Gedunin and photogedunin of Xylocarpus granatum possess antifilarial activity against human lymphatic filarial parasite Brugia malayi in experimental rodent host

Abstract

The present study is aimed to evaluate antifilarial activity of Xylocarpus granatum (fruit from Andaman) against human lymphatic filarial parasite Brugia malayi in vivo. The in vitro antifilarial activity has already been reported earlier for this mangrove plant which has traditionally been used against several ailments. Aqueous ethanolic crude extract, four fractions (ethyl acetate fraction, n-butanol fraction, water-soluble fraction and water-insoluble fraction) and pure molecule/s of X. granatum (fruit) were tested in vitro on adult worms and microfilariae (mf) of B. malayi and the active samples were further evaluated in vivo in B. malayi (intraperitoneally) i.p. transplanted in the jird model (Meriones unguiculatus) and Mastomys coucha subcutaneously infected with infective larvae (L3). The crude aqueous ethanolic extract was active in vitro (IC50: adult = 15.46 μg/ml; mf = 13.17 μg/ml) and demonstrated 52.8% and 62.7% adulticidal and embryostatic effect on B. malayi, respectively, in Mastomys at a dose of 5 × 50 mg/kg by oral route. The antifilarial activity was primarily localized in the ethyl acetate-soluble fraction which revealed IC50 of 8.5 and 6.9 μg/ml in adult and mf, respectively. This fraction possessed moderate adulticidal and embryostatic action in vivo in Mastomys. Out of eight pure molecules isolated from the active fraction, two compounds gedunin (IC50 = 0.239 μg/ml, CC50 = 212.5 μg/ml, SI = 889.1) and photogedunin (IC50 = 0.213 μg/ml, CC50 = 262.3 μg/ml, SI = 1231.4) at 5 × 100 mg/kg by subcutaneous route revealed excellent adulticidal efficacy resulting in to the death of 80% and 70% transplanted adult B. malayi in the peritoneal cavity of jirds respectively in addition to noticeable microfilaricidalo action on the day of autopsy. The findings reveal that the extract from the fruit X. granatum contains promising in vitro and in vivo antifilarial activity against human lymphatic filarial parasite B. malayi which could be attributed to the presence of two pure compounds gedunin and photogedunin.

Molecular Characterization of an rsmD -Like rRNA Methyltransferase from the Wolbachia Endosymbiont of Brugia malayi and Antifilarial Activity of Specific Inhibitors of the Enzyme

“…The IC 50 was determined by use of an Excel software-based line graphic template after plotting the concentration value of each sample against percent inhibition of motility of the parasite on the x and y axes, respectively (41). The motility data were considered for evaluating IC 50 s. An in vitro cytotoxicity assay with all the test samples was carried out for assessment of the 50% cytotoxicity concentration (CC 50 ), as described earlier (42). The selectivity index (SI) was calculated as CC 50 /IC 50 to determine the therapeutic window for safety for the use of the compounds in animals.…”

“…All the surviving females were teased individually in a drop of PBS (pH 7.2) to examine the condition of the intrauterine contents (43). Any abnormality or death/distortion detected in the uterine stages, including oocytes, eggs, embryos, or mf, was considered an embryostatic/sterilization effect of the compound on the female worm, and the percentage of sterile females was assessed (42).…”

Antifilarial Activity of Eucalyptus globulus Labill. Leaves Against Brugia malayi

“…IC50 values were determined by Excel based line graphic template after plotting concentration values of each sample versus percent motility inhibition of parasite on x-and y-axis. In vitro CC50 assay on Verocells (monkey kidney cell line) was performed as mentioned earlier (Misra et al 2011). In brief, Vero cells (104/well/100 ml) in 96 well plate were exposed to seven three-fold serial dilutions of active test samples starting from 100 mM at 37 C in a CO2 incubator.…”

“…The motility of the adult worms and microfilariae was scored as 0% motility reduction (4þ); 1-49% motility reduction (3þ); 50-74% motility reduction (2þ); 75-99% motility reduction (1þ) and 100% motility reduction (dead) (Misra et al 2011).…”

Homology Modeling of NAD + -Dependent DNA Ligase of the Wolbachia Endosymbiont of Brugia malayi and Its Drug Target Potential Using Dispiro-Cycloalkanones

“…The medium was replaced with fresh medium containing the same concentration of each compound on every alternate day up to day 9. Worms were exposed to different dispiro-cycloalkanone compounds, starting with a 100 M concentration and subsequently lowering the concentrations to determine the 100% lethal concentration (LC 100 ) and the 50% inhibitory concentration (IC 50 ) (27). At the end of the test period, the worms were processed for a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction assay as described previously (28).…”