Immunomodulatory Effects of Carob (Ceratonia siliqua) Extract in Pregnant Rats: A Histological Evaluation of Embryonic Liver

Zainab Hasan Majeed

doi:10.59167/srw0t384

Authors

Zainab Hasan Majeed Department of Biology, College of Education for Pure Sciences, University of Kirkuk, Kirkuk, Iraq. Author

DOI:

https://doi.org/10.59167/srw0t384

Keywords:

Ceratonia siliqua, Pregnancy, Embryonic Liver, Immunomodulation, Cytokines, Histology, Polyphenols

Abstract

Background: Carob (Ceratonia siliqua) is a polyphenol-containing plant that has anti-oxidant and anti-inflammatory qualities, which can affect maternal immunity in pregnancy. Nevertheless, it has not been studied how it affects maternal immunity and the integrity of embryonic organs. Objective. The current paper aimed to test the immunomodulatory properties of carob extract on pregnant rats affected with induced hepatitis and to examine the histological alterations of embryonic liver tissue. Methods: Pregnant female Wistar rats (200-230 g) were chosen randomly and distributed into four groups (n=7/group): control (vehicle only), carob-only (400mg/kg/day carob extract), infected (induced hepatitis by concanavalin A), and carob + infected (carob pretreatment then ConA induced hepatitis). Carob aqueous extract was administered on gestational days 12-18. At gestational day 19 (GD19), hepatic enzyme levels (ALT, AST, ALP, GGT) and pro-inflammatory cytokine levels (IL-6, IL-12, IL-18, IL-29, TNF-α) were assessed in maternal blood using ELISA. Cesarean delivery was used to harvest embryos, and embryonic livers were subjected to histological analysis using hematoxylin and eosin staining. Results: Pretreatment with carob significantly attenuated maternal hepatic infection by reducing ALT (345 ± 30 to 120 ± 20 U/L, 65%) and AST (290 ± 25 to 105 ± 18 U/L, 64%). There was a significant decrease in pro-inflammatory cytokines, namely, IL-6 (reduced by 62.5% [320 ± 50 to 120 ± 30 pg/mL, p < 0.01]), TNF-α (reduced by 63% [2500 ± 400 to 920 ± 150 pg/mL, p < 0.001]), IL-12 (reduced by 50% [110 ± 20 to 55 ± 10, p < 0.01]) and IL-18 (reduction by 55% [400 ± 50 to 180 ± 30 pg/mL, p < 0.01]). Embryonic livers of carob-treated dams were observed to have preserved hepatic architecture with visible central veins and ordered hepatocyte cords, but those of embryos of damaged dams that did not receive carotenogenic treatment had a significant structural disorganization, cellular necrosis, and architectural distortion. Conclusion: Carob extract has strong immunomodulatory activity in pregnant rats, suppressing inflammatory changes and hepatic damage, which is associated with the maintenance of embryonic liver architecture. These effects have not yet been verified in other models, and the mechanisms behind them remain unclear.

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