Vijai Lakshmi

Antiamoebic activity of Piper longum fruits against Entamoeba histolytica in vitro and in vivo

The fruits of Piper longum used in traditional remedies against intestinal distress have been tested for their efficacy against experimental caecal amoebiasis of rats. The ethanolic extract, hexane fraction, n-butanol soluble fraction exerted in vitro amoebicidal action at 1000 micrograms/mL and the chloroform fraction at 500 micrograms/mL. The ethanolic extract and piperine, a pure compound, from this plant material cured 90% and 40% of rats with caecal amoebiasis, respectively.

Immunostimulant principles from Curculigo orchioides.

Curculigo orchioides Gaerten belongs to the family Amaryllidaceae. The rhizomes of the plants are used for the treatment of decline in strength, jaundice and asthma. Its methanolic extract has been shown to enhance phagocytic activity of macrophages. Present studies have led to the isolation of two phenolic glycosides and a purified glycoside fraction. These were studied for their effect on macrophage migration index (MMI), haemagglutination (HA) titre, plaque forming cell (PFC), PHA-induced blast transformation of lymphocytes (BTL) and delayed type hypersensitivity (DTH). Significant immunostimulant activity was found in purified glycoside-rich fraction isolated from the ethyl acetate extract. The exact structure of the active glycoside is yet to be determined. The enhancement of HA titre and PFC count on one hand and that of DTH response on the other indicates that glycoside fraction stimulates both humoral and Cell-mediated immune responses. Glycoside fraction stimulates immune response by acting both on macrophages and the lymphocytes.

Gedunin and photogedunin of Xylocarpus granatum show significant anti-secretory effects and protect the gastric mucosa of peptic ulcer in rats.

In the present study, the gastroprotective mechanism of Xylocarpus granatum fruit and its active constituents gedunin and photogedunin was investigated. Chloroform fraction (Fr-CHCl(3)) of X. granatum fruit was evaluated against cold restraint (CRU), aspirin (AS), alcohol (AL) and pyloric ligation (PL) induced gastric ulcer models in rats and histamine (HA) induced duodenal ulcer model in guinea pigs. Potential anti-ulcer activity of Fr-CHCl(3) was observed against CRU (58.28%), AS (67.81%), AL (84.38%), PL (65.66%) and HA (61.93%) induced ulcer models. The standard drug omeprazole (10mg/kg, p.o.) showed 68.25% protection against CRU, 57.08% against AS and 69.42% against PL model and 70.79% against HA induced duodenal ulcer. Sucralfate, another standard drug (500 mg/kg, p.o.) showed 62.72% protection in AL induced ulcer model. Fr-CHCl(3) significantly reduced free acidity (51.42%), total acidity (30.76%) and upregulated mucin secretion by 58.37% respectively. Phytochemical investigations of Fr-CHCl(3) yielded gedunin (36%), photogedunin (2%). Further, Fr-CHCl(3) and its compounds gedunin and photogedunin significantly inhibited H(+) K(+)-ATPase activity in vitro with IC(50) of 89.37, 56.86 and 66.54 microg/ml respectively as compared to the IC(50) value of omeprazole (30.24 microg/ml) confirming their anti-secretory activity. Conclusively, Fr-CHCl(3) of Xylocarpus granatum was found to possess anti-ulcerogenic activity which might be due to its anti-secretory activity and subsequent strengthening of the defensive mechanism. This study is the first of its kind to show significant anti-secretory effect of gedunin and photogedunin. Therefore it could act as a potent therapeutic agent against peptic ulcer disease.

Metabolites from Sinularia species

This review covers about 40 species of the genus Sinularia, in which many compounds with novel chemical structures have been isolated, characterised and bioassayed for various activities since the beginning of marine chemistry until now. The bioactivities of the metabolites have been reported in the tables wherever found in the literature.

Monoterpenoid furanocoumarin lactones from clausena anisata

Abstract A reinvestigation of Clausena anisata has yielded imperatorin, xanthotoxol, lansamide-I and three new furanocoumarin lactone derivatives: indicolactone, anisolactone and 2′,3′-epoxyanisolactone. The structures of these compounds have been elucidated by a combination of spectroscopic and chemical methods.

Inhibition of hyaluronidase activity of human and rat spermatozoa in vitro and antispermatogenic activity in rats in vivo by Terminalia chebula, a flavonoid rich plant ☆

Our interest in development of hyaluronidase inhibitors as male antifertility agents led to identification of Terminalia chebula (T. chebula) plant with hyaluronidase (HAase) inhibitory activity of human spermatozoa ( approximately 93% inhibition) and rat caudal epididymal spermatozoa ( approximately 86% inhibition) in vitro at 30 mg/ml. We further demonstrated inhibition of hyaluronidase activity of testis and epididymal spermatozoa in vivo coincident with antispermatogenic activity and contraceptive efficacy of TC extract administered at 50 and 100mg/kg/day orally for 60 days in male albino rats. The significant decrease in motility, count and increase in morphological abnormalities of epididymal spermatozoa and severe reduction in fertility (-100%) of male rats treated with T. chebula fruit extract at 100mg/kg dose could be attributed to either direct effect on testis or direct or indirect interference with sperm maturation in epididymis, and/or inhibition of testicular and epididymal sperm hyaluronidase enzyme in vivo probably caused by flavonoids like tannins present in T. chebula.

Antidyslipidemic effect and antioxidant activity of anthraquinone derivatives from Rheum emodi rhizomes in dyslipidemic rats

The aim of the present study was to evaluate the antidyslipidemic effect of ethanolic extract of Rheum emodi rhizomes and its constituents in Triton-WR-1339 and high-fat diet (HFD)-induced dyslipidemic rats. In preliminary screening, the ethanolic extract showed significant activity in Triton-treated rats. Bioassay-guided fractionation of the ethanolic extract resulted in the identification of four anthraquinone derivatives, viz. chrysophanol, emodin, chrysophanol 8-O-β-d-glucopyranoside and emodin 8-O-β-d-glucopyranoside as active constituents. All these compounds significantly reduced plasma lipid levels. The most active compound emodin showed significant lipid-lowering activity in the HFD-fed model. In addition, these compounds showed significant antioxidant activity. The effect of emodin on enzymes modulating lipid metabolism confirms and supports the efficiency of emodin as a potent antidyslipidemic agent.

Pregnancy interceptive activity of Melia azedarach Linn. in adult female Sprague-Dawley rats

Ethanolic extract of the root of Melia azedarach Linn. (family: Meliaceae) collected from the Institute campus intercepted pregnancy in 60% and 75% adult female rats when administered at 250 and 500 mg/kg daily doses, respectively, on Days 1-10 post-coitum by the oral route. On fractionation, the activity was localized in the chloroform fraction of the ethanolic extract, which showed 80-100% activity at 250 mg/kg daily dose in repeat tests. In animals that became pregnant, there was also a significant reduction in mean number of implantations and all the implantations exhibited signs of resorption. Of the four major compounds isolated in sufficient quantity and characterized from the active chloroform fraction, two compounds showed only marginal (50%) contragestational effect. Further exploration of the active chloroform fraction, which is also devoid of estrogen agonistic activity at the contraceptive dose in immature rat bioassay, is being undertaken to identify and characterize the active principle(s).

An overview of the genus Xylocarpus

The article deals with the chemical constituents isolated from all the Indian species of Xylocarpus viz. X. granatum, X. moluccensis, and X. mekongensis. A total of about 70 pure compounds of different classes have been covered. The article describes the biosynthetic pathway of limonoids and sources, bioactivities and chemical and physical constants of the different classes of compounds.

Antifilarial activity of marine sponge Haliclona oculata against experimental Brugia malayi infection

The present study incorporates the findings on in vitro and in vivo antifilarial activity in the marine sponge, Haliclona oculata using an experimental rodent infection of human lymphatic filarial parasite, Brugia malayi. The in vitro antifilarial action was determined on both adult female worms as well as microfilariae using two parameters viz. adverse effect on motility and inhibition in MTT reduction by the treated adult parasite over control worm. The antifilarial activity could be located in the methanol extract and one of its four fractions (chloroform). Bioactivity guided fractionation of chloroform fraction led to localization of in vitro activity in one of its eight chromatographic fractions. Methanol extract, chloroform fraction and one of the chromatographic fractions revealed IC(50) values of 5.00, 1.80, and 1.62μg/ml, respectively when adult B. malayi were exposed to these test samples for 72h at 37°C. Under similar exposure conditions, the IC(50) values for microfilariae were 1.88, 1.72 and 1.19μg/ml, respectively. The active test samples were found to be safe revealing >10 selectivity indices (SI) on the basis of cytotoxicity to Vero cells (monkey kidney cells) and therefore selected for in vivo evaluation against primary (adult B. malayi intraperitoneal transplanted jird) and secondary (subcutaneous infective larvae induced mastomys) screens. In primary jird model, the three test samples at 100mg/kg for five consecutive days by subcutaneous route demonstrated significant macrofilaricidal efficacy to the tune of 51.3%, 64% and 70.7% by methanol extract, chloroform and chromatographic fraction, respectively. The three samples demonstrated 45-50% macrofilaricidal activity with moderate embryostatic effect in secondary model at 5×500, 5×250 and 5×125mg/kg by oral route. Chromatographic fraction possessing highest antifilarial action was primarily found to be a mixture of four alkaloids Mimosamycin, Xestospongin-C, Xestospongin-D and Araguspongin-C in addition to few minor compounds.