Preparation and in-vivo evaluation of dimenhydrinate buccal mucoadhesive films with enhanced bioavailability.

Dimenhydrinate (DMH)-loaded buccal bioadhesive films for the prevention and treatment of motion sickness were prepared and optimized. This study examines the rate of drug release from the films for prolonged periods of time to reduce or limit the frequency of DMH administration. Based on preliminary studies using various polymers and concentrations, hydroxyethylcellulose (2.5, 3.0, and 3.2%), and xanthan gum (2.8%) were chosen as matrix polymers. The films were analyzed with respect to their mechanical, physicochemical, bioadhesive, swelling, and in-vitro release properties. In in-vivo pharmacokinetic studies, xanthan gum-based DMH buccal film was associated with significantly increased DMH plasma levels between 1 h and 5 h after DMH dosing when compared with an oral drug solution. The area under the curve AUC0-7 h value of the mucoadhesive buccal film was two-fold higher than the oral DMH solution. Histological analysis revealed that DMH films cause mild morphological and inflammatory changes in rabbit buccal mucosa. The DMH buccal film is effective for approximately 7 h, thus representing an option for single-dose antiemetic therapy. This dosage regimen could be particularly beneficial for chain travelers who travel for long periods of time.

[Effects of atovaquone and astragalus combination on the treatment and IL-2, IL-12, IFN-γ levels on mouse models of acute toxoplasmosis]. / Atovakuon ve astragalus kombinasyonunun akut toksoplazmozlu fare modeli tedavisi ve IL-2, IL-12, IFN-γ düzeyleri üzerindeki etkileri.

Reactivation of Toxoplasma gondii infections and serious clinical manifestations such as encephalitis may develop in immunocompromised subjects and AIDS patients. Different protocols are used for the treatment of toxoplasmosis in high-risk patient groups, however life-long prophylactic therapy against reactivation risk in AIDS patients may lead to several undesired results. Atovaquone is an effective antiprotozoal agent against toxoplasmosis with minor side effects. On the other hand, Astragalus membranaceus root extract (AmE) has been shown to have immunomodulatory and antimicrobial activities, empowering immunity by enhancing proliferation and activation of phagocytic cells mainly macrophages, and inducing Th1 type immune response. The aim of this study was to investigate the effectiveness of atovaquone alone and in combination with AmE, in the treatment of toxoplasmosis, and on the levels of IL-2, IL-12 and IFN-γ in experimentally infected mice with T.gondii. For this purpose, four experimental groups, each consisting of eight BALB/c mice, were set with the approval of Ethics Committee for the Animal Experiments. All the mice were infected with 0.5 ml of a suspension containing 2 x 104/ml trophozoites prepared from T.gondii RH strain by intraperitoneal injection. Twenty-four hours after the infection, atovaquone (100 mg/kg/day) was given to atovaquone group, AmE (0.075 mg/g) to astragalus group and atovaquone (100 mg/kg/day) plus AmE (0.075 mg/g) to Atovaquone + Astragalus (Ato + Astra) group by oral gavage. The mice in the fourth group, which was the control group, were all infected but untreated. The above administrations were carried out for seven days. On the 8th day peritoneal fluids of mice were collected under anaesthesia and trophozoite numbers per 1 ml were detected by counting on the Thoma slide. In addition, the heart bloods of mice were drawn and IL-2, IL-12, IFN-γ levels were determined in serum samples by using commercial ELISA kits (eBioscience, Austria). The mean number of trophozoites in Ato + Astra group was found significantly lower than the number of trophozoites in the other three groups (p< 0.05). The number of trophozoites in the atovaquone and astragalus groups were found significantly lower than the number of trophozoites in the control group (p< 0.05). There was a significant increase in IL-2 levels of astragalus group compared with the other three groups, in addition when IL-2 levels of Ato + Astra group were compared with ones in other three groups, a significant decrease was noticed (p< 0.05). There was a definite increase in IL-12 levels of atovaquone, astragalus and the control groups compared to those in Ato + Astra group (p< 0.05). A significant increase was found in IFN-γ levels in atovaquone and Ato + Astra groups compared with those in the control group (p< 0.05). Within the reach of our literature survey, this study was the first research in which the effectiveness of the combination of atovaquone and AmE was investigated in the treatment of acute toxoplasmosis. The results of our study suggested that there might be a synergy between atovaquone and AmE in the treatment of acute toxoplasmosis. In case these results are supported by further studies, atovaquone and AmE combination may have a potential to be used for therapy in immunocompromized patients such as AIDS patients who have a risk for toxoplasmosis.

[Investigation of combined effectiveness of spiramycin and beta-glucan in mice models of acute toxoplasmosis and determination of IL-10, IL-12 and TNF-α levels]. / Spiramisin ve Beta-Glukan Kombinasyonu Etkinliginin Akut Toksoplazmozlu Fare Modelinde Arastirilmasi ve IL-10, IL-12 ve TNF-α Düzeylerinin Belirlenmesi.

Toxoplasmosis which is caused by Toxoplasma gondii, has a high risk of fetal infection development if the infection occurs during pregnancy. Treatment with oral spiramycin is recommended during pregnancy in order to prevent the transmission of protozoa to fetus and development of infection. Since beta- glucan is known to stimulate the immune system and increase the phagocytic activity of the cells, it has been shown to exhibit immunomodulatory effect on many infectious diseases. The objectives of this study were to investigate the effectiveness of beta-glucan alone and in combination with spiramycin and to determinate the levels of interlökin (IL)-10, IL-12 and tumor nekrosis factor (TNF)-α in mice experimentally infected with T.gondii. For this purpose, four experimental groups each consisting of eight BALB/c mice, were formed with the approval of Ethics Committee for the Animal Experiments. All the mice were infected with 2 ml of suspension containing 2 x 102/ml of trophozoite prepared from T.gondii RH strain (Refik Saydam National Public Health Agency, Parasitology Laboratory of Communicable Diseases Research Department, Ankara, Turkey), by intraperitoneal injection. Twenty-four hours after the infection, beta-glucan (3 mg/day) was given to the beta-glucan group, spiramycin (200 mg/kg/day) to the spiramycin group, beta-glucan (3 mg/day) plus spiramycin (200 mg/kg/day) to the beta-glucan-spiramycin (BG-S) group by oral gavage. The fourth group which was the control group was infected but untreated. The above administration was carried out for seven days. On the 8th day, under anaesthesia, 1 ml normal saline was given into the peritoneum, drawn back later and the number of trophozoites in 1 ml of peritoneal fluid was determined by counting them on the Thoma slide. Moreover, by drawing the heart blood; IL-10, IL-12, TNF-α levels were determined in serum samples by ELISA method (eBioscience Platinum, Austria). The number of trophozoites in the BG-S group was found significantly lower than the number of trophozoites in control, beta-glucan and spiramycin groups (p< 0.05). There was no significant difference between the beta-glucan and spiramycin groups, however the number of trophozoites in both groups was significantly lower than the number of trophozoites in the control group (p< 0.05). There was a certain decrease in IL-10 level in spiramycin and BG-S groups, compared to the control group, in addition when IL-10 levels in spiramycin and BG-S groups were compared with BG group, a significant decrease was noticed (p< 0.05). There was no difference in IL-12 levels between the groups, while there was a certain decrease in TNF-α level in beta-glucan, spiramycin, BG-S group in comparison to the control group. Within the reach of our literature survey, this study is the first research in which the effectiveness of the combination of beta-glucan and spiramycin in the treatment of acute toxoplasmosis was investigated. The results of our study suggested that there might be synergy between beta-glucan and spiramycin in the treatment of acute toxoplasmosis.

The effect of vitamin C on ischemia reperfusion injury because of prolonged tourniquet application with reperfusion intervals.

We examined the effect of vitamin C on muscle injury distal to the tourniquet which was applied for 4 hours with 10- and 20-minute reperfusion intervals after 2 hours of tourniquet. Sixty-four Sprague-Dawley rats were allocated to 4 randomized groups. After 2 hours tourniquet, 10- and 20-minutes of reperfusion were allowed to half of each group respectively. Afterward an additional 2 hours compression was applied. Except the control group the animals received vitamin C intravenously, before the first tourniquet in Group I, at the reperfusion interval in Group II, and at both times in Group III. Malondialdehyde levels were measured in blood and the tibialis anterior muscle. The muscle was histopathologically examined. The data was evaluated statistically. The effects of timing and the dose of vitamin C on ischemia reperfusion injury remain controversial and there was no statistical difference between 10- and 20-minute reperfusion intervals. But the blood malondialdehyde levels showed that vitamin C has a positive effect on the muscle injury caused by ischemia-reperfusion.

Male rats exhibit higher oxidative protein damage than females of the same chronological age.

The basis of the difference in life expectancy between males and females is still unknown. Previous studies have provided compelling evidence for the presence of oxidized proteins, and lipids in advanced human atherosclerotic lesions. The gender factor responsible for such protein oxidation is unknown and controversial. Our aim was to reveal the difference between protein oxidation parameters of male and female rats of the same chronological age to understand the protein oxidation mechanisms enabling females live longer than males. In the current study, we investigated the relation between protein hydroperoxide levels (P-OOH) and other protein oxidation parameters such as protein carbonyl (PCO), total thiol (T-SH), advanced oxidation protein products (AOPP), and nitrotyrosine (NT). Our study also covered other oxidative stress parameters such as lipid hydroperoxides (L-OOH), and superoxide dismutase (SOD) activity in the plasma of male and female aged rats. Plasma P-OOH and AOPP levels of male rats were significantly higher compared with those of the female rats. T-SH levels were significantly lower in the aged male rats compared with those of the female rats. On the other hand, PCO, NT, and L-OOH levels, and SOD activity were all found to be not different. These data support the hypothesis that elevated levels of P-OOH and AOPP contribute to the extent of protein, but not lipid, oxidation in plasma of aged male rats. Furthermore, the results presented here may also rationalize studies, which have shown that protein oxidation is modulated on the basis of gender dependency.

Prooxidant activities of alpha-lipoic acid on oxidative protein damage in the aging rat heart muscle.

In the present study, we investigated whether alpha-lipoic acid (ALA) supplementation could have prooxidant or antioxidant effects on protein oxidation parameters such as protein carbonyl (PCO), nitrotyrosine (NT), advanced oxidation protein products (AOPP), and protein thiol (P-SH), as well as oxidative stress parameters such as total thiol (T-SH), non-protein thiol (Np-SH), and lipid hydroperoxide (LHP) in the heart muscle tissue of aged rats. ALA (100 mg/kg body wt/day) was administered intraperitoneally to the experimental animals for 14 days. PCO, NT, AOPP, and P-SH levels were increased, T-SH and Np-SH levels were not changed, and only LHP levels were decreased in the heart muscle tissue of aged rats with ALA supplementation. When compared with non-supplemented aged rats, increasing levels of protein oxidation markers such as PCO, NT, and AOPP in ALA-supplemented aged rats may suggest that oxidative protein damage is increased in ALA-supplemented aged rats. We assume that an explanation for our findings regarding ALA supplementation on protein oxidation markers in the heart muscle tissue of aged rats may be due to the prooxidant effects of ALA. The prooxidant effects of ALA supplementation should be considered in future studies.

Relation of aging with oxidative protein damage parameters in the rat skeletal muscle.

OBJECTIVES: An increase in oxidative stress may contribute to the development of oxidative protein damage in the aging rat skeletal muscle. Our aim was to reveal protein carbonyl (PCO), advanced oxidation protein products (AOPP), a novel marker of oxidative stress, and protein thiol (P-SH) levels as markers of protein oxidation, as well as lipid hydroperoxide (LHP) levels as a marker of lipid peroxidation, and relation of nitrotyrosine (NT) levels with these markers in skeletal muscle tissue of young, adult, and old male Wistar rats. DESIGN AND METHODS: In the present study, we investigated the relation between aging and oxidative protein damage parameters such as PCO, NT, AOPP, and P-SH, as well as oxidative stress parameters such as total thiol, nonprotein thiol, and LHP in the skeletal muscle tissue of young, adult, and old Wistar rats. RESULTS: PCO and NT levels of old rats were significantly increased compared with those of young and adult rats. Skeletal muscle AOPP levels were significantly increased in old rats compared with those of adult rats. P-SH levels were significantly decreased in old rats compared with those of young rats. CONCLUSIONS: The finding that the increase in PCO levels of young vs. old group was more significant than that of adult vs. old group may suggest that PCO formation is an early specific marker of aging process in skeletal muscle. In addition, increased levels of nitrotyrosine in the skeletal muscle of the old rat group may be a novel specific marker of oxidative protein damage in the aging muscle. The absence of correlation between oxidative protein damage markers mentioned above and LHP levels may indicate that protein oxidation and lipid peroxidation in the aging rat skeletal tissue are two distinct mechanisms.