Hypericum sp.: essential oil composition and biological activities

Phytochemical composition of Hypericum genus has been investigated for many years. In the recent past, studies on the essential oils (EO) of this genus have been progressing and many of them have reported interesting biological activities. Variations in the EO composition of Hypericum species influenced by seasonal variation, geographic distribution, phenological cycle and type of the organ in which EO are produced and/or accumulated have also been reported. Although many reviews attributed to the characterization as well as biological activities of H. perforatum crude extracts have been published, no review has been published on the EO composition and biological activities of Hypericum species until recently (Crockett in Nat Prod Commun 5(9):1493–1506, 2010; Bertoli et al. in Global Sci Books 5:29–47, 2011). In this article, we summarize and update information regarding the composition and biological activities of Hypericum species EO. Based on experimental work carried out in our laboratory we also mention possible biotechnology approaches envisaging EO improvement of some species of the genus.Fundação para a Ciência e a Tecnologia (FCT) - project PTDC/AGR AAM/70418/2006, SFRH/BD/ 13283/2003

Evaluation of Silybum marianum seed extract and vitamin B6 derivatives on methylglyoxal and sugar-induced oxidative DNA damage

Reducing sugars are known to generate reactive oxygen species (ROS), mainly by means of the glycation reaction. The hydroxyl radical, a prominent entity of ROS, is known to alter cellular DNA and induces damage to DNA, and plays a role in diseases such as diabetes mellitus. In this study, the oxidative damage of DNA induced by the lysine/Fe 3+ /MG reaction was investigated. Silybum marianum seeds extract ( Sly E), standard silymarin (Sly), and vitamin B6 derivatives, pyridoxal-5-phosphate (PLP), pyridoxamine (PM), and pyridoxine (P) in reversing glycation-induced damage in DNA were evaluated. In addition, different sugars and sugar phosphates were incubated with plasmid pBR 322 DNA to control and compare their harmful effects. Our results revealed that Sly E protected lysine/Fe 3+ /MG induced oxidative DNA damage more effectively than Sly. Vitamins, on the other hand, prevented this DNA damage in the order of PLP>P>PM. The DNA altering and damaging intensity of sugars and sugar phosphates tested increased considerably in the following order: Ribose-5-phosphate > fructose-6-phosphate > ribose > fructose > fructose-1,6 biphosphate > glucose-6 phosphate > glucose. The results show that the lysine/Fe 3+ /MG glycation reaction can cause oxidative damage of DNA through a mechanism involving hydroxyl radicals. It also provides evidence that ribose-5-phosphate and fructose and its phosphate metabolites can alter DNA more rapidly in vitro than glucose and its phosphate metabolites

The effect of vitamin E treatment during preovulatory period on reproductive performance of goats following estrous synchronization using intravaginal sponges

The objectives of this study were to investigate whether the use of intravaginal sponge for estrous synchronization of goats causes oxidative stress, and to examine the effect of administering vitamin E during preovulatory period on reproductive performance of estrous synchronized goats. Estrus was synchronized in 36 nonlactating adult does using intravaginal sponges containing 30mg of fluorogestane acetate (FGA) for 14 days. All females received 500 IU of eCG at the sponge withdrawal. The goats were allocated at random to two groups balanced for breed, age and body weight. Treatment group (n = 18) received 200mg of vitamin E i.m. at the time of sponge removal and again at the time of second artificial insemination. The other 18 goats (control) were administered 1 ml of physiological saline instead of vitamin E on each of these two occasions. All does in estrus was intracervically inseminated at 12 and 24 h after the onset of estrus. Blood samples were collected every 72 h during the experimental period for evaluation of malondialdehyde (MDA) and vitamin E concentrations. Serum MDA level increased and vitamin E concentration decreased during the period of vaginal sponge application. Following the sponge removal, MDA level declined rapidly to below basal level in the treatment group but remained high in the control group. Conversely, vitamin E concentration increased in the treatment group after the sponge withdrawal and remained at a low level in the control group. No statistically significant differences (P > 0.05) were observed between groups in terms of estrous response, conception rate, gestation length or kidding rate.However, thenumber of multiple births (70.0% versus 50.0%) and prolificacy rate (2.40±0.37 versus 1.63±0.26 kids per kidding) were significantly higher (P < 0.05) for the treatment group than those of the control group. The results indicate that the use of intravaginal sponges for estrous synchronization of goats causes an increase in level of oxidative stress. However, the vitamin E treatment during preovulatory period can prevent the overproduction of reactive oxygen species (ROS), and it may improve the multiple birth rates and the number of kids born in estrous synchronized goats

Reliability of SleepStrip as a screening test in obstructive sleep apnea patients

Obstructive sleep apnea syndrome (OSAS) is a common sleep disorder and related to multiple conditions that cause mortality in adults. In the present study, reliability of SleepStrip, a disposable screening device for detection of OSAS, is tested. In this prospective, nonrandomized double-blinded single cohort study at an academic health center, the performance of the SleepStrip in detecting respiratory events and establishing an SleepStrip score (Sscore) in domestic use were compared to the apnea-hypopnea index (AHI) obtained by the standard polysomnography (PSG) recordings in the sleep laboratory. Forty-one patients who have the PSG results participated the study and wore the SleepStrips at home. Test efficiency rate was 75% and there was a positive correlation between PSG-AHI scores and Sscores (r = 0.71, p 30 levels. The SleepStrip has 100% specificity and positive predictive values, but it also has low negative predictive and sensitivity values. The SleepStrip is not a reliable screening test in differential diagnosis among simple snorers, mild, moderate and severe OSAS patients. However, high Sscores highly indicate the presence of moderate-severe OSAS. We can safely send these patients to split-night PSG and continuous, automatic, bi-level positive airway pressure (CPAP/BPAP/APAP) titration at the same night. The SleepStrip may increase the effective use of the sleep laboratories