Showkat R. Mir

Formulation of Self-Nanoemulsifying Drug Delivery System for Telmisartan with Improved Dissolution and Oral Bioavailability

To improve the dissolution and oral absorption of poorly water soluble drug-telmisartan, a self-nanoemulsifying system (SNES) was developed, characterized, and its relative bioavailability was compared to commercially available formulation. Safsol-218, Tween-20, and Transcutol P were chosen as oil, surfactants, and cosurfactants respectively as they show highest solubility for telmisartan. The solubility of drug was further improved by adding sodium hydroxide (0.67%). The droplet size of the optimized emulsion was also evaluated and was observed to be in nano range. The dissolution of drug was rapid in simulated gastric fluid (pH 1.2) as well as in simulated intestinal fluid (pH 6.8) and was found to be pH independent. The pharmacokinetic parameters (AUC0→t ± SD, Cmax, and Tmax) of optimized formulation of telmisartan after oral administration as SNES were compared with oral tablet and API suspension of drug. The results showed a 4.34-fold increase in oral bioavailability of drug in comparison to tablet. The results demonstrate that SNES composed of Sefsol-218, Tween-20, and Transcutol P substantially enhanced the bioavailability of telmisartan. Further, it showed highly significant fall (p < 0.001) in mean blood pressure of hypertensive rats for 48 hours. Thus, our study provides a useful oral dosage form for telmisartan.

Cucurbitacins - An insight into medicinal leads from nature

Cucurbitacins which are structurally diverse triterpenes found in the members of Cucurbitaceae and several other plant families possess immense pharmacological potential. This diverse group of compounds may prove to be important lead molecules for future research. Research focused on these unattended medicinal leads from the nature can prove to be of immense significance in generating scientifically validated data with regard to their efficacy and possible role in various diseases. This review is aimed to provide an insight into the chemical nature and medicinal potential of these compounds exploring their proposed mode of action, probable molecular targets and to have an outlook on future directions of their use as medicinal agents.

Antidiabetic Activity of Some Indian Medicinal Plants

Abstract The effect of aqueous extracts of Syzygium cumini. Linn., Gymnema sylvestre. (Retz.) Schult., and Portulaca olearacea. Linn. were investigated in fasting normal and streptozotocin (STZ)-induced diabetic rats. The effects of extracts on oral glucose tolerance in normal fasting rats were also studied. The aqueous extracts of S. cumini. (200 mg/kg) and G. sylvestre. (200 mg/kg) decreased the blood glucose in normal rats significantly at 2 and 4 h of extract administration (p < 0.05, p < 0.01). The S. cumini. and G. sylvestre. extracts decreased the increase of glucose levels significantly (p < 0.05) at 90 and 180 min after the glucose load in glucose tolerance test. In STZ diabetic animals, the aqueous extracts of S. cumini. and G. sylvestre. decreased the blood glucose significantly (p < 0.05) at 4 h. The aqueous extract of P. olearacea. did not show any hypoglycemic activity.

A study of the chemical composition of black cumin oil and its effect on penetration enhancement from transdermal formulations.

The chemical composition of the solvent extracted fixed oil of black cumin (Nigella sativa L.) seeds was determined by capillary GC and GC/MS. Thirty-two fatty acids (99.9%) have been identified in the fixed oil. The major fatty acids were linoleic acid (50.2%), oleic acid (19.9%), margaric acid (10.3%), cis-11,14-eicosadienoic acid (7.7%) and stearic acid (2.5%). The effect of black cumin oil on in vitro percutaneous absorption of the model lipophilic drug carvedilol was investigated using excised rat abdominal skin. Transdermal flux, permeability coefficient and enhancement factor were calculated for different concentrations of oil in isopropyl alcohol. Black cumin oil (5% v/v) exhibited the highest enhancement in permeation. The increase in the permeability of the drug is due to increased drug diffusivity through the stratum corneum under the influence of black cumin oil. A higher content of linoleic acid (and other unsaturated fatty acids) in the oil has been postulated to be responsible for the enhancement of in vitro percutaneous absorption of the drug.

High-performance thin layer chromatographic quantification of bioactive psoralen and daidzein in leaves of Ficus carica L.

This study was undertaken to quantify psoralen and daidzein by high-performance thin layer chromatography (HPTLC). The methanolic extract of 10u2009mgu2009mL−1 concentration solution was prepared for HPTLC quantification of psoralen and daidzein. HPTLC aluminium-backed plates coated with 0.2u2009mm layers of silica gel 60 F254 were used as the stationary phase. The working standard solution of psoralen and daidzein was applied along with the test sample solution by means of Camag Linomat IV sample applicator. R f values of psoralen and daidzein were found to be 0.60 and 0.88, whilst as their percentage values in methanolic extract were found to be 3.02% and 5.64% (w/w), respectively. A simple quantitative estimation method of psoralen and daidzein by HPTLC is reported that can be used for the quality control of marketed preparations containing Ficus carica. However, further study is warranted to isolate and quantify active constituents present in the leaves of F. carica by sophisticated techniques.

A new withanolide from the roots of Withania somnifera

Phytochemical studies on the roots of Withania somnifera (Solanaceae) resulted in the isolation of a new withanolide glycoside, glucosomniferanolide, characterized as (20R, 22S)-1-oxo-witha-2, 5, 24-tricnolide-20-β-ol-20-D-glucopyranoside by spectral analyses and chemical reactions.

Inhibition of α-glucosidase by new prenylated flavonoids from euphorbia hirta L. herb

ETHNOPHARMACOLOGICAL RELEVANCEnEuphorbia hirta L. (Euphorbiaceae) is a pantropical medicinal rhizomatous herb, traditionally used in the treatment of diabetes, respiratory and gastro-intestinal disorders.nnnAIM OF THE STUDYnTo isolate and characterize the constituents of Euphorbia hirta and evaluate their in-vitro α-glucosidase inhibitory activity. The study is also aimed at describing structural activity relationship, type of α-glucosidase inhibition and in-vivo potential to regulate post prandial hyperglycemia in Wistar rats.nnnMATERIALS AND METHODSnMethanolic extract of whole plant was suspended in water, and sequentially fractionated with n-hexane and ethyl acetate. Further ethyl acetate fraction was subjected to medium pressure liquid chromatography (MPLC) to isolate the active molecules under the following experimental conditions, pressure (up to 5 kg/cm(2)) and flow rate (2 in./min). The structural elucidation of isolated compounds was done on the basis of detailed spectral analysis. The α-glucosidase inhibitory potential of isolated compounds was evaluated and compared with standard drug acarbose. In addition, type of inhibition was dwelled by Lineweaver-Burk plot analysis. Further, sucrose tolerance test was performed in Wistar rats pre-treated with the isolated compounds and acarbose (0.015 mM) followed by a sucrose load (2g/kg, p.o.) and blood glucose level was measured up to 120 min by the glucose oxidase method.nnnRESULTSnThe ethyl acetate fraction afforded quercetrin (1), dimethoxy quercetrin (2), along with two new prenylated flavonosides designated as hirtacoumaroflavonoside (3) and hirtaflavonoside-B (4) characterized as 7-O-(p-coumaroyl)-5,7,4-trihydroxy-6-(3,3-dimethyl allyl)-flavonol-3-O-β-D-glucopyranosyl-(2 → 1)-O-α-L-rhamnopyranoside and 5, 7, 3, 4-trihydroxy-6-(3, 3-dimethyl allyl)-8-(iso-butenyl)-flavonol-3-C-β-d-glucopyranoside, respectively. All the isolated compounds showed dose dependent inhibition of α-glucosidase which was found to be comparable to acarbose. Maximum α-glucosidase inhibition was achieved with compound 3 (IC50 0.022 mM) followed by 4 (IC50 0.071 mM) in comparison to acarbose (IC50 0.092 mM). The results revealed that 5,7,4- trihydroxyflavone structure is imperative for the inhibitory activity. The prenylation in the flavonoids increase the potency and p-coumaroyl substitution at C-7 further enriched the α-glucosidase inhibition. Compound 3 exhibited non-competitive inhibition while compounds 1, 2 and 4 showed mixed non-competitive inhibitory pattern. The results of sucrose tolerance test corresponded well with the in vitro studies.nnnCONCLUSIONnα-Glucosidase inhibitory activity and sucrose tolerance test demonstrated by the prenylated flavonoids present in E. hirta provide credence to the ethnomedicinal use of the plant in the management of diabetes in folk medicine.

Prevention of Carbon Tetrachloride-Induced Hepatotoxicity by the Ethanol Extract of Capparis moonii Fruits in Rats

The effect of the ethanol extract of Capparis moonii Hook. f. Thoms. (Capparidaceae) fruits was studied in carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. The hepatotoxicity was induced in rats with the administration of 1 : 1 (v/v) mixture of CCl4 in olive oil at the dose of 1 ml/kg subcutaneously on day 7. The ethanol extract of C. moonii (200 mg/kg) and the standard drug silymarin (25 mg/kg) were given orally from day 1 to day 9. The extract of C. moonii produced significant (p < 0.001) lowering of the elevated Serum glutamic oxaloacetic transaminace (SGOT) Serum glutamicpyraric transaminase (SGPT), alkaline phosphatase (ALP), and a rise of depleted total protein when compared with the toxic control. The results were comparable with the standard drug silymarin.

GC-MS Analysis of Volatile Oil of Aerial Parts of Artemisia annua Linn

Abstract GC-MS Analysis of the volatile oil of Artemisia annua Linn. resulted in isolation of 39 components, 37 of which comprising 99.2% of total volatiles were completely identified. Quantitatively the volatile oil was characterized by 65.7% of monoterpenes and 27.3% of sesquiter-penes. 1,8-cineole (15.1%) was prominent component followed by α-terpineole (14%), p-cymene (12.9%), carvone (12%), γ-elemene (6.2%) and Z-α-bisabolene (5.4%).

Composition of Volatile Oil of Syzygium aromaticum Buds

Abstract A steam-distilled essential oil obtained from buds of Syzygium aromaticum was characterized by a high percentage of oxygenated monoterpenes (53.2%) dominated by myrtenone (49.1%) and pulegone (4.1%). Oil contained three sesquiterpenes (about 10%), which consisted of β-caryophyllene (8.7%), α-humulene (1.1%) and caryophyllene oxide (1%). The major non- terpenic component is eugenol (27.1%) followed by palmitic acid (4.3%), and formic acid (1.6%).