Caffeic acid assists microwave heating to inhibit the formation of mutagenic and carcinogenic PhIP

Caffeic Acid and Diseases-Mechanisms of Action

Caffeic acid belongs to the polyphenol compounds we consume daily, often in the form of coffee. Even though it is less explored than caffeic acid phenethyl ester, it still has many positive effects on human health. Caffeic acid can affect cancer, diabetes, atherosclerosis, Alzheimer's disease, or bacterial and viral infections. This review focuses on the molecular mechanisms of how caffeic acid achieves its effects.

Inhibitory effects of hyperoside and quercitrin from Zanthoxylum bungeanum Maxim. leaf on 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine formation by trapping phenylacetaldehyde

2-amino-1-methyl-6-phenylimidazole[4,5-b]pyridine (PhIP) is one of the most abundant Heterocyclic amines (HAs) in meat products. Zanthoxylum bungeanum Maxim. leaf (ZML) extract has been shown to be rich in polyphenols, which are gaining increasing interest as efficient tools for inhibiting the formation of HAs. In the present work, the effects of ZML extract, major polyphenols, chlorogenic acid, hyperoside and quercitrin on the formation of PhIP in both roast beef patties and chemical model systems were investigated. UPLC-MS showed that ZML extract and those three polyphenols effectively inhibited PhIP formation. Additionally, GC-MS analysis showed that those three polyphenols significantly reduced the content of phenylacetaldehyde in the model systems, a key intermediate involved in PhIP formation. The subsequent UPLC-MS and TOF-MS/MS analysis found that hyperoside and quercitrin reacted with phenyacetaldehyde to form those four adducts, 8-C-(E-Phenylethenyl)hyperoside, 6-C-(E-Phenylethenyl)hyperoside, 8-C-(E-Phenylethenyl)quercitrin and 6-C-(E-Phenylethenyl)quercitrin, respectively. The results revealed that hyperoside and quercitrin could trap phenylacetaldehyde to form adducts, thereby, retarding the reaction of phenylacetaldehyde and creatinine, blocking the generation of PhIP.

Nontargeted metabolomics reveals the discrimination of Cyclocarya paliurus leaves brewed by different methods

An original way of brewing Cyclocarya paliurus leaves, especially in China, is to steep leaves in hot water before people drink it directly. Recently, infusing tea leaves with cold water, a creative way in Taiwan, has become a popular way of making tea. This study was designed to investigate the differences in metabolites among three brewing methods (cold-brewing, steep-brewing, and boil-brewing) based on UPLC-QTOF-MS metabolomics experiments and the feasibility of cold-brewing methods for C. paliurus leaves. Unsupervised analysis (PCA) explained 54.6% (positive ion mode) and 57.4% (negative ion mode) of the total variance, whereas supervised analysis (OPLS-DA) with cross-validated R²Y and Q² values > 0.5, could reveal potential metabolites with better discrimination among the three brewing methods. Fifteen potential differential metabolites were chosen and identified, and nine of them were further confirmed with reference standards. This study suggested that the cold-brewing method without an increase in temperature protected the phenol aromatic ring, thereby obtaining more phenolic acid compounds from C. paliurus leaves. These results provided a basis for making cold tea and promoting the development of cold tea with C. paliurus leaves as raw materials.

Blended Natural Support Materials-Collagen Based Hydrogels Used in Biomedicine

Due to their unique properties-the are biocompatible, easily accessible, and inexpensive with programmable properties-biopolymers are used in pharmaceutical and biomedical research, as well as in cosmetics and food. Collagen is one of the most-used biomaterials in biomedicine, being the most abundant protein in animals with a triple helices structure, biocompatible, biomimetic, biodegradable, and hemostatic. Its disadvantages are its poor mechanical and thermal properties and enzymatic degradation. In order to solve this problem and to use its benefits, collagen can be used blended with other biomaterials such as alginate, chitosan, and cellulose. The purpose of this review article is to offer a brief paper with updated information on blended collagen-based formulations and their potential application in biomedicine.

A novel potent inhibitor of 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine (PhIP) formation from Chinese chive: Identification, inhibitory effect and action mechanism

Differential solvent extraction and phytochemical profiling of Chinse chive were employed to identify its principal PhIP-formation inhibitory constituents. Six compounds (mangiferin, isorhamnetin, luteolin, rosmarinic acid, 6-methylcoumarin, and cyanidin-3-glucoside) were further analyzed in a PhIP-producing chemical model to identify the dominant inhibitor. Its inhibitory mechanism was investigated by assessing the contribution of antioxidation and scavenging of key PhIP precursor/intermediate. No significant correlation was observed between PhIP inhibition rates and antioxidant activities. Further evaluation of the novel potent inhibitor mangiferin revealed a highly significant correlation between its dose-dependent inhibition of PhIP formation and phenylacetaldehyde scavenging. Finally, the proposed mechanism was corroborated through organic synthesis and structural elucidation of the mangiferin-phenylacetaldehyde adduct. This study has identified a potent novel inhibitor of the most abundant HA in heat-processed food and characterized its action mechanism. These findings may provide insight for future studies on mitigation of dietary exposure to toxic Maillard products by polyphenolic phytochemicals.

Effects of caffeine and caffeic acid on selected biochemical parameters in L-NAME-induced hypertensive rats

Biologically active compounds such as caffeine and caffeic acid can be obtained in plants especially cocoa and coffee. Hence, the combinatory effect of caffeine and caffeic acid as well as their individual effect were assessed on the activities of arginase, angiotensin-1-converting enzyme (ACE) as well as nitric oxide (NOx), and malondialdehyde (MDA) level in the Nω-Nitro-L-arginine-methylester (L-NAME)-induced hypertensive rats. The individual and combinatory effect of caffeine and caffeic acid were investigated in L-NAME-induced rats. Animals were grouped into eleven containing six animals each. Hemodynamic parameter was determined by tail-cuff plethysmography. Furthermore, the result showed a notable rise in ACE and arginase activities of L-NAME-induced group compared with the control group. However, pretreatment with test compounds lowered ACE, arginase activities, and MDA content with rise in NOx. This study supports that caffeine and caffeic acid combinations demonstrated antihypertensive properties by lowering the systolic blood pressure in L-NAME-induced rats. PRATICAL APPLICATIONS: This duo bioactive compounds; caffeine (alkaloid) and caffeic acid (phenolic acid) are lavishly distributed in coffee. Their cardiopotective and cardiomodulatory roles have been investigated due to their biological activities. As far as we are aware, this could be foremost in-depth study on the antihypertensive and cardioprotective effect of the combinations of caffeine and caffeic acid targeting the key enzymes system relevant to hypertension. Decreased ACE and arginase activities as well as high nitric oxide (NOx) and low MDA level may be associated with its antihypertensive effect. This present study suggests that the combinations of this phenolics and alkaloid compound might proffer a therapeutic strategy in the management of hypertension.