Karla Slowing

Lippia: traditional uses, chemistry and pharmacology: a review

The chemical composition, pharmacological activity and traditional uses of 52 species attributed to the genus Lippia (Verbenaceae) as used in the South and Central America, and Tropical Africa, were revised and compared. A survey of the available literature shows that these species are used mostly for the treatment of gastrointestinal and respiratory disorders and as seasoning. Additionally, some of these Lippia species showed antimalarial, spasmolitic, sedative, hypotensive and, anti-inflammatory activities. Generally, the essential oil or the phenolic compounds (flavonoids) from these plant extracts are assumed to be the active principles.

Antiinflammatory and antioxidant activity of plants used in traditional medicine in Ecuador

Ethanolic extracts from 15 plant species, representing eight different families, used in traditional medicine in Ecuador were evaluated for antiinflammatory and antioxidant activities. Conyza floribunda, Eupatorium articulatum, Bonafousia longituba, Bonafousia sananho, Tagetes pusilla and Piper lenticellosum extracts showed a significant antiinflammatory activity in vivo in the carrageenan-induced paw oedema model in mice. The extracts were also tested in vitro for their ability to inhibit lipid peroxidation and to scavenge superoxide and hydroxyl radicals. E. articulatum extract possesses both activities. Baccharis trinervis, E. articulatum and Phytolacca rivinoides extracts were active as antioxidants.

Anti-inflammatory activity of leaf extracts of Eugenia jambos in rats

The anti-inflammatory activities of four organic extracts from the leaves of Eugenia jambos were investigated in rats using the Mizushima et al. model of acute and chronic inflammation (Mizushima et al. (1972) Journal of Pharmacy and Pharmacology 24, 781-785). Orally administered organic extracts of E. jambos (hexane, dichloromethane, ethyl acetate and methanol), given at daily doses equivalent to 12.5 g/kg of dried leaf material, inhibited both the acute and chronic phases of this experimental model of inflammation. The ethyl acetate and methanol extracts were the most effective and were equal or more effective than 80 mg/kg of phenylbutazone. The methanolic extract was the most active in the chronic phase. A 10% aqueous extract (infusion) of the leaves tested in the same model was more effective than all of the organic extracts.

Study of polyphenols in grape berries by reversed-phase high-performance liquid chromatography.

Several polyphenols have been tested in grape berries from Spain. The flavonoid content is important because of the pharmacological properties of these compounds, whereas resveratrol has been proved to be an antifungal, antiinflammatory and an anticarcinogenic compound. A reversed-phase HPLC method has been developed and applied to determine resveratrol, quercetine, quercitrine and rutine content in several grape berries samples in a single analysis. Covering the grapes with a preservative paper yields a healthier product, but one which has a lower polyphenol content than unprotected grapes.

Flavonoid glycosides from Eugenia jambos.

Two flavonol diglycosides isolated from the leaves of Eugenia jambos were characterized as quercetin and myricetin 3-O-beta-D-xylopyranosyl(1-->2) alpha-L-rhamnopyranosides by means of spectral analyses applying 2D NMR techniques and NOE experiments.

Simplified Screening by TLC of Plant Drugs

A rapid and economical procedure for the determination of the main active principles of medicinal plants (alkaloids, anthraquinones, cardiac glycosides, coumarins, flavonoids, saponins, tannins, essential oils) is proposed. The extraction of these active principles has been performed by means of three solvents, based on a method of increasing polarity. The plant extracts, whose compositions are known, were analysed on silica gel layers with the aid of three solvent systems and six spray reagents.

An effective novel delivery strategy of rasagiline for Parkinson's disease.

This is the first report on the efficacy of a new controlled release system developed for rasagiline mesylate (RM) in a rotenone-induced rat model of Parkinsons disease (PD). PLGA microspheres in vitro released RM at a constant rate of 62.3 μg/day for two weeks. Intraperitoneal injection of rotenone (2 mg/kg/day) to Wistar rats produced typical PD symptoms. Catalepsy, akinesia and swim tests outcomes in animals receiving RM either in solution or within microspheres showed a reversal in descent latency when compared to rotenone-treated animals, being this reversal specially pronounced in animals receiving RM microspheres (dose equivalent to 1 mg/kg/day RM injected i.p. every 15 days). Nissl-staining of brain sections showed selective degeneration of the substantia nigra (SNc) dopaminergic neurons in rotenone-treated animals which was markedly reverted by RM microspheres. PET/CT with (18)F-DG resulted in mean increases of accumulation of radiotracer in striatum and SNc of around 40% in animals treated with RM microspheres which also had significant beneficial effects on Bcl-2, Bax, TNF-α mRNA and SOD2 levels as detected by real-time RT-PCR. Our results confirm the robust effect achieved by the new controlled release system developed for RM which exhibited better in vivo efficacy than RM given in solution.

Controlled release of rasagiline mesylate promotes neuroprotection in a rotenone-induced advanced model of Parkinson's disease

Microencapsulation of rasagiline mesylate (RM) into PLGA microspheres was performed by method A (O/W emulsion) and method B (W/O/W double emulsion). The best formulation regarding process yield, encapsulation efficiency and in vitro drug release was that prepared with method A, which exhibited constant drug release for two weeks (K(0)=62.3 μg/day/20mg microspheres). Exposure of SKN-AS cells to peroxide-induced oxidative stress (1 mM) resulted in cell apoptosis which was significantly reduced by RM (40.7-102.5 μM) as determined by cell viability, ROS production and DNA fragmentation. Daily doses of rotenone (2 mg/kg) given i.p. to rats for 45 days induced neuronal and behavioral changes similar to those occurring in PD. Once an advanced stage of PD was achieved, animals received RM in saline (1 mg/kg/day) or encapsulated within PLGA microspheres (amount of microspheres equivalent to 15 mg/kg RM given on days 15 and 30). After 45 days RM showed a robust effect on all analytical outcomes evaluated with non-statistically significant differences found between its administration in solution or within microparticles however; with this controlled release system administration of RM could be performed every two weeks thereby making this new therapeutic system an interesting approach for the treatment of PD.

Cytotoxicity and biocompatibility evaluation of a poly(magnesium acrylate) hydrogel synthesized for drug delivery.

We report the synthesis and characterization as well as cytotoxicity and biocompatibility studies of a poly(magnesium acrylate) hydrogel (PAMgA) developed for drug delivery applications. Two hydrogels with different mesh sizes, large and short, were synthesized (L-C PAMgA and S-C PAMgA). The hydrogels were characterized through swelling, FT-IR and DSC. Cytotoxicity in vitro was evaluated on cell line NIH-3T3 fibroblasts via direct contact and two indirect contact methods (MTT and flow citometry). Both PAMgA hydrogels exhibited low cytotoxicity with survival rates higher than 90%. To select their administration route, biocompatibility was evaluated after intraperitoneal, subcutaneous, and oral administration to mice of both hydrogels at different dose ranges. Swelling percentages obtained were 33.3 ± 4.2% and 166.7 ± 8.3% for L-C PAMgA and S-C PAMgA respectively, showing a great difference in both hydrogels. Among the administration routes assayed, the hydrogels were well tolerated after oral administration of a wide dose range (10-500 mg/kg), thereby indicating that both PAMgA hydrogels are excellent candidates for oral administration due to their in vitro biocompatibility and oral non-toxicity. These results together with the fact that their synthesis is simple and inexpensive make them good candidates for the design of oral drug delivery devices.

New celecoxib multiparticulate systems to improve glioblastoma treatment.

Treatment of malignant gliomas consists of resection followed by radiotherapy and chemotherapy. Celecoxib (CXB), a selective COX-2 inhibitor, is able to control inflammation and pain, to improve the efficacy of radiotherapy, and to inhibit at high doses the growth of cancer cells. Two new delivery systems for CXB are developed: microspheres (MPs) for implantation in the brain after partial/complete removal of the tumor, and nanoparticles (NPs) for their potential to cross the blood brain barrier and deliver CXB into the CNS. Cell culture assays performed in PC12, SKN-AS and U373-MG cells demonstrate the antiproliferative affects of CXB, with EC50 values of 99.81 μM and 82.4 μM in U373-MG and SKN-AS cells. Encapsulation efficacy of CXB in formulation MP2 (20% CXB) was 74.6 ± 2.2% with a zero-order release rate of 47.8 μg/day/20mg microspheres for 34 days. Uncoated and polysorbate 80-coated CXB-NPs are prepared by nanoprecipitation. Mean sizes of uncoated and coated CXB-NPs were 173.6 ± 44.9 nm and 100.6 ± 62.1 nm. Cerebral cortex images showed a marked increase of fluorescence when the surfactant-coated NPs were administered to rats. These results suggest that both CXB formulations (MPs and NPs) are adequate systems to enhance the effects of chemotherapy in the treatment of malignant brain tumor.