Fig 2: A working model illustrating the effect of maternal VDD on MetS in their offspring. A working model depicting how maternal VDD effects offspring metabolic function was shown. Maternal VDD leads to the inhibition of Nrf2/CBR1 pathway both in mother and their offspring. Further, the depression of the Nrf2/CBR1 pathway in both the mother and her offspring is the main cause of oxidative stress leading to MetS.

Fig 3: Maternal 25-hydroxyvitamin D deficiency altered expression levels of Nrf2, CBR1, and inflammatory cytokine in offspring at week 0 and 16. (A) Nrf2 and CBR1 immunohistochemical staining in offspring liver and pancreas tissues obtained in normal group (Con) and 25-hydroxyvitamin D deficiency group (VDD) at week 0 and 16 (magnification, ×200). (B, C) Western blotting analysis was used to detect theNrf2 and CBR1 expression level at week 0 and 16 in offspring rat liver (B) and pancreas (C). Densitometry data for Nrf2 and CBR1 from the blots shown were normalized for analysis to GAPDH, the loading control. (D, E) The Nrf2 and CBR1 levels in offspring liver (D) and pancreas (E) at week 0 and 16 were determined by qRT-PCR. (F) IL-1β, IL-6and TNF-α IH staining in offspring liver and pancreas tissues obtained in normal group (Con) and 25-hydroxyvitamin D deficiency group (VDD) at week 0 and 16 (magnification, ×200). Mean ± SD, n = 5 rats per group. ***P < 0.01, vs. control group. Normal group, Con, Con-1, and Con-2 represent different rats; maternal 25-hydroxyvitamin D deficiency group, VDD, VDD-1, and VDD-2 represent different rats; week, w.

Fig 4: Effect of isoquercitrin and quercetin on the Nrf2/HO-1 and autophagy pathways. (a) Representative blot images showing the effect of compounds without Glu treatment; (b–e) Quantitative data of protein levels of Nrf2, Keap1, HO-1, and ratio of LC3AB-II/-I in blot (a); (f) Representative blot images showing the effect of compounds with Glu treatment; (g–j) Quantitative data of protein levels of Nrf2, Keap1, HO-1, and ratio of LC3AB-II/-I in blot (f); After HT22 cells were incubated with compound or Glu for 8 h, cell lysates were analyzed using Western blotting; Student’s t-test (N vs. C, # p < 0.05, ### p < 0.001); One-way ANOVA (C vs. Glu + drugs, * p < 0.05, ** p < 0.01, *** p < 0.001); Glu, glutamate; N, non-treated normal cell; C, control cells treated with Glu only; I, isoquercitrin; Q, quercetin; I/Q, combination of 50 μM of I and 7.0 μM of Q; DMLE, 100 μg/mL of ethyl acetate-soluble extracts of Dendropanax morbifera leaves; NAC, 1 mM of N-acetyl-L-cysteine.

Fig 5: 1-MNA administration improved the oxidative stress and inflammation of the heart induced by HFD. (A) Western blotting analysis of IκB expression. Quantification of protein expression shown is normalized to β-actin. (B) qRT-PCR analysis of oxidative stress related gene expression. (C) Western blotting analysis of TNF-α. β-actin was taken as an internal control gene. (D) qRT-PCR analysis of inflammation related gene expression. (E) Western blotting analysis of NRF2, HO-1, and NQO-1. β-actin was taken as an internal control gene. (n = 3, NS = no significance, *p < 0.05, **p < 0.01, ***p < 0.001).