In Vitro Screening of Seed Extracts of Medicinal Plants for Protease Inhibitory Activity

Protease inhibitors (PIs) are deployed in the plant kingdom as storage proteins or peptides, regulators of endogenous proteases, and plant protection agents against insect pests and pathogen attack. In humans, they are identified as chemopreventive agents against a range of cancers and have potential as drug to treat an array of disease associated with aberrant activity of proteases. The present investigation reports PIs activity data from 30 medicinal plants. The screening for PIs activity was done by dot blot assay using X-ray film coated with gelatin. Among screened seed extracts, Albizia lebbeck, Raphanus sativus, Mucuna pruriens, Achyranthes aspera, and Coffea arabica showed high inhibitory activities with trypsin protease. Most of seed extracts exhibited moderate activity, whereas Ocimum sanctum showed moderate to low activity against trypsin. The presence of varied protein content is reported from all seed extracts with highest in A. lebbeck (50.0 ± 3.4 mg/ml). The data produced in the present investigation could be helpful for further exploration of PIs as therapeutic agent

Exploration of Amylases Producing Competency of Helicoverpa armigera Gut Bacterial Strain, Bacillus subtilis RTSBA6 6.00

The Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) is a polyphagous insect pest of agriculturally important crops. The alkaline gut of this insect pest possesses diverse bacterial communities which may assist in digestive physiology. As part our investigations of understanding the role of gut bacterial communities in insect gut, here amylase producing competency of earlier identified H. armigera gut bacterial strain, i.e., Bacillus subtilis RTSBA6 6.00 is reported. Initial screening for amylase activity was assessed by starch agar plate. Upon 7% sodium dodecyl sulfate polyacrylamide gel electrophoresis amylase zymography, bacterial culture supernatant produced seven amylase bands on the gel. The observed molecular weights of amylases were 191.2 KDa, 158.0 KDa, 131.7 KDa, 54.0 KDa, 31.3 KDa, 67.2 KDa, and 44.6 KDa, respectively. Considerable amylase activity was observed in neutral to alkaline pH with optimum at pH 6.8. The optimal activity temperature of amylases was found to be 50°C, and the activity decreased dramatically at temperatures above 75°C

Proteinase inhibitors of pigeonpea cv. BSMR 736: Characterization and bioefficacy against Helicoverpa armigera

Pigeonpea is an agriculturally important leguminous crop with high vulnerability to insect pest attack specifically, Helicoverpa armigera. The proteinase inhibitors (PIs) mediated host plant resistance against insect pests is a promising sustainable agricultural research practice. The current study was carried out to perceive biochemical characterization of proteinase inhibitors named PPTI in the pigeonpea (cv. BSMR 736). The purification of PPTI from crude protein seed extract was achieved by acetone precipitation, N-LP-IEF, and trypsin affinity chromatography. It was found to inhibit bovine trypsin and HaGPs in vitro. The optimal conditions for inhibition were pH 8 and temperature 40ºC. The PPTI showed four isoinhibitors bands on native, non-reducing and reducing SDS-PAGE in the range of 26.7–19.3 KDa. Upon resolution on two-dimensional gel electrophoresis (2-DE), PPTI produced nine pI variant spots having isoelectric point (pI) 6.6, 6.6, 6.3, 6.1, 5.9, 5.8, 5.7, 5.6 and 5.6. An artificial diet containing PPTI reduced the H. armigera larval weight about 69%, with 25% mortality. For eco-friendly sustainable agricultural practices, natural compounds like PPTI could be expressed in transgenic crops to prevent the invasion of H. armigera in pigeonpea