Diffusion of Hydroxyl Ions from Calcium Hydroxide and Aloe vera Pastes

This study evaluated the diffusion through the dentinal tubules of hydroxyl ions from different calcium hydroxide (CH) pastes containing Aloe vera. Sixty single-rooted bovine teeth were used. The tooth crowns were removed, the root canals were instrumented and the specimens were assigned to 4 groups (n=15) according to the intracanal medication: Group CH/S - CH powder and saline paste; Group CH/P - CH powder and propylene glycol paste; Group CH/A - calcium hydroxide powder and Aloe vera gel paste; Group CH/A/P - CH powder, Aloe vera powder and propylene glycol paste. After placement of the root canal dressings, the teeth were sealed coronally and apically with a two-step epoxy adhesive. The teeth were placed in identified flasks containing deionized water and stored in an oven with 100% humidity at 37 °C. After 3 h, 24 h, 72 h, 7 days, 15 days and 30 days, the deionized water in the flasks was collected and its pH was measured by a pH meter. The obtained data were subjected to statistical analysis at a significance level of 5%. The results demonstrated that all pastes provided diffusion of hydroxyl ions through the dentinal tubules. The combination of Aloe vera and CH (group CH/A) provided a constant release of calcium ions. Group CH/A/P showed the highest pH at 24 and 72 h. In conclusion, the experimental pastes containing Aloe vera were able to enable the diffusion of hydroxyl ions through the dentinal tubules.

Este estudo avaliou a difusão de íons hidroxila de diferentes pastas de hidróxido de cálcio contendo Aloe vera através dos túbulos dentinários. Foram utilizados 60 dentes bovinos unirradiculares. As coroas dos dentes foram removidas, os canais radiculares foram instrumentados e divididos em 4 grupos (n=15) de acordo com a medicação intracanal: Grupo HC/SF - pasta de hidróxido de cálcio e soro fisiológico; Grupo HC/P - pasta de hidróxido de cálcio e propilenoglicol; Grupo HC/A - pasta de hidróxido de cálcio e Aloe vera gel; Grupo HC/A/P - pasta de hidróxido de cálcio, propilenoglicol e Aloe vera. Após o preenchimento dos canais radiculares com as respectivas pastas, os dentes foram selados coronalmente e na região do ápice radicular com adesivo epóxi. Os dentes foram colocados em frascos identificados contendo água deionizada e armazenados em estufa, com 100% de umidade, a 37°C. Após 3h, 24h, 72h, 7 dias, 15 dias e 30 dias, a água deionizada dos frascos foi coletada e realizada a medição do pH com auxílio de um pHmetro. Os dados obtidos foram submetidos à análise estatística, com grau de significância de 5%. Os resultados mostraram que todas as pastas estudadas promoveram a difusão dos íons hidroxila através dos túbulos dentinários. A associação do Aloe vera ao HC (grupo HC/A) resultou em uma liberação de forma constante de íons cálcio. O grupo HC/A/P mostrou o pH mais elevado que as demais pastas em 24 e 72 horas. Concluiu-se que as pastas experimentais contendo Aloe vera foram capazes de permitir a difusão de íons hidroxila através dos túbulos dentinários.

Nutritional values and antioxidant potential of some edible mushrooms of Kashmir valley

Mushrooms are considered rich in proteins, carbohydrates and other nutrients. The present study was carried out to evaluate some edible mushrooms of Kashmir valley for their protein, carbohydrate and lipid contents. The highest protein content was found in Boletus edulis [2.20g] followed by Agaricus bisporus [1.80g], Pleurotus ostreatus [1.68g], Morchella esculenta [1.62g] and Pleurotus sajor caju [1.6g]. Carbohydrate content also showed variation in all the five tested edible mushroom species, the highest carbohydrate content observed in Boletus edulis [6.0g] followed by Agaricus bisporus [4.85g], Pleurotus ostreatus [4.30g], Morchella esculenta [4.25g] and Pleurotus sajor caju [3.35g] respectively. Similar results were observed for lipid content. The present study was also investigated for the antioxidant potential of aqueous extract of mushroom species by the methods of DPPH radical scavenging activity, hydroxyl radical scavenging activity and superoxide radical scavenging activity. All these in vitro antioxidant activities were concentration dependent, which were compared with standard antioxidant Catechin

Evaluation of free radical scavenging activity of Butea monosperma Lam.

In the present study, ethyl acetate, butanol and aqueous fractions derived from total methanol extract of Butea monosperma flowers were evaluated for radical scavenging activities using different in vitro models like reducing power assay, scavenging of 2,2 diphenyl-1-picrylhydrazyl (DPPH) radical, nitric oxide radical, superoxide anion radical, hydroxyl radical and inhibition of erythrocyte hemolysis using 2, 2' azo-bis (amidinopropane) dihydrochloride (AAPH). Methanol extract along with its ethyl acetate and butanol fractions showed potent free radical scavenging activity, whereas aqueous fraction was found to be devoid of any radical scavenging properties. The observed activity could be due to the higher phenolic content in the extracts (16.1, 25.29, and 17.74% w/w in methanol extract, ethyl acetate and butanol fractions respectively). HPTLC fingerprint profile of the ethyl acetate and butanol fractions were developed which would serve as reference standard for quality control of the extracts.

Bacteriostatic action of synthetic polyhydroxylated chalcones against Escherichia coli

In previous work the bacteriostatic action of trihydroxylated chalcones against Staphylococcus aureus ATCC 25 923 was investigated. In this work the action of 2',4',2-(OH)3-chalcone, 2',4',3-(OH)3-chalcone and 2',4',4-(OH)3-chalcone against Escherichia coli ATCC 25 922 was evaluated. Growth kinetic curves of E. coli were made in nutritive broth added with increasing drug concentrations. The specific growth rates of the microorganisms were calculated by a kinetic turbidimetric method, which was previously probed and the minimal inhibitory concentrations (MIC's) were evaluated by a mechanism of action proposed. The MICs of 2',4',3-(OH)3-chalcone and 2',4',2-(OH)3-chalcone were 46 microg/ml and 122 microg/ml, respectively. The 2',4',4-(OH)3-chalcone was inactive. The MIC value of 2',4',3-(OH)3-chalcone (46 microg/ml), more active than 2',3-(OH)2-chalcone (72.2 microg/ml) may be due to the introduction of an electron donating group (-OH) at position 4' in the aromatic A-ring, which activates the region that includes the 2'-hydroxyl neighbor group and the alpha,beta-unsaturated carbonyl group.

Development of semi-empirical model for radiochemical reactions

A mathematical model, which represents the radio-chemical reactions in water, was developed to study the effect of the radio-chemical products on cell kiling. The five differential equations were solved using dose rate equation and cell survival as a function of dose was computed. The known chemical rate constants were taken from the literature and unknown constants were determined by curve fitting to an experimental data. Sensitivity studies were performed by varying the rate constants and showed that the yield of H-radical had little effect whereas the change in concentration of OH-radical and direct interaction resulted in significant change on cell survival. The sensitivity studies showed good agreement with the observed effects. In conclusion, we developed a mathematical model that could be used as a means for the estimation of radiation damage.