DEVELOPMENT AND VALIDATION OF A DISSOLUTION METHOD FOR FROVATRIPTAN TABLETS BY REVERSED PHASE UPLC

Objective: The main objective of the method was to develop a simple, rapid, efficient and reproducible, stability indicating reverse phase ultra performance liquid chromatography (RP-UPLC) method for the estimation of frovatriptan in tablet dosage form.Methods: The RP-UPLC method for estimation of frovatriptan (FRT) in their tablets was carried out on Acquity UPLCTM, BEH C-18 (100 × 2.1 mm, 1.7 µm) column using 0.1% trifluroacetic acid buffer and a mixture of methanol and acetonitrile (50:50) using isocratic program. The flow rate of the mobile phase was 0.2 mL min-1and detection wavelength was carried out at 244 nm. Total runtime is 3 minutes for chromatographic run. The method was validated in terms of specificity, linearity, accuracy, precision and robustness as per ICH guidelines.Results: The method was found to be linear in the range of 1.41-3.67 μg mL-1. Recovery was found to be in the range of 97.8-101.8%. Relative standard deviation for precision and intermediate precision was found to be less than 3%. The developed method was successfully applied for the estimation of frovatriptan in tablet formulation and average dissolution rate was found to be 93%. The results obtained from the validation experiments prove that the developed method is suitable for routine analysis.Conclusion: The developed RP-UPLC method was simple, rapid, accurate, and precise for the estimation of dissolution rate in frovatriptan tablet dosage form.Â

Stability of binary complexes of Pb(II), Cd(II) and Hg(II) with maleic acid in TX100-water mixtures

Binary complexes of maleic acid with toxic metal ions such as Pb(II), Cd(II) and Hg(II) have been studied in 0.0-2.5% v/v tritonX-100 (TX100) - water media at 303 K  at an ionic strength of 0.16 M. The active forms of the ligand are LH2, LH- and L2-. The derived ‘best fit’ chemical speciation models are based on crystallographic R-factors, χ2 and Skewness and Kurtosis factors. The predominant species formed are of the type ML2, ML2H and ML3. The trend in variation of complex stability constants with change in the mole fraction of the medium is explained on the basis of prevailing electrostatic and non-electrostatic forces. The species distribution as a function of pH at different compositions of TX100-water mixtures and plausible speciation equilibria are presented and discussed. KEY WORDS: Maleic acid, TritonX-100, Toxic metal ions, Mole fraction, Binary complexes Bull. Chem. Soc. Ethiop. 2014, 28(3), 383-391.DOI: http://dx.doi.org/10.4314/bcse.v28i3.

Comparative studies on mydriatic effect of tropicamide 0.8% and phenylephrin 5.0% in teenagers & geriatric people

Prospective study on the comparison of mydiriatic effect of Tropicamide 0.8% and Phenylephrine 5% in teenagers and geriatric people was carried out in suthrama Eye Hospital madanapalle, India. The main objective of this study was to compare the mydriatic effect of a combination of drug in teenagers and geriatric people. It also evaluated the ADR’s produced and the efficacy of the drug in two age groups. In this study population majority of the subjects were female in group A and male in group B. Among the whole population under study in group A and B no one has reported with any case of congenital anomalies. A number of ADR’s are reported but no serious adverse events had occurred. The study was carried out in 100 eyes ie. 50 subjects whom are divided into 2 groups based on age. The comparison of mydriatic effect was done in each group after instilling one drop of a combination of 0.08% Tropicamide and 0.5% Phenynilephrine. The pupillary size where measured before and after administration of drug and the results were compared. The results showed that there is a large difference in the normal pupil size between teenagers and geriatric people. After dilation the difference in pupil size was statistically significant among the two groups. The study concludes that the pupillary dilation produced by administering 0.8% Tropicamide and 5% Phenylephrine produces higher mydriatic effect in teenagers than geriatric people

Expression Analysis of Novel microRNAs in Rice During High Temperature Stress

MicroRNAs (miRNAs) are small non-coding RNAs which play an important role in regulating the genes involved in plant growth and development. Several studies showed that miRNAs are involved in plants response to different kinds of abiotic stresses also. In our previous study, temperature responsive miRNAs were predicted in O.sativa. 27 miRNAs were predicted to be novel in rice using homology search. In continuation to our previous study, expression of 14 novel miRNAs was done in shoot and root of 13 days old seedlings of five different rice cultivars using real time PCR. Expression these miRNAs was analyzed in control and high temperature stress environment. Out of 14 predicted novel miRNAs, two novel miRNAs- miR157a and miR165a showed expression in all five rice cultivars. Interestingly, miR165a showed a differential expression pattern among heat tolerant (N22, IR64 and Rasi) and susceptible (Vandana and Sampada) cultivars suggesting that it might have specific role in high temperature tolerance

Vorinostat Eliminates Multicellular Resistance of Mesothelioma 3D Spheroids via Restoration of Noxa Expression

When grown in 3D cultures as spheroids, mesothelioma cells acquire a multicellular resistance to apoptosis that resembles that of solid tumors. We have previously found that resistance to the proteasome inhibitor bortezomib in 3D can be explained by a lack of upregulation of Noxa, the pro-apoptotic BH3 sensitizer that acts via displacement of the Bak/Bax-activator BH3-only protein, Bim. We hypothesized that the histone deacetylase inhibitor vorinostat might reverse this block to Noxa upregulation in 3D. Indeed, we found that vorinostat effectively restored upregulation of Noxa protein and message and abolished multicellular resistance to bortezomib in the 3D spheroids. The ability of vorinostat to reverse resistance was ablated by knockdown of Noxa or Bim, confirming the essential role of the Noxa/Bim axis in the response to vorinostat. Addition of vorinostat similarly increased the apoptotic response to bortezomib in another 3D model, the tumor fragment spheroid, which is grown from human mesothelioma ex vivo. In addition to its benefit when used with bortezomib, vorinostat also enhanced the response to cisplatin plus pemetrexed, as shown in both 3D models. Our results using clinically relevant 3D models show that the manipulation of the core apoptotic repertoire may improve the chemosensitivity of mesothelioma. Whereas neither vorinostat nor bortezomib alone has been clinically effective in mesothelioma, vorinostat may undermine chemoresistance to bortezomib and to other therapies thereby providing a rationale for combinatorial strategies

Deep sequencing of small RNAs reveals ribosomal origin of microRNAs in Oryza sativa and their regulatory role in high temperature

MicroRNAs are small noncoding regulatory RNAs which control gene expression by mRNA degradation or translational repression. They are significant molecular players regulating important biological processes such as developmental timing and stress response. We report here the discovery of miRNAs derived from ribosomal DNA using the small RNA datasets of 16 deep sequencing libraries of rice. Twelve putative miRNAs were identified based on highly stringent criteria of novel miRNA prediction. Surprisingly, 10 putative miRNAs (mi_7403, mi_8435, mi_12675, mi_4266, mi_4758, mi_4218, mi_8200, mi_4644, mi_14291, mi_16235) originated from rDNA of rice chromosome 9. Expression analysis of putative miRNAs and their target genes in heat tolerant and susceptible rice cultivars in control and high temperature treated seedlings revealed differential regulation of rDNA derived miRNAs. This is the first report of rDNA derived miRNAs in rice which indicates their role in gene regulation during high temperature stress in plants. Further studies in this area will open new research challenges and opportunities to broaden our knowledge on gene regulation mechanisms

A multi-dimensional approach from seed-to-seed to understand and improve heat stress tolerance in rice

In changing climatic conditions, stress caused by high temperature poses a serious threat to rice cultivation. Physiological, biochemical, and molecular analysis of rice cultivars revealed that Nagina22 (N22) shows lesser reduction in chlorophyll content, net photosynthetic rate, spikelet fertility and grain yield, but increased membrane thermal stability, antioxidant enzymes activity and transpiration rate (E) at high temperature. DREB, RAB, LEA, and genes associated with hormones signalling were induced during germination, while OsFd (an iron sulphur cluster binding protein) and CWIP (cell wall integrity protein) emerged as high priority candidate genes in seedling and reproductive stages. Their function is being analysed by transgene expression and CRISPR/Cas genome editing approaches. Field screening in polyhouse, late sowing and temperature gradient chamber for 20 morpho-physiological traits indicated the importance of both yield and spikelet fertility, and photosynthesis traits. N22 showed the least Heat Susceptibility Index (HSI) for yield/plant, spikelet fertility, flag leaf SPAD and stomatal conductance, while Vandana showed the highest HSI for spikelet fertility and flag leaf temperature. QTLs for HSI of spikelet fertility were identified on chromosome 1 and HSI of yield per plant on chromosomes 1, 2, 3, 4, 7 and 8; and PV of 6% to 57% using 174 F2-3 Vandana x N22 mapping population. Simultaneously, RNAseq was performed to identify the genome wide miRNAs and transcriptome of N22 and Vandana from shoot and root after short and long duration of heat stress treatments; and recovery phase for an eQTL-guided function-related co-expression analysis to identify the putative regulators and gene regulatory networks

Nanostructured carriers as innovative tools for cancer diagnosis and therapy

Cancer accounts for millions of deaths every year and, due to the increase and aging of the world population, the number of new diagnosed cases is continuously rising. Although many progresses in early diagnosis and innovative therapeutic protocols have been already set in clinical practice, still a lot of critical aspects need to be addressed in order to efficiently treat cancer and to reduce several drawbacks caused by conventional therapies. Nanomedicine has emerged as a very promising approach to support both early diagnosis and effective therapy of tumors, and a plethora of different inorganic and organic multifunctional nanomaterials have been ad hoc designed to meet the constant demand for new solutions in cancer treatment. Given their unique features and extreme versatility, nanocarriers represent an innovative and easily adaptable tool both for imaging and targeted therapy purposes, in order to improve the specific delivery of drugs administered to cancer patients. The current review reports an in-depth analysis of the most recent research studies aiming at developing both inorganic and organic materials for nanomedical applications in cancer diagnosis and therapy. A detailed overview of different approaches currently undergoing clinical trials or already approved in clinical practice is provided

Pectin induced transcriptome of a Rhizoctonia solani strain causing sheath blight disease in rice reveals insights on key genes and RNAi machinery for development of pathogen derived resistance

Key message RNAi mediated silencing of pectin degrading enzyme of R. solani gives a high level of resistance against sheath blight disease of rice. Abstract Rice sheath blight disease caused by Rhizoctonia solani Kuhn (telemorph; Thanatephorus cucumeris) is one of the most devastating fungal diseases which cause severe loss to rice grain production. In the absence of resistant cultivars, the disease is currently managed through fungicides which add to environmental pollution. To explore the potential of utilizing RNA interference (RNAi)-mediated resistance against sheath blight disease, we identified genes encoding proteins and enzymes involved in the RNAi pathway in this fungal pathogen. The RNAi target genes were deciphered by RNAseq analysis of a highly virulent strain of the R. solani grown in pectin medium. Additionally, pectin metabolism associated genes of R. solani were analyzed through transcriptome sequencing of infected rice tissues obtained from six diverse rice cultivars. One of the key candidate gene AG1IA_04727 encoding polygalacturonase (PG), which was observed to be significantly upregulated during infection, was targeted through RNAi to develop disease resistance. Stable expression of PG-RNAi construct in rice showed efficient silencing of AG1IA_04727 and suppression of sheath blight disease. This study highlights important information about the existence of RNAi machinery and key genes of R. solani which can be targeted through RNAi to develop pathogen-derived resistance, thus opening an alternative strategy for developing sheath blight-resistant rice cultivars

The glutathione biosynthetic pathway of Plasmodium is essential for mosquito transmission

1Infection of red blood cells (RBC) subjects the malaria parasite to oxidative stress. Therefore, efficient antioxidant and redox systems are required to prevent damage by reactive oxygen species. Plasmodium spp. have thioredoxin and glutathione (GSH) systems that are thought to play a major role as antioxidants during blood stage infection. In this report, we analyzed a critical component of the GSH biosynthesis pathway using reverse genetics. Plasmodium berghei parasites lacking expression of gamma-glutamylcysteine synthetase (γ-GCS), the rate limiting enzyme in de novo synthesis of GSH, were generated through targeted gene disruption thus demonstrating, quite unexpectedly, that γ-GCS is not essential for blood stage development. Despite a significant reduction in GSH levels, blood stage forms of pbggcs− parasites showed only a defect in growth as compared to wild type. In contrast, a dramatic effect on development of the parasites in the mosquito was observed. Infection of mosquitoes with pbggcs− parasites resulted in reduced numbers of stunted oocysts that did not produce sporozoites. These results have important implications for the design of drugs aiming at interfering with the GSH redox-system in blood stages and demonstrate that de novo synthesis of GSH is pivotal for development of Plasmodium in the mosquito