Multiple free-radical scavenging (MULTIS) capacity in cattle serum

Abstract

Multiple free-radical scavenging (MULTIS) activity in cattle and human sera was evaluated with electron spin resonance spectroscopy. Scavenging rates against six active species, namely hydroxyl radical, superoxide anion, alkoxyl radical, alkylperoxyl radical, methyl radical, and singlet oxygen were quantified. The difference in the electron spin resonance signal intensity in the presence and absence of the serum was converted into the scavenging rates. Comparative MULTIS measurements were made in sera from eight beef cattle, three fetal calves and fifteen healthy human volunteers. Further, we determined the MULTIS value of albumin, the most abundant component in serum. MULTIS values in cattle sera indicated higher scavenging activity against most free radical species tested than human sera. In particular, cattle serum scavenging activities against superoxide and methyl radical were higher than human serum by 2.6 and 3.7 fold, respectively. In cattle serum, albumin appears to play a dominant role in MULTIS activity, but in human serum that is not the case. Previous data indicated that the abundance of uric acid in bovine blood is nearly 80% less than humans; however, this difference does not explain the deviation in MULTIS profile.

Keywords: MULTIS; antioxidants; cattle serum; multiple radical scavenging capacity; spin trapping.

Fig. 1

ESR spectra of HO^• adduct produced after photolysis of hydrogen peroxide (5 mM) solution containing DMPO (5 mM), and DETAPAC (1 mM) in the absence (A) and the presence (B) of 3% human serum. Peak heights used for the calculation of the scavenging rate are shown in the spectra.

Fig. 2

A bar graph that represents relative scavenging rates in fetal bovine serum, cattle serum, and bovine serum albumin. The symbol of * denotes that statistical difference is significant (p<0.05 vs fetal bovine serum).

Fig. 3

A bar graph that represents relative scavenging rates in human serum, human albumin, and cattle serum. The symbol of * denotes the presence of significant difference (p<0.05 vs human serum).

Fig. 4

(A) Radar chart illustration of relative MULTIS values of human and cattle serum. MULTIS values in human serum are set to 100, thus its radar chart is a normal hexagon. (B) The previously published MULTIS radar chart for the healthy human and CKD patients group.⁽⁴⁾