Antimicrobial activity of Phyllanthus amarus Schumach. & Thonn and inhibition of the NorA efflux pump of Staphylococcus aureus by Phyllanthin.

The aim of this study was to evaluate the antimicrobial activity of ethanoic extract of P. amarus (PAEE) and its compound Phyllanthin, as well as, investigate if these natural products could modulate the fluoroquinolone-resistance in S. aureus SA1199-B by way of overexpression of the NorA efflux pump. Microdilution tests were carried out to determine the minimal inhibitory concentration (MIC) of the PAEE or Phyllanthin against several bacterial and yeast strains. To evaluate if PAEE or Phyllanthin were able to act as modulators of the fluoroquinolone-resistance, MICs for Norfloxacin and ethidium bromide were determined in the presence or absence of PAEE or Phyllanthin against S. aureus SA1199-B. PAEE showed antimicrobial activity against Gram-negative strains, meanwhile Phyllanthin was inactive against all strains tested. Addition of PAEE or Phyllanthin, to the growth media at sub-inhibitory concentrations enhanced the activity of the Norfloxacin as well as, Ethidium Bromide, against S. aureus SA1199-B. These results indicate that Phyllanthin is able to modulate the fluoroquinolone-resistance possibly by inhibition of NorA. This hypothesis was supported by in silico docking analysis which confirmed that Phyllantin is a NorA ligand. Thus, this compound could be used as a potentiating agent of the Norfloxacin activity in the treatment of infections caused by fluoroquinolone-resistant S. aureus.

Lycopene-Rich Extract from Red Guava (Psidium guajava L.) Decreases Plasma Triglycerides and Improves Oxidative Stress Biomarkers on Experimentally-Induced Dyslipidemia in Hamsters.

This work assessed the effects of a 28-day treatment with lycopene-rich extract (LRE) from red guava fruit (Psidium guajava L.) on the lipid profile and oxidative stress in an experimental model of dyslipidemia. Male hamsters (116.5 ± 2.16 g) were fed with the AIN 93G diet containing casein (20%), coconut fat (13.5%) and cholesterol (0.1%). The animals were divided into four groups: normolipidemic control (standard feed; NC, n = 7); hypercholesterolemic control (HC, n = 7); LRE 25 mg/kg/day (LRE-25, n = 7) and LRE 50 mg/kg/day (LRE-50, n = 9). After treatment, plasma concentrations of triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL) cholesterol (LDL-c), high-density lipoprotein (HDL) cholesterol (HDL-c), malondialdehyde (MDA-p) and myeloperoxidase (MPO), as well as erythrocytic superoxide dismutase (SOD-e) and the atherogenic index, were determined. Malondialdehyde (MDA-h), catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD-h) levels were assessed. Feed intake (FI) and weight gain (WG) were also determined. The LRE-25 group presented significantly lower TG levels and atherogenic index than did the HC group (p < 0.05). Both LRE-25 and LRE-50 groups presented lower levels of MDA-p and MPO than did the HC group (p < 0.05). LRE demonstrated a promising effect against dyslipidemia and oxidative stress.

In vitro effects of Pilocarpus microphyllus extracts and pilocarpine hydrochloride on Rhipicephalus (Boophilus) microplus.

The aim of this study was to assess the activity of aqueous (AE) and ethanolic extracts (EE) and pilocarpine hydrochloride, which were extracted and isolated from Pilocarpus microphyllus (Jaborandi), respectively, on Rhipicephalus (Boophilus) microplus. High performance liquid chromatography (HPLC) was performed to quantify these compounds. Larval packet and adult immersion tests were conducted with different concentrations. Five AE and EE concentrations, ranging from 6.2 to 100.0 mg mL-1, and six concentrations of pilocarpine hydrochloride, ranging from 0.7 to 24.0 mg mL-1, were tested. The lethal concentration (LC50) of each extract for larvae and engorged females was calculated through Probit analysis. The concentration of pilocarpine hydrochloride obtained from the EE and the AE was 1.3 and 0.3% (m/m), respectively. Pilocarpine hydrochloride presented the highest acaricidal activity on larvae (LC50 2.6 mg mL-1) and engorged females (LC50 11.8 mg mL-1) of R.(B.) microplus, followed by the EE which presented LC50 of 56.4 and 15.9 mg mL-1, for larvae and engorged females, respectively. Such results indicate that pilocarpine hydrochloride has acaricidal activity, and may be the primary compound responsible for this activity by P. microphyllus EE.

In vitro effects of Pilocarpus microphyllus extracts and pilocarpine hydrochloride on Rhipicephalus (Boophilus) microplus / Efeitos in vitro do extrato de Pilocarpus microphyllus e do cloridrato de pilocarpina sobre Rhipicephalus (Boophilus) microplus

Abstract The aim of this study was to assess the activity of aqueous (AE) and ethanolic extracts (EE) and pilocarpine hydrochloride, which were extracted and isolated from Pilocarpus microphyllus (Jaborandi), respectively, on Rhipicephalus (Boophilus) microplus. High performance liquid chromatography (HPLC) was performed to quantify these compounds. Larval packet and adult immersion tests were conducted with different concentrations. Five AE and EE concentrations, ranging from 6.2 to 100.0 mg mL–1, and six concentrations of pilocarpine hydrochloride, ranging from 0.7 to 24.0 mg mL–1, were tested. The lethal concentration (LC50) of each extract for larvae and engorged females was calculated through Probit analysis. The concentration of pilocarpine hydrochloride obtained from the EE and the AE was 1.3 and 0.3% (m/m), respectively. Pilocarpine hydrochloride presented the highest acaricidal activity on larvae (LC50 2.6 mg mL–1) and engorged females (LC50 11.8 mg mL–1) of R.(B.) microplus, followed by the EE which presented LC50 of 56.4 and 15.9 mg mL–1, for larvae and engorged females, respectively. Such results indicate that pilocarpine hydrochloride has acaricidal activity, and may be the primary compound responsible for this activity by P. microphyllus EE.

Resumo O objetivo desse estudo foi avaliar a atividade dos extratos aquoso (AE) e etanólico (EE) e do cloridrato de pilocarpina, que foram, respectivamente, extraídos e isolado de Pilocarpus microphyllus (Jaborandi), sobre Rhipicephalus (Boophilus) microplus. Cromatografia líquida de alta eficiência foi realizada para quantificação dos compostos. Testes de pacote de larvas e de imersão de adultos foram realizados com diferentes concentrações. Cinco concentrações do AE e EE variando de 6,2 a 100,0 mg mL–1 e seis concentrações do cloridrato de pilocarpina variando de 0,7 a 24,0 mg mL–1 foram testadas. A concentração letal (CL50) de cada extrato para larvas e fêmeas ingurgitadas foi estimada por meio da análise Probit. A concentração de cloridrato de pilocarpina obtida do EE e AE foi de 1,3 e 0,3% (m/m), respectivamente. O cloridrato de pilocarpina apresentou a maior atividade carrapaticida sobre larvas (CL50 2,6 mg mL–1) e fêmeas ingurgitadas (CL50 11,8 mg mL–1) de R. (B.) microplus, seguido do EE que apresentou CL50 de 56,4 e 15,9 mg mL–1, para larvas e fêmeas ingurgitadas, respectivamente. Tais resultados indicam que o cloridrato de pilocarpina apresenta atividade carrapaticida e pode ser o principal responsável pela atividade acaricida do EE de P. microphyllus.

Composição química e eficácia do óleo essencial e do extrato etanólico de Alpinia zerumbet sobre Staphylococcus aureus / Chemical composition and efficacy of essential oil and ethanol extract of Alpinia zerumbet on Staphylococcus aureus

O presente trabalho descreve a atividade antibacteriana do óleo essencial e do extrato etanólico das folhas de Alpinia zerumbet (colônia) sobre cepas de Staphylococcus aureus isoladas de vacas com mastite subclínica e cepas padrão ATCC 29213 e ATCC 25923, por meio do método de difusão em ágar. Foram utilizados 10 tratamentos contendo diferentes concentrações do óleo essencial e do extrato etanólico (100,0; 50,0; 25,0; 12,5 e 6,3 mg.mL-1) e o grupo controle (álcool etílico a 50% e Tween a 1%). Os constituintes majoritários do óleo essencial foram p -cimeno (32,72%), 1,8-cineol (24,05%) e 4-terpineol (20,23%), sendo esses determinados por cromatografia a gás acoplada a espectrometria de massas e cromatografia a gás com detector de ionização de chama (CG-EM/DIC). No extrato etanólico foi detectado o ácido elágico e três flavonoides: rutina, quercetina e campferol, por meio de cromatografia a líquido de alta eficiência acoplada a detector de arranjo de diodo (CLAE-DAD). Todas as cepas apresentaram sensibilidade aos tratamentos com óleo essencial e extrato etanólico. A melhor resposta foi obtida com o óleo essencial de A. zerumbet que, na concentração de 100 mg.mL-1 proporcionou inibição total do crescimento bacteriano. Esses resultados sugerem o potencial antibacteriano do óleo essencial e do extrato etanólico de A. zerumbet no controle da mastite bovina.(AU)

The present work describes the antibacterial activity of the essential oil and the ethanol extract from leaves of Alpinia zerumbet (colônia) on Staphylococcus aureus strains isolated from cows with subclinical mastitis and standard strains ATCC 29213 and ATCC 25923, using the agar diffusion method. Ten treatments containing different concentrations of essential oil and ethanol extract (100.0; 50.0; 25.0; 12.5 and 6.3 mg.mL-1) and the control group (50% ethyl alcohol and 1% Tween solutions) were used for antimicrobial testing. The major constituents of the essential oil were p -cimeno (32.72%), 1.8-cineol (24.05%) and 4-terpineol (20.23%), which were determined by gas chromatographymass spectrometry and gas chromatography - flame ionization detector (CG-MS/FID). Ellagic acid and three flavonoids (rutin, quercetin and campferol) were detected in the ethanol extract by means of high performance liquid chromatography-photodiode array detector (HPLC-PDA). All strains showed sensitivity to the treatments with essential oil and the ethanol extract. The best response was obtained with A. zerumbet essential oil at a 100 mg.mL-1, showing complete inhibition of bacterial growth. These results demonstrate the antibacterial potential of essential oil and ethanol extract of A. zerumbet in the control of bovine mastitis.(AU)