Dumitru Cojocaru

Methanolic extract of Hibiscus asper leaves improves spatial memory deficits in the 6-hydroxydopamine-lesion rodent model of Parkinson's disease.

ETHNOPHARMACOLOGICAL RELEVANCE While the Hibiscus asper Hook.f. (Malvaceae) is a traditional herb largely used in tropical region of the Africa as vegetable, potent sedative, tonic and restorative, anti-inflammatory and antidepressive drug, there is very little scientific data concerning the efficacy of this. AIM OF THE STUDY We investigated antioxidant activity and the effects of methanolic extract of Hibiscus asper leaves on neurological capacity of male Wistar rats subjected to unilateral 6-hydroxydopamine (6-OHDA)-lesion. MATERIALS AND METHODS Two model systems: 2,4-dinitrophenyl-1-picryl hydrazyl (DPPH) radical scavenging activity and β-carotene bleaching inhibition assay were used to measure the antioxidant activities of the plan extract. We also investigated the neuroprotective effect of methanolic extract of Hibiscus asper leaves (50 and 100 mg/kg) in male Wistar rats subjected to unilateral 6-hydroxydopamine (6-OHDA)-lesion rat model. RESULTS Methanolic extract of Hibiscus asper leaves showed potent antioxidant and free radical scavenging activity. Chronic administration of methanolic extract (50 and 100 mg/kg, i.p., daily, for 7 days) significantly reduce anxiety-like behavior and inhibit depression in elevated plus-maze and forced swimming tests, suggesting anxiolytic and antidepressant activity. Also, spatial memory performance in Y-maze and radial arm-maze tasks was improved, suggesting positive effects on memory formation. CONCLUSIONS Taken together, our results suggest that the methanolic extract of Hibiscus asper leaves have antioxidant effects and might provide an opportunity to management neurological abnormalities in Parkinsons disease conditions.

In Vitro antibacterial and antibiotic-potentiation activities of four edible plants against multidrug-resistant gram-negative species

BackgroundThe present study was designed to investigate the antibacterial activities of the methanol extracts of four Cameroonian edible plants, locally used to treat microbial infections, and their synergistic effects with antibiotics against a panel of twenty nine Gram-negative bacteria including Multi-drug resistant (MDR) phenotypes expressing active efflux pumps.MethodsThe broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) of the extracts [alone and in the presence of the efflux pumps inhibitor (EPI) Phenylalanine-Arginine β- Naphtylamide (PAβN)], and those of antibiotics in association with the two of the most active ones, Piper nigrum and Telfairia occidentalis. The preliminary phytochemical screening of the extracts was conducted according to the standard phytochemical methods.ResultsPhytochemical analysis showed the presence of alkaloids and flavonoids in all studied extracts. Other chemical classes of secondary metabolites were selectively present in the extracts. The results of the MIC determination indicated that the crude extracts from P. nigrum and V. amygdalina were able to inhibit the growth of all the twenty nine studied bacteria within a concentration range of 32 to 1024 μg/mL. At a similar concentration range (32 to 1024 μg/mL) the extract from T. occidentalis inhibited the growth of 93.1% of the tested microorganisms. At MIC/2 and MIC/5, synergistic effects were noted between the extracts from P. nigrum and T. occidentalis and seven of the tested antibiotics on more than 70% of the tested bacteria.ConclusionThe overall results of the present study provide information for the possible use of the studied edible plants extracts in the control of bacterial infections including MDR phenotypes.

The effects of a 6-OHDA induced lesion in murine nuccleus accumbens on memory and oxidative stress status

Nucleus accumbens (NAcc) are a collection of neurons that form the main part of the ventral striatum, which is a significant dopaminergic structure. Also, NAcc is thought to play an important role in reward, pleasure, laughter, addiction, aggression, fear, and the placebo effect. In the present work we were interested in studying the effects of a 6-OHDA induced lesion in the nucleus accumbens (NAcc), which is known as an important dopaminergic structure, on a specific behavioral task that involves both short term and long term spatial memory (the radial-8-arm-maze task), as well as on the oxidative stress markers (two antioxidant enzymes: superoxide dismutase-SOD and glutathione peroxidase-GPX and a lipid peroxidation marker: malondialdehyde-MDA, as well as the total antioxidant status-TAS) from the temporal lobe, which is considered to be the most vulnerable cortical area to oxygen levels fluctuations and hypoxia. Our results showed some significant effects of this lesion on the reference memory errors and time necessary to finish the test in the radial-8-arm-maze task. Additionally, increased oxidative stress status was demonstrated in the temporal lobe of the lesioned rats, as demonstrated by the high levels of lipid peroxidation and decreased total antioxidant status. Moreover, significant correlations are reported here between the behavioral parameters which we studied in the radial-8-arm-maze task and the aforementioned oxidative stress markers.

Increased oxidative stress status in rat serum after five minutes treadmill exercise

Although it is accepted that an important correlation exists between the physical exercise and the oxidative stress status, the data regarding the levels of the main oxidative stress markers after physical training have been difficult to interpret and a subject of many controversies. There are also very few studies regarding the effects of short-time exercise on the oxidative stress status modifications. Thus, in the present report we were interested in studying the modifications of some oxidative stress markers (two antioxidant enzymes-superoxide dismutase and glutathione peroxidase, a lipid peroxidation parameter — malondyaldehide, the total antioxidant status and protein carbonyl levels), from the serum of rats that were subject to one bout of five minutes exercise on a treadmill, when compared to a control sedentary group. In this way, we observed a decrease of superoxide dismutase specific activity in the rats which performed the exercises. Still, no modifications of glutathione peroxidase specific activity were found between groups. In addition, increased levels of malondyaldehide and protein carbonyls were observed in the rats subjected to exercises. In conclusion, our data provides new evidence regarding the increase of the oxidative stress status, as a result of a 5-minutes bout of treadmill exercising in rats, expressed through a decrease in the SOD specific activity and the total antioxidant status and also an increase of the lipid peroxidation and protein oxidation processes.

Factors Influencing The Breeding Success of White Storks Ciconia ciconia in Eastern Romania

Summary. The White Stork is a farmland and wetland bird that has become part of village communities by nesting in urban areas. Despite breeding close to people, allowing easy access for monitoring, its population in Eastern Europe is poorly studied. This paper presents the breeding success and habitat selection of a White Stork population from Eastern Romania. During the 2016 breeding season their breeding performance was poor compared to other European countries; on average only 2.25 nestlings fledged per nest. With respect to their habitat selection, the Eastern Romanian population uses similar habitats to storks elsewhere in Europe. Parameters influencing their breeding success could include weather conditions, geomorphology, habitat, landscape and intraspecific variables. To find those variables involved in the fluctuation of chick numbers General Linear Model (GLM) analyses, with a step procedure selection, were used. These analyses covered 55 variables. The best model of breeding success included altitude (P = 0.001); a higher elevation is associated with a lower number of chicks per nest. The number of river sectors (P = 0.045) and the distance to the nearest empty nest (P = 0.001) also have a positive influence on breeding success. These two variables could relate to the food availability in the study area. —Fasolă-Mătăsaru, L., Baltag, E.Ş., Ichim, P. & Cojocaru, D. (2018). Factors influencing the breeding success of White Storks Ciconia ciconia in Eastern Romania. Ardeola, 65: 271–282.

The Influence of Vitamin C on the Oxidative Stress in Untrained Smoking Subjects

Some researchers that have analyzed the connection between physical effort and oxidative stress parameters have reported changes, that is increase, decrease or stagnation of these biochemical indicators measured afterphysical effort. It is a known fact that the people who smoke are exposed to oxidative stress, which is accelerated during physical exercise. The study aims to assess the changes that occur following easy physical exercise, dosed at 50 % of maximal aerobic power, performed for 40 minutes on the cycle ergometer, and after the administration of 1000 mg of vitamin C, 12 hours before the same type of effort, on indicators of oxidative stress in untrained smokers. The evaluation of the VO2max, for the accurate calculation of maximal aerobic power and the percentage of the workout, was done by ergospirometry with aFitMate PRO Cosmed device. There were recorded changes in the activity of the superoxide dismutase, catalase, glutathione peroxidase and malondialdehyde concentration, which certifies the acceleration of oxidative stress after strenuous efforts of the subjects whereas after the administration of vitamin C, improvements have been achieved . The results lead to the recommendation of introducing vitamin C in the diet of the people who smoke and exercise regularly.

The Effects of Central Angiotensin II and Its Specific Blockers on Nociception. Possible Interactions with Oxidative Stress Status / Efekti Centralnog Angiotenzina II I Njegovih Specifičnih Blokatora Na Nocicepciju. Moguće Interakcije Sa Statusom Oksidativnog Stresa

Summary It has already been demonstrated that a complete brain renin-angiotensin system (RAS) exists distinctly separate from the peripheral system and is implicated in complex functions such as memory, emotional responses and pain. Regarding the implications of angiotensin II (the main bioactive peptide of RAS) in pain, although there are many studies in this area of research, most of the results are controversial. Also, it seems that oxidative stress follows angiotensin II infusion, but the role of AT1 vs. AT2 receptors is not well established. In this context, we were interested in studying the effects of central RAS on nociception, through the intracerebroventricular administration of losartan and PD-123177 (antagonists for the AT1/AT2 receptors), as well as an ACE inhibitor (captopril) and also angiotensin II in rats, which were subsequently tested using the hot-plate task, a well known behavioral test for pain perception. We present here the analgesic effect of angiotensin II administration, as shown by in creased latency-time in the hot-plate, as well as a nociceptive effect of angiotensin II blockers like AT1 and AT2 specific antagonists (losartan and PD-123177) and an ACE inhibitor (captopril), as their administration resulted in decreased latency-time. Moreover, we demonstrated a significant correlation between the results of the nociceptive behavioral task and the levels of some main oxidative stress markers. This provides additional evidence for an analgesic effect of Ang II administration, as well as for a nociceptive effect of Ang II blockers. Moreover, a significant correlation between the nociception and angiotensin II-induced oxidative stress is presented. Kratak sadržaj Do sada je već pokazano da kompletan moždani renin-angiotenzin sistem (RAS) postoji zasebno od perifernog sistema i da je uključen u složene funkcije kao što su memorija, emocionalni odgovori i bol. Sto se tiče implikacija angiotenzina II (glavnog bioaktivnog peptida RAS) u bolu, mada u ovoj oblasti istraživanja postoje mnoge studije, rezultati su većinom oprečni. Takođe, izgleda da infuziju angiotenzina II prati oksidativni stres, ali uloga receptora ATI i AT2 još nije razjašnjena. U tom kontekstu hteli smo da proučimo efekte centralnog RAS na nocicepciju preko intracerebroventrikularne administracije lozartana i PD-123177 (antagonista za receptore AT1/AT2) kao i jednog ACE inhibitora (kaptopril) i angiotenzina II kod pacova, koji su potom testirani metodom grejne ploče, poznatim bihevioralnim testom za percepciju bola. Predstavljamo analgetički efekat administracije angiotenzina II pokazan kroz povećanu latenciju na grejnoj ploči, kao i nociceptivni efekat blokatora angiotenzina II kao što su antagonisti specifični za ATI i AT2 (lozartan i PD-123177) i ACE inhibitora (kaptopril), pošto je rezultat njihove administracije bila smanjena latencija. Staviše, uočili smo značajnu korelaciju između rezultata nociceptivnog bihevioralnog testa i nivoa nekih od glavnih markera oksidativnog stresa. Na taj način obezbeđeni su novi dokazi u korist analgetičkog efekta administracije Ang II, kao i nociceptivnog efekta blokatora Ang II. Uz to, predstavljena je značajna korelacija između nocicepcije i oksidativnog stresa izazvanog angiotenzinom II.