Acetylcholinesterase Inhibitory Potential and Insecticidal Activity of an Endophytic Alternaria sp. from Ricinus communis

Abstract

Keeping in view the vast potential of endophytic fungi to produce bioactive molecules, this study aimed at isolating and screening endophytes for the production of acetylcholinesterase inhibitors. Fifty-four endophytic fungi were isolated from Ricinus communis and screened for their AChE inhibitory activity using Ellman's colorimetric assay method. Six isolates were found to possess AChE inhibitory activity with maximum inhibition of 78 % being evinced by culture Cas1 which was identified to be Alternaria sp. on the basis of molecular as well as microscopic methods. Optimization of inhibitor production was carried out using one factor at a time approach. Maximum production of inhibitor was obtained on potato dextrose broth after 10 days incubation. The IC(50) of the chloroform extract was observed to be 40 μg/ml. The extract was purified on silica gel and eluted stepwise with a gradient of chloroform/methanol. The insecticidal potential of the extract was evaluated by feeding the larvae of Spodoptera litura on diet containing varying concentrations of the extract. It was observed that with increase in the concentration of the extract, mortality of the larvae increased. The culture has the potential of being exploited in medicine as well as a biocontrol agent.

Production of biopolyester poly(3-hydroxybutyrate) by Bacillus cereus RCL 02, a leaf endophyte of Ricinus communis L.

“…It accumulates high amount of lipid inclusions in the internal tissues especially ricinoleic acids in seeds. So far, a range of biologically active compounds have been isolated especially from rhizosphere and endosphere associated fungi of R. communis L. [8,9]. However, the bacterial endophytes harbouring the plant still remained a relatively untapped source of novel natural products including biodegradable and biocompatible PHAs.…”

Cholinesterase inhibitory potential of different Alternaria spp. and their phylogenetic relationships

“…Alternaria is also gaining importance as a biological control agent (Singh et al 2012). Alternaria infectoria and Alternaria alternata have been reported for the biolog- Christias et al 2001).…”

“…It is possible that the insecticidal potential of Alternaria could be due to the production of these inhibitors. The insecticidal activity of an AChE inhibitor produced by a species of Alternaria has been demonstrated against Spodoptera litura (Singh et al 2012). The study highlights the importance of Alternaria as a novel source of cholinesterase inhibitor.…”

“…The concentrated samples were then re-suspended in HPLC grade water for further assay (Singh et al 2012).…”

“…In our previous studies conducted in the laboratory, an endophytic Alternaria sp. isolated from Ricinus communis was found to evince good cholinesterase inhibitory activity (Singh et al 2012). With regard to this, the endophytes were isolated and those identified as Alternaria were analyzed for their ability to produce the inhibitors and an attempt was made to study the variation concerning the inhibitor production.…”