Mechanistic study on the anti-proinflammatory activity of Kunitz type inhibitor from Caesalpinia decapetala seeds.

The study reports the biochemical characterization and mechanism of action of a novel 19.6 kDa protease inhibitor (PIs) isolated from the seeds of Caesalpinia decapetala belonging to the Fabaceae family. A systematic study was performed to ascertain the purity, specificity, biochemical and structural characterization, and its potential in curbing inflammation in vitro conditions. A two-step chromatography technique was used to purify the PIs. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization time of flight were employed to detect the molecular mass of the protein. N-terminal sequence analysis of the inhibitor showed sequence similarity with the Kunitz family PIs. The in vitro test tube assay was performed for determining the anti-inflammatory activity and the inhibitor is antiproliferative against macrophage (RAW264.7) and lung cancer cell lines (A549). An effective decrease in the release of inflammatory mediators (NO, IL-6, TNF-α) and on the activity of elastase was observed in macrophage cell lines (RAW264.7) which were treated with PIs. The purified inhibitor shows promising results against inflammation.

Curcumin-sunflower protein nanoparticles-A potential antiinflammatory agent.

Curcumin is an antiinflammatory molecule, however, due to its lipophilic nature, has the limitation of very low aqueous solubility and degrades rapidly when dispersed in aqueous media. The potential of sunflower seed protein isolate (SFPI), one of the underutilized plant protein, as a drug carrier was studied by synthesizing SFPI nanoparticles (NPs) and encapsulating curcumin in NPs. Increase in solubility of encapsulated curcumin was observed with an encapsulation efficiency of 83%. Stability studies showed that curcumin-SFPI NPs are stable in water and in gastrointestinal condition. The mechanism of interaction of curcumin involves the binding with the hydrophobic patches of protein. In complex with NPs, curcumin showed potent antioxidant activity; antiinflammatory effect of curcumin was studied by following lipoxygenase inhibition (IC50  = 45.3 µM). The study explores the potential of sunflower seed protein to be used as carrier for delivery of nutraceutical by taking curcumin as model compound. PRACTICAL APPLICATIONS: Sunflower seed protein is one of the versatile, quality proteins found in abundance; yet it is an underutilized plant protein. The study exploits the use of sunflower seed protein as a delivery system for lipophilic nutraceuticals by synthesizing NPs and encapsulating them. Solubility and stability of curcumin is increased along with enhanced antioxidant and antiinflammatory activity in complex with SFPI NPs when compared to free curcumin.