B. Suresh

Antioxidant activity of the ethanolic extract of Striga orobanchioides.

Plants containing flavonoids have been reported to possess strong antioxidant properties. The ethanolic extract of Striga orobanchioides was screened for in vitro and in vivo antioxidant properties using standard procedures. The ethanol extract exhibited IC(50) values of 18.65+/-1.46 and 11.20+/-0.52 micro g/ml, respectively in DPPH and nitric oxide radical inhibition assays. These values were less than those obtained for ascorbic acid and rutin, used as standards. In the in vivo experiments the extract treatment at 100mg/kg body weight dose caused a significant increase in the level of the catalase in the liver and the kidneys. A significant increase in the level of SOD in the liver was observed. The treatment also caused a significant decrease in the TBA-RS and increase in the ascorbic acid levels. These results suggest strong antioxidant potentials of the ethanolic extract of S. orobanchioides.

Hepatoprotective effect of the total alkaloid fraction of Solanum pseudocapsicum leaves

The total alkaloid fraction of the methanol extract of leaves of Solanum pseudocapsicum was tested for its hepatoprotective activity against CCl 4 induced toxicity in freshly isolated rat hepatocytes, HepG2 cells and animal models. The total alkaloid fraction was able to normalise the levels of aspartate amino transferase (ASAT), alanine aminotransferase (ALAT), alkaline phosphatase (ALP), triglycerides (TGL), total proteins, albumin, total bilirubin and direct bilirubin, which were altered due to CCl 4 intoxication in freshly isolated rat hepatocytes and also in animal models. The antihepatotoxic effect of the total alkaloid fraction was observed at very low concentrations (6–10µg/ml) and was found to be superior to that of the standard used. A dose dependent increase in the percentage viability was observed when CCl 4 exposed HepG2 cells were treated with different concentrations of the total alkaloid fraction. The highest percentage viability of HepG2 was observed at a concentration of 10µg/ml. Its in vivo hepatoprotective effect at 20 mg/kg body weight was comparable with that of the standard at 250mg/kg body weight. The total alkaloid fraction merits further investigation to identify the active principles responsible for the hepatoprotective properties. The results from the present investigation also indicate well correlation between the in vivo and in vitro studies.

Antifertility activity of Derris brevipes variety coriacea.

Traditional physicians in and around Kotagiri village near Ootacamund, use a mixture of powdered roots of Cassia occidentalis, Derris brevipes variety coriacea and Justicia simplex to control female fertility. A mixture of powdered roots of these three plants, powdered root of Derris brevipes variety coriacea and its ethanolic extract were screened for antifertility activity in proven fertile female rats at 200 and 600 mg/kg body weight, respectively and given orally on D(1-7) of pregnancy. Both doses of the root powder of Derris brevipes variety coriacea showed 50% anti-implantation activity and also a significant reduction in the number of litters born. The ethanolic extract exhibited 40% anti-implantation activity when given orally at 600 mg/kg body weight. The rats, which continued their pregnancy, did not deliver any litters after their full term. Hence, the combined antifertility (anti-implantation and abortifacient) activity of the ethanolic extract was 100%. The results suggest that the ethanolic extract possesses more abortifacient type effect than the anti-implantation activity. The ethanolic extract also exhibited weak estrogenic activity when given alone and tested in immature ovariectomised female albino rats. But, when given along with ethinyl estradiol, it exhibited slight antiestrogenic activity. Histological and biochemical estimations were carried out to confirm this.

In Vitro Cytotoxicity and Anti-tumor Properties of the Total Alkaloid Fraction of Unripe Fruits of Solanum pseudocapsicum

The total alkaloid fraction of the methanol extract of unripe fruits of Solanum pseudocapsicum was tested for in vitro cytotoxicity on HEp-2, RD and Vero cell lines and anti-tumor activity using DLA and HEp-2 cell lines. Cell viability and morphological changes were assessed. The total alkaloid fraction exhibited strong cytotoxic activity against all the cell lines tested. The CTC 50 (50 % of cytotoxicity inhibition) was found to be 1.65 µg/ml for the RD cell line, 6.32 µg/ml for the HEp-2 cell line and 12.01 µg/ml for the Vero cell line. In the clonogenic assay, no colony formation was observed even up to a concentration of 25 µg/ml. In the short term, antitumor, studies using DLA cells, the total alkaloid fraction was associated with 50 % viability in the concentration range of 6.25-12.5 µg/ml. In long term, anti-tumor activity using the HEp-2 cell line, no colony formation was observed up to a concentration of 20 µg/ml. Hence, there is a correlation between the results obtained in the cytotoxicity and antitumor studies carried out. Morphological observation by phase contrast microscopy revealed intense damage on all the cell lines. The total alkaloid fraction has the potential for further investigation in animal models.

Formulation and evaluation of dextromethorphan hydrobromide sustained release tablets.

Sustained release (SR) matrix tablets of dextromethorphan hydrobromide were prepared by wet granulation using hydroxypropyl methyl cellulose (HPMC-K-100 CR) as the hydrophilic rate controlling polymer. The effect of the concentration of the polymer and different fillers on the in vitro drug release rate was studied. The studies indicated that the drug release can be modulated by varying the concentration of the polymer and the fillers. A complete cross-over bioavailability study of the optimized formulation of the developed sustained tablets and marketed immediate release tablets was performed on six healthy male volunteers. The extent of absorption of drug from the SR tablets was significantly higher than that for the marketed dextromethorphan hydrobromide tablet because of lower elimination rate and longer half-life.

HPTLC determination of lupeol in Grewia tiliaefolia

Among the complex mixture of biologically active compounds in the bark of Grewia tiliaefolia, a plant used in folklore, lupeol, a constituent of the bark, has been used as an analytical marker indicative of the quality of the plant. A sensitive and reliable quantitative high-performance thin-layer chromatographic method has been developed for the determination of lupeol from Grewia tiliaefolia. Chloroform extracts of bark from five different sources were used for HPTLC on silica gel with benzene-ethyl acetate, 95 + 5, as mobile phase. Under these conditions the RF of lupeol was 0.40. The calibration plot was linear in the range 0.5 to 1.5 (μg lupeol and the correlation coefficient, 0.999, was indicative of good linear dependence of peak area on concentration. The mean assay of lupeol was 2.902 ± 0.243 mg g- bark. The method enables reliable quantification of lupeol and good resolution and separation of lupeol from other constituents of Grewia tiliaefolia. To ascertain the purity of the peak from the test sample its in-situ reflectance spectrum was compared with that from standard lupeol; clear superimposibility indicated the purity of the peaks. Recovery values from 98.00 to 99.78% showed the reliability and reproducibility of the method were excellent. The HPTLC method proposed for quantitative monitoring of lupeol in Grewia tiliaefolia is rapid, simple, and accurate and can be used for routine quality testing.

Microwave-assisted rapid extraction of red dye from Caesalpinia sappan heartwood

Since ancient times Caesalpinia sappan heartwood dye has been well-known for its medicinal and dyeing properties. Isolation of the red dye using both conventional and newly developed microwave method was carried out. The conventional heating of 2u2009h provided 0.656u2009±u20090.049u2009g of the dye and by microwave heating at 540u2009W for 20u2009min, the yield obtained was 0.747u2009±u20090.047u2009g. Both the dyes were found to be the same as evidenced by UV, TLC and HPTLC studies. Antioxidant activity of the dyes was also carried out using DPPH and nitric oxide methods to confirm the similarity in their biological activity. The procedure developed can be used for the fast extraction of the red dye of C. sappan without affecting the nature of the product.

Validated HPTLC method of analysis of dexibuprofen in its formulation

A simple, sensitive, precise, and rapid high-performance thin-layer chromatographic (HPTLC) method for analysis of dexibuprofen in pharmaceutical formulation has been developed and validated. The method uses aluminum foil HPTLC plates coated with silica gel 60F254 as stationary phase and hexane—ethyl acetate—glacial acetic acid 7.5:2.5:0.5 (v/v) as mobile phase. Densitometric analysis of dexibuprofen and the internal standard (aceclofenac) was performed in reflectance mode at 217 nm. The system was found to give compact bands for dexibuprofen (RF 0.50). Linear regression analysis of the calibration data revealed a good linear relationship between response and concentration in the range 50–300 ng per band (r2 = 0.9902). The method was validated for precision, accuracy, recovery, and robustness. The method has been successfully applied to analysis of an oral solid dosage formulation.

Pharmacokinetic Evaluation of Metolazone Tablets using healthy Human Volunteers

A sensitive and reproducible high performance liqui d chromatography (HPLC) method has been developed and validated for the quantification of metolazone in h uman plasma, after solid phase extraction (SPE). A Good reso- lution was achieved on a reverse-phase LichroCART Purospher ® C 18 column using the mobile phase acetoni- trile–0.5% triethylamine (35:65) in isocratic eluti on with a total run time of 15 min. The analyte, metolazone , was detected by using high performance liquid chromatog ra- phy with the support of photo diode array detector. Limit of detection and Lower limit of quantification was found to be 1 and 2.5 ng/mL. The present method was succe ss- fully applied in the pharmacokinetic study of metol azone in human plasma.