Amir Zada Khan

Simultaneous determination of timolol maleate, rosuvastatin calcium and diclofenac sodium in pharmaceuticals and physiological fluids using HPLC-UV.

A novel HPLC-UV method was developed for the simultaneous determination of timolol (TM), rosuvastatin (RST), and diclofenac sodium (DS) in pharmaceuticals, human plasma and aqueous humor using naproxen sodium as internal standard (IS). The target compounds were analyzed on Hypersil BDS C(18) column (250 mm × 4.6 mm, 5 μm), applying 0.2% triethylamine (TEA) and acetonitrile (ACN) (40:60, v/v), in isocratic mode as mobile phase, pH 2.75 adjusted with 85% phosphoric acid at a flow rate of 1 ml/min. The column oven temperature was kept at 45°C and the peak response was monitored at 284 nm after injecting a 50 μl sample into HPLC system. The direct liquid-liquid extraction procedure was applied to human plasma and bovine aqueous humor samples using mobile phase as an extraction solvent after deproteination with methanol. The different HPLC experimental parameters were optimized and the method was validated according to standard guidelines. The recoveries of the suggested method in human plasma were 98.72, 96.04, and 95.14%, for TM, RST, and DS, while in aqueous humor were 94.99, and 98.23%, for TM, and DS, respectively. The LOD values were found to be 0.800, 0.500, and 0.250 ng/ml, for TM, RST, and DS, respectively, while their respective LOQ values were 2.00, 1.50, and 1.00 ng/ml. The co-efficient of variation (CV) were in the range of 0.1492-1.1729% and 1.0516-4.0104%, for intra-day and inter-day studies, respectively. The method was found accurate in human plasma and bovine aqueous humor and will be applied for the quantification of these compounds in plasma, and aqueous humor samples using animal models and in pharmaceuticals.

In vivo screening of essential oils of Skimmia laureola leaves for antinociceptive and antipyretic activity

OBJECTIVE To study the screening of essential oils of Skimmia laureola leaves (SLO) for acute toxicity, antinociceptive, antipyretic and anticonvulsant activities in various animal models. METHODS SLO were extracted using modified Clevenger type apparatus. Acute toxicity test was used in mice to observe its safety level. Antinociceptive activity of SLO was evaluated in acetic acid induced writhing and hot plate tests. Yeast induced hyperthermic mice and pentylenetetrazole induced convulsive mice were used for the assessment of its antipyretic and anticonvulsant profile respectively. RESULTS Substantial safety was observed for SLO in acute toxicity test. SLO showed a high significant activity in acetic acid induced writhing test in a dose dependent manner with maximum pain attenuation of 68.48% at 200 mg/kg i.p. However, it did not produce any relief in thermal induced pain at test doses. When challenged against pyrexia evoked by yeast, SLO manifested marked amelioration in hyperthermic mice, dose dependently. Maximum anti-hyperthermic activity (75%) was observed at 200 mg/kg i.p. after 4 h of drug administration. Nevertheless, SLO had no effect on seizures control and mortality caused by pentylenetetrazole. CONCLUSIONS In vivo studies of SLO showed prominent antinociceptive and antipyretic activities with ample safety profile and thus provided pharmacological base for the traditional uses of the plant in various painful conditions and pyrexia. Additional detail studies are required to ascertain its clinical application.

First evidence of the analgesic activity of govaniadine, an alkaloid isolated from Corydalis govaniana Wall.

In this work, govaniadine, an alkaloid isolated from Corydalis govaniana Wall. was evaluated for its analgesic activity by writhing and hot-plate tests. Govaniadine did not display any toxic effects in mice up to 20 mg/kg during 24 h assessment study. The acetic acid-induced writhing was significantly reduced by pretreatment with govaniadine in a dose-dependent manner (1.25–5.0 mg/kg, intraperitoneally (i.p.)). Furthermore, molecular docking study has shown that this alkaloid binds the COX-2 enzyme. In the hot-plate test, govaniadine at dose of 2.5 and 5 mg/kg, i.p. displayed analgesic effect at all time points (30, 60, 90 and 120 min). The analgesic effect of govaniadine was significantly antagonised by naloxone administration. Our results demonstrate for the first time that the peripheral and central analgesic effects of govaniadine could be in part related to the involvement of COX-2 activity and by its interaction with the opioid system.

Molecular interactions of 4-acetoxy-plakinamine B with peripheral anionic and other catalytic subsites of the aromatic gorge of acetylcholinesterase: Computational and structural insights

Abstract Context: A steroidal alkaloid, 4-acetoxy-plakinamine B (4APB), is a recently discovered marine natural product with inhibitory effect against acetylcholinesterase (AChE), but its mechanism of interaction with the enzyme remains to be elucidated. Objective: The main objective was to study molecular binding mode of the compound, its interactions with catalytic subsites and molecular mechanism behind its significant inhibitory effect. Materials and methods: All possible interactions of ligands in the binding sites were analyzed using FRED 2.1 and the OMEGA pre-generated multi-conformer library. Results: Dipole–dipole interactions were observed between the secondary amino group of 4APB and Ser200 at a distance of 3.91 Å and also with Gly117 and Gly118. A further dipole–dipole interaction was between Arg289 and the heterocyclic nitrogen. Hydrogen bonding interactions were observed between Tyr130 and secondary amino and C-4 acetyl groups as well as between heterocyclic nitrogen and Phe288 at a distance of 3.04 Å. Hydrophobic interactions were evident between rings C/D of 4APB and with Phe288, Phe330 and Phe331. The computational studies revealed 4APB’s critical molecular interaction with amino acids of peripheral active (PAS) and anionic (AS) subsites. Discussion: Our data provided molecular evidence for the mixed competitive inhibitory effect of 4APB. For lead optimization, structural insights revealed the N-methyl group of 4APB could be replaced by NH2 moiety to generate a more favorable hydrogen bonding with Glu199. A polar group insertion such as NH2 or OH at certain sites of the 4APB skeleton is also recommended. Conclusion: These computational insights explained the mixed-competitive enzyme kinetic behavior of 4APB. This study outlines a strategy for designing novel derivatives of 4APB with potentially better AChE inhibitory activities through interaction at the PAS and AS sites.

Method development and validation for simultaneous determination of lumefantrine and its major metabolite, desbutyl lumefantrine in human plasma using RP-HPLC/UV detection

A simple, specific, precise and rapid RP-HPLC-UV method was developed for simultaneous determination of lumefantrine and its metabolite desbutyl lumefantrine in human plasma. Experimental parameters were optimized and the method was validated according to standard guidelines. The method showed adequate separation for lumefantrine and desbutyl lumefantrine and best resolution was achieved with Supelco Discovery HS C18 RP (150mm×4.6mm, 5μm) column using acetonitrile and 0.05% trifluroacetic acid (70:30, v/v) as a mobile phase pumped at a flow rate of 1.0ml/min and wavelength of 335nm. The method was linear over the concentration range of 10-12,000ng/ml. The lower limit of detection (LLOD) and lower limit of quantification (LLOQ) for lumefantrine were 10.0 and 18.0ng/ml, while for desbutyl lumefantrine were 7.5 and 15.0ng/ml, respectively. The proposed method was efficiently applied for determination of lumefantrine and desbutyl lumefantrine concentrations in plasma samples for pharmacokinetic studies.

Antioxidant profile of constituents isolated from Polygonatum verticillatum rhizomes

The purpose of the current study was to estimate the antioxidant profile of two compounds, diosgenin and santonin, isolated from Polygonatum verticillatum rhizomes. Stable free radical, 2, 2-diphenyl-1-picrylhydrazyl and reducing power assays were employed for this purpose. The results showed profound free radical scavenging effect of both diosgenin and santonin in a concentration-dependent manner. The calculated half maximal inhibitory concentration (IC50) values for both diosgenin and santonin was 65.80 and 50.03 μg/ml, respectively. Similarly, in reducing power assay, diosgenin and santonin exhibited marked quenching effect. The corresponding IC50 values for both the compounds were 62.10 and 46.40 μg/ml, respectively. In conclusion, both the isolated compounds have strong antioxidant potential, which is consistent with the results of the extracts of the plant.

Sustainable Management of Root Knot Nematode Meloidogyne incognita through Organic Amendment on Solanum lycopersicum L.

Aims: To evaluate the nematicidal potential of wild spinach powder in combination with fresh chopped leaves of different plants viz., Indian mallow, Mexican poppy, Ivy gourd, Trailing eclipta, Wild eggplant and Black pigweed against Meloidogyne incognita on plant growth characters of tomato cv. K-21. Place and Duration of Study: A glasshouse pot experiment was carried out in the Department of Botany, Aligarh Muslim University, Aligarh. Methodology: A mixture of soil and organic manure was prepared in the ratio 3:1. The pots were treated with fresh chopped leaves of different plants viz., Indian mallow, Mexican poppy, Ivy gourd, Trailing eclipta, Wild eggplant and Black pig weed applied 50 g of fresh chopped leaves of plants were applied combined with seed powder 10 g of seed powder of Black nightshade”. Results: Combined application of wild spinach powder along with the fresh chopped leaves of all the plants suppressed pathogenic effect of nematode and thereby resulted in significant reduction Original Research Article Asif et al.; AJOB, 1(1): 1-8, 2016; Article no.AJOB.30739 2 in Meloidogyne incognita infestation and population density of Meloidogyne incognita in soil. The highest reduction in Meloidogyne incognita infestation was reported in plants employed with 10 g of wild spinach powder combined with 50 g of Mexican poppy leaves. Plants applied 10 g of wild spinach powder combined with 50 g of Mexican poppy leaves were the best followed by 50 g of Trailing eclipta, 50 g of Wild eggplant, 50 g of Black pigweed, 50 g of Indian mallow, 50 g of Ivy gourd in the descending order. However the lowest reduction was recorded with the application 10 g of wild spinach powder plus 50 g of fresh chopped Ivy gourd. Organic additives of wild spinach powder along with the fresh chopped leaves would work for sustainable management by increasing the nutrient status of the soil which further enhances the plant growth. Conclusion: The application of Mexican poppy, Trailing eclipta and Wild eggplant in combination with wild spinach powder are quite efficient alternatives of chemical nematicides for the Meloidogyne incognita management and yield enhancement. Although the utilization of chopped leaves of Indian mallow and Ivy gourd along with wild spinach powder is not potentially active replacement of synthetic nematicides however further characterization is needed.