Effect of Volume and Renewal of the Storage Media on the Release of Monomer from Dental Composites

This study evaluated the effect of the volume and renewing of storage media on monomer leachability from dental composite. Samples of two dental composites (BEAUTIFIL II Gingiva (BG) and Filtek Bulk-Fill Flowable (FBF)) were stored after polymerization in 1 and 3 milt storage media (ethanol/water 75%) for seven days. Refreshing of storage media was done in half of the samples of each group. The amounts of releasing monomers (UDMA, BisGMA, TEGDMA) in storage media were measured by high-performance liquid chromatography (HPLC). Data was analyzed using two-way ANOVA and t-test (α = 0.05). Elution of TEGDMA and UDMA from both composites was significantly higher in 3 mL storage media. In groups with refreshing of storage media, BisGMA had higher amounts of release. Saturation makes the storage media volume important factor in monomer elution. Refreshing of storage media had significant effect on monomer release before the elution of 50% of total released monomer.

HPLC-DAD Fingerprints Combined With Multivariate Analysis of Epimedii Folium From Major Producing Areas in Eastern Asia: Effect of Geographical Origin and Species

The growth location and plant variety may influence the active components and biological activities of plants used in phytomedicine. In this study, nine sets of different Epimedii Folium, from different representative cultivation locations and Epimedium species, were collected for comparison, using HPLC-DAD combined with multivariate analysis. The objective was to investigate the influence of geographical origin and Epimedium species on the quality of Epimedii Folium, and provide applicable guidance for cultivation and quality control of Epimedii Folium. Several Epimedium spp. sets were used to establish the HPLC-DAD fingerprints and 91 peaks (compounds) were selected for the multivariate analysis. Major compounds were analyzed by HPLC-DAD combined with principal component analysis (PCA). HPLC quantitative analysis of known bioactive compounds was performed. Application of PCA to HPLC data showed that Epimedium samples sharing the same geographical origin or species clustered together, indicating that both species and geographical origin have impacts on the quality of Epimedii Folium. The major bioactive flavonoid compounds, epimedin C, icariin and baohuoside I, were identified and quantified. The concentration of bioactive compounds was significantly influenced both by species and geographical origin. E. sagittatum from Sichuan showed the highest content of bioactive compounds. The results showed that both Epimedium species and geographical origin have strong impact into quality of Epimedii Folium. HPLC data combined with multivariate analysis is a suitable approach to inform the selection of cultivation areas and choose Epimedium spp. most suitable for different geographical areas, resulting in improved quality of Epimedii Folium.

Microcystis species and their toxigenic strains in phytoplankton of ten Bulgarian waterbodies

The summer phytoplankton structure of ten Bulgarian waterbodies was studied by HPLC analysis of marker pigments, light microscopy (LM) and PCR amplification of mcyB and mcyE gene sequences. The aim was to detect biodiversity and spread of toxigenic strains of potential microcystin producers and the important bloom-forming genus Microcystis in particular. The screening was done in three waterbodies, where Microcystis had already been found (Lakes Ezerets and Durankulak and Reservoir Koprinka), three waterbodies from which it had not been reported (Reservoirs Shilkovtsi, Zhrebchevo, Suedinenie) and four reservoirs that were sampled for the first time (Malka Smolnitsa, Plachidol 2, Preselka, Duvanli). LM and HPLC data similarly showed that cyanoprokaryotes contributed significantly to the total phytoplankton composition (29%) and biomass (15–87%) in nine sampled waterbodies. Microcystis aeruginosa, M. natans, M. smithii, M. wesenbergii, Microcystis spp., M. cf. comperei and M. pseudofilamentosa, were identified using LM (the last two tropical species were found for the first time in the country). Despite the low contribution of Microcystis to the phytoplankton diversity (1–4 taxa per sample) and to the total phytoplankton biomass (< 0.01–0.5%), 57 toxigenic strains of this genus were revealed by PCR, most of which demonstrated high similarity with NCBI M. aeruginosa and M. wesenbergii strains.

ANALISIS KADAR BENZOAT DAN SORBAT PADA SAUS SAMBAL KEMASAN YANG DIJUAL DI PASAR BARU BEKASI DENGAN METODE HPLC

Pendahuluan: Bahan Tambahan Pangan (BTP) digunakan secara luas oleh masyarakat. Bahan Tambahan Pangan (BTP) yang banyak digunakan dalam saus sambal adalah pengawet seperti benzoat dan sorbat. Penggunaan pengawet pada bahan pangan tidak boleh melebihi ambang batas yang sudah ditentukan karena dapat memberikan efek bagi kesehatan, seperti benzoat yang dapat menimbulkan reaksi alergi dan bersifat karsinogenik karena adanya benzene serta sorbat yang dapat menyebabkan mutasi gen bila dikombinasikan dengan asam askorbat. Penelitian ini bertujuan untuk mengetahui kadar benzoat dan sorbat pada saus sambal kemasan yang dijual di Pasar Baru Bekasi dan melihat kesesuaian kadar pengawet dengan ambang batas yang sudah ditentukan. Metode: Metode penelitian yang digunakan adalah deskriptif kuantitatif dengan pendekatan cross-sectional. Kadar benzoat dan sorbat diperiksa menggunakan metode High Performance Liquid Chromatography (HPLC). Data kuantitatif yang diperoleh dari hasil pengukuran dianalisis dengan membandingkan kadar maksimum benzoat dan sorbat yang diperbolehkan pada saus menurut Peraturan Kepala BPOM No. 36 Tahun 2013, yaitu 1000 mg/kg. Kadar benzoat dan sorbat yang melebihi ambang batas menandakan bahwa saus sambal tersebut tidak boleh untuk dikonsumsi. Hasil: Hasil penelitian menunjukkan bahwa seluruh 100% sampel mengandung benzoat melebihi kadar maksimum yang telah ditetapkan dan 50% sampel mengandung sorbat dengan kadar di bawah ambang batas yang telah ditentukan. Kesimpulan: Berdasarkan penelitian yang telah dilakukan, saran yang dapat diberikan untuk penelitian selanjutnya adalah melakukan analisis kadar benzoat dan sorbat pada sampel bahan pangan yang lain mengingat bahwa benzoat dan sorbat sering digunakan sebagai kombinasi pengawet dan diperbolehkan untuk digunakan dalam bahan pangan.

Design, Synthesis and Enhanced BBB Penetration Studies of L-serine-Tethered Nipecotic Acid-Prodrug

Nipecotic acid is considered to be one of the most potent inhibitors of neuronal and glial-aminobutyric acid (GABA) uptake in vitro. Due to its hydrophilic nature, nipecotic acid does not readily cross the blood-brain barrier (BBB). Large neutral amino acids (LAT1)-knotted nipecotic acid prodrug was designed and synthesized with the aim to enhance the BBB permeation by the use of carrier-mediated transport. The synthesized prodrug was tested in animal models of Pentylenetetrazole (PTZ)-induced convulsions in mice. Further pain studies were carried out followed by neurotoxicity estimation by writhing and rota-rod test respectively. HPLC data suggests that the synthesized prodrug has improved penetration through BBB. Nipecotic acid-L-serine ester prodrug with considerable anti-epileptic activity, and the ability to permeate the BBB has been successfully synthesized. Graphical Abstract.

Low efficiency of β-alanine supplementation to increase muscle carnosine

Supplementation with β-alanine (BA) increases muscle carnosine content, although the amount of BA used for muscle carnosine loading has been suggested to be low. However, methodological issues may have underestimated the amount of BA used. The aim of this study was to determine the estimated amount of BA converted to muscle carnosine, using a retrospective analysis from a 4-week randomized controlled trial investigating the effects of BA supplementation on muscle carnosine content of the m. vastus lateralis. Twenty-five males (age 27±5 years, height 1.74±0.09 m, body mass 77.4±11.5 kg) were supplemented with 6.4 g·day-1 of BA (N=17) or placebo (PL; N=8) for 28 days. Pre- and postsupplementation participants provided a muscle biopsy subsequently analysed for carnosine content using HPLC. Data were analysed using mixed-models and Pearson’s correlations. Muscle carnosine content increased by +11.0±6.7 mmol·kg-1dm (P<0.0001) in BA, with no change in PL (P=0.99). The estimated amount of BA converted to muscle carnosine was 2.1±1.2% (Range: 0.5 to 4.5%) of the total dose ingested. Pearson’s correlations showed that pre-supplementation carnosine was correlated to post-supplementation carnosine in the BA group (r=0.65, r2=0.38, P=0.009), but not the absolute change in carnosine (r=-0.28, r2=0.08, P=0.28) or the amount of BA used (r=-0.31, r2=0.10, P=0.22). The estimated amount of ingested BA used for carnosine synthesis was extremely low following 4 weeks of BA supplementation at 6.4 g·day-1. Data suggest that very little of the BA ingested is used for muscle carnosine synthesis and highlights the potential for further work to optimise BA supplementation in humans.