Proteins from hemp bran (HPB), a byproduct of the hemp seed food-processing chain, were chemically extracted, hydrolyzed by Alcalase, and separated by membrane ultrafiltration into four fractions (MW 5 kDa). The antioxidant and antihypertensive properties of the initial extract and the fractions were evaluated by in vitro assays for their ability to scavenge radical species, bind with metal ions, reduce ferric ions, and inhibit angiotensin-converting enzyme (ACE) activity. Bioactive peptides were identified by high-resolution mass spectrometry and sequence comparison with BIOPEP and BioPep DB databases. The hydrolysate was strongly antioxidant and ACE-inhibiting; the most bioactive peptides were further concentrated by ultrafiltration. Of the 239 peptides identified, 47 (12 antioxidant and 35 ACE-inhibitory) exhibited structural features correlated with the specific bioactivity. These results highlight the promise of hydrolysate and size-based HPB fractions as natural functional ingredients for the food or pharmaceutical industry.

Background and purpose: Given the crucial role of the skeletal muscle chloride conductance (gCl), supported by the voltage‐gated chloride channel CLC‐1, in controlling muscle excitability, the availability of ligands modulating CLC‐1 are of potential medical as well as toxicological importance. Here, we focused our attention on niflumic acid (NFA), a molecule belonging to the fenamates group of non‐steroidal anti‐inflammatory drugs (NSAID).Experimental approach: Rat muscle Cl⁻conductance (gCl) and heterologously expressed CLC‐1 currents were evaluated by means of current‐clamp (using two‐microelectrodes) and patch‐clamp techniques, respectively. Fura‐2 fluorescence was used to determine intracellular calcium concentration, [Ca²⁺]_i, in native muscle fibres.Key results: NFA inhibited native gCl with an IC₅₀of 42 μM and blocked CLC‐1 by interacting with an intracellular binding site. Additionally, NFA increased basal [Ca²⁺]_iin myofibres by promoting a mitochondrial calcium efflux that was not dependent on cyclooxygenase or CLC‐1. A structure‐activity study revealed that the molecular conditions that mediate the two effects are different. Pretreatment with the Ca‐dependent protein kinase C (PKC) inhibitor chelerythrine partially inhibited the NFA effect. Therefore, in addition to direct channel block, NFA also inhibits gCl indirectly by promoting PKC activation.Conclusions and Implications: These cellular effects of NFA on skeletal muscle demonstrate that it is possible to modify CLC‐1 and consequently gCl directly by interacting with channel proteins and indirectly by interfering with the calcium‐dependent regulation of the channel. The effect of NFA on mitochondrial calcium stores suggests that NSAIDs, widely used drugs, could have potentially dangerous side‐effects.British Journal of Pharmacology(2007)150, 235–247. doi:10.1038/sj.bjp.0706954

The rice-starch processing industry produces large amounts of a protein-rich byproducts during the conversion of broken rice to powder and crystal starch. Given the poor protein solubility, this material is currently discarded or used as animal feed. To fully exploit rice’s nutritional properties and reduce this waste, a biotechnological approach was adopted, inducing fermentation with selected microorganisms capable of converting the substrate into peptide fractions with health-related bioactivity. Lactic acid bacteria were preferred to other microorganisms for their safety, efficient proteolytic system, and adaptability to different environments. Peptide fractions with different molecular weight ranges were recovered from the fermented substrate by means of cross-flow membrane filtration. The fractions displayed in vitro antioxidant, antihypertensive, and anti-tyrosinase activities as well as cell-based anti-inflammatory and anti-aging effects. In the future, the peptide fractions isolated from this rice byproduct could be directly exploited as health-promoting functional foods, dietary supplements, and pharmaceutical preparations. The suggested biotechnological process harnessing microbial bioconversion may represent a potential solution for many different protein-containing substrates currently treated as byproducts (or worse, waste) by the food industry.