Comparison of the protective effects of curcumin and caffeic acid phenethyl ester against doxorubicin-induced testicular toxicity

Whether testicular toxicity is mediated by matrix metalloproteinases (MMPs) is an important question that has not been examined. This study investigated the suppressive effect of curcumin and caffeic acid phenethyl ester (CAPE) on oxidative stress, apoptosis, and whether MMPs mediate doxorubicin (DOX)-induced testicular injury. Male rats were randomly divided into eight groups (n = 8 per group). The groups were as follows: sham, dimethyl sulphoxide (100 µL), DOX (3 mg/kg), CAPE (2.68 mg/kg), curcumin (30 mg/kg), DOX+CAPE (3 mg/kg DOX and 2.68 mg/kg CAPE), DOX+curcumin (3 mg/kg DOX and 30 mg/kg curcumin) and DOX+CAPE+curcumin (3 mg/kg DOX, 2.68 mg/kg CAPE and 30 mg/kg curcumin). Injections were administered daily for 21 days. The oxidative stress, MMPs, proinflammatory cytokines and apoptotic markers in the DOX group were higher than the sham group (p < .05); these measures were lower in the groups treated with CAPE and curcumin together with DOX compared with the DOX group (p < .05). The results showed that MMPs mediated DOX-induced testicular injury, but CAPE and especially curcumin suppressed testis injury and cell apoptosis by suppressing DOX-induced increases in MMPs, oxidative stress and proinflammatory cytokines. However, curcumin exhibited more pronounced effects than CAPE in terms of all studied parameters.

Investigation of the preventive effects of dehydroepiandrosterone (DHEA) and Caffeic acid phenethyl ester (CAPE) on cisplatin-induced ovarian damage in rats

To investigate whether Dehydroepiandrosterone (DHEA) and Caffeic acid phenethyl ester (CAPE) had any preventive effect against the ovarian damage caused by cisplatin (CP) (cis-diamminedichloroplatinum) in rats. On the first day ovaries were removed, Anti-Müllerian hormone (AMH) was measured (Group1, n:6), in the other groups 7.5 mg/kg cisplatin was administered intraperitoneally. In Group 2 (n = 6), 0.1 ml saline, in Group 3 (n = 5), 20 umol/kg CAPE, in Group 4 (n = 7), DHEA 6 mg/kg were administered every day. On the 10th day, ovaries were removed, AMH was measured. Ovary reserve (primordial/primary/secondary/tertiary/atretic follicles, AMH), ovarian damage scores (follicular degeneration, congestion, hemorrhage, edema, inflammation) were compared. The number of tertiary follicles were statistically high in the CAPE group (p = .015), the inflammation score in the DHEA group (p = .012), AMH level (p = .009) in the control group. The lowest number of atretic follicles (AF) was in the control group, while the highest number of AF was in the DHEA group (p = .002). Significant decreases in AF were the case in the cisplatin and DHEA groups compared to the control group (p < .008). The AMH values had the highest positive correlation with the number of primordial follicles and the highest negative correlation with the number of AF. The cut off point for AMH was 1.57 ng/ml as an indicator of low ovarian reserve. Cisplatin causes total damage and increased numbers of AF on the ovary. Depending on this, AMH levels fall. These negative effects of cisplatin are not obstructed by CAPE or DHEA, and may even be increased by DHEA.

Effects of caffeic acid phenethyl ester application on dentin MMP-2, stability of bond strength and failure mode of total-etch and self-etch adhesive systems

OBJECTIVE

Investigate the long-term effect of dentin pretreatment with 0.05 or 0.1% caffeic acid phenethyl ester (CAPE) on (1) bond strength of resin composite to dentin by a three-step etch-and-rinse (Adper Scotchbond Multipurpose/ ASB) or a two-step self-etch adhesive system (Clearfil SE Bond/ CSE), (2) their fracture mode, (3) the micromorphological features of the hybrid layer formed; and (4) the level of MMP-2 in dentin (after application, using a correlative immunoexpression/quantification approach).

DESIGN

Composite resin blocks were fabricated on 48 third molars (n = 6), according to the type of adhesive and treatment (control, CAPE 0.05% and CAPE 0.1%). Slices were obtained for scanning electron microscopy (SEM) evaluation, and sticks were fabricated for microtensile tests (24 h and 1 year). Aliquots of dentin powder were distributed (n = 12) according to the treatment and the MMP-2 concentration was determined by ELISA.

RESULTS

Tukey test showed that ASB groups presented higher BS in 24 h than CSE groups. ASB presented a reduction in BS values after 1-year. ASB and CSE presented no significant differences in BS after 1-year. CAPE had no effect on BS for both adhesive systems. The predominant failure mode for the ASB groups were adhesive; when 0.1% CAPE was applied there was a predominance of mixed fractures. Regarding the CSE group, 0.05% CAPE led to more adhesive failures, and the 0.1% concentration resulted in a higher number of cohesive failures in dentin. Higher MMP-2 concentrations were detected for the groups that did not undergo demineralization treatment, and the lowest values for the ASB groups treated with CAPE. SEM analysis showed no influence of pretreatment with CAPE.

CONCLUSIONS

CAPE did not influence the BS of the adhesives tested, or the micromorphology of the hybrid layer, irrespective of concentration or storage time. CAPE affected the fracture pattern at 24 h, depending on the concentration and the adhesive system used. Immunoassay analysis showed that CAPE 0.1% reduced the MMP-2 concentration in the ASB adhesive without affecting bond strength to dentin.

Caffeic Acid Phenethyl Ester: A Review of Its Antioxidant Activity, Protective Effects against Ischemia-reperfusion Injury and Drug Adverse Reactions

Propolis, a honey bee product, has been used in folk medicine for centuries for the treatment of abscesses, canker sores and for wound healing. Caffeic acid phenethyl ester (CAPE) is one of the most extensively investigated active components of propolis which possess many biological activities, including antibacterial, antiviral, antioxidant, anti-inflammatory, and anti-cancer effects. CAPE is a polyphenolic compound characterized by potent antioxidant and cytoprotective activities and protective effects against ischemia-reperfusion (I/R)-induced injury in multiple tissues such as brain, retina, heart, skeletal muscles, testis, ovaries, intestine, colon, and liver. Furthermore, several studies indicated the protective effects of CAPE against chemotherapy-induced adverse drug reactions (ADRs) including several antibiotics (streptomycin, vancomycin, isoniazid, ethambutol) and chemotherapeutic agents (mitomycin, doxorubicin, cisplatin, methotrexate). Due to the broad spectrum of pharmacological activities of CAPE, this review makes a special focus on the recently published data about CAPE antioxidant activity as well as its protective effects against I/R-induced injury and many adverse drug reactions.

Possible molecular targets for therapeutic applications of caffeic acid phenethyl ester in inflammation and cancer

Of the various derivatives of caffeic acid, caffeic acid phenethyl ester (CAPE) is a hydrophobic, bioactive polyphenolic ester obtained from propolis extract. The objective in writing this review article was to summarize all published studies on therapeutics of CAPE in inflammation and cancer to extract direction for future research. The possible molecular targets for the action of CAPE, include various transcription factors such as nuclear factor-κB, tissue necrosis factor-α, interleukin-6, cyclooxygenase-2, Nrf2, inducible nitric oxide synthase, nuclear factor of activated T cells, hypoxia-inducible factor-1α, and signal transducers and activators of transcription. Based on the valuable data on its therapeutics in inflammation and cancer, clinical studies of CAPE should also be conducted to explore its toxicities, if any.

Bioinspired syntheses of dimeric hydroxycinnamic acids (lignans) and hybrids, using phenol oxidative coupling as key reaction, and medicinal significance thereof

Lignans are mainly dimers of 4-hydroxycinnamic acids (HCAs) and reduced analogs thereof which are produced in Nature through phenol oxidative coupling (POC) as the primary C-C or C-O bond-forming reaction under the action of the enzymes peroxidases and laccases. They present a large structural variety and particularly interesting biological activities, therefore, significant efforts has been devoted to the development of efficient methodologies for the synthesis of lignans isolated from natural sources, analogs and hybrids with other biologically interesting small molecules. We summarize in the present review those methods which mimic Nature for the assembly of the most common lignan skeleta by using either enzymes or one-electron inorganic oxidants to effect POC of HCAs and derivatives, such as esters and amides, or cross-POC of pairs of HCAs or HCAs with 4-hydrocycinnamyl alcohols. We, furthermore, provide outlines of mechanistic schemes accounting for the formation of the coupled products and, where applicable, indicate their potential application in medicine.

Development of novel molecular probes of the Rio1 atypical protein kinase

The RIO kinases are essential protein factors required for the synthesis of new ribosomes in eukaryotes. Conserved in archaeal organisms as well, RIO kinases are among the most ancient of protein kinases. Their exact molecular mechanisms are under investigation and progress of this research would be significantly improved with the availability of suitable molecular probes that selectively block RIO kinases. RIO kinases contain a canonical eukaryotic protein kinase fold, but also display several unusual structural features that potentially create opportunity for the design of selective inhibitors. In an attempt to identify structural leads to target the RIO kinases, a series of pyridine caffeic acid benzyl amides (CABA) were tested for their ability to inhibit the autophosphorylation activity of Archeaoglobus fulgidus Rio1 (AfRio1). Screening of a small library of CABA molecules resulted in the identification of four compounds that measurably inhibited AfRio1 activity. Additional biochemical characterization of binding and inhibition activity of these compounds demonstrated an ATP competitive inhibition mode, and allowed identification of the functional groups that result in the highest binding affinity. In addition, docking of the compound to the structure of Rio1 and determination of the X-ray crystal structure of a model compound (WP1086) containing the desired functional groups allowed detailed analysis of the interactions between these compounds and the enzyme. Furthermore, the X-ray crystal structure demonstrated that these compounds stabilize an inactive form of the enzyme. Taken together, these results provide an important step in identification of a scaffold for the design of selective molecular probes to study molecular mechanisms of Rio1 kinases in vitro and in vivo. In addition, it provides a rationale for the future design of potent inhibitors with drug-like properties targeting an inactive form of the enzyme. This article is part of a Special Issue entitled: Inhibitors of Protein Kinases (2012).