Luis Fernando Ospina

Fuscoside E: A strong anti-inflammatory diterpene from Caribbean octocoral Eunicea fusca

The screen of 10 soft coral extracts collected from the Colombian Caribbean Sea in the TPA-induced ear edema model allowed us to identify Eunicea fusca extract among others as an interesting source of active compounds. The new diterpene, fuscoside E (1), along with the known fuscoside B (2), fuscol (3), (+)-germacrene D (4) and a mixture of six sterols (5-10), were isolated from this soft coral. Their structures were elucidated by 1D and 2D NMR spectroscopy techniques. Fuscoside E (1) absolute stereochemistry was determined by chiroptical methods. Fuscoside E (1) and B (2) showed strong anti-inflammatory in the above mentioned bioassay. Additionally, fuscoside E (1) and the sterol mixture (5-10) presented antifouling activity against bacterial strains involved in surface colonization.

In vitro studies on the relationship between the anti-inflammatory activity of Physalis peruviana extracts and the phagocytic process

The study of plants used in traditional medicine has drawn the attention of researchers as an alternative in the development of new therapeutics agents, such as the American Solanaceae Physalis peruviana, which has significant anti-inflammatory activity. The Physalis peruviana anti-inflammatory effect of ethanol or ether calyces extracts on the phagocytic process was assessed by using an in vitro phagocytosis model (Leishmania panamensis infection to murine macrophages). The Physalis peruviana extracts do not inhibit microorganism internalization and have no parasiticide effect. Most ET and EP extracts negatively affected the parasite’s invasion of macrophages (Infected cells increased.). This observation might result from a down-regulation of the macrophage’s microbicide ability associated with a selective reduction of proinflammatory cytokines levels. Physalis peruviana’s anti-inflammatory activity described in this model is related to an immunomodulatory effect exerted on macrophages infected, which directly or indirectly “blocks” their ability to secrete soluble proinflammatory mediators.

Sucrose esters from Physalis peruviana calyces with anti-inflammatory activity.

Physalis peruviana is a native plant from the South American Andes and is widely used in traditional Colombian medicine of as an anti-inflammatory medicinal plant, specifically the leaves, calyces, and small stems in poultice form. Previous studies performed by our group on P. peruviana calyces showed potent anti-inflammatory activity in an enriched fraction obtained from an ether total extract. The objective of the present study was to obtain and elucidate the active compounds from this fraction and evaluate their anti-inflammatory activity in vivo and in vitro. The enriched fraction of P. peruviana was purified by several chromatographic methods to obtain an inseparable mixture of two new sucrose esters named peruviose A (1) and peruviose B (2). Structures of the new compounds were elucidated using spectroscopic methods and chemical transformations. The anti-inflammatory activity of the peruvioses mixture was evaluated using λ-carrageenan-induced paw edema in rats and lipopolysaccharide-activated peritoneal macrophages. Results showed that the peruvioses did not produce side effects on the liver and kidneys and significantly attenuated the inflammation induced by λ-carrageenan in a dosage-dependent manner, probably due to an inhibition of nitric oxide and prostaglandin E2, which was demonstrated in vitro. To our knowledge, this is the first report of the presence of sucrose esters in P. peruviana that showed a potent anti-inflammatory effect. These results suggest the potential of sucrose esters from the Physalis genus as a novel natural alternative to treat inflammatory diseases.

Anti-inflammatory R-prostaglandins from Caribbean Colombian soft coral Plexaura homomalla

This study aims to evaluate the effect of prostaglandins isolated from soft coral Plexaura homomalla, collected in Colombian Caribbean Sea, on in vivo and in vitro inflammation models.

Alterations in the reproduction of mice induced by rapanone

Oral administration of rapanone to a group of female mice at doses of 60 and 120 mg/kg, reduced the percentage of pregnancies compared to control group, suggesting an anovulatory effect. Postcoital administration induced uterine alteration in both the first and second gestation periods. These results seem to indicate inhibition of trophoblast implantation in the first period, and an abortive effect and/or reabsorption in the second. Daily administration of rapanone to a group of male mice resulted in fertility alteration, which is attributed to an antispermatogenic effect. Rapanone did not show acute toxic effects at the doses tested in this research.

Biodistribution study of free and microencapsulated 6‐methylcoumarin in Wistar rats by HPLC

A sensitive, specific and reproducible HPLC method has been developed and validated for the quantitative determination of 6-methylcoumarin (6MC) in plasma and other tissues in Wistar rats. A C18 column was used with UV detection at 321 nm and a gradient system consisting of methanol-deionized water was used as mobile phase. The retention time for 6MC was 14.921 min and no interfering peaks were observed for any of the matrices. Linear relationships (r(2)  > 0.997) were obtained between the peak height ratios and the corresponding biological sample concentrations over the range 0.4-12.8 µg/mL. Precision and accuracy were evaluated; the coefficient of variation and the relative error for all of the organs were <2 and 7%, respectively. The limit of quantitation was 0.20 µg/mL for the heart and 0.30 µg/mL for the other tissues evaluated. This HPLC method was successfully used in the determination of 6MC in the biodistribution study after administration of 200 mg/kg of both 6MC-free and 6MC-loaded polymeric microparticles. In this study, extensive 6MC was found, in both free and microencapsulated forms, in all the organs tested. The 6MC-free showed a range of between 1.7 and 11.5 µg/g, while the microencapsulated 6MC showed concentrations of between 6.35 and 17.7 µg/g, suggesting that 6MC improved absorption rate.

Identification of differentially expressed genes in microarray data in a principal component space.

Microarray experiments are often conducted in order to compare gene expression between two conditions. Tests to detected mean differential expression of genes between conditions are conducted applying correction for multiple testing. Seldom, relationships between gene expression and microarray conditions are investigated in a multivariate approach. Here we propose determining the relationship between genes and conditions using a Principal Component Analysis (PCA) space and classifying genes to one of two biological conditions based on their position relative to a direction on the PC space representing each condition.

Using multivariate methods to infer knowledge from genomic data

Since the introduction of genome sequencing techniques several methods for genomic data preprocessing and analysis have been published and applied to answer different biological questions. Rarely, multivariate methods have been used to extract knowledge about protein roles. Two of the most informative types of data are gene expression data (microarrays) and phylogenetic profiles indicating presence of genes in other organisms and therefore providing information about their co-evolution. Here we show that these two types of data, analyzed by means of principal component analysis and non parametric discriminant analysis, provide useful information about protein function and their participation in virulence processes.