Studies On The Immunomodulatory Effects Of Different Levels Of Mung Bean Peptides On RAW264.7 Cells

Plant source protein peptides have fast absorption,low sensitization,no side effects,and have a variety of biological activities such as anti-oxidation,lowering blood pressure,and anti-tumor.Some studies have shown that mung bean peptide has a good immunomodulatory effect,but it is not clear whether its immunomodulatory effect on mung bean peptide is related to its molecular weight and structure.In this study,mung bean peptide(Mung bean protein hydrolysate,MBPH)was used as the raw material,and macrophage RAW264.7 was used as the model.The sephadex G-15 chromato bar was used for isolation and purification,and its immune activity was determined.To screen out the peptides with the best immune effect,analyze their amino acid composition and amino acid sequence,so as to elucidate the immunomodulatory mechanism of mung bean bioactive peptides.1.the mung bean peptides are classified and purify by sephadex G-15 chromato bar,obtaining three fractions of the mung bean peptide(MBPH-1,MBPH-2,and MBPH-3).When applied to cells,it was found that MBPH promoted the normal growth of macrophages,and the pseudopodia were much longer than those in the control group,but it did not reach an excessive activation state compared to the LPS group.MBPH has a certain enhancement effect on the proliferation rate and phagocytic ability of macrophages,of which the effect of MBPH-3 grade is more significant,and the absorption values of the proliferation rate and phagocytic ability are9.05% and 0.588,respectively,compared with the blank control group(P < 0.05).MBPH promoted the expression of cytokines(IL-6,IL-1?,TNF-?)in macrophages,and the expression level in the MBPH group was higher than that at other time points at 24 h,among which the MBPH-3 group was the best,the secretory amounts were 1634.30,598.89 and 852.13 pg/m L,which were significantly different from the blank control group(P < 0.05)and significantly lower than the LPS group.MBPH can also significantly inhibit the secretion level of LPS-induced macrophages cytokines,and the inhibition effect is the best at 12 h,among which the effect of MBPH-3 group is significantly better than other grades,the average levels of IL-6,IL-1? and TNF-? were 2046.38,937.64,and 821.65 pg/m L,respectively,which had a certain inhibitory effect compared with that of the LPS group(P < 0.05).The results indicated that the immune activity of mung bean peptide was correlated with its molecular weight.2.The immune capacity of the high active mung bean peptide was comprehensively investigated.The results showed that MBPH could promote the increase of glucose metabolism and nucleic acid contents in macrophages,and promote the expression of macrophage factor(IL-6,IL-1?,TNF-?)in macrophages,the promotion effect of MBPH-3 was the best.At the same time,different levels of mung bean peptide can inhibit the secretion of cytokines by LPS-induced macrophages,with obvious inhibitory effect.Different levels of mung bean peptide can alleviate the cell apoptosis caused by LPS,Thus,the cell contents of G1,S and G2 phase are close to the normal level,the cell contents of G1 phase are reduced,and the cell contents of S and G2 phase are increased.The normal cycle level of the cells was restored,and the normal proliferation rate of macrophages was restored.The MBPH group promoted the expression of p65 protein and the activation of I-?B? protein in the nucleus.In addition,MBPH alleviated the excessive activation of NF-?B pathway by inhibiting the expression of p65 and I-?B? protein.3.The structure of MBPH-3 was analyzed,and the amino acid sequence was speculated to be composed of Asn,Asn,Tyr,Gly,Pro,Thr and Met by mass spectrometry,with the molecular weight of 903 Da.The composition of free amino acids was analyzed by amino acid automatic analyzer,and a large number of hydrophobic amino acids were found.It was speculated that the immune activity was related to the content of hydrophobic amino acids.In summary,MBPH has a certain immune regulatory effect,which is related to the composition and molecular weight of amino acids.