Sesquiterpenes from the leaves of Tithonia diversifolia
ABSTRACT Two new compounds, a germacrane sesquiterpene, 1-acetyltagitinin A (1), and a guaianane sesquiterpene, 8beta-isobutyryloxycumambranolide (2), were isolated from leaves of Tithonia diversifolia, together with two known compounds, methyl 3alpha-acetoxy-4alpha-hydroxy-11(13)-eudesmen-12-oa te and tagitinin A. The structures of compounds 1 and 2 were elucidated on the basis of spectral and chemical evidence.
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ABSTRACT: Extracts from the leaf of Tithonia diversifolia used in folk medicine for treatment of various ailments were tested for antimalaria and mosquito repellency properties in experimental animals and human volunteers, under the laboratory conditions. Comparison of the effectiveness of Chloroquine with the aqueous and methanolic extracts from the plant (T. diversifolia) showed that Chloroquine was 100% effective in clearing the parasite while the aqueous and methanolic extracts were 50 and 74% effective in clearing the parasites respectively. Both aqueous and methanolic extracts were more effective when administered before the onset of the infection, probably indicating the time-dependency of the antimalaria effects. Earlier application of the extracts at the onset of the malaria symptoms was more effective in reducing the parasitemia within a few days. The administration of the plant extracts during the malaria episode was also effective with longer period of administration. The LC 50 of the aqueous extract in mice was 1.2ml/100g body weight while the Maximum Tolerated Dose (MTD) was found to be 1.0ml/g. The repellent activity of volatile oil at different concentrations was measured by protection period against the bites of Anopheles gambiae, Aedes aegypti and Culex quinquefasciatus. The volatile oil extract showed higher repellent effect on A. gambiae at higher concentrations however its repellent and protective effects at various concentrations on all other species of mosquito tested can not be underestimated.
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ABSTRACT: Resumo Tendo em conta o elevado número de casos de malária por P. falciparum resistente à cloroquina em São Tomé e Príncipe (STP), pretendemos dar o nosso contributo para a melhoria das condições de saúde da população, através da Investigação da Actividade Antimalárica de plantas medicinais usadas na Medicina Tradicional, e através do desenvolvimento de novos compostos que possam ser usados para o controlo da malária, nomeadamente compostos activos contra Plasmodium falciparum resistente à cloroquina. Levou-se a cabo um estudo etnofarmacológico de 13 plantas medicinais usadas pelos terapeutas tradicionais de STP no tratamento de malária e/ou febres. Este estudo corroborou o uso tradicional da maioria das plantas medicinais, e a sua actividade farmacológica foi comprovada laboratorialmente. Foram igualmente realizados estudos fitoquímicos biodireccionados e ensaios de toxicidade nas plantas que apresentaram melhores resultados de actividade antimalárica. A planta Tithonia diversifolia (Hemsl.) A. Gray foi submetida a Ensaios Fitoquímicos, por ser a que apresentou os melhores resultados de actividade antimalárica e simultaneamente apresentar garantias de inocuidade, relativamente aos resultados de toxicidade, pelo que poderá servir de base para um futuro desenvolvimento de novos fármacos antimaláricos.Plantas Medicinais e Práticas Fitoterapêuticas nos Trópicos, Lisboa, Portugal; 01/2009
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ABSTRACT: Spinal cord injury (SCI)-induced secondary oxidative stress associates with a clinical complication and high mortality. Treatments to improve the neurological outcome of secondary injury are considered as important issues. The objective of the current study is to evaluate the anti-oxidative effect of Tithonia diversifolia ethanolic extracts (TDE) on cells and apply the pharmacological effect to SCI model using a MRI imaging algorism. The anti-oxidation properties were tested in a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Rat liver cells (clone-9) were treated with various doses of TDE (0 ~ 50 mug/ml) before exposed to 250 muM H2O2 and cell survival was determined by MTT and LDH assays. We performed water apparent diffusion coefficient (ADC) map in MR techniques to investigate the efficacy of TDE treatment on SCI animal model. We performed T5 laminectomy and compression (50 g, 1 min) to induce SCI. PHILIP 3.0 T MRI was used to image 24 male Sprague-Dawley rats weighing 280-320 g. Rats were randomly divided into three groups: sham group, SCI group, SCI treated with TDE group. The MRI images were taken and ADC were acquired before and after of treatment of TDE (50 mg/kg B. W. orally, 5 days) in SCI model. TDE protected clone-9 cells against H2O2-induced toxicity through DPPH scavenging mechanism. In addition, SCI induced the increase in ADC after 6 hours. TDE treatment slightly decreased the ADC level after 1-week SCI compared with control animals. Our studies have proved that the cytoprotection effect of TDE, at least in part, is through scavenging ROS to eliminate intracellular oxidative stress and highlight a potential therapeutic consideration of TDE in alternative and complementary medicine.BMC Complementary and Alternative Medicine 11/2014; 14(1):447. DOI:10.1186/1472-6882-14-447 · 1.88 Impact Factor