Tag Archives: maturation

Neonate Maturation – Cytochrome P450

VLA Comment:  Clearly cyp 450 family of enzymes are “maturing”.  Many vaccine excipients given to neonates and children (such as formaldahyde (cyp4501A2), polysorbate 80 (cyp4503A4) cannot be metabolized, therefore poisoning the neonate, infant, child potentially at every 2 month well baby visit.

Some CYP450 enzymes are active in utero while others do not demonstrate activity until some time after birth. When corrected for weight the content of CYP enzymes in fetal livers is 30–60% of adult values. The link below has a table that indicates maturation times in some cyp 450 enzymes.

Neonatal maturation of Cyp 450 enzymes study*

Excerpt: Maturation rates are difficult to generalize and enzyme‐specific information needs to be determined for an accurate estimate of drug metabolism 7. Polymorphisms, diseases such as sepsis and complex surgery can all increase the variability of drug metabolism 32. A diet based on infant formula rather than breast milk 14 and antenatal exposure to cigarette smoke 33 can increase the rate of CYP enzyme development. Further, the routes of metabolism seen in adults may not be mirrored in neonates due to the activity or inactivity of particular CYP enzymes 3, summarized in Table 1. (click link above for table)

The Ontogeny of Cytochrome P450 Enzyme Activity and Protein Abundance in Conventional Pigs in Support of Preclinical Pediatric Drug Research

CYP450 enzymes are the most important phase I drug metabolizing enzymes, located on the smooth endoplasmic reticulum and highly expressed in liver compared to other tissues in pigs (Antonovic and Martinez, 2011; Nielsen et al., 2017). They metabolize between 70 and 80% of the human drugs used, most frequently by hydroxylation (Matalová et al., 2016). The ontogeny of the human CYP450 enzymes is rather well known. For example CYP2C9 enzyme activity increases rapidly after birth reaching adult values around 3 months of age, whereas CYP1A2 reaches adult values around 10 years of age (Alcorn and McNamara, 2002; Johnson et al., 2006; Matalová et al., 2016).

Click here for study

Drugs metabolized by 1A2  (as an example), such as formaldahyde in vaccines