Plant Protein-based Diet Fortified With Isoleucine, Leucine, and Valine Mitigates the Carbon Tetrachloride-induced Damage on Caspase-3 Gene Expression and Tissue Architecture: Histomorphological and Immunohistochemical Approaches

Abstract Maintaining a strong immune system and protecting the body from chemicals is essential for overall well-being. The exploitation of the major plant-derived bioactive compounds potentially accounts for prospective immunomodulators. The advantages of plant protein and/or branched-chain amino acids (BCAAs) likely suggest their potential as effective alternative treatment against sustainable chemical damage; existing research regarding their biological impact remains inconclusive. Specifically, limited clarity on the effects of plant protein alone or in combination with BCAAs on the toxic model of carbon tetrachloride (CCl4) on tissue structure and apoptosis-related caspase-3 expression. The concern of this study was with the effectiveness of a plant protein composite with BCAAs in mitigating CCl4-induced histo-immunocytotoxicity using experimental rats (n = 28). Wistar rats were randomly divided into four groups (n = 7 each): Group 1 was control; group 2 was CCl4 only; group 3 was CCl4+BCAAs; while group 4 was CCl4+plant protein. CCl4 model was performed through intraperitoneal injection of l mL/kg b.wt. for three consecutive weeks. However, combined treatment by BCAAs or dietary protein groups exploited 30 g for seven consecutive weeks. Systemic evaluations focused on cell integrity and apoptosis-related gene expression, using Toluidine blue stain and caspase-3 immunohistochemistry, respectively. Histomorphological analysis confirmed tissue distortion significantly induced by CCl4. Immunohistochemical assessment accentuated that the apoptotic index regarding CCl4-treated organs was significantly higher (p < 0.05) than that of CCl4 + BCAAs, indicating the suppressive expression of caspase-3. Contradictory findings by co-administration of dietary protein and BCAAs with CCl4 protruded more substantial protective effects compared to combined BCAAs alone, indicating augmented protection against CCl4-induced immunotoxicity and cellular damage. In conclusion, dietary protein rich with BCAAs exhibited immunomodulatory properties and effectively preserved cellular integrity, particularly when challenged with CCl4. Our findings can serve as a valuable reference for future research aimed at refining recommendations on how dietary protein in combination with BCAAs specifically constrains cancer risks.