Antioxidant Activity of Various Soluble Melanoidins Isolated from Black Garlic after Different Thermal Processing Steps

Isolation, structural characterization and biological activity evaluation of melanoidins from thermally processed cocoa beans, carob kibbles and acorns as potential cytotoxic agents

The aim of this study was to determine the chemical structure and biological activity of melanoidin fractions derived from cocoa beans, carob kibbles, and acorns roasted at different temperature-time conditions. The results showed that plant origin and roasting conditions had significant effects on the chemical composition, structural features, and morphology of melanoidins. All tested melanoidins exhibited significant antioxidant properties in three in vitro assays. In addition, they show significant in vitro anti-inflammatory activity by reducing lipoxygenase. The results from MTT assay showed that the all studied melanoidins had a cytotoxic effect against SW-480 cells in a dose- and time-dependent manner. Furthermore, the most pronounced activity was observed for acorn melanoidins. This is a unique finding, as the specific cytotoxic effect has not been reported for cocoa, carob and acorn melanoidins, and opens up a great opportunity to develop a potential novel cytotoxic agent against deadly colon cancer in the future.

Protective effects of melanoidins from black garlic on zearalenone-induced toxicity in zebrafish embryonic developmental model

Zearalenone (ZEN), a ubiquitous mycotoxin that widely occurs in grain and foodstuff may induce serious toxic effects after accumulation in vivo. Melanoidins (MLDs) have shown multiple bio-functional properties such as antioxidant, anti-bacterial and prebiotic activities. Black garlic exhibits several advantages over fresh garlic related to health improvement. In this study, the alleviative effects of black garlic MLDs on ZEN-induced toxicity and the potential mechanisms were studied using zebrafish embryonic developmental model. The results showed that MLDs restored the ZEN-induced adverse influences on zebrafish embryonic development, including delay in hatching time, morphological abnormality and the impairment of nervous development. Further studies showed that MLDs significantly inhibited the ZEN-induced production of reactive oxygen species (ROS) and enhanced the intrinsic antioxidant ability by increasing the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) and the content of glutathione (GSH). In addition, co-exposure of MLDs significantly inhibited the ZEN-stimulated cellular apoptosis in zebrafish larvae through down-regulation of pro-apoptotic genes of bax, caspase-3 and caspase-9 and up-regulation of anti-apoptotic gene bcl-2. Moreover, MLDs inhibited the in vivo accumulation of ZEN in zebrafish larvae. To sum up, MLDs attenuated the ZEN-induced zebrafish embryonic developmental toxicity through suppression of the oxidative stress and intervention on mitochondria apoptosis pathway as well as inhibiting the absorption of ZEN in zebrafish embryos/larvae. The results suggest that black garlic MLDs have potential to be used as a functional ingredient against the adverse effects of exogenous toxins.

Garlic (Allium sativum L.) in diabetes and its complications: Recent advances in mechanisms of action

Diabetes mellitus (DM) is a metabolic disease characterized by chronic hyperglycemia and impaired islet secretion that places a heavy burden on the global health care system due to its high incidence rate, long disease course and many complications. Fortunately, garlic (Allium sativum L.), a well-known medicinal plant and functional food without the toxicity and side effects of conventional drugs, has shown positive effects in the treatment of diabetes and its complications. With interdisciplinary development and in-depth exploration, we offer a clear and comprehensive summary of the research from the past ten years, focusing on the mechanisms and development processes of garlic in the treatment of diabetes and its complications, aiming to provide a new perspective for the treatment of diabetes and promote the efficient development of this field.