The caffeic acid moiety plays an essential role in attenuating lipid accumulation by chlorogenic acid and its analogues

Chlorogenic Acid Derivatives: Structural Modifications, Drug Design, and Biological Activities: A Review

BACKGROUND

Phenolic acids have recently gained considerable attention because of their numerous practical, biological, and pharmacological benefits. Various polyphenolic compounds are widely distributed in plant sources. Flavonoids and phenolic acids are the two main polyphenolic compounds that many plants contain abundant polyphenols. Chlorogenic acid, one of the most abundant phenolic acids, has various biological activities, but it is chemically unstable and degrades into other compounds or different enzymatic processes.

METHODS

In this review, we have studied many publications about CA and its derivatives. CA derivatives were classified into three categories in terms of structure and determined each part's effects on the body. The biological evaluations, structure-activity relationship, and mechanism of action of CA derivatives were investigated. The search databases for this review were ScienceDirect, Scopus, Pub- Med and google scholar.

RESULTS

Many studies have reported that CA derivatives have demonstrated several biological effects, including anti-oxidant, anti-inflammatory, anti-microbes, anti-mutation, anti-carcinogenic, anti-viral, anti-hypercholesterolemia, anti-hypertensive, anti-bacterial, and hypoglycemic actions. The synthesis of new stable CA derivatives can enhance its metabolic stability and biological activity.

CONCLUSION

The present study represented different synthetic methods and biological activities of CA derivatives. These compounds showed high antioxidant activity across a wide range of biological effects. Our goal was to help other researchers design and develop stable analogs of CA for the improvement of its metabolic stability and the promotion of its biological activity.

The effects of co-administration of artichoke leaf extract supplementation with metformin and vitamin E in patients with nonalcoholic fatty liver disease: A randomized clinical trial

Medicinal plants are widely used as a complementary therapy to treat complex diseases, such as nonalcoholic fatty liver disease (NAFLD). Therefore, this study was done to investigate the effect of co-administration of artichoke leaf extract supplement (ALES) with conventional medicines on patients with NAFLD. The clinical trial was based on patients randomly divided into three groups involving metformin-vitamin E (ME), metformin-ALES (MA), and vitamin E-ALES (EA). The effectiveness of treatment in the treated groups was evaluated using liver ultrasonography and biochemical markers. After 12 weeks of treatment, the results showed that the rate of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was significantly reduced within all the study groups (p < .05). Liver ultrasonographic findings revealed that the rate of fat accumulation in liver of patients was decreased significantly within all the study groups and it was increased in the subjects with grade 0 fatty liver (without fat accumulation) in the MA and EA groups by 23.3 and 17.2%, respectively. In summary, the results of the present study showed that the concomitant use of ALES with metformin and vitamin E can have beneficial effects on amelioration of complications in patients with NAFLD. However, larger-scale clinical trial studies are required in this regard.

Cinnamic acid ameliorate gentamicin-induced liver dysfunctions and nephrotoxicity in rats through induction of antioxidant activities

This study was the first to evaluate the possible protective effects of cinnamic acid (CA) against Gentamicin (GM) induced liver and kidney dysfunctions in rats. Adult male Wistar rats were randomly assigned to 4 equal groups (n = 8): Control group (saline, 0.5 ml/day), CA group (CA, 50 mg/kg/day), GM group (GM, 100 mg/kg/day), and GM + CA group (100 & 50 mg/kg/day). Following 12 days of treatments, blood and 24 h urine samples were collected and kidneys were taken out for biochemical, histopathological, and molecular studies. Following CA treatment, renal function markers and transaminases activities including serum urea (59.92%) and creatinine (50.41%), protein excretion rate (43.67%), and serum activities of aspartate aminotransferase (AST) (54.34%) and alanine aminotransferase (ALT) (47.26%) significantly reduced in the treated group as compared with the GM group (P < 0.05). Also, CA could significantly ameliorate the levels of triglyceride (29.70%), cholesterol (13.02%), very low-density lipoprotein (29.69%) and high-density lipoprotein-cholesterol (7.28%). CA could also attenuate oxidative stress through a decrease of serum malondialdehyde (MDA) (50.86%) and nitric oxide (NO) (0.85%) and an increase of renal catalase (CAT) (196.14%) and glutathione peroxidase (GPX) activities (45.88%) as well as GPX mRNA expression (44.42-fold) as compared with the GM group (P < 0.05). Moreover, histopathological evaluations revealed attenuated tubular damages and reduced inflammatory cellular infiltration in CA treated animals. Overall, CA alleviates GM-induced nephrotoxicity and alterations in transaminases activities in rats through its antioxidant activities.

Caffeic Acid Protects against Iron-Induced Cardiotoxicity by Suppressing Angiotensin-Converting Enzyme Activity and Modulating Lipid Spectrum, Gluconeogenesis and Nucleotide Hydrolyzing Enzyme Activities

The protective effects of caffeic acid on angiotensin-converting enzyme (ACE) and purinergic enzyme activities, as well as gluconeogenesis was investigated in iron-induced cardiotoxicity. Cardiotoxicity was induced in heart tissues harvested from healthy male SD rats by 0.1 mM FeSO₄. Treatment was carried out by co-incubating hearts tissues with caffeic acid and 0.1 mM FeSO₄. Cardiotoxicity induction significantly (p < 0.05) depleted GSH level, SOD, catalase, and ENTPDase activities, with concomitant elevation of the levels of malondialdehyde (MDA), nitric oxide, ACE, ATPase, glycogen phosphorylase, glucose 6-phosphatase, fructose 6-biphsophatase, and lipase activities. There was significant (p < 0.05) reversion in these levels and activities on treatment with caffeic acid. Caffeic acid also caused depletion in cardiac levels of cholesterol, triglyceride, LDL-c, while elevating HDL-c level. Our results suggest the protective effect of caffeic acid against iron-mediated cardiotoxicity as indicated by its ability to suppress oxidative imbalance and ACE activity, while concomitantly modulating nucleotide hydrolysis and metabolic switch.

Amino acid ester-coupled caffeoylquinic acid derivatives as potential hypolipidemic agents: synthesis and biological evaluation

Pandanus tectorius (L.) Parkins. (PTPs) is rich in caffeoylquinic acids and amino acids, especially some essential amino acids, such as valine, phenylalanine, and so forth. A series of novel amino acid ester-coupled caffeoylquinic acid derivatives have been designed and synthesized. Biological evaluation suggested that some amino acid ester-coupled derivatives exhibited varying degrees of lipid-lowering effects on oleic acid-elicited lipid accumulation in HepG2 liver cells. Particularly, derivatives 6c, 6d, 6e and 6f exhibited comparable potential lipid-lowering effect with the positive control simvastatin and chlorogenic acid. Further studies on the mechanism of 6c, 6d, 6e and 6f revealed that the lipid-lowering effects were related to their regulation of TG levels and mRNA levels of lipometabolic-modulating genes, and merit further investigation.

Different Phenolic Extracts of Oil Palm Fruits and Caffeic Acid Prevent Palmitic Acid-Induced Lipotoxicity in HepG2 Cells via Improving Mitochondrial Function

Oil palm (Elaeis guineensis Jacq.) fruits are rich in antioxidative phenolic compounds, which exert various health improving effects. This study aimed to comparatively study the protective effects of different phenolic fractions from the fruits treated with or without ultrahigh pressure (UHP) and their most abundant phenolic substance, caffeic acid, against the palmitic acid-induced lipotoxicity in HepG2 cells and to clarify the potential mechanisms. Results showed that the TG accumulation, intracellular reactive oxygen species content, cell apoptosis, and mitochondrial membrane potential depolarization were relieved by the administration of those phenolic fractions and caffeic acid. The protection of insoluble-bound (IB) phenolic fraction was the best, and UHP treatment significantly enhanced its protective effect on lipotoxicity. The lipotoxicity preventive effect may be achieved by alleviating intracellular oxidative stress, downregulating the expression of P-P38, COX-2, and iNOS to relieve inflammation, and downregulating Bax and cytochrome C and upregulating Bcl-2 to suppress the mitochondrial-mediated apoptosis. Therefore, the oil palm fruits phenolic fractions, especially the IB phenolic fraction, might be utilized as dietary antioxidants to relieve the adverse effects of a high-fat diet on the body, and UHP treatment is a potential method to increase this bioactivity.