Screening of antibacterial extracts from plants native to the Brazilian Amazon Rain Forest and Atlantic Forest

Abstract

More than 20% of the world's biodiversity is located in Brazilian forests and only a few plant extracts have been evaluated for potential antibacterial activity. In the present study, 705 organic and aqueous extracts of plants obtained from different Amazon Rain Forest and Atlantic Forest plants were screened for antibacterial activity at 100 µg/ml, using a microdilution broth assay against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli. One extract, VO581, was active against S. aureus (minimum inhibitory concentration (MIC) = 140 µg/ml and minimal bactericidal concentration (MBC) = 160 µg/ml, organic extract obtained from stems) and two extracts were active against E. faecalis, SM053 (MIC = 80 µg/ml and MBC = 90 µg/ml, organic extract obtained from aerial parts), and MY841 (MIC = 30 µg/ml and MBC = 50 µg/ml, organic extract obtained from stems). The most active fractions are being fractionated to identify their active substances. Higher concentrations of other extracts are currently being evaluated against the same microorganisms. Correspondence

Antioxidant and cytotoxic activity of Tecoma stans against lung cancer cell line (A549)

“…The alcoholic and aqueous extract of T.stans on phytochemical analysis has revealed the presence of polyphenolic,ß-sitosterol and flavonoids. In earlier reports by Hamburger and Hostettmann (1991), Beltrame et al (2002) and Suffredimi et al (2004), these compounds have exhibited anti-bacterial, antiviral, immunological and cytotoxic property on different cancer cell lines.…”

Antibacterial and cytotoxic activity of Brazilian plant extracts - Clusiaceae

“…MIC was determined as the lowest concentration visually analyzed as "L" that implied in bacterial growth when subcultured; and MBC was determined as the lowest concentration that showed no bacterial growth in the subcultures (Suffredini et al 2004). Gentamycin and tetracycline were used as standard drugs.…”

“…For this reason, our research team has been systematically studying the antibacterial activity of organic and aqueous plant extracts obtained from plants native to the rain forest against Gram-positive Staphylococcus aureus ATCC 29213 (Sau) and Enterococcus faecalis ATCC 29212 (Efae) and Gram-negative Pseudomonas aeruginosa ATCC 27853 (Psa) and Escherichia coli ATCC 25922 (Ecol) with the aim of discovering new natural product compounds that can be used as antibiotics. Twelve aqueous and organic extracts obtained from plants belonging to six different genera of Clusiaceae (Vismia, Garcinia, Haploclathra, Tovomita, Caraipa, and Clusia) were submitted to the determination of the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) using the microdilution broth assay (Suffredini et al 2004). The extracts were also tested against brine shrimp nauplii in order to evaluate their potential as cytotoxic agents and to determine if there is any relationship between brine shrimp toxicity and antibacterial activity for those twelve extracts.…”

“…The bacterial inoculum of each ATCC strain was obtained from fresh colonies in Müeller-Hinton agar plates. Inoculums were initially prepared to a concentration of 1.5 × 10 8 CFU/ ml (0.5 MacFarland), and then diluted to 3 × 10 2 CFU/ml (Suffredini et al 2004). From these diluted bacteria suspensions, 190 ml were transferred to each well of the microplates.…”

Discovery of New Antitumoral and Antibacterial Drugs From Brazilian Plant Extracts Using High Throughput Screening

“…The extracts are added to the corresponding wells at a single concentration of 100 mg/mL. 22 After 24-h incubation, the extracts are evaluated and the active ones, i.e., those able to inhibit bacterial growth, are subjected to the analysis of minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Extracts showing MIC d•200 mg/mL are selected for further bioguided fractionation.…”