Maternal supplementation of high-value PUFA-Rich Isochrysis sp. biomass prevents monosodium glutamate-induced neurotoxicity in first-generation Wistar rats

Abstract

Prenatal supplementation of high-value PUFA (HVPUFA) is essential for adequate brain development in infants. As marine microalgal derived omega-3 fatty acids are considered an alternative source of fish oil, their neuroprotective role on monosodium glutamate (MSG)-induced neurotoxicity, bioavailability, and disease prevention in first-generation (F₁) animals need to be explored at molecular level. This study tested the long term supplementation of microalgal derived ω-3 PUFAs from parent rats to its offspring rats and studied the neuroprotective role in monosodium glutamate (MSG)-induced neurotoxicity in F₁ rats. The parent animals were divided into three groups: control, microalgal-administered group (5.7 mg of EPA and 1.4 mg of DHA/kg BW from Isochrysis sp.), and fish oil-administered group (4.2 mg of EPA and 2.9 mg of DHA/kg BW derived from fish oil) (FG) and continued up to F₁ generation. The F₁ male rats from respective parents were separated for disease induction: group I animals (control) were administered with 500 μl of Milli-q water alone and group II (disease control), III (Microalga), and IV (fish oil) animals were administered with 2 g/kg bodyweight of MSG for 10 alternative days. Microalga-treated F₁ rats showed significant HDL (43 mg/dl) levels when compared to their experimental groups. Brain tissues of microalga-treated F₁ rats (MG) showed higher concentration of DHA (10.1 mg/100 mg tissue) and ARA (18.7 mg/100 mg tissue) levels and significant reduction of MDA (30 nM mg protein) levels. Furthermore, MSG induced neurotoxicity was ameliorated through the activation of CREB and BDNF genes The mRNA expressions of CREB and BDNF were 1.5-fold higher and NMDA levels were 2.0-fold higher in treated groups compared to disease control group. However, the expressions of antioxidant genes (SOD, catalase, and GPX) and apoptotic genes (Bcl-2 and Caspase-3) were significantly reduced in MG treated F1 rats when compared to disease control rats. Histopathological results also showed minimal focal damage in the tissues of MG F₁ rats. Prenatal and continuous supply of microalgal biomass improves brain DHA and greatly reduced the consequences of MSG neurotoxicity in F₁ rats.

Keywords: Isochrysis sp.; MSG; Microalgae; Offspring; PUFAs; Wistar rat.