In vivo developmental studies of Helicoverpa armigera and in silico molecular interactions with trypsin reveal the bio-insecticidal potential of trypsin inhibitor (SSTI) isolated from Solanum surattense.

We report the impact of gut protease inhibition on the development of Helicoverpa armigera by trypsin inhibitor and the use of molecular modeling to understand the mechanism of trypsin inhibition. Larvae of H. armigera fed on an artificial diet containing 150 and 300 µg/ml SSTI showed a negative impact on the insects' development in terms of mean larval weight, larval fatality, survival rate, and nutritional indices. Prominent physical abnormalities like curled wings, malformed appendages, and small body size were observed during the development. Gene expression studies revealed down regulation in trypsin (HaTry 1, 2, 3, 4, 6, 8) and chymotrypsin (HaChy 1, 2, 3, 4) genes of the larval gut upon treatment of SSTI. Homology modeling has been used to build the three-dimensional structure of SSTI, which showed ß-sheets having a stable canonical inhibitory loop (CIL) with conserved lysine residue. Molecular docking studies showed the strong binding of SSTI at the active site of trypsin. Molecular dynamic (MD) simulation revealed the stable interactions of the rigid CIL of SSTI at the active site of trypsin, leading to its destabilization. Conserved lysine63 of the P1 site in SSTI forms a strong hydrogen bonding network with residues Asp189 and Ser190 of trypsin.

Biofilm inhibition mechanism from extract of Hymenocallis littoralis leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: Hymenocallis littoralis (Jacq.) Salisb. has been referred as beach spider lily and commonly known for its rich phytochemical diversity. Phytochemicals such as alkaloids, volatile constituents, phenols, flavonoids, flavonols extracted from different parts of these plants like bulbs, flowers, leaf, stem and root had been used in folk medicines from ancient times because of their excellent antimicrobial and antioxidant properties. The leaf and bulb extract of H. littoralis plant was traditionally used for wound healing. Alkaloids extracted from bulb of this plant possess anti-viral, anti-neoplastic and cytotoxic properties. However, these phytochemicals have also shown antibiofilm activity, which is considered as one of the important factor accountable for the drug resistance in microorganisms. Thus, the investigation of medicinal properties of H. littoralis could be useful to control biofilm producing pathogens. AIM OF THE STUDY: Explore antimicrobial, antibiofilm and antioxidant potentials of H. littoralis against pathogenic microorganisms using experimental and computational biology approach. MATERIALS AND METHODS: Phytochemical extraction from dried powder of H. littoralis leaves was done by solvent extraction using methanol. Antimicrobial and antibiofilm activities of leaves extract were carried out using agar well diffusion method, growth curve, minimum inhibitory concentration (MIC) and Scanning Electron Microscopy (SEM). Liquid Chromatography and Mass Spectroscopy (LCMS) technique was used for the identification of phytochemicals. Molecular docking studies of antibiofilm agents with adhesin proteins were performed using Autodock 4.2. Antioxidant activity of extract was carried out by FRAP assay. The noxious effect of extract was investigated by histological studies on rat skin. RESULTS: The preliminary phytochemical analysis of methanolic leaves extract revealed the presence of alkaloids, flavonoids, terpenoid, glycosides, terpene, terpenoids and phenolics. The various phytochemicals such as Apigenin 7-(4'', 6'' diacetylalloside)-4'- alloside, Catechin 7-O- apiofuranoside, Emodic acid, Epicatechin 3-O- ß-D-glucopyranoside, 4 - Methylesculetin, Methylisoeugenol, Quercetin 5,7,3',4'-tetramethyl ether 3-rutinoside, 4 - Methylumbelliferyl ß-D- glucuronide were extracted, characterized and recognized from the leaves extract of H. littoralis. The identification of these phytochemicals was performed using LC-MS. The antimicrobial property of H. littoralis leaf extract was investigated against different pathogenic microorganisms. Out of these tested microorganisms, promising antibiofilm and antimicrobial activities were confirmed against S. aureus NCIM 2654 and C. albicans NCIM 3466 by using growth curve and SEM analysis. MIC of this leaf extract was identified as 45 µg/ml and 70 µg/ml for S. aureus NCIM 2654 and C. albicans NCIM 3466 respectively. The leaves extract also showed good antioxidant activity due to presence of phenols and flavonoids. Molecular docking of these identified antibiofilm components interacts with the active site residues of adhesin proteins, Sortase A and Als3 from S. aureus and C. albicans respectively. Histological studies of extracted phytochemicals revealed non-noxious effects on rat skin. CONCLUSION: Thus, the present study revealed that the leaves extract of H. littoralis contains various phytochemicals having good extent of antimicrobial, antibiofilm and antioxidant properties. The in-vitro and in-silico results would be useful to design new lead compounds against biofilm producing pathogenic microorganisms.

FERN Ethnomedicinal Plant Database: Exploring Fern Ethnomedicinal Plants Knowledge for Computational Drug Discovery.

Fern plants are known for their ethnomedicinal applications. Huge amount of fern medicinal plants information is scattered in the form of text. Hence, database development would be an appropriate endeavor to cope with the situation. So by looking at the importance of medicinally useful fern plants, we developed a web based database which contains information about several group of ferns, their medicinal uses, chemical constituents as well as protein/enzyme sequences isolated from different fern plants. Fern ethnomedicinal plant database is an all-embracing, content management web-based database system, used to retrieve collection of factual knowledge related to the ethnomedicinal fern species. Most of the protein/enzyme sequences have been extracted from NCBI Protein sequence database. The fern species, family name, identification, taxonomy ID from NCBI, geographical occurrence, trial for, plant parts used, ethnomedicinal importance, morphological characteristics, collected from various scientific literatures and journals available in the text form. NCBI's BLAST, InterPro, phylogeny, Clustal W web source has also been provided for the future comparative studies. So users can get information related to fern plants and their medicinal applications at one place. This Fern ethnomedicinal plant database includes information of 100 fern medicinal species. This web based database would be an advantageous to derive information specifically for computational drug discovery, botanists or botanical interested persons, pharmacologists, researchers, biochemists, plant biotechnologists, ayurvedic practitioners, doctors/pharmacists, traditional medicinal users, farmers, agricultural students and teachers from universities as well as colleges and finally fern plant lovers. This effort would be useful to provide essential knowledge for the users about the adventitious applications for drug discovery, applications, conservation of fern species around the world and finally to create social awareness.