Are they safe for pregnant women?

A recent article published in NatureResearchers evaluate T-cell Balancing effects of St. John’s Wort, Valerian, Hops, Lavender and California Poppy.

Research: Immunological evaluation of plant extracts commonly used to treat psychiatric disorders during pregnancy. Image credit: PattPaulStudio / Shutterstock.com

Background

Nonpsychotic mental disorders (NMDs), depression, anxiety, dissociative and adjustment disorders, somatoform, and reactions to traumatic stressors affect about 15 percent of pregnant women in the United States.

Conventional medicine, antidepressants, selective serotonin reuptake inhibitors (SSRIs) such as paroxetine, and benzodiazepines can disrupt the immune balance that compromises fetal tolerance to NMDs and maternal and child protection. Therefore, changes in T-cell activity are required for successful pregnancy.

Fear of potential teratogenic effects prevents nearly 86% of pregnant women from seeking treatment for NMDs, which can have fatal consequences for both mother and fetus. Untreated NMDs increase the risk of spontaneous preterm birth, miscarriage, preeclampsia, low birth weight, and postpartum depression.

Herbal medicines are a safe alternative to conventional medicines which have many side effects. A study involving nearly 10,000 women from 23 countries found that 28% of pregnant women (used herbal medicines for NMDs. Similarly, according to a Swiss study, 90% of pregnant women used herbal preparations, 53.6% used these agents to treat) mild NMDs.

Regulatory T-cells (Tregs) in the blood increase during pregnancy, increasing levels of forkhead box P3 (FoxP) with increasing estrogen. Other functions of the immune system are altered during pregnancy, with a higher threshold to activate innate immune cells and regulate adaptive immune responses.

About the study

In the current study, researchers obtained peripheral blood mononuclear cells (PBMCs) from healthy donors. PBMCs were treated in culture medium with concentrations of 0.03–100 μg/ml and 0.01–30 μM of concentrated and pure compounds, respectively.

After 72 h incubation, the fraction of apoptotic cells was calculated via flow cytometric reading. Likewise, a spectrometric assay was used to assess cell viability.

The genotoxic potential of the compounds was determined using single cell deoxyribonucleic acid (DNA) gel electrophoresis.

Results

The present study evaluated the safety of St. John’s wort, hops, valerian, lavender, and California poppy and their compounds protopine, hyperforin and hypercin, valeric acid, valerate, and linalool. The effects of these agents on the viability and function of primary human lymphocytes have also been determined.

None of the herbal extracts evaluated showed significant changes in T-cell viability or function. In vitro At physiological concentrations, they did not induce apoptosis or genotoxicity.

Previous studies have described the anti-inflammatory effects of St. John’s wort. In this study, 30 µg/ml of St. John’s wort and valerian showed a significant inhibitory effect on the proliferation of T-cells. Preliminary evidence of valerian’s immunogenicity, particularly the adaptive immune system, has been observed. Importantly, the current study did not identify any immunosuppressive effects of lavender.

Valerinic acid, protopine, and linalool did not show any effect on T-cell function, including their viability, proliferation, induced apoptosis, or genotoxicity. In contrast, hyperforin, hypercin, and valerate induced apoptosis, as well as viability and cell division at 3.0 µM.

At the functional level, all herbal compounds showed differential effects. For example, hyperforin and hypercin stimulated interferon gamma (IFN-γ) production but inhibited cytokine production by T-helper and cytotoxic T-cells.

In contrast, Valtrate decreased the expression of T-helper cell activation markers, but not cytotoxic T-cell activation markers. Stimulating effects were observed for all other evaluated indicators.

Conclusions

The use of herbal medicinals for NMD treatment against human immune cell subsets expressed in vitro did not show any risk for impaired immune balance during pregnancy. Despite its use, pregnant women can tolerate an allogeneic embryo and be adequately protected against NMDs.

There is an urgent need for further investigations to confirm the effects of plant extracts and their metabolites on the adaptive immune system, especially on T-cells, as stronger effects have been reported.