Background: Natural milk peptides are known for their bioactivity in regulating lipid metabolism and immune responses, but their therapeutic application is limited due to instability and low bioavailability. Synthetic milk peptide analogues (SMPAs) offer enhanced stability and targeted action. Objectives: This study aimed to evaluate the dual modulatory potential of SMPAs on lipid and immune homeostasis. 

Methods: SMPAs were synthesized via solid-phase peptide synthesis, purified by HPLC, and characterized by mass spectrometry. Human hepatocyte (HepG2) and macrophage (THP-1) cell lines were treated with SMPAs (1–50 µM). Lipid accumulation, PPARα, ABCA1 gene expression, and cytokine levels (TNF-α, IL-6, IL-10) were measured using Oil Red O assay, qPCR, and ELISA. Findings: SMPAs significantly reduced intracellular lipid accumulation, enhanced PPARα and ABCA1 expression, and modulated cytokines by decreasing TNF-α and IL-6 while increasing IL-10 levels, indicating dual lipid-lowering and immunoregulatory effects. 

Main Conclusions: SMPAs act as dual modulators of lipid metabolism and immune function, suggesting their potential as bioinspired therapeutic candidates for dyslipidemia and inflammation-related disorders.

Milk-derived peptides are naturally occurring bioactive molecules generated during the enzymatic digestion of milk proteins such as casein and whey. They exhibit a wide range of biological functions, including antioxidant, antihypertensive, and immunomodulatory effects (1,2). Among these, their lipid-lowering and anti-inflammatory properties have gained increasing attention for therapeutic applications (3). However, natural milk peptides often suffer from instability, degradation, and poor bioavailability, which limit their clinical potential (4). Recent advancements in peptide synthesis have enabled the design of synthetic milk peptide analogues (SMPAs) that mimic the bioactivity of their natural counterparts while providing enhanced stability and bioefficacy (5). These bioinspired molecules offer a unique opportunity to address metabolic disorders characterized by lipid imbalance and immune dysfunction, such as dyslipidemia and metabolic syndrome (6). This study investigates the dual modulatory potential of SMPAs on lipid and immune regulation in human cell models. By examining their molecular targets and biological outcomes, the research aims to establish SMPAs as promising bioinspired therapeutics for metabolic and inflammatory conditions.

Several studies have highlighted the lipid-regulating properties of milk-derived peptides. Casein hydrolysates were shown to decrease serum triglycerides and total cholesterol in experimental models (7). Whey protein-derived peptides have demonstrated similar effects by enhancing lipid catabolism through activation of PPARα and AMPK pathways (8). Lactoferrin-derived peptides exhibit potent immunomodulatory effects by regulating cytokine expression, reducing pro-inflammatory markers, and promoting anti-inflammatory responses (9,10). Synthetic analogues designed from these bioactive domains have shown improved receptor binding and resistance to proteolytic degradation, supporting their therapeutic relevance (11). Collectively, these findings provide a scientific foundation for the development of synthetic milk peptides that can simultaneously regulate lipid metabolism and immune homeostasis.

This experimental study was conducted in vitro using human hepatocyte (HepG2) and macrophage (THP-1) cell lines. Synthesis and Characterization: Synthetic milk peptide analogues (SMPAs) were produced using solid-phase peptide synthesis (SPPS) techniques. Peptides were purified using high-performance liquid chromatography (HPLC) and analyzed through mass spectrometry (MS) for confirmation of molecular weight and purity.

Cell Culture and Treatment:

HepG2 and THP-1 cells were cultured in DMEM supplemented with 10?tal bovine serum under standard conditions. Cells were treated with SMPAs (1, 10, and 50 µM) for 24 hours.

Lipid Analysis:

Intracellular lipid accumulation was assessed using Oil Red O staining and quantified spectrophotometrically. Expression of lipid regulatory genes (PPARα and ABCA1) was measured by quantitative PCR.

Cytokine Assessment:

ELISA kits were used to quantify cytokine levels (TNF-α, IL-6, IL-10) in cell culture supernatants after treatment. Statistical Analysis All experiments were performed in triplicate. Data were expressed as mean ± standard deviation (SD). Statistical comparisons were made using one-way ANOVA followed by Tukey’s post hoc test. A p-value of <0>

SMPA treatment significantly reduced lipid accumulation in HepG2 cells in a dose-dependent manner compared with controls (p < 0>

Table 1: Effect of Synthetic Milk Peptide Analogues (SMPAs) on Lipid Metabolism and Cytokine Levels

Note: Data are expressed as mean ± SD (n = 3). p < 0>

Figure 1: Dual Modulatory Mechanism of Synthetic Milk Peptide Analogues (SMPAs)

Source: Created by the authors based on experimental findings (Haider et al., 2025).

The schematic illustrates the proposed dual mechanism of synthetic milk peptide analogues (SMPAs). In hepatocytes, SMPAs activate PPARα and upregulate ABCA1, leading to enhanced fatty acid oxidation and cholesterol efflux. In macrophages, SMPAs suppress TNF-α and IL-6 while elevating IL-10, promoting an anti-inflammatory response. Together, these mechanisms contribute to the restoration of lipid and immune homeostasis

The findings demonstrate that SMPAs exert dual lipid-lowering and immunomodulatory effects, supporting their potential as bioinspired therapeutics. The activation of PPARα and ABCA1 pathways aligns with previous studies indicating their central role in lipid metabolism and reverse cholesterol transport (12). Moreover, the observed cytokine modulation suggests that SMPAs can restore immune balance by downregulating inflammatory mediators and enhancing anti-inflammatory signaling, consistent with reports on natural lactoferrin and α-lactalbumin peptides (13). The synthetic design offers added advantages of molecular stability and targeted bioavailability, making SMPAs more suitable for pharmaceutical development. Future research should include in vivo validation and pharmacokinetic profiling to confirm bioefficacy and safety, potentially paving the way for clinical application in metabolic and inflammatory diseases.

Synthetic milk peptide analogues serve as potent dual modulators of lipid and immune homeostasis. Their combined effects on metabolic and inflammatory pathways provide a strong foundation for their development as next-generation bioinspired therapeutics in the management of dyslipidemia, metabolic syndrome, and chronic inflammatory conditions.

Acknowledgment

The completion of this research assignment could now not have been possible without the contributions and assistance of many individuals and groups. We’re. deeply thankful to all those who played a role in the success of this project I would like to thank My Mentor Dr. Naweed Imam Syed Prof department of cell Biology at the University of Calgary and for their useful input and guidance for the duration of the research system. Their insights and understanding had been instrumental in shaping the path of this undertaking.

Authors ‘Contribution                                                                                                                                                                                       

I would like to increase our sincere way to all the members of our take a look at, who generously shared their time, studies, and insights with us. Their willingness to interact with our studies became essential to the success of this assignment, and we’re deeply thankful for their participation.                                                                                                                                               

Conflict of Interest                                                                                                                                                                                             

The authors declare no conflict of interest                                                                                                                 

Funding and Financial Support                                                                                                                                                                                          

The authors received no financial support for the research, authorship, and/or publication of this article