Maternal pomegranate juice attenuates maternal inflammation-induced fetal brain injury by inhibition of apoptosis, neuronal nitric oxide synthase, and NF-κB in a rat model

Abstract

Background: Maternal inflammation is a risk factor for neonatal brain injury and future neurological deficits. Pomegranates have been shown to exhibit anti-inflammatory, anti-apoptotic and anti-oxidant activities.

Objective: We hypothesized that pomegranate juice (POM) may attenuate fetal brain injury in a rat model of maternal inflammation.

Study design: Pregnant rats (24 total) were randomized for intraperitoneal lipopolysaccharide (100 μg/kg) or saline at time 0 at 18 days of gestation. From day 11 of gestation, 12 dams were provided ad libitum access to drinking water, and 12 dams were provided ad libitum access to drinking water with pomegranate juice (5 mL per day), resulting in 4 groups of 6 dams (saline/saline, pomegranate juice/saline, saline/lipopolysaccharide, pomegranate juice/lipopolysaccharide). All dams were sacrificed 4 hours following the injection and maternal blood and fetal brains were collected from the 4 treatment groups. Maternal interleukin-6 serum levels and fetal brain caspase 3 active form, nuclear factor-κB p65, neuronal nitric oxide synthase (phosphoneuronal nitric oxide synthase), and proinflammatory cytokine levels were determined by enzyme-linked immunosorbent assay and Western blot.

Results: Maternal lipopolysaccharide significantly increased maternal serum interleukin-6 levels (6039 ± 1039 vs 66 ± 46 pg/mL; P < .05) and fetal brain caspase 3 active form, nuclear factor-κB p65, phosphoneuronal nitric oxide synthase, and the proinflammatory cytokines compared to the control group (caspase 3 active form 0.26 ± 0.01 vs 0.20 ± 0.01 U; nuclear factor-κB p65 0.24 ± 0.01 vs 0.1 ± 0.01 U; phosphoneuronal nitric oxide synthase 0.23 ± 0.01 vs 0.11 ± 0.01 U; interleukin-6 0.25 ± 0.01 vs 0.09 ± 0.01 U; tumor necrosis factor-α 0.26 ± 0.01 vs 0.12 ± 0.01 U; chemokine (C-C motif) ligand 2 0.23 ± 0.01 vs 0.1 ± 0.01 U). Maternal supplementation of pomegranate juice to lipopolysaccharide-exposed dams (pomegranate juice/lipopolysaccharide) significantly reduced maternal serum interleukin-6 levels (3059 ± 1121 pg/mL, fetal brain: caspase 3 active form (0.2 ± 0.01 U), nuclear factor-κB p65 (0.22 ± 0.01 U), phosphoneuronal nitric oxide synthase (0.19 ± 0.01 U) as well as the brain proinflammatory cytokines (interleukin-6, tumor necrosis factor-α and chemokine [C-C motif] ligand 2) compared to lipopolysaccharide group.

Conclusion: Maternal pomegranate juice supplementation may attenuate maternal inflammation-induced fetal brain injury. Pomegranate juice neuroprotective effects might be secondary to the suppression of both the maternal inflammatory response and inhibition of fetal brain apoptosis, neuronal nitric oxide synthase, and nuclear factor-κB activation.

Keywords: fetal brain injury; maternal inflammation; oxidative stress; pomegranate.