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

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.

Structured form of DHA prevents neurodegenerative disorders: A better insight into the pathophysiology and the mechanism of DHA transport to the brain.

Docosahexaenoic acid (DHA) is one of the most important fatty acids that plays a critical role in maintaining proper brain function and cognitive development. Deficiency of DHA leads to several neurodegenerative disorders and, therefore, dietary supplementations of these fatty acids are essential to maintain cognitive health. However, the complete picture of how DHA is incorporated into the brain is yet to be explored. In general, the de novo synthesis of DHA is poor, and targeting the brain with specific phospholipid carriers provides novel insights into the process of reduction of disease progression. Recent studies have suggested that compared to triacylglycerol form of DHA, esterified form of DHA (i.e., lysophosphatidylcholine [lysoPC]) is better incorporated into the brain. Free DHA is transported across the outer membrane leaflet of the blood-brain barrier via APOE4 receptors, whereas DHA-lysoPC is transported across the inner membrane leaflet of the blood-brain barrier via a specific protein called Mfsd2a. Dietary supplementation of this lysoPC specific form of DHA is a novel therapy and is used to decrease the risk of various neurodegenerative disorders. Currently, structured glycerides of DHA - novel nutraceutical agents - are being widely used for the prevention and treatment of various neurological diseases. However, it is important to fully understand their metabolic regulation and mechanism of transportation to the brain. This article comprehensively reviews various studies that have evaluated the bioavailability of DHA, mechanisms of DHA transport, and role of DHA in preventing neurodegenerative disorders, which provides better insight into the pathophysiology of these disorders and use of structured DHA in improving neurological health.

Omega-3-rich Isochrysis sp. biomass enhances brain docosahexaenoic acid levels and improves serum lipid profile and antioxidant status in Wistar rats.

BACKGROUND: Isochrysis sp. is a marine microalga, rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The potential use of its biomass as an alternative source of polyunsaturated fatty acids (PUFAs) has not been studied in animal models. Male albino Wistar rats were divided into three groups and treated for 28 days. The rats were fed with (1) standard chow (control group), (2) microalgal biomass rich in EPA and DHA along with standard chow (microalga group), and (3) fish oil that contains equivalent amounts of EPA and DHA along with standard chow (fish oil group). After intervention, biochemical indices, histopathological indices, relative mRNA expression of PUFA genes, antioxidant genes, inflammatory markers, and the fatty acid profile of major tissues were studied. RESULTS: Animals treated with microalgal biomass showed significantly increased serum HDL levels (P < 0.05) and reduced oxidative stress markers with a concomitant decrease in urea and creatinine levels. Oral supplementation of microalgal biomass did not show any toxicity or damage in any major organs. The mRNA expression of PUFA genes was significantly downregulated (P < 0.05) and antioxidant genes were upregulated. Furthermore, the mRNA expression of pro-inflammatory markers was significantly downregulated (P < 0.05) and anti-inflammatory markers were upregulated. Oral supplementation of microalgal biomass improved DHA status in brain and liver. CONCLUSION: The present study demonstrated that Isochrysis sp. can be used as a safe, alternative food supplement for ω-3 fatty acids. © 2019 Society of Chemical Industry.