Evaluation of postpartum behaviour in rats treated with Hypericum perforatum during gestation

The safety of St John's wort (Hypericum perforatum) in pregnancy and lactation: A systematic review of rodent studies

“…M. L. Vieira, Hamada, et al () also worked with Wistar rats in their study of effects of fetal exposure to SJW or fluoxetine and assessed reproductive physiology and various behaviour in male pups. The same research group used fluorescence imaging to measure hypericin levels in maternal and fetal tissue samples, the behaviour of exposed dams post‐parturition and male offspring using models that assess anxiety and depression (Campos, Guerra, Peters, & E Sá, ; V. A. Vieira, Campos, et al, ). In another study, Campos, Vieira, et al (), while not specifically assessing toxicity, explored the effects of perinatal exposure and the potential for central nervous system (CNS) changes in female offspring.…”

“…Gregoretti et al () did not cite a source for their human reference dose, whereas M. L. Vieira, Hamada, et al () cites Gregorreti as their source, in effect using an un‐referenced secondary source as the basis for their calculation. Campos, Guerra, et al () and V. A. Vieira, Campos, et al () justify their dose in part on the dose associated with CNS or behavioural changes in animal models, but not to human use. Only Rayburn et al (), Rayburn, Gonzalez, Christensen, and Stewart (), and Rayburn, Gonzalez, Christensen, Harkins, et al () referred to the extract characteristics including a description relating to the extract potency (hypericin concentration) in relation to dosage.…”

“…The outcome assessor was described as blinded for at least some of the outcomes assessed in three papers, but it is unclear how this was achieved and whether it was effective (Gregoretti et al, ; Rayburn, Gonzalez, Christensen, Harkins, et al, ; M. L. Vieira, Hamada, et al, ). Automated recording techniques reduced bias in some assessments, such as the photoelectric monitoring of activity in the hole board test (V. A. Vieira, Campos, et al, ). Rates of attrition among the rodents were clearly described by M. L. Vieira, Hamada, et al (), Rayburn et al (), and Rayburn, Gonzalez, Christensen, and Stewart (), but this aspect was unclear in the remaining trials.…”

Effect of the extract of Hypericum perforatum on neurodevelopment of regions related to pain control and convulsion

“…The analgesic effect of EHP reaches its maximum point 120 min after administration and tends to decrease thereafter (Galeotti et al, 2010a). Vieira et al (2013) demonstrated that EHP promoted reduction of states of anxiety and depression in rats treated throughout pregnancy, with effects that lasted up to 60 days after the end of treatment (Vieira et al, 2013). In this case, it is believed that the maintenance of anti-nociceptive effects, and anticonvulsants, from the birth of rats born to treated mothers, is a result of cellular changes that overlap the pharmacokinetic effects of extract components, since these modifications persist into adulthood.…”

“…However, with the end of treatment with EHP, it is assumed that there has been upregulation as a rebound effect so as to increase the number of receptors in F1 rats, above normal levels of brain growth for this period of post-natal neurogenesis (Bouza, 2009), reprogramming these regions to a new state of normality. As the changes caused by EHP are lasting (Vieira et al, 2013) and plasma concentrations of enkephalins are not altered by treatment with this extract (Uchida et al, 2008), it is believed that the functional response of the receptor has become more marked, increasing the antinociceptive response in the offspring of mothers treated with EHP as compared to the control group young.…”