In silico investigation on the probable macromolecular drug targets involved in the anti-schizophrenia activity of Nardostachys jatamansi

Abstract Existing medications i.e. the antipsychotic drugs are known to be effective in treating only the positive symptoms of schizophrenia, while being ineffective on negative and cognitive symptoms of the disease. In addition, these medications cause extrapyramidal symptoms, forcing many patients towards natural medicine in the hope of minimizing the unwanted adverse effects. Nardostachys jatamansi is a medicinal plant that has been traditionally prescribed for various types of brain disorders. The active constituents of the plant have beneficial effects on the negative and cognitive symptoms of schizophrenia. This study was designed to identify the active constituents of Nardostachys jatamansi with the highest binding affinities for the key macromolecular drug targets involved in the pathophysiology of schizophrenia and thereby elucidate the possible mechanism of action. These targets are dopamine receptors, Gamma-aminobutyric acid receptors, N-methyl-D-aspartate receptors and Phosphodiesterase 10A. The results of molecular docking showed that, β-sitosterol, chlorogenic acid, oleanic acid and ursolic acid, displayed high binding affinity toward all the macromolecular drug targets. Ligands with steroid backbone and pentacyclic triterpene structure have been found to possess high binding affinity toward the dopamine receptor and phosphodiesterase 10A. While ligands with carbonyl group form stronger binding interactions with the N-methyl-D-aspartate receptor.

Coding of insertion-deletion events of the chloroplastic intergene atp beta-rbcL for the phylogeny of the Valerianeae tribe (Valerianaceae).

A preliminary analysis of the sequence alignment of the chloroplast intergene atp beta-rbcL in tribe Valerianeae reveals that insertion-deletion evolutionary events ('indels'), combined with nucleotide substitutions, have occurred in large zones in some of the studied taxa. Due to the frequent occurrence and large size of indels within this tribe, intergene length varies from 531 to 788 base pairs within the studied species. This situation poses gap coding problems that we had to tackle before phylogenetic analysis. Four methods of gap coding were used: elimination of gapped sites ('complete omission'), 'missing data', 'fifth base' and Barriel's coding method, which translates indels into new multistate characters in the data matrix. After application of these four methods of data treatment, phylogenetic analyses (maximum parsimony) did not lead to very different results. Three robust clades emerged in each case, corresponding to the Centranthinae subtribe (genus Centranthus), the Fediinae subtribe (genera Fedia and Valerianella), and the American species of Valeriana. The theoretical basis and biological significance of these four methods are discussed in order to apply the best ones in future studies.