SEARCH CONTENT

You are looking at 31 - 40 of 2,865 items :

Clear All

Abstract

Poly(3-hydroxybutyrate) is a natural polymer, produced by different bacteria, with good biocompatibility and biodegradability. Cardiovascular patches, scaffolds in tissue engineering and drug carriers are some of the possible biomedical applications of poly(3-hydroxybutyrate). In the past decade, many researchers examined the different physico-chemical modifications of poly(3-hydroxybutyrate) in order to improve its properties for use in the field of bone tissue engineering. Poly(3-hydroxybutyrate) composites with hydroxyapatite and bioglass are intensively tested with animal and human osteoblasts in vitro to provide information about their biocompatibility, biodegradability and osteoinductivity. Good bone regeneration was proven when poly(3-hydroxy-butyrate) patches were implanted in vivo in bone tissue of cats, minipigs and rats. This review summarizes the recent reports of in vitro and in vivo studies of pure poly(3-hydroxy-butyrate) and poly(3-hydroxybutyrate) composites with the emphasis on their bioactivity and biocompatibility with bone cells.

Abstract

The present study is aimed at computational prediction of the molecular interactions between resveratrol, celecoxib, leflunomide and human serum albumin (HSA) and then investigates the plasma protein binding of resveratrol combined with celecoxib or leflunomide by an ultrafiltration technique. Molecular operating environment (MOE, 2008.10) software package was used to explore molecular interactions between the drugs and HSA. Molecular docking was adopted to predict the interactions between resveratrol and other drugs and then the ultrafiltration technique was used to verify the docking results. In in vitro experiments, a mixture of resveratrol and celecoxib or leflunomide was added to rat plasma for determination of the plasma protein binding rate. Molecular docking results have shown that resveratrol interacts with HSA mainly through hydrogen bond and π-π stacking, while celecoxib and leflunomide bind only with the hydrogen bond. Celecoxib or leflunomide, even at high tested doses, did not affect the plasma protein binding of resveratrol, thus suggesting pharmacological suitability of the investigated combinations.

Abstract

Nicotiana glauca (Solanaceae), or tree tobacco, is found in dry arid climates of North America, Africa and Europe. It has been reported to have both toxic and medicinal properties. The main aim of this study was to analyze the phytochemical screening and quantitative estimation of polyphenols, flavonoids and flavonols of crude extracts from the leaves of Nicotiana glauca and to evaluate its in vitro antioxidant properties. Three different solvents were used to extract bioactive compounds from powdered leaves of Nicotiana glauca: dichloromethane (DCM), ethyl acetate (AE) and n-buthanol (n-BuOH). The three extracts were then subjected to qualitative phytochemical screening using standard procedures. Total phenolics, total flavonoids and total flavonols contents of the extracts were measured by Folin Ciocalteu and Aluminium chloride methods respectively. Furthermore, the antioxidant capacity evaluation was performed using the DPPH, ABTS, DMSO alcalin, Phenantroline, FRAP and CUPRAC methods. The three extracts were then subjected to qualitative phytochemical screening using standard procedures. These methods showed the presence of polyphenols and comarines in all extracts. Moreover, flavonoids, tannins, steroids and quinones were reported in the AE and n-BuOH extracts. In addition, alkaloids were seen to be present in DCM extract, while saponines and phlobatannins were absent in all extracts. The antioxidant capacity evaluation was performed using the DPPH, ABTS, DMSO alcalin, Phenantroline, FRAP and CUPRAC methods.

Results using the DPPH method showed strong free radical scavinging activity for three extracts. This activity decreased with increasing concentration in the following order: n-BuOH>AE>DCM. In other assays, all extracts showed good antioxidant activity which decreased with increasing concentration in the following order: AE > n-BuOH > DCM. Extracts were compared with standards: BHT, BHA, Tanic acid and α-Tocopherol. The antioxidant of these extracts is probably related to polyphenols content (351.55±0.07, 284.98±0.08 and 133.8±0.06 mg/g), flavonoids (105.97±0.04, 164.44±0.07 and 1.18±0.005 mg/g) and flavonols (22.41±0.24, 18.75±0.46 mg/g) in AE and n-BuOH, respectively.

As a conclusion, the results of the present study indicate that Nicotiana glauca leaves could be considered as a potential source of natural antioxidants.

Abstract

Fenugreek seeds are known as a source of various compounds, the most common of which are steroidal saponins. However, despite the growing interest in this plant material as a healing agent, spice and dietary supplement ingredient, the composition of Polish fenugreek seeds remains unknown. Therefore, the steroidal saponin complex in the seeds of T. foenum-graecum cultivated in Poland was qualitatively and quantitatively analyzed by the HPLC-ELSDESI-MS method. Two C-18 columns connected in series were used for the first time in analysis of fenugreek saponins and ELS detector parameters were optimized. A total of 26 furostanol saponins were revealed, of which 24 were tentatively identified. The HPLC-ELSD method developed for quantitative analysis was preliminarily validated and the determined amount of steroidal saponins in Polish fenugreek seeds was 0.14 %.

Abstract

Despite a fairly large amount of literature data about the involvement of hydrogen sulfide in physiological and pathophysiological processes, its role in gastrointestinal tract functioning has not been studied sufficiently. This review systematizes and generalizes the mechanisms of H2S-associated regulation of gastrointestinal secretion and motility on the basis of literature sources processing and own research results. We analysed world professional literature and sources in Google Scholar, PubMed, MedLine, Embase, Cochrane, and data from more than 50 articles and books on the problem were processed in the article. This review gives a synopsis of the H2S function in the regulation of the secretory and motor-evacuation function, and in stimulating the reparative properties of the digestive tract, and indicates the main mechanisms.

Abstract

The aim of the present study was to develop self-microemulsifying drug delivery systems (SMEDDS) of the extract of Moringa oleifera, a herbal medicinal plant. Kaempferol and quercetin, the flavonoids present in the leaf extract of M. oleifera, were chosen as markers for quantification. The optimized formulation of SMEDDS consisted of propylene glycol dicaprylocaprate, polysorbate 80, and polyethylene glycol 400 (PEG 400) in a percentage ratio of 20:60:20 (m/m). SMEDDS emulsified immediately (within 20 s) after dilution in water, resulting in transparent microemulsions with a droplet size of 49 nm. SMEDDS could increase the solubility of kaempferol and quercetin to nearly 100 % within 15 min, whereas only a 30 % improvement in solubility was achieved in the case of crude extract. These results demonstrated SMEDDS to be a promising strategy to improve the solubility of M. oleifera extract-derived drugs, which, in turn, could prove beneficial to the herbal medicine field.

Abstract

The aim of the present study was to determine the effect of sildenafil on dopamine, 5-hydroxyindol acetic acid (5-HIAA) and selected biomarkers of oxidative stress in the brain of hypoglycemic rats. The animals were treated intraperitoneally as follows: group 1 (control), saline solution; group 2, insulin (10 U per rat or 50 U kg−1); group 3, insulin + single dose of sildenafil (50 U kg−1 + 50 mg kg–1); group 4, insulin + three doses of sildenafil every 24 hours (50 U kg−1 + 50 mg kg−1). In groups 2, 3 and 4, insulin was administered every 24 hours for 10 days. Blood glucose was measured after the last treatment. On the last day of the treatment, the animals´ brains were extracted to measure the levels of oxidative stress markers [H2O2, Ca2+,Mg2+-ATPase, glutathione and lipid peroxidation (TBARS)], dopamine and 5-HIAA in the cortex, striatum and cerebellum/medulla oblongata by validated methods. The results suggest that administration of insulin in combination with sildenafil induces hypoglycemia and hypotension, enhances oxidative damage and provokes changes in the brain metabolism of biogenic amines. Administration of insulin and sildenafil promotes biometabolic responses in glucose control, namely, it induces hypoglycemia and hypotension. It also enhances oxidative damage and provokes changes in the brain metabolism of biogenic amines.

Abstract

A TLC-densitometric method for determination of allantoin in Symphytum officinale root was developed. Densitometric quantification of allantoin was carried out on TLC Si60 plates with butanol-50 % methanol/formic acid, 66.5:33.2:0.3 (V/V/V) as developing solvent, at a wavelength of 190 nm. The method was preliminarily validated in terms of specificity, linearity, precision, limit of detection, limit of quantification, recovery and robustness. The results of TLC quantification were compared with HPLC analysis carried out on a HILIC Luna NH2 100A column, with mobile phase consisting of acetonitrile/water 80:20 (V/V) and UV detection at 190 and 210 nm. Allantoin content was determined in two herbal products and it varied from 0.94 to 2.09 %, depending on the producer, and was in agreement with literature reports.

Abstract

This study presents the results of our comparative evaluation of diagnostic morphological characteristics of raw material from 11 species of genus Thymus L. of medicinal and raw material importance occurring in Ukraine. The following taxa were evaluated: T. serpyllum L., T. odoratissimus Mill. (T. glabrescens Willd.), T. borysthenicus Klokov & Des.-Shost., T. pallasianus Heinr. Braun, T. moldavicus Klokov & Des.-Shost., T. calcareus Klokov & Des.-Shost., T. alpestris Tausch ex A. Kern., T. × dimorphus Klokov & Des.-Shost., T. pannonicus All. s.l. (including T. marschallianus Willd.), T. pulegioides L. and T. roegneri K. Koch (T. alternans Klokov). Among wild species of thyme, only raw material of Thymus serpyllum is officially allowed for use with the purpose for production of pharmaceuticals and medicines. A comparison of the main characteristics is particularly important in view of the fact that raw material is represented by parts of plants (stems, leaves and flowers), which makes any whole comparison of species hardly possible. This study has revealed that stem pubescence, calyx structure, configuration/arrangement and type of leaf venation can provide valuable information for diagnostics of raw material of Thymus species. The results exhibited that according to characters of stem pubescence, calyx structure, shape and size of leaves the most similar are raw material samples of T. serpyllum and T. moldavicus. However, these species are rather well separated geographically, so the possibility of mixing of their raw material is negligible. Other species have significant morphological differences in certain characteristics by which they can be diagnosed in the raw material.

Abstract

Background

Carbidopa is a drug mainly used to treat Parkinson’s disease. Associations with levodopa or with levodopa/entacapone are commercialized, but there is no oral formulation of carbidopa alone available in Europe. As carbidopa can also be used as premedication of adult patients for insulinoma diagnosis, it must be compounded as single dose mg capsules. The single dose administration of a magistral preparation implies the compounding of only one capsule, or the loss of consequent quantities of active pharmaceutical ingredient. As an alternative solution, carbidopa capsules could be compounded as batches of hospital preparation.

Method

With this objective, a stability-indicating dosing method for 200 mg carbidopa capsules was developed. Then, the compounding process was assessed according to the European Pharmacopeia requirements. Finally, the stability of carbidopa capsules stored protected from light at room temperature was studied for one year.

Results

200 mg carbidopa capsules compounding process was validated on three independent batches. The beyond use date was fixed at one year.

Conclusion

Our work confirms that carbidopa 200 mg capsules can be realized in hospital pharmacy and its stability allows the compounding of large batches.