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In the present study, we investigated to the antioxidant and angiotensin I-converting enzyme (ACE) inhibitory activities of the northern shrimp (Pandalus borealis) by-products (PBB) hydrolysates prepared by enzymatic hydrolysis. The antioxidant and ACE inhibitory activities of five enzymatic hydrolysates (alcalase, protamex, flavourzyme, papain, and trypsin) of PBB were evaluated by the 2, 2′-azino-bis [3-ethylbenzothiazoline-6-sulfonic acid] (ABTS + ) radical scavenging and superoxide dismutase (SOD)-like activities, reducing power and Li's method for ACE inhibitory activity. Of these PBB hydrolysates, the protamex hydrolysate exhibited the most potent ACE inhibitory activity with IC 50 value of 0.08 ± 0.00 mg/mL. The PBB protamex hydrolysate was fractionated by two ultrafiltration membranes with 3 and 10 kDa (below 3 kDa, between 3 and 10 kDa, and above 10 kDa). These three fractions were evaluated for the total amino acids composition, antioxidant, and ACE inhibitory activities. Among these fractions, the < 3 kDa and 3-10 kDa fractions showed more potent ABTS + radical scavenging activity than that of > 10 kDa fraction, while the > 10 kDa fraction exhibited the significant reducing power than others. In addition, 3-10 kDa and > 10 kDa fractions showed the significant ACE inhibitory activity. These results suggested that the high molecular weight enzymatic hydrolysate derived from PBB could be used for control oxidative stress and prevent hypertension.

We investigated the antioxidant and angiotensin I converting enzyme (ACE) inhibitory activities of red snow crab Chionoecetes japonicas shell (RSCS) hydrolysate by enzymatic hydrolysis and its molecular weight cutoff fractions. The RSCS hydrolysate was fractionated through two ultrafiltration membranes of 3 and 10 kDa cutoffs. Three fractions (<3 kDa, 3-10 kDa, and >10 kDa) were evaluated for total amino acid composition, antioxidant activities using 2′-azino-bis[3-ethylbenzthiazoline-6-sulfonic acid] (ABTS +) radical scavenging and superoxide dismutase (SOD)-like activities and reducing power assays, and ACE inhibitory activity using Hou's method. Although all fractions showed activity, the <3 kDa fraction of RSCS hydrolysate exhibited the greatest ABTS + radical scavenging, SOD-like and ACE inhibitory activities. However, these fractions exhibited low reducing power. These results suggest that the low-molecular-weight enzymatic hydrolysate of RSCS could be used as a functional ingredient to control oxidative stress and ACE activity.

The antioxidant and cholinesterase inhibitory activities of the acetone and dichloromethane (CH 2 Cl 2 ) extracts of the by-products (heads, shells, and tails) of Pandalus borealis, Pandalus hypsinotus, and Pandalopsis japonica belonging to the family Pandalidae were investigated and their bioactivities were compared. The antioxidant and cholinesterase inhibitory activities of the organic solvent extracts of three shrimp by-products were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2´-Azino-bis[3ethylbenzothiazoline-6-sulfonic acid] (ABTS + ) radical scavenging activities, reducing power and xanthine oxidase (XO) inhibitory activity assays and Ellman's colorimetric method. The extracts of P. hypsinotus exhibited the highest antioxidant and cholinesterase inhibitory activities. The acetone extracts showed more potent activities toward antioxidant and cholinesterase inhibition compared with the CH 2 Cl 2 extracts. Furthermore, the total carotenoid contents of the acetone extracts were higher than those of the CH 2 Cl 2 extracts. Thus, the carotenoid contents may affect antioxidant and cholinesterase inhibition. Our results suggest that the shrimp by-products could act as a nutraceutical agent to prevent oxidative stress and Alzheimer's disease.

In this study, we investigated the anti-inflammation effect of Persicaria thunbergii (P. thunbergii) on RAW 264.7 murine macrophage cells. The anti-inflammatory activity of P. thunbergii was determined by measuring expression of the LPS-induced inflammatory proteins, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and nuclear factor-κB (NF-κB), and the production of nitric oxide (NO) and prostaglandin E2 (PGE2). Methanol extract of P. thunbergii decreased the expression of iNOS, COX-2 and NF-κB, and increased the expression of HO-1 in LPS-stimulated RAW264.7 cells. Methanol extract was fractioned by n-butanol, hexane and ethyl acetate (EtOAc) and each fraction was tested for inhibitory effects on inflammation. Among the sequential solvent fractions, the EtOAc soluble fraction was investigated by the expression of prostaglandin E2 (PGE2), and showed decreasing form to the dose-dependent manner. EtOAc extract showed the most effective inhibitory activity of the expression of iNOS, COX-2 and NF-κB, and the production of NO. The study showed that P. thunbergii has anti-inflammatory activity through the decrease of NO and inhibition of iNOS, COX-2, PGE2 and NF-κB expression, and by the increase of HO-1 enzyme. This study needs for more investigation to find out the most effective single compound with anti-inflammatory activity.