Larvicidal and adulticidal activity of essential oils from plants of the Lamiaceae family against the West Nile virus vector,Culex pipiens (Diptera: Culicidae)

Culex pipiens mosquitoes are the most widely distributed primary vector of the West Nile virus worldwide. Many attempts for investigation of botanical pesticides to avoid the development of pesticide resistance to conventional synthetic pesticides that are recognized as a threat to the diversity of ecosystems. The study aimed to determine the components of three essential oils of Lamiaceae family, lavender (Lavandula angustifolia), peppermint (Mentha piperita L.), and rosemary (Rosmarinus officinalis L.) by gas chromatography-mass spectrometry (GC–MS) analysis. Furthermore, aimed to validate the insecticidal activities of these oils as larvicidal agents against the third instar larvae of Culex pipiens using five different concentrations (62.5, 125, 250, 500, and 1000 ppm) for each oil in five replicates and as an adulticidal agent against approximately three-day-old female adults of Cx. Pipiens using 0.5, 1, 2, 4, and 5% concentrations in three replicates. The results generally showed a dose-related response. At 1000 ppm, rosemary oil showed the highest larvicidal (100%) (LC₅₀, 214.97 ppm), followed by peppermint oil (92.00% mortality and LC₅₀ (269.35 ppm). Lavender oil showed the lowest efficacy with 87.20% mortality and LC₅₀ (301.11 ppm). At 5% oil concentration, the highest knockdown rate at 1 h was recorded for lavender oil (95.55%), followed by peppermint oil (88.89%) and lastly rosemary oil (84.44%). After 24 h, rosemary oil showed the lowest adult mortality rate (88.89%; LC₅₀, 1.44%), while lavender and peppermint oils both showed a 100% mortality rate, with (LC₅₀, 0.81% and 0.91%, respectively). The chemical constituents of the oils consisted of monoterpenes and sesquiterpenes that determined their insecticidal activities against the target insect stage. The study proposed that rosemary essential oil may be useful for the control of Cx. pipiens larvae as part of an integrated water treatment strategy, and lavender and peppermint oils may be used in an integrated plan for adult’s control.     

Anti-biofilm potential of Lactobacillus plantarum Y3 culture and its cell-free supernatant against multidrug-resistant uropathogen Escherichia coli U12

Uropathogens develop biofilms on urinary catheters, resulting in persistent and chronic infections that are associated with resistance to antimicrobial therapy. Therefore, the current study was performed to control biofilm-associated urinary tract infections through assaying the anti-biofilm ability of lactic acid bacteria (LAB) against multidrug-resistant (MDR) uropathogens. Twenty LAB were obtained from pickles and fermented dairy products, and screened for their anti-biofilm and antimicrobial effects against MDR Escherichia coli U12 (ECU12). Lactobacillus plantarum Y3 (LPY3) ({"type":"entrez-nucleotide","attrs":{"text":"MT498405","term_id":"1843980272","term_text":"MT498405"}}MT498405), showed the highest inhibitory effect and biofilm production. Pre-coating of a microtitre plate with LPY3 culture was more potent than co-incubation. Pre-coating with LPY3 culture generated a higher anti-biofilm effect with an adherence of 14.5% than cell free supernatant (CFS) (31.2%). Anti-biofilm effect of CFS was heat stable up to 100 °C with higher effect at pH 4–6. Pre-coating urinary catheter with LPY3 culture reduced the CFU/cm² of ECU12 attached to the catheter for up to seven days. Meanwhile, CFS reduced the ECU12 CFU/cm² for up to four days. Scanning electron microscope confirmed the reduction of ECU12 adherence to catheters after treatment with CFS. Therefore, Lactobacillus plantarum can be applied in medical devices as prophylactic agent and as a natural biointervention to treat urinary tract infections.     

Metabolomic Profiling and Neuroprotective Effects of Purslane Seeds Extract Against Acrylamide Toxicity in Rat’s Brain

Neurochemical Research - Acrylamide (ACR) is an environmental pollutant with well-demonstrated neurotoxic and neurodegenerative effects in both humans and experimental animals. The present study...     

Real-Time PCR Assays for the Specific Identification of Probiotic Strains Lactobacillus gasseri BNR17 and Lactobacillus reuteri LRC (NCIMB 30242)

The broad spectrum of health benefits attributed to probiotics has contributed to a rapid increase in the value of the probiotic market. Probiotic health benefits can be strain specific. Thus, strain-level identification of probiotic strains is of paramount importance to ensure probiotic efficacy. Both Lactobacillus gasseri BNR17 and Lactobacillus reuteri LRC (NCIMB 30242) strains have clinically proven health benefits; however, no assays were developed to enable strain-level identification of either of these strains. The objective of this study is to develop strain-specific PCR-based methods for Lactobacillus gasseri BNR17 and Lactobacillus reuteri LRC strains, and to validate these assays according to the guidelines for validating qualitative real-time PCR assays. Using RAST (Rapid Annotation using Subsystem Technology), unique sequence regions were identified in the genome sequences of both strains. Probe-based assays were designed and validated for specificity, sensitivity, efficiency, repeatability, and reproducibility. Both assays were specific to target strain with 100% true positive and 0% false positive rates. Reaction efficiency for both assays was in the range of 90 to 108% with R square values > 0.99. Repeatability and reproducibility were evaluated using five samples at three DNA concentrations each and relative standard deviation was < 4% for repeatability and < 8% for reproducibility. Both of the assays developed and validated in this study for the specific identification of Lactobacillus gasseri BNR17 and Lactobacillus reuteri LRC strains are specific, sensitive, and precise. These assays can be applied to evaluate and ensure compliance in probiotic products.

     

Pharmacokinetic and pharmacodynamic interaction of Rosuvastatin calcium with guggulipid extract in rats

Background & objectivesRosuvastatin calcium (RC) is a potent and competitive synthetic inhibitor of HMG-CoA reductase used for the treatment of dyslipidemia. Guggulipid obtained from Commiphora mukul is used in the treatment of a wide variety of diseases such as atherosclerosis, hypercholesterolemia, rheumatism, and obesity. The present study evaluates the pharmacokinetic and pharmacodynamic interactions between RC and the standardized guggulipid extract in rats.Materials and methodsThe guggulipid extract was standardized for the presence of guggulsterones. The pharmacokinetic interaction was determined after a single dose administration of RC alone or in combination with the guggulipid extract or after multiple-dose administration of RC alone or RC along with the guggulipid extract for 14 days. To determine the pharmacodynamic interaction, RC and guggulipid extract were administered to hyperlipidemic rats for 14 days. The level of significance was determined using unpaired student’s t-test, one way ANOVA, the post-ANOVA Tukey test.ResultsStandardization of guggulipid extract showed it contains 7.5%w/w of guggulsterones. Guggulipid extract increased the bioavailability of RC in both single-dose and multiple-dose studies. Guggulipid extract reduced the rate of absorption (Ka) of RC but showed an increase in maximum serum concentration (Cmax). An in-vitro study using isolated rat intestine revealed that guggulipid extract decreased the rate of absorption of RC in the intestinal lumen. The hypolipidemic activity of RC was augmented by the guggulipid extract in hyperlipidemic rats.Interpretation & conclusionTherefore it is concluded that guggulipid extract increases the bioavailability of RC by delaying its Ka and augments its hypolipidemic action. However, it is recommended that a combination of RC with guggulipid extract should be used only after an adverse effect(s) of this combination are determined.     

Hypoglycemic and hepatoprotective activity of Rosmarinus officinalis extract in diabetic rats

The present study examined the effect of water extract (200 mg/kg body weight) of Rosmarinus officinalis L. in streptozotocin (STZ)-induced diabetic rats for 21 days. The hepatoprotective effects were investigated in the liver tissues sections. There was a significant increase in serum liver biochemical parameters (aspartate aminotransferase, alanine transaminase, and alkaline phosphatase), accompanied by a significant decrease in the level of total protein and albumin in the STZ-induced rats when compared with that of the normal group. The high-dose treatment group (200 mg/kg body wt) significantly restored the elevated liver function enzymes near to normal. This study revealed that rosemary extracts exerted a hepatoprotective effect. The results indicate that the extract exhibits the protective effect on tissues and prove its potentials as an antidiabetic agent.     

Executive Function and IQ Predict Mathematical and Attention Problems in Very Preterm Children

Objective of this study was to examine the impact of executive function (EF) on mathematical and attention problems in very preterm (gestational age ≤ 30 weeks) children. Participants were 200 very preterm (mean age 8.2 ± 2.5 years) and 230 term children (mean age 8.3 ± 2.3 years) without severe disabilities, born between 1996 and 2004. EFs assessed included verbal fluency, verbal working memory, visuospatial span, planning, and impulse control. Mathematics was assessed with the Dutch Pupil Monitoring System and parents and teachers rated attention problems using standardized behavior questionnaires. The impact of EF was calculated over and above processing speed indices and IQ. Interactions with group (very preterm versus term birth status) were examined. Analyses were conducted separately for two subsamples: children in preschool and children in primary school. Very preterm children performed poorer on tests for mathematics and had more parent and teacher rated attention problems than term controls (ß_s>.11, P_s<.01). IQ contributed unique variance to mathematics in preschool and in primary school (ß_s>.16, P_s<.007). A significant interaction of group with IQ (ß = −. 24, P = .02) showed that IQ contributed unique variance to attention problems as rated by teachers, but that effects were stronger for very preterm than for term infants. Over and above IQ, EF contributed unique variance to mathematics in primary school (ß = .13, P<.001), to parent rated inattention in preschool and in primary school (ß_s>−.16, P_s<.04), and to teacher rated inattention in primary school (ß = −.19; ß = .19, P_s<.009). In conclusion, impaired EF is, over and above impaired IQ, an important predictor for poor mathematics and attention problems following very preterm birth.