Thermal treatment of luteolin-7-O-β-glucoside improves its immunomodulatory and antioxidant potencies

Abstract

Phytochemicals extracted from flowers, roots and bark, leaves, and other plant sources have been used extensively throughout human history with varying levels of efficacy in prevention and treatment of disease. Recently, advanced methods for characterization and clinical use of these materials have allowed modern understanding of their properties to be used as immunomodulatory agents that act by enhancement of endogenous cytoprotective mechanisms, avoiding interference with normal physiologic signaling and highly effective medical treatment with minimal adverse side effects. Simple methods have been identified for improving their biological effects, such as thermal conditioning by heating or freezing-prominent example being heat treatment of lycopene and tetrahydrocannabinol. The present investigation shows improvement of the ability of heat to augment splenocyte proliferation, natural killer (NK) cell activities, and antioxidant capacity of the flavonoid luteolin-7-O-β-glucoside (L7G) in comparison with the native (non heat-treated) molecule, while further demonstrating that both the native and the heat-treated variants exhibit comparable antioxidant properties, as evidenced by their effects in macrophages by inhibition of nitric oxide production and lysosomal enzyme activity in experiments that strengthen lysosomal membrane integrity. Outcomes of these studies suggest that heat-treated L7G shows promise for use in immunotherapy, including anti-cancer regimens, as shown by its improvement of NK cell cytotoxicity.

Comparison extraction methods for evaluating antioxidant and antibacterial properties of Vernonia amygdalina leaves extract

“…The content of flavonoid in the ethyl acetate with the maceration method is 38.36 ± 0.14 mg QE/g. 29,30 . The research showed that the extraction methods influence the yield percentage, the phenolic and flavonoid content of extract, and the antioxidant properties and antibacterial activity.…”

<p>Delivery luteolin with folacin-modified nanoparticle for glioma therapy</p>

“…6,7 Clinical epidemiology study demonstrates that luteolin has various biological and pharmacological activities, such as antibacterial action, antiviral action, antioxidation activity, antitumor activity, hypoglycemic effect, hypolipidemic effect, hypotensive effect and immunomodulatory functions, etc. [8][9][10] In recent years, numerous researchers have found that luteolin has broad-spectrum antitumor activities with many different forms. By regulating intricate signal transduction pathways, luteolin presents multiple antineoplastic effects, such as antitumor cell proliferation, anticarcinogen effects, blocking cell cycle progression, inducing tumor cells apoptosis,inhibiting the infiltration and metastasis of tumor and the growth of new vessels, etc.…”

Effect of Heat Treatment and Light Exposure on the Antioxidant Activity of Flavonoids

“…Figure 7 revealed that the oxidation of DCFH-DA by peroxyl radicals, derived from ABAP, was significantly reduced by heated NG, heated L7G and heated Erio, reaching 52.68%, 72.3% and 83.88%, respectively, at the highest tested concentrations. Heated molecules seem to be more efficient in protecting splenocytes against peroxyl radical-induced oxidation compared to native molecules (13.6%, 60%, and 46.5% respectively) [39,40,57]. These findings are confirmed by in vivo assay.…”

“…The antioxidant activities in vitro and in vivo were assessed from model solutions of flavonoids treated at a temperature of 130 • C during 2 h [39,40].…”