Antifilarial activity of Caesalpinia bonducella against experimental filarial infections.

BACKGROUND & OBJECTIVE: Lymphatic filariasis is a disabling disease that continues to cripple population in tropical countries. Currently available antifilarial drugs are not able to control the disease. Therefore, a better antifilarial is urgently required for proper management of the disease. We undertook this study to assess the antifilarial activity of Caesalpinia bonducella-seed kernel against rodent filarial parasite in experimental model. METHODS: Microfilaraemic cotton rats and Mastomys coucha harbouring Litomosoides sigmodontis and Brugia malayi respectively, were treated with crude extract or fractions of the seed kernel C. bonducella through oral route for 5 consecutive days. Microfilaricidal, macrofilaricidal and female worm sterilizing efficacy was assessed. RESULTS: Crude extract showed gradual fall in microfilariae (mf) count in L. sigmodontis-cotton rat model from day 8 post-treatment attaining more than 95 per cent fall by the end of observation period. It also exhibited 96 per cent macrofilaricidal and 100 per cent female sterilizing efficacy. The butanol fraction F018 caused 73.7 per cent reduction in mf count and 82.5 per cent mortality in adult worms with 100 per cent female sterilization. The aqueous fraction F019 exerted more than 90 per cent microfilaricidal activity and 100 per cent worm sterilization. Two chromatographic fractions, F024 and F025 of hexane soluble fraction exhibited 64 and 95 per cent macrofilaricidal activity, respectively. Both the fractions caused gradual fall in microfilaraemia and 100 per cent worm sterilization. In B. malayi-M. coucha model F025 showed gradual reduction in microfilaraemia and caused 80 per cent sterilization of female parasites INTERPRETATION & CONCLUSION: In conclusion, C. bonducella- seed kernel extract and fractions showed microfilaricidal, macrofilaricidal and female-sterilizing efficacy against L. sigmodontis and microfilaricidal and female-sterilizing efficacy against B. malayi in animal models, indicating the potential of this plant in providing a lead for new antifilarial drug development.

Antifungal activity of Agapanthus africanus extractives.

The ethanolic extract of the rhizomes of Agapanthus africanus showed antifungal activity. In bioassay guided fractionation, n-butanol fraction exhibited significant activity against human pathogens. A saponin, (25R)-spirost-7-en-2alpha,3beta,5alpha-triol-3-O-[alpha-L-rhamnopyranosyl(1-->2)-[beta-D-galactopyranosyl (1-->3)] beta-D-glucopyranoside (1), responsible for the antifungal activity and having MIC value of 15.6 microg/ml against Trychophyton mentagrophytes and Sporothrix schenekii, was isolated and identified as active constituent of the plant.

Antifungal anthraquinones from Saprosma fragrans.

A new 3,4-dihydroxy-1-methoxy anthraquinone-2-corboxaldehyde (1) together with a known anthraquinone, damnacanthal (2), were isolated from the chloroform fraction of the aerial part (whole plant without root) of Saprosma fragrans. The isolated anthraquinones (1) and (2) were found to exhibit antifungal activity against Trichophyton mentagrophytes and Sporitrichum schenckii. Their structures were established by chemical and spectral analysis.

Bioactivity of marine organisms: Part IX--screening of some marine flora from the Indian coasts.

Alcoholic extracts of 48 identified species of marine flora were screened for a wide range of biological activities. Of these, 3 extracts showed diuretic activity while 2 extracts showed hypotensive effect.

Chemical constituents of Bacopa procumbens.

Phytochemical investigation of Bacopa procumbens afforded two new phenolic glycosides 1 and 2, for the first time, along with 12 known compounds 3-14. Structures of these compounds were established based on spectral and chemical evidences.

Synthesis of combinatorial libraries based on terpenoid scaffolds.

Triterpenoid-based scaffolds betulinic acid (1a) and ursolic acid (1b), have been used for the generation of combinatorial libraries in parallel format using solid phase organic synthesis method. These templates have the potential for the synthesis and amplification of triterpenoid-based compounds with one and two-point diversity. This has been demonstrated by the synthesis of two small libraries comprising 18 derivatives each of betulinic acid and ursolic acid with structural diversity at C-3 and C-28 positions. The primary screening of antimalarial activity of these libraries against P. falciparum in vitro led to the identification of four compounds with 5 fold increase in the activity compared to betulinic and ursolic acids.

Screening of Indian plants for biological activity: Part XVI.

Alcoholic extracts of 288 of plant materials from 199 plant species have been tested for various biological activities including chemotherapeutic and pharmacological screening. Biological activities, ranging from moderate to good degree, have been observed in 61 plants extracts. Follow up studies have been carried out in these extracts and some of them have shown moderate degree of activities at this Institute. However, none of the extracts was found to be good enough for further development. Results of the present studies, along with chemical investigations on different species of similar genera which were screened earlier, are also discussed.

A new alkaloid and other anti-implantation principles from Tabernaemontana heyneana.

A new alkaloid designated as ervatine, in addition to seven known alkaloids, viz. tabersonine, coronaridine, heyneanine, voacristine, voacristine hydroxyindolenine, hydroxyibogamine, and coronaridine hydroxyindolenine, were isolated from the fruit of Tabernaemontana heyneana Wall. Characterisation and structure elucidation of these compounds was made on the basis of their spectral analyses. The ethanolic extract and isolated alkaloids heyneanine and voacristine prevented pregnancy when administered during the preimplantation period in Sprague-Dawley rats. These were, however, found to possess significant uterotrophic activity.

Picroliv preconditioning protects the rat liver against ischemia-reperfusion injury.

Cell death following ischemia-reperfusion injury is a major concern in clinical issues such as organ transplantation and trauma. The need to identify agents with a potential for preventing such damage has assumed great importance. We have evaluated the efficacy of picroliv, a potent antioxidant derived from the plant Picrorhiza kurrooa, in protecting against hepatic ischemia-reperfusion injury in vivo. Picroliv was fed to male Sprague Dawley rats in a dose of 12 mg/kg once daily by oral gavage for 7 days prior to hepatic ischemia. Ischemia was induced by occluding the hepatic pedicel with a microaneurysm clip for 30 min and reperfusion was allowed thereafter for varying period (15-120 min) by releasing the microaneurysm clip. Picroliv pretreatment resulted in better hepatocyte glycogen preservation and reduced apoptosis. Reduction in apoptosis was associated with decreased mRNA expression of caspase-3 and Fas. Oxidant induced cellular damage as measured by tissue malondialdehyde (MDA) levels was significantly less following picroliv pretreatment. Both a reduction in neutrophil infiltration and an increased level of intracellular antioxidant enzyme superoxide dismutase possibly contributed to the reduction in tissue lipid peroxidation. Tissue inflammatory cytokines level of interleukin-1alpha (IL-1alpha) and interleukin-1beta (IL-1beta) was also lower in picroliv group. Furthermore, picroliv pretreatment resulted in enhanced proliferating cell nuclear antigen (PCNA) immunoreactivity. These studies strongly suggest picroliv to be a promising agent for ameliorating injury following ischemia-reperfusion.

Prevention of renal ischemia-reperfusion-induced injury in rats by picroliv.

Picroliv is a potent antioxidant extracted from the roots and rhizome of Picrorhiza kurrooa. It has been shown to impart significant hepatoprotective activities, partly by modulation of free radical-induced lipid peroxidation. Lipid peroxidation and reactive oxygen species are associated with tissue injury in post-ischemic acute renal failure. The efficacy of picroliv was assessed in an in vivo model of renal ischemia-reperfusion injury (IRI) in rats at a dose of 12 mg/kg orally for 7 days. The animals were killed at various times after reperfusion. Increased lipid peroxidation and apoptotic cell number reflected the oxidative damage following renal IRI. Picroliv-pretreated rats exhibited lower lipid peroxidation, improved antioxidant status, and reduced apoptosis, indicating better viability of renal cells. Immunohistochemical studies revealed that picroliv pretreatment attenuated the expression of intercellular adhesion molecule-1 in the glomerular region. These results suggested that picroliv pretreatment protects rat kidneys from IRI, perhaps by modulation of free radical damage and adhesion molecules.

Picroliv modulates the expression of insulin-like growth factor (IGF)-I, IGF-II and IGF-I receptor during hypoxia in rats.

The insulin-like growth factors (IGFs), IGF-I and IGF-II, play important roles in normal growth and differentiation. In recent studies, IGFs have been implicated in tissue repair and regeneration after hypoxicischemic injury. The growth effects of these genes are exerted primarily through IGF-I receptor (IGF-IR). We have earlier shown that picroliv, obtained from the roots of Picrorhiza kurrooa, reduces cellular damage caused by hypoxia in vitro. We have now studied the modulation of IGF-I, IGF-II and IGF-IR in hypoxia and the ability of picroliv to modify their expression in vivo. Male Sprague-Dawley rats, placed in 10% oxygen for 4 days, were sacrificed, and the expression of IGF-I, IGF-II and IGF-IR was determined by immunohistochemistry, in situ hybridization and reverse transcriptase polymerase chain reaction (RT-PCR) in brain, liver and lung. One group of animals was pretreated with picroliv and the other served as control. IGF-I and IGF-IR were expressed in distinct regions of the brain but not in liver or lung. IGF-I was mainly expressed in the hippocampus and cerebellum, whereas IGF-IR expression was also observed in the cortex. A significant reduction in the messenger RNA (mRNA) level of these genes was observed in response to hypoxia. Pretreatment with picroliv not only prevented such downregulation but more importantly resulted in increased levels of IGF-I and IGF-IR. These observations correlated with reduced neuronal cell death observed in these animals. The mRNA of IGF-II was constitutively expressed and was not altered by hypoxia. Modulation of IGF-I and IGF-II expression by picroliv, a novel pharmacological agent, could benefit in similar clinical settings such as myocardial ischemia and certain cerebral injuries.

Activity of certain fractions of Tribulus terrestris fruits against experimentally induced urolithiasis in rats.

An ethanolic extract of the fruits of T. terrestris showed significant dose dependent protection against uroliths induced by glass bead implantation in albino rats. On subsequent fractionation of the ethanol extract, maximum activity was localised in the 10% aqueous methanol fraction. It provided significant protection against deposition of calculogenic material around the glass bead. It also protected leucocytosis and elevation in serum urea levels. Further, fractionation lead to decreased activity. This could be either due to loss of active compounds during fractionation, or the antiurolithiatic activity of T. terrestris being a combined effect of several constituents present in the methanolic fraction.

Antigestagenic activity of Ixora finlaysoniana in rat.

Oral administration of crude ethanolic extract of the serial parts of Ixora finlaysoniana Wall. ex G. Don to adult female rats at 250 mg/kg dose on days 1-5 or 1-7 post-coitum prevented pregnancy in 100% rats. The extract was also effective when administered on days 1 or 1-3 post-coitum, but the minimum effective dose increased with decreased duration of administration and was 1000 mg/kg and 500 mg/kg, respectively, in the two schedules. At lower doses, a significant reduction in implantation number and increased post-implantation resorption rate were observed in all the schedules. Almost complete resorption of all implantations was observed after administration of 1000 mg/kg dose of the extract during the peri-implantation period. A slight acceleration in tubal transport rate of embryos and delay in blastocyst formation were observed in rats treated postcoitally with the single anti-implantation dose of the extract. Significantly fewer embryos were recovered after their entry into the uterus. Except in one rat receiving 250 mg/kg dose of the extract on days 1-5, in which one apparently normal zona-free blastocyst was recovered from the uterus, uterine flushings of none of the nonpregnant animals contained any unimplanted embryos by day 10 post-coitum. In immature rat bioassay, the extract was found to possess estrogenic activity as evidenced by dose-dependent increase in uterine weight and cornification of the vaginal epithelium at doses ranging from 50-1000 mg/kg. At the 500 and 1000 mg/kg doses, it also induced premature opening of the vagina. Taking 100% increase in uterine weight as the parameter, the extract was found to be about 1.6X10(5) times less estrogenic than ethinylestradiol. The extent and duration of estrogenic responses exerted by single contraceptive dose of the extract were also markedly lower than that induced by ethinylestradiol. The extract was devoid of any estrogen antagonistic or synergistic activity and did not affect ovarian prenidatory estrogen or progesterone synthesis. The findings indicate that the extract at its contraceptive dose a) exerts a differential estrogenic response at the fallopian tube and the uterine levels, b) does not appear embryocidal, but causes slight asynchrony in development and tubal transport rate of pre-implantation embryos, which together with their loss through vagina after entry into the uterus, due to estrogenic action of the extract, might contribute to its anti-implantation action, and c) its anti-implantation and post-implantation resorptive actions are not mediated via altered ovarian function.

PIP: Colony-bred immature (25-35 gm) and adult (180-220 gm) Sprague-Dawley rats were administered orally an 85% ethanolic extract of powdered aerial parts of Ixora finlaysoniana suspended in distilled water. The extract prevented pregnancy in 100% of rats at a dose of 250 mg/kg on days 1-5 or 1-7 post coitus. However, 1000 mg/kg and 500 mg/kg doses were required to achieve complete contraception increasing with decreased duration of administration of the extract. At sub contraceptive doses, a significant reduction in implantation and a marked increase in post implantation resorption rate were observed in all the schedules. Almost complete resorption of all implantations was observed at 1000 mg/kg dose of the extract administered on days 5-7 post coitus. Single oral anti implantation dose (1000 mg/kg) of the extract administered within 24 hours of coitus induced slight acceleration of tubal transport of embryos. Fewer extract-treated rat embryos were recovered from the Fallopian tubes compared with controls on days 4 and 5 to (p 0.01). 1 normal zona free blastocyst was also recovered from the uterine flushings of a rat treated with a 250 mg/kg dose on days 1-5 post coitus, but uterine flushings of none of the 43 remaining nonpregnant rats treated with the various doses on days 1, 1-3, 1-5, or 1-7 yielded any unimplanted embryos by day 10 post coitus. Doses ranging from 50 to 1000 mg/kg once daily for 3 consecutive days induced a dose-independent increase in uterine weight (p 0.001) vs. controls and cornification of the vaginal epithelium in bilaterally ovariectomized rats. Premature opening of the vagina was observed only at 500 and 1000 mg/kg doses. A single oral contraceptive dose of 1000 mg/kg induced a significant increase (p 0.05) vs. the control group in uterine weight and premature opening of the vagina and 40-60% vaginal cornification in all treated rats. In comparison, a single oral contraceptive dose (1.5 mg/kg) of ethinyl estradiol induced stronger and longer estrogenic responses; uterine weight gain at all time intervals was significantly more than with the extract.

Immunostimulant activity of Picroliv, the iridoid glycoside fraction of Picrorhiza kurroa, and its protective action against Leishmania donovani infection in hamsters.

Picroliv, a standardised fraction from root and rhizome of Picrorhiza kurroa, consisting of iridoid glycosides and shown to be responsible for its hepatoprotective activity, was studied for immunostimulant activity. Oral administration of Picroliv (10 mg/kg x 7 days) in mice prior to immunization with sheep red blood cells (SRBC) resulted in a significant increase in haemagglutinating antibody (HA) titre, plaque forming cells (PFC), and delayed hypersensitivity (DTH) response to SRBC. Picroliv enhanced the non-specific immune response characterized by an increase in macrophage migration index (MMI), [14C]-glucosamine uptake, phagocytosis of [14C]-leucine labelled Escherichia coli, chemiluminescence of peritoneal macrophages, and higher uptake of [3H]-thymidine in the lymphocytes of treated mice. It also induced a high degree of protection in golden hamsters against challenge infection with Leishmania donovani promastigotes.

Immunostimulant Activity of Picroliv, the Iridoid Glycoside Fraction of Picrorhiza kurroa, and its Protective Action against Leishmania donovani Infection in Hamsters1.

Picroliv, a standardised fraction from root and rhizome of PICRORHIZA KURROA, consisting of iridoid glycosides and shown to be responsible for its hepatoprotective activity, was studied for immunostimulant activity. Oral administration of Picroliv (10 mg/kg x 7 days) in mice prior to immunization with sheep red blood cells (SRBC) resulted in a significant increase in haemagglutinating antibody (HA) titre, plaque forming cells (PFC), and delayed hypersensitivity (DTH) response to SRBC. Picroliv enhanced the non-specific immune response characterized by an increase in macrophage migration index (MMI), [ (14)C]-glucosamine uptake, phagocytosis of [ (14)C]-leucine labelled ESCHERICHIA COLI, chemiluminescence of peritoneal macrophages, and higher uptake of [ (3)H]-thymidine in the lymphocytes of treated mice. It also induced a high degree of protection in golden hamsters against challenge infection with LEISHMANIA DONOVANI promastigotes.

Structure of pescaproside E, a fatty acid glycoside from Ipomoea pescaprae.

Three fatty acid glycosides, designated pescaprosides A, B, and E, have been isolated from Ipomoea pescaprae (family Convolvulaceae). Chemical studies on pescaproside E, the major product, led to its characterisation as a pentaglycoside of 11-hydroxyhexadecanoic acid. Its sugar chain was esterified with 2-methylbutanoic and lauric acids. The structure of the pentaglycoside has been established as O-alpha-L-rhamnopyranosyl-(1----3)-O-[alpha-L-rhamnopyranosyl- (1----4)]-O-alpha-L-rhamnopyranosyl-(1----4)-O-beta-D-fucopyranosyl-(1-- --2)- O-alpha-L-rhamnopyranosyl-(1----11)-oxyhexadecanoic acid.

In vitro effect of Phyllanthus amarus on hepatitis B virus.

To evaluate the effects of P. amarus on hepatitis B virus (HBV) antigens and HBV-DNA, initial ethanolic extract and subsequent fractions of the plants were prepared. The whole plant material was dried, powdered and extracted with alcohol and subsequently fractionated in hexane, chloroform, butanol and finally in water. All the material were tested for in vitro effects on HBsAg, HBeAg and HBV-DNA in serum samples positive for HBV antigens followed by the screening of respective antigens by Elisa. HBV-DNA was determined by molecular hybridization. The extracts were effective against HBV antigens, the butanol extract being the most potent. Further chromatographic fractions showed an enhanced activity. The active fractions inhibited the interaction between HBsAg/HBeAg and their corresponding antibodies suggesting anti-HBs, anti-HBe-like activity and also an effect on HBV-DNA.

In vitro studies on the effect of certain natural products against hepatitis B virus.

Picroliv (active principle from Picrorrhiza kurroa), its major components picroside I, catalpol, kutkoside I, kutkoside, andrographolide (active constituent of Andrographis paniculata), silymarin and Phyllanthus niruri extract were tested for the presence of anti hepatitis B virus surface antigen (anti HBs) like activity. HBsAg positive serum samples obtained from hepatitis B virus (HBV) associated acute and chronic liver diseases and healthy HBsAg carriers were used to evaluate the anti-HBs like activity of compounds/extract. The latter were mixed with serum samples and incubated at 37 degrees C overnight followed by HBsAg screening in the Elisa system. A promising anti-HBsAg like activity was noted in picroliv (and its major components) catalpol, P. niruri which differed from the classical viral neutralization. Picroliv also inhibited purified HBV antigens (HBsAg and HBsAg) prepared from healthy HBsAg carriers. The in vitro testing system appears to be a suitable model to identify an agent active against HBV, prior to undertaking detailed studies.

Dodonic Acid, A New Diterpenoid from Dodonaea viscosa1.

The aerial parts of DODONAEA VISCOSA afforded a new diterpenoid, dodonic acid, the structure and stereochemistry of which have been established by chemical and spectroscopic means.