Enhanced inhibition of Pseudomonas aeruginosa virulence factor production and biofilm development by sublethal concentrations of eugenol and phenyllactic acid.

Biofilm development in Pseudomonas aeruginosa is regulated by its quorum sensing (QS) systems. It has three major QS systems: LasI/R, RhlI/R and PQS/MvfR. Previous studies showed that phenyllactic acid (PLA) binds to RhlR and PqsR and inhibits the Rhl and PQS QS; and eugenol at sublethal concentration inhibits Las and PQS QS systems. Here, we have demonstrated that a combination of sublethal doses of eugenol and PLA enhanced the inhibition of the QS mediated production of the virulence factors and biofilm development of this pathogen. A combination of 50 µmol l-1 eugenol and 0·3 mmol l-1 PLA significantly inhibited the pyocyanin production, protease activity, swarming motility and cytotoxic activities of P. aeruginosa strain PAO1, whereas eugenol and PLA when added individually to PAO1 cultures were less effective in inhibiting its virulence factor expression. Biofilm formation of PAO1 was reduced by 32, 19 and 87% on glass surfaces; and 54, 49 and 93% on catheter surfaces when treated using 50 µmol l-1 eugenol or 0·3 mmol l-1 PLA and their combinations, respectively. The in vitro finding in the reduction of biofilm development was further validated in vivo using a catheter associated medaka fish biofilm model. Our results indicate that a combination of QS inhibitors targeting different QS pathways should be selected while designing therapeutic molecules to achieve maximum QS mediated biofilm inhibition and clinical outcome against P. aeruginosa.

Alleviation of transient global ischemia/reperfusion-induced brain injury in rats with 1,2,3,4,6-penta-O-galloyl-ß-d-glucopyranose isolated from Mangifera indica.

Present study was undertaken to evaluate the protective effect of 1,2,3,4,6-penta-O-galloyl-ß-d-glucopyranose (PGG) against transient global ischemia/reperfusion (I/R)-induced brain injury in rats. Sixty minutes of global ischemia, followed by 24h of reperfusion caused significant alterations in cognition and memory (p<0.01), significant deterioration of motor coordination, grip strength, and limb tone (P<0.01) associated with neurological deficit. In addition, significant decrease in catalase (P<0.01), and superoxide dismutase (SOD) (P<0.01) activities, increase in lipid peroxidation (P<0.01), depletion of reduced glutathione (GSH) (P<0.01), and increase in brain volume (P<0.01) was observed. Additionally, I/R insult has aggravated the cerebral infarct formation (P<0.01), and the histopathology of brain showed congestion of blood vessels, edema of brain parenchyma, leukocyte infiltration as signs of neuroinflammation, and necrosis of brain tissue. Interestingly, pre-treatment with quercetin (20mg/kg, i.p.), and PGG (5 and 10mg/kg, i.p.) for 7 days showed significant, and dose dependent protection against I/R-induced brain injury by alleviating all the behavioral, neurological, morphological, and histological changes induced by I/R. Besides, PGG is a well-known antioxidant, and its protective effect against I/R-induced brain injury is thought to be due to its potent antioxidant property.

Anti-oxidant and anti-inflammatory activity of leaf extracts and fractions of Mangifera indica.

OBJECTIVE: To evaluate the anti-oxidant and anti-inflammatory activity of leaf extracts and fractions of Mangifera indica in in vitro conditions. METHODS: In vitro DPPH radical scavenging activity and lipoxygenase (LOX) inhibition assays were used to evaluate the anti-oxidant and anti-inflammatory activities respectively. Methanolic extract (MEMI), successive water extract (SWMI) and ethyl acetate fraction (EMEMI), n-butanol fraction (BMEMI) and water soluble fraction (WMEMI) of methanolic extract were evaluated along with respective reference standards. RESULTS: In in vitro DPPH radical scavenging activity, the MEMI, EMEMI and BMEMI have offered significant antioxidant activity with IC(50) values of 13.37, 3.55 and 14.19 µg/mL respectively. Gallic acid, a reference standard showed significant antioxidant activity with IC(50) value of 1.88 and found to be more potent compared to all the extracts and fractions. In in vitro LOX inhibition assay, the MEMI, EMEMI and BMEMI have showed significant inhibition of LOX enzyme activity with IC(50) values of 96.71, 63.21 and 107.44 µg/mL respectively. While, reference drug Indomethacin also offered significant inhibition against LOX enzyme activity with IC(50) of 57.75. Furthermore, MEMI was found to more potent than SWMI and among the fractions EMEMI was found to possess more potent antioxidant and anti-inflammatory activity. CONCLUSIONS: These findings suggest that the MEMI and EMEMI possess potent anti-oxidant and anti-inflammatory activities in in vitro conditions.

Anticonvulsant activity of 1,2,3,4,6-penta-O-galloyl-ß-D-glucopyranose isolated from leaves of Mangifera indica.

The present study was aimed to evaluate the anticonvulsant activity of 1,2,3,4,6-penta-O-galloyl-ß-D-glucopyranose (PGG) isolated from methanolic leaf extracts of Mangifera indica in mice. Anticonvulsant activity of PGG was evaluated against pentylenetetrazole (PTZ)-induced and maximal electroshock (MES)-induced convulsions in mice. Additionally, locomotor activity and GABA levels in the brain were estimated to explore the possible CNS-depressant activity and mechanism behind the anticonvulsant activity, respectively. In these studies, PGG (2.5, 5, and 10 mg/kg, intraperitoneal (i.p.)) showed significant and dose-dependent inhibition of PTZ and MES-induced convulsions. Furthermore, PGG administration showed significant decrease in the locomotor activity as an indication of its CNS-depressant property; also, PGG has significantly increased the GABA levels in the cerebellum and whole brain other than the cerebellum. In conclusion, PGG isolated from M. indica showed potent anticonvulsant activity, and possible mechanism may be due to enhanced GABA levels in the brain.

1,2,3,4,6 Penta-O-galloyl-ß-d-glucose, a bioactivity guided isolated compound from Mangifera indica inhibits 11ß-HSD-1 and ameliorates high fat diet-induced diabetes in C57BL/6 mice.

Methanolic leaf extract of Mangifera indica (MEMI) was subjected to bioactivity guided fractionation in order to identify the active antidiabetic constituent. 32 fractions were evaluated for possible 11ß-HSD-1 inhibition activity under in vitro conditions. The EA-7/8-9/10-4 fraction was evolved as a most potent fraction among all the fractions and it was identified as well known gallotannin compound 1,2,3,4,6 penta-O-galloyl-ß-d-glucose (PGG) by spectral analysis. Based on these results the PGG was further evaluated in ex vivo 11ß-HSD-1 inhibition assay and high fat diet (HFD)-induced diabetes in male C57BL/6 mice. Single dose (10, 25, 50 and 100mg/kg) of PGG and carbenoxolone (CBX) have dose dependently inhibited the 11ß-HSD-1 activity in liver and adipose tissue. Furthermore, HFD appraisal to male C57BL/6 mice caused severe hyperglycemia, hypertriglyceridemia, elevated levels of plasma corticosterone and insulin, increased liver and white adipose mass with increase in body weight was observed compare to normal control. Also, oral glucose tolerance was significantly impaired compare to normal control. Interestingly, post-treatment with PGG for 21 days had alleviated the HFD-induced biochemical alterations and improved oral glucose tolerance compare to HFD-control. In conclusion, the PGG isolated from MEMI inhibits 11ß-HSD-1 activity and ameliorates HFD-induced diabetes in male C57BL/6 mice.

Fluoxetine toxicity in a preterm infant.

We describe a preterm infant with marked motor automatism and skin manifestations after being exposed to fluoxetine in utero. The fluoxetine level drawn at 96 hours of age was 92 ng/ml, which was in adult therapeutic range. The neurologic symptoms resolved by 7 days and follow-up at 4 months revealed normal neurodevelopmental examination.

Weekly telephone contact does not enhance the compliance of home apnea monitoring.

OBJECTIVE: To evaluate the effect of weekly telephone contact with families in enhancing the use of home apnea monitors. STUDY DESIGN: This was a prospective, randomized, single-blinded study of 65 infants who were prescribed home apnea monitoring at the time of initial discharge from the hospital. Exclusion criteria included participation in any other study involving home monitoring or nonavailability of home telephone. Infants were randomized either to the "standard" or "telephone" group by a stratified balanced block technique. All families were instructed to use the monitor during the first 4-week period at all times except during bathing and during the second 4-week period at all unattended times and at night. The families in the telephone group were contacted weekly for 8 weeks. The telephone interview reviewed the events of the previous week but did not include specific encouragement to use the monitor. Both groups received routine pediatric care and follow-up at our high-risk premature clinic. The primary outcome measure was compliance measured as the percentage of time as well as the hours per day that the infant spent on the monitor as recorded by the documented monitor. RESULTS: The telephone (n = 30) and standard (n = 32) groups were similar (p > 0.10) with respect to birth weight (1567 +/- 778 versus 1710 +/- 777 gm), gestational age (30.9 +/- 4.2 versus 31.1 +/- 4.6 weeks), maternal age (24.9 +/- 6.0 versus 25.3 +/- 5.4 years), and commercial insurance (46.7% versus 46.9%), a marker of higher socioeconomic status. Compliance of the telephone versus the standard group was similar during the first 4-week period (74.7 +/- 24.9 versus 75 +/- 27.8%, p = 0.85) (17.9 +/- 5.9 versus 18.2 +/- 6.6 hours/day), the second 4 week period (63.4 +/- 29.1 versus 58.9 +/- 30.9%, p = 0.59) (15.2 +/- 7.0 versus 14.1 +/- 7.4 hours/day) and the entire 8-week period (69.3 +/- 24.7 versus 67.7 +/- 26.2%, p = 0.82, Mann-Whitney U-test) (16.7 +/- 6.0 versus 16.1 +/- 6.5 hours/day), respectively. An abnormal pneumocardiogram at the time of discharge was the only identified factor that improved the compliance for the entire 8-week period (73.1 +/- 22 versus 52.1 +/- 28.5%, p = 0.02) (17.5 +/- 5.2 versus 12.5 +/- 6.8 hours/day) and the first 4-week period of monitoring (81.7 +/- 22.9 versus 59.5 +/- 31.3%, p = 0.01) (19.6 +/- 5.5 versus 14.2 +/- 7.5 hours/day). CONCLUSION: Weekly telephone contact, without specific encouragement to use the monitor, did not improve compliance. Compliance was greater in subjects who had abnormal pneumocardiogram results at the time of discharge from hospital regardless of their telephone/standard group assignment. We speculate that in this already compliant population, more targeted advice is necessary to increase compliance.

Comparison of analgesics in ameliorating the pain of circumcision.

OBJECTIVE: Our objective was to compare two methods of pain control during neonatal circumcision: a sucrose-dipped pacifier and an analgesic cream (EMLA). STUDY DESIGN: This study was conducted in our well-baby nursery where 80 male infants were placed into one of four groups: control (water-dipped pacifier only), sucrose alone, EMLA alone, or sucrose and EMLA. Heart rate, oxygen saturation, systolic and diastolic blood pressure, and crying time were measured as indicators of pain. The primary data analysis was a 2 x 2 factorial analysis of variance with repeated measures. RESULTS: Physiologic and behavioral parameters indicated significantly (p < 0.05) decreased pain response in all treatment groups compared with that in the control group. The combination of sucrose and EMLA was most effective in reducing pain responses; sucrose alone was significantly less effective. There were no side effects of treatment. CONCLUSION: Pain during neonatal circumcision can be optimally ameliorated by combined use of a sucrose-dipped pacifier and a local analgesic cream.

Electric field mapping and structure-activity relationship for cardiotonic activities of medorinone and some of its analogs.

Medorinone 5-methyl-1,6-napthyridin-2(1H)-one and some of its analogs having varying degrees of cardiotonic potency have been studied by molecular orbital and electric field mapping methods. Ground state geometries of the molecules were optimized using the MNDO molecular orbital method. Hybridization displacement charges (HDC) combined with Löwdin charges as well as Mulliken charges were used for electric field mapping around the molecules. Electric fields near the O2 site of medorinone and its analogs correlate well with their observed cardiotonic potencies. This result is in agreement with certain pharmacological models for cardiotonics.