Molecular Profiling and FTIR Characterization of Wheat Germ Oil, Supported by the Screening of Its Anti-Inflammatory and Cytotoxic Properties

Abstract

Wheat germ oil (WGO), derived from the nutrient-dense germ of wheat kernels, is a functional bioactive product, known for its rich composition of essential fatty acids, sterols, tocopherols, and polyphenols. This study aimed to comprehensively profile the molecular and therapeutic properties of WGO, focusing on its antioxidant, cytotoxic, and anti-inflammatory activity. Using advanced analytical techniques such as gas chromatography-mass spectrometry (GC-MS), Fourier Transform Infrared (FTIR) spectroscopy, and fluorescence analysis, WGO was shown to contain high levels of linoleic acid (45.3%), squalene (2.52 g/100 g), and polyphenols. WGO displayed selective cytotoxicity, inhibiting cancer cells' viability in melanoma, prostate, and colorectal cancer cell lines, but not normal cells, highlighting its chemoprevention potential. Furthermore, WGO significantly reduced LPS-induced nitric oxide and IL-6 production in macrophages, with effects plateauing at higher doses. The 3D fluorescence spectra showed a significant decrease in fluorescence intensity when human serum albumin interacted with the WGO polyphenol fraction, indicating a strong binding affinity and stable complex formation. These findings emphasize the nutritional and therapeutic potential of WGO as a natural bioactive agent, warranting further mechanistic investigation and broader applications in health and disease management.

Keywords: FTIR; anti-inflammatory effect; cytotoxic potential; fatty acids; human protein binding; squalene; wheat germ oil.

Figure 1

FTIR spectra in the range 4000–500 cm⁻¹ of wheat germ oil combined with squalene as reference material. For each point, 3 samples were analyzed and are shown in the figure. y-axis = absorbance, x-axis = wavelength (cm⁻¹).

Figure 2

Cytotoxic activity of wheat germ oil (WGO) on non-cancerous and cancer cells in the skin, prostate, and gastrointestinal panel. Cells were incubated with 50 and 100 μg/mL of WGO. Cell viability was expressed as % of control (untreated) cells (n = 3). The significant differences (p < 0.05) between used concentration in each cell line are marked with asterisks (*).

Figure 3

Effect of wheat germ oil (WGO) on TNF-alpha, IL-6, and NO release in LPS-stimulated RAW 264.7 macrophages. RAW cells were pre-treated with 5 (WGO 5) and 20 (WGO 20) µg/mL of oil for 1 h and then incubated with (10 ng/mL) or without LPS (untreated) overnight, in relation to dexamethasone (DEX) as a reference. Values are presented as the mean ± SD (standard deviation) of three independent experiments. The significant differences (p < 0.05) in each parameter in comparison to LPS are marked with asterisks (*).

Figure 4

Counter maps (A,B) and their three-dimensional fluorescence (3D-FL) spectra (C,D) of interaction of human serum albumin (HSA) with Tween drop + NaCl (A,C) and with polyphenol extracts of wheat germ oil (WGO) (B,D); two-dimensional (2D-FL) fluorescence intensities (FIs) from the top (E): 1, HSA in buffer (purple line); 2, HSA + NaCl (blue line); 3, HSA + WGO extract (black line) with λem (nm) of 355, 354, and 354; FIs of 960.01, 862.18, and 787.01 arbitrary units. The polyphenols were extracted from 250 µL of oil with a mixture of 35 µL of Tween 80 and 4.5 mL of NaCl.