A rapid method for isolation of piperine from the fruits of Piper nigrum Linn

A simple, rapid and efficient method has been developed for the isolation of piperine from the fruits of Piper nigrum. The method involves extraction of the fruit powder with glacial acetic acid, from which piperine is partitioned into chloroform and subsequently crystallized. The identity of the compound was confirmed by its melting point, comparison of UV, IR, and mass spectral data with those from a reference standard, and co-chromatography with the reference standard using thin-layer chromatography (TLC). The purity of the compound was ascertained by TLC, by recording UV absorption spectra at the start, middle, and end positions of the spot on the plate, and by differential scanning calorimetry (DSC).

Identification and characterization of lipids from endosomes purified by electromagnetic chromatography

Traditional separation techniques do not yield endolysosomes of sufficient purity to permit detailed biochemical characterization of this important class of intracellular vesicles. Here, we have used a magnetic chromatography technique to isolate the endosomes from rat peritoneal macrophages and studied their lipid composition. Electromagnetic isolation works by retention of colloidal iron containing vesicles on magnetic column. The data suggested that both early and late endosomes were rich in cholesterol, whereas sphingomyelin (SM) and specific phospholipids like phosphatidylcholine. phosphatidylethanolamine, phosphatidylglycerol and phosphatidylserine are enriched in the late compartments. Our results also indicated that the purified fractions are enriched in raft lipids like SM, but not in cholesterol. The endosomal purification method described here yields pure endosomes with little or no contamination from mitochondria and hence could be used for further biochemical and marker analysis, giving insight into mechanisms of endocytic traffic.

Plant genomic DNA isolation: an art or a science

Isolating quality DNA from tissues/cells presents a variety of problems in particular when plants are used as the source material. The specific characteristics of plants like the presence of rigid polysaccharide cell wall, pigments, chemical heterogeneity of secondary metabolites found in diverse species of plants, etc., necessitate special consideration and skill during isolation procedure. Until now, numerous protocols have been published for the purpose, but none is found to be universally applicable. Various factors starting from the selection of source material to the concentration of metabolites present in the plant decide the course of the isolation procedure. The present review is an update of various methods used for plant genomic DNA isolation, and it epitomizes the various problems faced and the solutions made to contend with them during DNA isolation from plant cells.

Estimation of carvedilol in human plasma by using HPLC-fluorescence detector and its application to pharmacokinetic study

A simple, precise and sensitive high performance liquid chromatography procedure has been developed for determination of carvedilol in human plasma. The method was developed on Lichrosphere R CN column using a mobile phase of acetonitrile/20 mM ammonium acetate buffer with 0.1% triethylamine (pH adjusted to 4.5) (40/60, v/v). The peaks were detected by using fluorescence detector (excitation wavelength 282 nm and emission wavelength 340 nm). Carvedilol and domperidone (internal standard) were extracted by liquid-liquid extraction procedure using dichloromethane. This method was specific and had a linearity range of 1-128 ng/ml with intra- and inter-day precision (%C.V.) less than 15%. The accuracy ranges from 87.3 to 100.88% and the recovery of carvedilol was 69.90%. The stability studies showed that carvedilol in human plasma was stable during short-term period for sample preparation and analysis. This method was used to assay the carvedilol in human plasma samples obtained from subjects who had been given an oral tablet of 12.5 mg carvedilol.

A new high performance liquid chromatographic method for quantification of atomoxetine in human plasma and its application for pharmacokinetic study

Atomoxetine is the first, non-stimulant alternative to other stimulant medications used for the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD). Reported methods for the determination of atomoxetine include expensive liquid chromatography tandem mass spectrometry (LCMS) and high performance liquid chromatography (HPLC) with liquid scintillation counting (LSC) detection. Till date, no method has been reported in literature to determine atomoxetine using HPLC with UV detection. In this paper, we describe a new HPLC method for the determination of atomoxetine using liquid-liquid extraction with tertiary butyl methyl ether and UV detector. This method was found to be linear over the concentration range of 0.05-3.0 microg/ml. The limit of quantification was 0.05 microg/ml. Intra- and inter-day precision was <15% and accuracy was in the range of 95.67-108.80%. Stability studies showed that atomoxetine was stable in human plasma for short- and long-term period for sample preparation and analysis. This method was used for sample analysis in a pharmacokinetic study of atomoxetine (25mg) in five healthy adult female volunteers. The observed mean+/-S.D. pharmacokinetic parameters Cmax, Tmax and AUC(0-t) were 0.40+/-0.06 microg/ml, 3.40+/-0.42 h and 1.34+/-0.52 microg h/ml, respectively.

2-Amino-5-thiazolyl motif: a novel scaffold for designing anti-inflammatory agents of diverse structures

Substituted thiazoles with different structural features were synthesized and screened for their anti-inflammatory activity in acute carrageenin induced rat paw edema model and chronic formalin induced rat paw edema model. The compounds 1-5 showed 83, 30, 63, 69 and 73% protection, respectively, in acute carrageenin induced rat paw edema model. In 5-day chronic formalin induced rat paw edema model on the fifth day 1 and 5 gave 66 and 41% protection. Both studies were carried out at a dose of 100mg/kg body weight. The activity was compared with that of Ibuprofen, Rofecoxib, and Dexamethasone both in acute and chronic anti-inflammatory models. Compound 1 without COX-1 and COX-2 inhibitory activity showed good activity profile almost mimicking the gold standard Dexamethasone in terms of efficacy. A 7-day study in rats at dose of 100mg/kg showed that this compound does not have any ulcerogenic activity and toxicity. The activity of 5 shows that incorporating two pharmacophoric features in one molecule can be a good drug designing strategy. 2,4-Diaminothiazoles with an aliphatic oxime esters attached via a ketone bridge to the 5th position of thiazole was identified as a novel scaffold for designing anti-inflammatory agents.

Search for antibacterial and antifungal agents from selected Indian medicinal plants

A series of 61 Indian medicinal plants belonging to 33 different families used in various infectious disorders, were screened for their antimicrobial properties. Screening was carried out at 1000 and 500 microg/ml concentrations by agar dilution method against Bacillus cereus var mycoides, Bacillus pumilus, Bacillus subtilis, Bordetella bronchiseptica, Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Streptococcus faecalis, Candida albicans, Aspergillus niger and Saccharomyces cerevisiae. Twenty-eight plant extracts showed activity against at least one of the test organisms used in the screening. On the basis of the results obtained, we conclude that the crude extracts of Dorema ammoniacum, Sphaeranthus indicus, Dracaena cinnabari, Mallotus philippinensis, Jatropha gossypifolia, Aristolochia indica, Lantana camara, Nardostachys jatamansi, Randia dumetorum and Cassia fistula exhibited significant antimicrobial activity and properties that support folkloric use in the treatment of some diseases as broad-spectrum antimicrobial agents. This probably explains the use of these plants by the indigenous people against a number of infections.

Tetra substituted thiophenes as anti-inflammatory agents: Exploitation of analogue-based drug design

A series of 17 novel tetra substituted thiophenes was designed, synthesized, and screened for anti-inflammatory activity in carrageenin induced rat paw edema model, an acute in vivo model. The lead molecule selected was Tenidap, a dual COX/LOX inhibitor. Compounds I (43%), III (60%), IV (60%), and VIII (64%) showed moderate to good anti-inflammatory activity. The best candidate among the whole series was VIII, which gave 64% protection to the inflamed paw. The side chain of candidate VIII had resemblance to that of Romazarit, a DMARD, which was withdrawn due to its toxicity profile. A probable reason for the metabolic stability of the proposed side chain not having the possibility of generating peroxy type radicals or acrylic acid moieties, unlike Romazarit, is discussed. The biological activity exhibited by the three designed series was in the order of methyl amino series > ethyl amino series > carbethoxy amino series. The -(C=O)-CH2-COOR side chain at the fifth position as in candidate VIII, the methyl amino group at the second position, and the ester at the third position of the thiophene can be considered as a three-point pharmacophore for designing better anti-inflammatory agents. The present study is a classical example of the exploitation of an analogue based drug design, which culminated in the development of good anti-inflammatory agents that have the potential of becoming dual inhibitors.

Analytical method development and validation of mianserin hydrochloride and its metabolite in human plasma by LC-MS

Mianserin is a tetracyclic antidepressant drug and administered as racemate of R (-) and S (+) mianserin hydrochloride in a dose of 30-90 mg/day in divided doses. Liquid chromatography-mass spectroscopy (LC-MS) is a tool, which is widely used for determination of drug and their metabolites in biological fluids because of its high sensitivity and precision. Here we describe a liquid chromatography mass spectroscopy method for simultaneous determination of mianserin and its metabolite, N-desmethylmianserin, from human plasma using a liquid-liquid extraction with hexane:isoamylalcohol (98:2) and back extraction with 0.005 M formic acid solution. This method is specific and linear over the concentration range of 1.00-60.00 ng/ml for mianserin and 0.50-14.00 ng/ml for N-desmethylmianserin in human plasma. The lowest limits of quantification (LLQ) is 1.00 ng/ml for mianserin and 0.50 ng/ml for N-desmethylmianserin. Intraday and interday precision (%C.V.) is <10% for both mianserin and N-desmethylmianserin. The accuracy ranges from 94.44 to 112.33% for mianserin and 91.85-100.13% for N-desmethylmianserin. The stability studies showed that mianserin and N-desmethylmianserin in human plasma are stable during short-term period for sample preparation and analysis. The method was used to assay mianserin and its metabolite, N-desmethylmianserin, in human plasma samples obtained from subjects who had been given an oral tablet of 30 mg of mianserin.

A rapid densitometric method for simultaneous quantification of gallic acid and ellagic acid in herbal raw materials using HPTLC

Gallic acid and ellagic acid are two widely occurring phenolic compounds of plant origin, to which many biological activities including anticancer and antiviral activity have been attributed. A simple HPTLC method has been developed for the simultaneous quantification of gallic acid and ellagic acid. The method was validated for precision, repeatability, and accuracy. Instrumental precision was found to be 0.083 and 0.78, and the repeatability of the method was found to be 1.07 and 1.50 (% CV) for gallic acid and ellagic acid, respectively. The accuracy of the method was checked by a recovery study conducted at two different levels and the average percentage recovery was found to be 101.02% for gallic acid and 102.42% for ellagic acid. The above method was used for the quantification of gallic acid and ellagic acid content in seeds of Abrus precatorius Linn., whole plant of Phyllanthus maderaspatensis Linn., and flowers of Nymphaea alba Linn. The proposed HPTLC method for the simultaneous quantification of gallic acid and ellagic acid was found to be simple, precise, specific, sensitive, and accurate and can be used for routine quality control of herbal raw materials and for the quantification of these compounds in plant materials.

Blastocyst implantation failure in mice due to “nonreceptive endometrium”: endometrial alterations by Hibiscus rosa-sinensis leaf extract

Many plants are known to possess antifertility activity. However, limited attempts have been made to scientifically evaluate these claims. Hibiscus rosa-sinensis flowers have been shown to possess antifertility and abortifacient activity. In this report, antiimplantation activity of water extract of leaves of H. rosa-sinensis was investigated. Pregnant female mice were dosed with extract (100 mg/kg body weight) from days 1 to 6 of pregnancy. No implantation sites were observed in treated animals when they were surgically opened on day 15 of pregnancy. Biochemical and biophysical alterations were observed in the endometrium in treated animals, especially on day 5, at 4:40 a.m., the day of implantation. A sharp increase in superoxide anion radical and a sharp fall in superoxide dismutase (SOD) activity, as seen in the endometrium from control animals, were altered in treated animals. The extract also exhibited antiestrogenic activity, as judged by increase in uterine weight. The physiological alterations induced by water extract of H. rosa-sinensis are discussed.

QSAR studies on some thiophene analogs as anti-inflammatory agents: enhancement of activity by electronic parameters and its utilization for chemical lead optimization

Small molecule heterocycle is an integral part of new drug discovery in anti-inflammatory research. In our previous papers we reported the synthesis of thiophene analogs substituted at the fifth position with alpha-oximino propionic ester moiety and the fact that such new chemical entities exhibit anti-inflammatory activity in male/female Sprague-Dawley rats. In this paper we report the quantitative structure activity relationship (QSAR) studies of a series of 43 thiophene analogs. The analogs when subjected to cluster analysis technique led to the formation of four homogeneous groups. The cluster analysis technique grouped the 2-anilino-5-substituted-4-methyl-thiophene-3-carboxylic acid methyl esters as one homogeneous group. The clusters were individually taken up for a Hansch type of QSAR study with 10 molecular descriptors. The QSAR equations generated were cross validated by the leave out one method. The studies gave an insight into the dominant role played by electronic properties like energy of the lowest unoccupied molecular orbital (ELUMO) and dipole moment (dipole) in modulating the anti-inflammatory activity. From the QSAR studies a three point pharmacophore has been established for designing novel anti-inflammatory molecules.

Olanzapine Induced Thrombocythemia in Sprague‐Dawley Rats

Olanzapine was administered orally (20 mg/kg/day) in Sprague-Dawley rats. Forty-eight male Sprague-Dawley rats were divided into eight groups of six animals each. Four groups of animals received olanzapine for 7, 14, 21 and 48 days. There were no significant changes in hematological, clinical biochemistry parameters and superoxide dismutase activity in pancreas, liver and brain of all the groups. No significant changes in malonaldehyde levels were observed in liver and brain of all the groups. A significant increase in malonaldehyde levels in pancreas were observed in all the treatment groups; however, no increase in serum glucose levels were seen in these animals. A significant increase in platelet numbers in the treatment groups poses a serious threat regarding long-term use of olanzapine.

Design, synthesis, and pharmacological evaluation of some 2-[4-morpholino]-3-aryl-5-substituted thiophenes as novel anti-inflammatory agents: generation of a novel anti-inflammatory pharmacophore

Compounds incorporating a thiophene moiety, a pi excess five membered heterocycle, have attracted a great deal of research interest owing to the therapeutic utility of the template as useful drug molecular scaffolding. Recently we reported the anti-inflammatory activity profile exhibited by two thiophene analogs, AP84 and AP82 in acute and chronic models of inflammation. The good activity profile exhibited by AP84, a 3-(substituted aryl)-2-(4-morpholino)-5-heteroaryl substituted analog of thiophene, in the formalin induced rat paw edema chronic model as compared to a weak activity in acute carrageenin induced rat paw edema, and the slightly better protection exhibited in the acute model by AP82 (27%), the 5-aroyl analog provided an impetus for a proper exploration of their structural types. In this paper we report the synthesis and pharmacological evaluation of some novel, 2-(4-morpholino)-3-(substituted aryl)-5-substituted thiophenes, as possible anti-inflammatory leads. The 3-(4-chlorophenyl)-2-(4-morpholino) thiophene analogs AP49, AP158, and AP88 provided a protection of 20%, 23%, and 20%, respectively, when screened for anti-inflammatory activity in carrageenin induced rat paw edema, an acute in vivo model, comparable to that of AP82, at a dose level of 100mg/kg body weight p.o. compared to ibuprofen as standard. The replacement of the 3-(4-chlorophenyl) moiety with the 3-phenyl moiety gave rise to AP50 (30%), AP159 (38%), AP27 (0%), and AP92 (38%), with three analogs being more active in the acute model. Alteration of the group para to the phenyl ring at third position, from chloro, to methyl mercapto gave rise to the 3-(4-methylmercapto-phenyl) analogs AP54 (20%), AP160 (0%), and AP73 (52%), with only one analog appearing to be better than AP82. These results indicate that 4-methane sulfonyl aroyl group at 5-position and other substituents of different quadrants of Craig plot on the phenyl moiety at the third position could lead to more potent candidates. However, alteration of aroyl to substituted pyridyl at 5-position with a phenyl group at the third position as in AP26 gave rise to much better protection (66%) again reinforcing the importance of the heteroaryl ring at the fifth position and implying its utility in the composition of a novel pharmacophore for designing better trisubstituted thiophenes as anti-inflammatory agents.

Design, synthesis, and SAR studies of some 5-aliphatic oximino esters of thiophene as potential anti-inflammatory leads: comparative biological activity profile of aliphatic oximes vs aromatic oximes

A series of novel tetra substituted thiophenes were synthesized, characterized, and evaluated for their anti-inflammatory activity in carrageenin induced rat paw edema model-an acute in vivo model. Compounds V1, V3, V11, V12, V17, and V18 showed good anti-inflammatory activity, indicating the importance of oxime moiety in modulating the activity. The structure-activity relationship studies explore "the aliphatic oxime esters" attached via a ketone bridge to fifth position of the thiophene, and indicate that this feature may enhance the anti-inflammatory activity as compared to aromatic oximes. Since free radicals are implicated in various inflammatory disorders, the free radical scavenging activity of some of the synthesized candidates was assessed using 1,1-diphenyl-2-picryl hydrazyl assay. The oxime containing analogs exhibited weak to moderate activity as free radical scavengers in DPPH assay. A plausible reasoning for its free radical scavenging ability is discussed. All the compounds were also screened in nitro blue tetrazolium model, to assess them as superoxide anion radical scavengers. A direct correlation between anti-inflammatory activity and free radical scavenging activity was not seen. The results disclose a new class of anti-inflammatory agents designed and synthesized for the first time wherein the utility of aliphatic oxime esters in modulating the anti-inflammatory activity profile is apparent. This will give us potential anti-inflammatory leads.

An insight into molecular mechanism of endocytosis

Endocytosis involving pinocytosis, phagocytosis and receptor-mediated pathway is a central process involved in numerous cellular events: receptor recycling, nutrient uptake, transcytosis, antigen processing and presentation, pathogen uptake etc. Traditionally, the process has been studied using uptake kinetics and immunocytochemistry. In last few decades, additional tools, like mutant analysis, density shift, semi-intact and cell-free systems and electromagnetic separation have helped us to obtain molecular insight into many of the steps involved in endocytosis. New chemical entities, like clathrin and coatomer proteins involved in internalization have been fully characterized. Biomolecules involved in vesicle budding and fusion reactions, like ARF (ADP ribosylation factors), COPs (coat proteins), and SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) have been identified and characterized. Compartment specific molecules, like Rab have also added to our understanding of complex process of endocytosis. Collectively these have led us to an era of molecular endocytosis. The present review gives an overview of the process and describes some of the molecular events of the endocytic process. It also describes methods and approaches used in deciphering the events at cellular and molecular levels.

Novel drug designing approach for dual inhibitors as anti-inflammatory agents: implication of pyridine template

Compounds incorporating thiophene moiety, a pi excess five membered heterocycle, have attracted a great deal of research interest, owing to the therapeutic utility of the template as useful drug molecular scaffolding. We report the synthesis and pharmacological evaluation of thiophenes substituted with 4-methanesulfonyl benzoyl moiety at the fifth position of the ring, as possible anti-inflammatory lead candidates. The aryl sulfonyl methyl thiophene analogs AP29, AP82, and AP37, when screened for anti-inflammatory activity in carrageenin induced rat paw edema, an acute in vivo model, exhibited moderate to good activity at a dose level of 100 mg/kg body weight P.o compared to Ibuprofen. In a five day formalin induced rat paw edema, a chronic in vivo anti-inflammatory model, candidates AP29, AP82, and AP37 inhibited the disease progression by 53%, 34%, and 65%, respectively on the fifth day, at a dose level of 100 mg/kg body weight P.o compared to Rofecoxib, Ibuprofen, and Dexamethasone at therapeutic doses which gave a protection of 53.8%, 81.5%, and 81.5%, respectively. The replacement of the 4-methanesulfonyl benzoyl moiety in AP82 with the pyridine template, 3,5-dimethyl-4-methoxy-2-pyridyl function, gave rise to AP84, which was less active in the acute model, but gave 54% and 75% protection both during the first day and fifth day, respectively, in the chronic model. A dual mechanism of action is proposed for AP84, a non-steroidal drug which has exhibited remarkable activity when compared to the steroid dexamethasone. These results open up new avenues in designing novel anti-inflammatory drugs as dual inhibitors with the incorporation of a pyridine template as part of the pharmacophore.