Estudio de la actividad biológica de los extractos de tres plantas de la familia Boraginaceae

Tesis (Doctor en Ciencias con Acentuación en Química de productos Naturales) UANL, 2010.UANLhttp://www.uanl.mx

Free radical scavenging and cytotoxic activity of five commercial standardized extracts (red wine, green tea, pine bark, polygonum and pomegranate)

The objective of extract standardization is to obtain optimum and consistent quality of herbal preparations with defined components. This paper presents the radical scavenging effect of extracts against DPPH free radical (2,2-diphenyl-1-picrylhydrazyl) and cytotoxic activity in vitro on the cervical cancer cell line HeLa of five commercial standardized extracts rich in phenolic compounds: red wine (Vitis vinifera), green tea (Camellia sinensis), pine bark (Pinus maritime), polygonum (Polygonum cuspidatum), and pomegranate (Punica granatum). It shows radical scavenging activity in the following order, according to their median effective concentration (EC<sub50): P. cuspidatum 85 µg/ml, C. sinensis 11 µg/ml, P. maritima 7 µg/ml, V. vinifera 6 µg/ml, P. granatum 1 µg/ml and for positive control, vitamin E was 21 µg/ml. The cytotoxic activity, according to their half maximal inhibitory concentration (IC50) was: P. granatum 22 µg/ml, C. sinensis 13.4 µg/ml, P. cuspidatum 12.8 µg/ml, P. maritima 11 µg/ml, and V. vinifera 7 µg/ml and for positive control, Triton X-100 was 3 µg/ml. Our results indicate that low concentrations of red wine, pomegranate, and pine bark extracts have high radical scavenging effect as well as cytotoxic activity on HeLa cells. Therefore, these extracts may be an important source for phytopharmaceuticals development.Key words: Radical scavenging, cytotoxicity, HeLa cells, standardized extracts

Antibacterial and Antibiofilm Activity of Methanolic Plant Extracts against Nosocomial Microorganisms

Biofilm is a complex microbial community highly resistant to antimicrobials.The formation of biofilms in biotic and abiotic surfaces is associated with high rates of morbidity and mortality in hospitalized patients. New alternatives for controlling infections have been proposed focusing on the therapeutic properties of medicinal plants and their antimicrobial effects. In the present study the antimicrobial and antibiofilm activities of 8 methanolic plant extracts were evaluated against clinical isolated microorganisms. Preliminary screening by diffusion well assay showed the antimicrobial activity of Prosopis laevigata, Opuntia ficus-indica, and Gutierrezia microcephala. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined ranging from 0.7 to >15 mg/mL. The specific biofilm formation index (SBF) was evaluated before and after the addition of plant extracts (MBC × 0.75). Opuntia ficus-indica caused the major reduction on SBF in dose-dependent manner. Cytotoxic activity of plant extracts was determined using brine shrimp lethality test (Artemia salina L.). Lethal Dose concentration (LD50 values) of the plant extracts was calculated. LD50 values for P. laevigata and G. microcephalawere 141.6 and 323.

Antiurolithic activity of Berberis trifoliate extract on induced urolithiasis in rats by zinc disc implantation

Background: In clinical therapy, there is no satisfactory drug available for treatment of urolithiasis, especially for the prevention of their recurrence. The aim of this work was to evaluate in vivo antiurolithic activity of methanolic extract of Berberis trifoliata leaves.Material and methods: Urolithiasis was induced in Wistar rats by zinc disc implantation in urinary bladder. Upon postsurgical recovery, different doses of the methanolic extract of B. trifoliata leaves (50, 100 and 150 mg/kg body weight) were administered orally to zinc disc implanted rats for a period of 20 days. Antiurolithiatic activity was evaluated by measuring the difference between the weight of the implanted zinc discs at the time of implantation and the final weight of the dried calculi taken out from the bladder at the end of the 20 days period of treatment.Results: Extract of B. trifoliata significantly reduced calculi deposition around the implanted zinc disc at all doses (50, 100, and 150 mg/kg).Conclusion: Treatment with methanolic extract of B. trifoliata is useful agent against the kidney stone formation.Keywords: Antiurolithic, Berberis trifoliata, urolithiasis, zinc disc implantation

Bactericidal Activity, Isolation and Identification of Most Active Compound from 20 Plants used in Traditional Mexican Medicine Against Multidrug-Resistant Bacteria

Abstract Background and Objective: Plants are used in Mexico as traditional medicine for the treatment of diverse illnesses such as stomach pain, fever, diarrhea, insomnia, flu and other respiratory diseases. Twenty were selected to determine their bactericidal activity. The aim of this study was the isolation of molecules from plants used in Mexican traditional medicine. Materials and Methods: Using chromatographic procedures, the responsible bactericidal molecules from rosemary was extracted and then identified by spectroscopic analysis IR, 1H NMR, 13C NMR, DEPT, HSQC and GC-MS. Measures of central tendency were determined by statistical analysis. Results: Ten of these plants showed bactericidal activity against multidrug-resistant bacteria. This biological activity was reported for Carya illinoensis against Pseudomonas aeruginosa , also for Equisetum robustum , Stevia rebaudiana and Castela texana against Methicillin resistant Staphylococcus aureus (MRSA). The methanolic extract of Rosmarinus officinalis (rosemary) showed important bactericidal activity against MRSA (ATCC BAA-44) and clinically isolated MRSA. Conclusion: Rosemary’s bactericidal molecules were isolated and then identified as a mixture of betulinic, oleanolic and ursolic acid (MIC = 725 µg mLG1). Key words: Rosmarinus officinalis , multidrug-resistance, MRSA, thin layer chromatography, flash chromatography, 1H NMR, 13C NMR, triterpenic acid

Actividad antimicrobiana y antioxidante de extractos etanólicos de hoja de Arbutus xalapensis Kunt, Mimosa malacophylla Gray y Teucrium cubense Jacquin

Se ha reportado un incremento en la emergencia de microorganismos resistentes a antibióticos, por lo que se busca desarrollar terapias para tratar dichas enfermedades. A este respecto se destaca el uso de productos naturales con propiedades antimicrobianas y antioxidantes. En la presente investigación se obtuvieron extractos etanólicos de hoja de Arbutus xalapensis, Mimosa malacophylla y Teucrium cubense las cuales fueron colectadas en la Localidad de Potrero Redondo, Santiago, Nuevo León, México para la determinación de dichas actividades. Estos extractos fueron probados contra cepas de importancia médica siendo la hoja de A. xalapensis quien manifestó la mayor actividad antimicrobiana (CMB = 2.9 ± 0.5 mg mL-1) en contra de Staphylococcus aureus ATCC 29213 que fue la cepa más sensible en el estudio. Además, este extracto obtuvo la mayor actividad antioxidante mediante los métodos de DPPH (1,206.6 ± 68.6 μmoles ET g-1) y ABTS•+ (1,750.7 ± 110.1 μmoles ET g-1).There has been a dramatic increase in the emergence of antibiotic resistant bacterial strains, because indiscriminate use of antibiotics. Therefore, it is vital to develop new therapies to treat these resistant pathogens. In recent years, interest in natural products has increased due to their biological activities, including, antimicrobial and antioxidant properties. In the present investigation, ethanolic leaf extracts of Arbutus xalapensis, Mimosa malacophylla and Teucrum cubense were obtained from plants collected in Potrero Redondo locality, Santiago Nuevo León, Mexico for determining the biological activities mentioned above. Extracts were tested against strains of medical importance being the A. xalapensis stem which had the best antimicrobial activity (CMB = 2.9 ± 0.5 mg mL-1) against Staphylococcus aureus. Furthermore, this extract óbtained the highest antióxidant activity by DPPH assay (1,206.6 ± 68.6 μmól ET g-1) and ABTS•+ (1,750.7 ± 110.1 μmól ET g-1)

ANTIUROLITHIC ACTIVITY OF BERBERIS TRIFOLIATA EXTRACT ON INDUCED UROLITHIASIS IN RATS BY ZINC DISC IMPLANTATION

Background: In clinical therapy, there is no satisfactory drug available for treatment of urolithiasis, especially for the prevention of their recurrence. The aim of this work was to evaluate in vivo antiurolithic activity of methanolic extract of Berberis trifoliata leaves. Material and methods: Urolithiasis was induced in Wistar rats by zinc disc implantation in urinary bladder. Upon postsurgical recovery, different doses of the methanolic extract of B. trifoliata leaves (50, 100 and 150 mg/kg body weight) were administered orally to zinc disc implanted rats for a period of 20 days. Antiurolithiatic activity was evaluated by measuring the difference between the weight of the implanted zinc discs at the time of implantation and the final weight of the dried calculi taken out from the bladder at the end of the 20 days period of treatment. Results: Extract of B. trifoliata significantly reduced calculi deposition around the implanted zinc disc at all doses (50, 100, and 150 mg/kg). Conclusion: Treatment with methanolic extract of B. trifoliata is useful agent against the kidney stone formation

Antibacterial and Antibiofilm Activity of Methanolic Plant Extracts against Nosocomial Microorganisms

Biofilm is a complex microbial community highly resistant to antimicrobials. The formation of biofilms in biotic and abiotic surfaces is associated with high rates of morbidity and mortality in hospitalized patients. New alternatives for controlling infections have been proposed focusing on the therapeutic properties of medicinal plants and their antimicrobial effects. In the present study the antimicrobial and antibiofilm activities of 8 methanolic plant extracts were evaluated against clinical isolated microorganisms. Preliminary screening by diffusion well assay showed the antimicrobial activity of Prosopis laevigata, Opuntia ficus-indica, and Gutierrezia microcephala. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined ranging from 0.7 to >15 mg/mL. The specific biofilm formation index (SBF) was evaluated before and after the addition of plant extracts (MBC × 0.75). Opuntia ficus-indica caused the major reduction on SBF in dose-dependent manner. Cytotoxic activity of plant extracts was determined using brine shrimp lethality test (Artemia salina L.). Lethal Dose concentration (LD 50 values) of the plant extracts was calculated. LD 50 values for P. laevigata and G. microcephala were 141.6 and 323.3 g/mL, respectively, while O. ficus-indica showed a slight lethality with 939.2 g/mL. Phytochemical analyses reveal the presence of flavonoids, tannins, and coumarines