Long-Term Overconsumption of Chia Seed Oil (Salvia hispanica L.) and Black Seed Oil (Nigella Sativa) in Relation to Metabolic and Inflammatory Markers Expressions in Rats

Abstract

Abstract Introduction: Notwithstanding their positive health effects, excessive usage of vegetable oils like chia seeds oil (CSO) and black seeds oil (BSO) could lead to an unbalanced intake of n-3 and n-6 fatty acids. This study assessed the impact of longterm consumption of CSO and BSO alone or blended at amounts of 1:1, 4: 1, and 1: 4, representing ratios of n-6 to n-3 fatty acids of 1.2:1, 1:1.8, and 4:1, respectively, on oxidative stress, inflammation, liver function, blood lipids, and relevant hepatic genes expression. Methods: Seventy-two adult rats were segregated into six groups (12 rats each). Rats in group one were provided with a standard diet. Rats in the group (2) were supplied with a CSO-containing diet. The third group of rats received a BSOcontaining diet. In groups four through six, rats received diets containing blended CSO and BSO at ratios 1:1, 4:1, and 1:4, respectively. Rats were fed their corresponding diets for 12 weeks. Results: Chemical analysis revealed that CSO has lower n-6/n-3 fatty acids, more active constituents, and more free radicals scavenging activity and reducing power than BSO. The in vivo study showed that long-term dietary over-consumption of BSO elicited an upsurge in the activity of COX-2 and serum values of PGE-2, nitric oxide, and IL-1β, along with a reduction in serum IL-10 levels. BSO over-supplementation also compromised the anti-oxidant status, evidenced by the decline in the serum content of GSH, SOD, Nrf2, and HO-1, together with marked lipid peroxidation leading to dyslipidemia, elevation in liver enzymes, downregulation in hepatic PPARγ, MAPK, UCP2, and Adipor2, and upregulation in NF-κB and SREBF1 hepatic gene expression. Conversely, CSO consumption reinforced the anti-inflammatory capacity, enhanced the antioxidant status, reduced lipid peroxidation, blood lipids, and liver enzyme activities, and regulated the transcription of genes implicated in the inflammation reaction. Furthermore, feeding the blended oils favorably enhanced these inflammatory oxidative and metabolic variables compared to feeding BSO or standard diets. These effects were more prominent when feeding a higher chia oil than black seed oil. Conclusion: Prolonged over-consumption of BSO, which has a very high n-6/ n-3 FA ratio, significantly instigated dyslipidemia, elevation in liver enzymes, oxidative stress, increase in serum COX-2 activity, and PGE-2 production, an upsurge in inflammatory cytokines and dysregulation in the expression of critical genes implicated in the inflammatory response. Feeding CSO either alone or blended with BSO favorably enhanced these metabolic, oxidative, and inflammatory consequences. Therefore, the diet’s background of n-6/n-3 fatty acid content is crucial, especially when consuming vegetable oils like CSO and BSO for a long time.