en ratas, similar al paracetamol. Por tanto, podrían servir como remedio natural para enfermedades respiratorias como la Influenza.

Brazilin isolated from the heartwood of Caesalpinia sappan L induces endothelium-dependent and -independent relaxation of rat aortic rings.

AIM: Brazilin is one of the major constituents of Caesalpinia sappan L with various biological activities. This study sought to investigate the vasorelaxant effect of brazilin on isolated rat thoracic aorta and explore the underlying mechanisms. METHODS: Endothelium-intact and -denuded aortic rings were prepared from rats. The tension of the preparations was recorded isometrically with a force displacement transducer connected to a polygraph. The phosphorylation levels of ERK1/2 and myosin light chain (MLC) were analyzed using Western blotting assay. RESULTS: Application of brazilin (10-100 µmol/L) dose-dependently relaxed the NE- or high K(+)-induced sustained contraction of endothelium-intact aortic rings (the EC50 was 83.51±5.6 and 79.79±4.57 µmol/L, respectively). The vasorelaxant effect of brazilin was significantly attenuated by endothelium removal or by pre-incubation with L-NAME, methylene blue or indomethacin. In addition, pre-incubation with brazilin dose-dependently attenuated the vasoconstriction induced by KCl, NE or Ang II. Pre-incubation with brazilin also markedly suppressed the high K(+)-induced extracellular Ca(2+) influx and NE-induced intracellular Ca(2+) release in endothelium-denuded aortic rings. Pre-incubation with brazilin dose-dependently inhibited the NE-stimulated phosphorylation of ERK1/2 and MLC in both endothelium-intact and -denuded aortic rings. CONCLUSION: Brazilin induces relaxation in rat aortic rings via both endothelium-dependent and -independent ways as well as inhibiting NE-stimulated phosphorylation of ERK1/2 and MLC. Brazilin also attenuates vasoconstriction via blocking voltage- and receptor-operated Ca(2+) channels.

Inhibitory effects of Brazilin on the vascular smooth muscle cell proliferation and migration induced by PDGF-BB.

Abnormal vascular smooth muscle cell (VSMC) proliferation and migration contribute to the pathogenesis of vascular diseases including atherosclerosis and restenosis. Brazilin isolated from the heartwood of Caesalpinia sappan L. has been reported to exhibit various biological activities, such as anti-platelet aggregation, anti-inflammation, vasorelaxation and pro-apoptosis. However, the functional effects of Brazilin on VSMCs remain unexplored. The present study investigated the potential effects of Brazilin on platelet-derived growth factor (PDGF)-BB induced VSMC proliferation and migration as well as the underlying mechanism of action. VSMC proliferation and migration were measured by Crystal Violet Staining, wound-healing and Boyden chamber assays, respectively. Cell cycle was analyzed by flow cytometry. Enzymatic action of matrix metalloproteinase-9 (MMP-9) was carried out by gelatin zymography. Expression of adhesion molecules, cell cycle regulatory proteins, the phosphorylated levels of PDGF receptor ß (PDGF-Rß), Src, extracellular signal regulated kinase (ERK) and Akt were tested by immunoblotting. The present study demonstrated that pretreatment with Brazilin dose-dependently inhibited PDGF-BB stimulated VSMC proliferation and migration, which were associated with a cell-cycle arrest at G0/G1 phase, a reduction in the adhesion molecule expression and MMP-9 activation in VSMCs. Furthermore, the increase in PDGF-Rß, Src, ERK1/2 and Akt phosphorylation induced by PDGF-BB were suppressed by Brazilin. These findings indicate that Brazilin inhibits PDGF-BB induced VSMC proliferation and migration, and the inhibitory effects of Brazilin may be associated with the blockade of PDGF-Rß - ERK1/2 and Akt signaling pathways. In conclusion, the present study implicates that Brazilin may be useful as an anti-proliferative agent for the treatment of vascular diseases.