In-vitro and in silico efficacy of isolated alkaloid compounds from Rauvolfia tetraphylla L. against bovine filarial parasite Setaria cervi: a drug discovery approach.

Bioassay guided isolation from the leaves of Rauvolfia tetraphylla L. resulted in the isolation and characterization of three compounds of alkaloid in nature namely, Curan-17-oic acid (F1); 18, 19-Secoyohimban (F2) and Reserpiline (F3). Macrofilaricidal activity of three compounds was tested against bovine filarial parasite Setaria cervi using in vitro assays and supported by in silico docking analysis on glutathione-S-transferase (GST) enzyme of Wuchereria bancrofti. All the molecules inhibited GST enzyme to some extent 35.78%, 78.22% and 64.21% respectively. Results were supported by molecular docking studies, which showed docking scores for compound F1 (- 5.14), compound F2 (- 7.19) and compound F3 (- 7.2) on GST enzyme. Thus, in conclusion the in vitro and in silico studies indicated that isolated compounds are promising, inexpensive and widely available natural leads, which can be designed and developed into the macrofilaricidal drugs.

Assessment of macrofilaricidal activity of leaf extracts of Terminalia sp. against bovine filarial parasite Setaria cervi.

Antifilarial potential of three medicinal plants namely, Terminalia bellerica, Terminalia chebula and Terminalia catappa was explored using Setaria cervi, a bovine filarial parasite at concentrations of 2.5, 5 and 10mg/ml. Amongst all the extracts, methanol extract of T. bellerica showed highest macrofilaricidal activity i.e. 84.63±1.11 at 10mg/ml in MTT reduction assay with IC50 value of 2.7mg/ml. which was better than the standard DEC i.e. 79.22±3.1% at 10mg/ml with IC50 value 2.84mg/ml. Other plant extracts showed mild in vitro macrofilaricidal activity. T. bellerica methanol extract exhibited significant GST activity of 18.86±0.21 and 12.83±0.03µM/ml/min at 5 and 10mg/ml with percentage inhibition value of 73.96% and 82.29% respectively. DEC showed GST activity value of 40.03±4.14 and 21.48±6.44µM/ml/min with percentage inhibition value of 21.76% and 58.01% at 5 and 10mg/ml respectively. Thus, methanol extract of leaves of T. bellerica exhibited highly significant antifilarial potential and needs detailed analysis.

Acanthocheilonema viteae in Mastomys coucha: chemotherapeutic and chemoprophylactic role of vitamin A in experimental filarial infection.

The role of vitamin A was evaluated for its chemotherapeutic and chemoprophylactic action against Acanthocheilonema viteae infection in Mastomys coucha. Vitamin A was administered for 10 days, five days before infection and five days post infection. On day 0 experimental animals as well as controls were infected with L3, the infective stage. Establishment of the worms revealed significantly less percentage of worm recovery over untreated controls. Cell-mediated response was found to be the cause of this reduction in worm recovery, whereas humoral response was not significant as IgG, IgA and IgM titres were low.

A 1.3 kb satellite DNA from Bubalus bubalis not conserved evolutionarily is transcribed.

A 1.3 kb satellite DNA from a size defined genomic library of mammal Bubalus bubalis was cloned and sequenced. The clone pSB1 is AT rich with 447 A (33.6%), 262 C (19.7%), 240 G (19.0%) and 383 T (28.8%). There were about 1400 copies of contig in the bubaline genome but it did not uncover allele length variation when used as probe in conjunction with a number of restriction enzymes. The contig pSB1 is not conserved evolutionarily and cross hybridizes only with the Bovideae family. A set of primers from 5' (nt 422 to 441) and 3' (nt 962 to 947) deduced from the clone used for PCR amplification with four members of the Bovideae family gave the expected 530 bp band of equal intensity indicating a similar number of copies in all the four species namely Bos indicus, Capra hircus, Ovis aries and Bubalus bubalis. Expression studies with pSB1 following slot-blot hybridization with total RNA isolated from ovary, testes, kidney, lung and spleen revealed varying signal intensities in all the tissues with a most prominent signal in spleen but a faint one in ovary. Further sequence analysis revealed the presence of several eukaryotic transcriptional elements such as NF-E1, Poly-A signal, lariat consensus sequences, and CTF/NF1 binding sites. Blast search showed 90% sequence similarity with the reverse transcriptase gene of Bos taurus and sequences from nt 283 to 636 within the contig showed highly conserved reverse transcriptase like signatures along with N-glycosylation and protein kinase C phosphorylation sites. From the data we conclude that the pSB1 representing satellite DNA is associated with transcribing sequences. The prospect of identifying functional genes linked with the satellite fraction in higher vertebrates is discussed.