Nazneen Parveen

PRO-OXIDANT, ANTI-OXIDANT AND CLEAVAGE ACTIVITIES ON DNA OF CURCUMIN AND ITS DERIVATIVES DEMETHOXYCURCUMIN AND BISDEMETHOXYCURCUMIN

Curcumin, a naturally occurring phytochemical responsible for the colour of turmeric shows a wide range of pharmacological properties including antioxidant, anti-inflammatory and anti-cancer effects. We have earlier shown that curcumin in the presence of Cu(II) causes strand cleavage in DNA through generation of reactive oxygen species, particularly the hydroxyl radical. Thus, curcumin shows both antioxidant as well as pro-oxidant effects. In order to understand the chemical basis of various biological properties of curcumin, we have studied the structure-activity relationship between curcumin and its two naturally occurring derivatives namely demethoxycurcumin (dmC) and bisdemethoxycurcumin (bdmC). Curcumin was found to be the most effective in the DNA cleavage reaction and a reducer of Cu(II) followed by dmC and bdmC. The rate of formation of hydroxyl radicals by the three curcuminoids also showed a similar pattern. The relative antioxidant activity was examined by studying the effect of these curcuminoids on cleavage of plasmid DNA by Fe(II)-EDTA system (hydroxyl radicals) and the generation of singlet oxygen by riboflavin. The results indicate that curcumin is considerably more active both as an antioxidant as well as an oxidative DNA cleaving agent. The DNA cleavage activity is the consequence of binding of Cu(II) to various sites on the curcumin molecule. Based on the present results, we propose three binding sites for Cu(II). Two of the sites are provided by the phenolic and methoxy groups on the two benzene rings and the third site is due to the presence of 1,3-diketone system between the rings. Furthermore, both the antioxidant as well as pro-oxidant effects of curcuminoids are determined by the same structural moieties.

Reactivities of flavonoids with different hydroxyl substituents for the cleavage of DNA in the presence of Cu(II).

DNA strand scission reactions of flavonoids in the presence of Cu(II) have been extended by using flavonoids with a variety of patterns of hydroxyl substitution. In particular we have examined for the first time a flavonoid (7,8‐dihydroxyflavone) that lacks the possibility of forming a complex involving the oxygen at position 4. By comparing the reactivities of several flavonoids, including data from the literature, we draw generalizations for the correlation of structure and activity and present evidence for at least three different modes of action of flavonoids as genotoxic agents. Copyright

Potential antifilarial activity of the leaves and seeds extracts of Psoralea corylifolia on cattle filarial parasite Setaria cervi

The effect of aqueous and alcohol extracts of the leaves and seeds of Psoralea corylifolia, on the spontaneous movements of both the whole worm and the nerve muscle preparation of Setaria cervi and on the survival of microfilariae in vitro was studied. Alcohol extracts of both leaves and seeds caused the inhibition of spontaneous movements of the whole worm and the nerve muscle preparation of S. cervi, characterised by initial, short lasting small increase in tone of contractions followed by paralysis. The initial stimulatory effect was not observed by alcohol extract of leaves on nerve muscle preparation. The concentrations required to inhibit the movements of whole worm and nerve muscle preparations for alcohol extracts of leaves and seeds were 160, 30, and 150, 20 microg/ml, respectively suggesting a cuticular permeability barrier. Alcohol extracts of both leaves and seeds caused death of microfilariae in vitro, LC(50) and LC(90) being 15 and 25 ng/ml for alcohol extract of leaves and 12 and 18 ng/ml for alcohol extract of seeds, respectively.

Semialatic Acid, a Triterpene from Rhus Semialata

Abstract A new compound, semialatic acid was isolated from Rhus semialata and identified from spectral and chemical data as 3α-hydroxy-3β,19-epoxydammara-20,24 E -dien-26-oic acid.

Two isomeric benzodipyranone derivatives from Calophyllum inophyllum

Abstract The new compound (2 S ,3 R )-2,3-dihydro-5-hydroxy-2,3,8,8-tetramethyl-6-(1-phenylethenyl)-4H,8H-benzo [1,2- b :3,4- b ′] dipyran-4-one along with (2 R ,3 R )-2,3-dihydro-5-hydroxy-2,3,8,8-tetramethyl-6-(1-phenylethenyl)-4H,8H-benzo [1,2- b :3,4- b ′] dipyran-4-one were isolated from the leaves of Calophyllum inophyllum and identified from their spectral and chemical data.

Luteolin 7,4′-dimethyl ether 3′-glucoside from Gelonium multiflorum

Abstract A new flavone glycoside has been isolated from the leaves of Gelonium multiflorum and characterized as luteolin 7,4′-dimethyl ether 3′-glucoside.

Ethyl brevifolin carboxylate and other constituents from Acer oblongum leaves

Abstract A new compound, ethyl brevifolin carboxylate, along with known compounds d -3-O-methyl chiroinositol, gb-amyrin, β-sitosterol, apigenin, kaempferol, ethyl gallate and quereetin were isolated from Acer oblongum and indentified from spectral and chemical data.

In vitro antifilarial potential of the leaves and stem extract of Pluchea lanceolata on the cattle filarial parasite Setaria cervi

The effect of alcohol and aqueous extracts of the leaves and stem of Pluchea lanceolata on the spontaneous movements of both the whole worm and the nerve muscle preparation of Setaria cervi, and on the survival of microfilariae in vitro was studied. Alcohol and aqueous extracts of the leaves and stem of P. lanceolata caused the inhibition of spontaneous movements of the whole worm and the nerve muscle preparation of S. cervi, characterized by short lasting small increase in tone and amplitude of contractions followed by paralysis. The concentrations required to inhibit the movements of whole worm and nerve muscle preparations for alcohol extract were 200 and , and for aqueous extract were 250 and , respectively, suggesting a cuticular permeability barrier. Both the extracts (alcohol and aqueous) caused death of microfilariae in vitro, and being 12 and 18 ng/ml for alcohol extract and 25 and 40 ng/ml for aqueous extract, respectively.

Antifilarial potential of the root extract of the Mirabilis jalapa Linn. (Nyctaginaceae) on cattle filarial parasite Setaria cervi

Effect of aqueous and alcoholic extracts of the roots of Mirabilis jalapa Linn. Four Oclock plant, onthe spontaneous movements of both the whole worm and the nerve-muscle (n.m.) preparation ofSetaria cervi and on the survival of microfilariae in vitro was studied. Alcoholic extract caused theinhibition of spontaneous movements of the whole worm and the n.m. preparation of S. cervi,whereas aqueous extract caused inhibition of spontaneous movements of the n.m. preparation.The initial stimulatory effect was not observed by aqueous and alcoholic extracts on n.m.preparation while effect of alcoholic extract on the whole worm was characterized by an increasein the amplitude of contractions followed by reversible paralysis. The concentrations required toinhibit the movements of the whole worm and n.m. preparation for alcoholic extract of root were270mg/mL and 40 mg/mL, respectively whereas an aqueous extract caused inhibition of n.m.preparation at 30 mg/mL suggesting a cuticular permeability barrier. Alcoholic extract of the rootsof M. jalapa caused concentration related effect on the survival of microfilariae of S. cervi. The LC50and LC90 for alcoholic extract as observed after 6 hrs. were found to be 10 ng/mL and 18 ng/mL.,respectively.