Dietary artepillin C suppresses the formation of aberrant crypt foci induced by azoxymethane in mouse colon

Polyphenols in the Prevention and Treatment of Colorectal Cancer: A Systematic Review of Clinical Evidence

Polyphenols are plant metabolites with potential anti-inflammatory and anti-proliferative effects, which may be advantageous for disorders like colorectal cancer (CRC). Despite promising in vitro and in vivo evidence, human clinical trials have yielded mixed results. The present study aimed to evaluate the clinical evidence of polyphenols for CRC prevention or treatment. A systematic review was performed according to PRISMA. Based on a PROSPERO registered protocol (CRD42024560044), online databases (PubMed and COCHRANE) were utilized for the literature search. A total of 100 studies articles were initially identified. After reviewing, 12 studies with a low risk of bias were selected, examining the effect of a variety of compounds. Curcumin demonstrated promise in various trials, mainly decreasing inflammatory cytokines, though results varied, and it did not lower intestinal adenomas or improve outcomes after chemotherapy. Neither epigallocatechin gallate nor artepillin C reduced the incidence of adenomas. Finally, fisetin seemed to improve the inflammatory status of patients under chemotherapy (5-fluorouracil). In summary, although certain polyphenols appear to exert some effect, their role in the prevention or treatment of CRC is inconclusive, and more clinical studies under more controlled conditions are needed.

Capillary Electrophoresis Separation of Artepillin C: Determination in Brazilian Green Propolis

Propolis is important in complementary and alternative medicine having well-known therapeutic applications. Artepillin C, a main component of Brazilian (green) propolis, has attracted great attention for its anticancer action. Consequently, the synthesis of artepillin C has been reported but, due to the limited yield and elevated costs, this biomolecule is largely produced from Brazilian propolis. We report the capillary electrophoresis (CE) separation of artepillin C in Brazilian propolis also comparing the results with those of HPLC-UV-MS. Optimal separation was obtained with a simple buffer constituted of sodium tetraborate 30 mM pH 9.2 and detection at 210 nm. Artepillin C and the polyphenols of propolis were fully separated with a voltage gradient of 30 to 8 kV and a current of 300 μA for a total run of 50 min. The sensitivity of CE-UV was 22 times greater than HPLC-UV and 100 times more than HPLC-MS with also a stronger reduction in the run time and a greater robustness and reproducibility. The development of CE as an effective and reliable method for the analysis of artepillin C is desired as the standardized quality controls are essential before propolis or its biomolecules can be adopted routinely in nutraceuticals, food ingredients and therapeutic applications.

Artepillin C: A comprehensive review of its chemistry, bioavailability, and pharmacological properties

Artepillin C (ARC), a prenylated derivative of p-coumaric acid, is one of the major phenolic compounds found in Brazilian green propolis (BGP) and its botanical source Baccharis dracunculifolia. Numerous studies on ARC show that its beneficial health effects correlate with the health effects of both BGP and B. dracunculifolia. Its wide range of pharmacological benefits include antioxidant, antimicrobial, anti-inflammatory, anti-diabetic, neuroprotective, gastroprotective, immunomodulatory, and anti-cancer effects. Most studies have focused on anti-oxidation, inflammation, diabetic, and cancers using both in vitro and in vivo approaches. Mechanisms underlying anti-cancer properties of ARC are apoptosis induction, cell cycle arrest, and the inhibition of p21-activated kinase 1 (PAK1), a protein characterized in many human diseases/disorders including COVID-19 infection. Therefore, further pre-clinical and clinical studies with ARC are necessary to explore its potential as intervention for a wide variety of diseases including the recent pandemic coronaviral infection. This review summarizes the comprehensive data on the pharmacological effects of ARC and could be a guideline for its future study and therapeutic usage.

Isolation of Artemisia capillaris membrane-bound di-prenyltransferase for phenylpropanoids and redesign of artepillin C in yeast

Plants produce various prenylated phenolic metabolites, including flavonoids, phloroglucinols, and coumarins, many of which have multiple prenyl moieties and display various biological activities. Prenylated phenylpropanes, such as artepillin C (3,5-diprenyl-p-coumaric acid), exhibit a broad range of pharmaceutical effects. To date, however, no prenyltransferases (PTs) involved in the biosynthesis of phenylpropanes and no plant enzymes that introduce multiple prenyl residues to native substrates with different regio-specificities have been identified. This study describes the isolation from Artemisia capillaris of a phenylpropane-specific PT gene, AcPT1, belonging to UbiA superfamily. This gene encodes a membrane-bound enzyme, which accepts p-coumaric acid as its specific substrate and transfers two prenyl residues stepwise to yield artepillin C. These findings provide novel insights into the molecular evolution of this gene family, contributing to the chemical diversification of plant specialized metabolites. These results also enabled the design of a yeast platform for the synthetic biology of artepillin C.

Chemopreventive and Antioxidant Effect of Polyphenol Free Spirulina maxima and Its Hydrolyzed Protein Content: Investigation on Azoxymethane Treated Mice

BACKGROUND

Spirulina maxima (Sm) is known to have nutritive value as well as a number of potentially useful biomedical properties.

OBJECTIVES

The initial purpose of this report was to evaluate the inhibitory effect of the alga (without its polyphenol content), on the induction of azoxymethane (AOM)-induced colon aberrant crypts (AC) in mouse. Besides, we hydrolyzed the protein content of such mixture. Our second aim was to determine the inhibitory potential of this last plant mixture on the AOM-induced colon AC in mouse. Moreover, we also determined the effect of the two indicated Sm samples on the oxidative damage caused by AOM in the colon and liver of treated mice.

MATERIALS AND METHODS

The experiment lasted 5 weeks. At the end, we registered the level of AC, nitric oxide, and the lipid and protein oxidation.

RESULTS

Our results showed the following: (1) the carcinogen increased more than 18 times the amount of the AC found in the control group. (2) On the contrary, the two tested mixtures of Sm produced a significant reduction over this damage (about 45%). (3) The two tested Sm mixtures were generally able to reduce the oxidative stress markers although with variable effects which go from 59% to 100% with respect to the control mice.

CONCLUSION

Therefore, the present report established that the tested Sm fractions have mouse colon anticarcinogenic potential, partially related with their antioxidant capacity. Our report also suggested the need to further evaluate specific Sm chemicals as chemopreventive agents.

Evaluation of genotoxicity and antigenotoxicity of artepillin C in V79 cells by the comet and micronucleus assays

Artepillin C (3,5-diprenyl-p-coumaric acid) is one of the major phenolic compounds found in Brazilian green propolis, as well as in its botanical source, Baccharis dracunculifolia DC (Asteraceae). The present study evaluated the possible genotoxic and protective activities of artepillin C, in vitro, using methyl methanesulfonate (MMS) as a positive control, by comet and micronucleus assays. The cultures of Chinese hamster lung fibroblasts (V79 cells) were treated with different concentrations of artepillin C (2.5, 5.0, 10.0, and 20 μM). In antigenotoxicity assessment, the 3 concentrations of artepillin C (2.5, 5.0, and 10.0 μM) were associated with MMS (200 μM-comet assay and 400 μM-micronucleus assay). A statistically significant increase in the DNA damage and micronucleus frequencies was observed in the culture treated with the highest concentration of the artepillin C in comparison to the control group. All concentrations of artepillin C showed protective activity in relation to MMS-induced genotoxicity, which may be due to its antioxidant properties.

Comparative Studies of the (Anti) Mutagenicity of Baccharis dracunculifolia and Artepillin C by the Bacterial Reverse Mutation Test

Baccharis dracunculifolia is a plant native from Brazil, commonly known as ‘Alecrim-do-campo’ and ‘Vassoura’ and used in alternative medicine for the treatment of inflammation, hepatic disorders and stomach ulcers. Previous studies reported that artepillin C (ArtC, 3-{4-hydroxy-3,5-di(3-methyl-2-butenyl)phenyl}-2(E)-propenoic acid), is the main compound of interest in the leaves. This study was undertaken to assess the mutagenic effect of the ethyl acetate extract of B. dracunculifolia leaves (Bd-EAE: 11.4–182.8 µg/plate) and ArtC (0.69–10.99 µg/plate) by the Ames test using Salmonella typhimurium strains TA98, TA97a, TA100 and TA102, and to compare the protective effects of Bd-EAE and ArtC against the mutagenicity of a variety of direct and indirect acting mutagens such as 4-nitro-O-phenylenediamine, sodium azide, mitomycin C, benzo[a]pyrene, aflatoxin B1, 2-aminoanthracene and 2-aminofluorene.The mutagenicity test showed that Bd-EAE and ArtC did not induce an increase in the number of revertant colonies indicating absence of mutagenic activity. ArtC showed a similar antimutagenic effect to that of Bd-EAE in some strains of S. typhimurium, demonstrating that the antimutagenic activity of Bd-EAE can be partially attributed to ArtC. The present results showed that the protective effect of whole plant extracts is due to the combined and synergistic effects of a complex mixture of phytochemicals, the total activity of which may result in health benefits.

Intestinal Anti-Inflammatory Activity of Baccharis dracunculifolia in the Trinitrobenzenesulphonic Acid Model of Rat Colitis

Baccharis dracunculifolia DC (Asteraceae) is a Brazilian medicinal plant popularly used for its antiulcer and anti-inflammatory properties. This plant is the main botanical source of Brazilian green propolis, a natural product incorporated into food and beverages to improve health. The present study aimed to investigate the chemical profile and intestinal anti-inflammatory activity of B. dracunculifolia extract on experimental ulcerative colitis induced by trinitrobenzenosulfonic acid (TNBS). Colonic damage was evaluated macroscopically and biochemically through its evaluation of glutathione content and its myeloperoxidase (MPO) and alkaline phosphatase activities. Additional in vitro experiments were performed in order to test the antioxidant activity by inhibition of induced lipid peroxidation in the rat brain membrane. Phytochemical analysis was performed by HPLC using authentic standards. The administration of plant extract (5 and 50 mg kg⁻¹) significantly attenuated the colonic damage induced by TNBS as evidenced both macroscopically and biochemically. This beneficial effect can be associated with an improvement in the colonic oxidative status, since plant extract prevented glutathione depletion, inhibited lipid peroxidation and reduced MPO activity. Caffeic acid, p-coumaric acid, aromadendrin-4-O-methyl ether, 3-prenyl-p-coumaric acid, 3,5-diprenyl-p-coumaric acid and baccharin were detected in the plant extract.

Brazilian green propolis inhibits inflammatory angiogenesis in a murine sponge model

Angiogenesis and inflammation are persistent features of several pathological conditions. Propolis, a sticky material that honeybees collect from living plants, has been reported to have multiple biological effects including anti-inflammatory and anti-neoplasic activities. Here, we investigated the effects of water extract of green propolis (WEP) on angiogenesis, inflammatory cell accumulation and endogenous production of cytokines in sponge implants of mice over a 14-day period. Blood vessel formation as assessed by hemoglobin content and by morphometric analysis of the implants was reduced by WEP (500 mg kg(-1) orally) compared to the untreated group. The levels of vascular endothelial growth factor (VEGF) increased progressively in the treated group but decreased after Day 10 in the control group. Accumulation of neutrophils and macrophages was determined by measuring myeloperoxidase (MPO) and N-acetyl-β-(D)-glucosaminidase (NAG) activities, respectively. Neutrophil accumulation was unaffected by propolis, but NAG activity was reduced by the treatment at Day 14. The levels TGF-β1 intra-implant increased progressively in both groups but were higher (40%) at Day 14 in the control implants. The pro-inflammatory levels of TNF-α peaked at Day 7 in the control implants, and at Day 14 in the propolis-treated group. Our results indicate that the anti-inflammatory/anti-angiogenic effects of propolis are associated with cytokine modulation.

Antigenotoxicity of artepillin C in vivo evaluated by the micronucleus and comet assays

Artepillin C (3,5-diprenyl-p-coumaric acid), a major compound found in Brazilian green propolis and Baccharis dracunculifolia, shows anti-inflammatory, antibacterial, antiviral, antioxidant and antitumoral activities, among others. The aim of this study was to evaluate the genotoxic potential of artepillin C and its ability to prevent the chemically induced chromosome breakage or loss and the primary DNA damage using the micronucleus and comet assays in male Swiss mice, respectively. The animals were treated by gavage with different doses of artepillin C (0.4, 0.8 and 1.6 mg kg(-1) b.w.). For the antigenotoxicity assays, the different doses of artepillin C were administered simultaneously to doxorubicin (DXR; micronucleus test; 15 mg kg(-1) b.w.) and to methyl methanesulfonate (MMS; comet assay; 40 mg kg(-1) b.w.). The results showed that artepillin C itself was not genotoxic in the mouse micronucleus and comet assays. In the animals treated with artepillin C and DXR, the number of micronucleated reticulocytes was significantly lower in comparison with the animals treated only with DXR. Regarding antigenotoxicity, artepillin C at the tested doses significantly reduced the extent of DNA damage in liver cells induced by MMS.

Artepillin C, as a PPARγ ligand, enhances adipocyte differentiation and glucose uptake in 3T3-L1 cells

The nuclear receptor peroxisome proliferator-activated receptor (PPAR) γ plays an important role in adipocyte differentiation. Its ligands, including thiazolidinediones, improve insulin sensitivity in type 2 diabetes. We investigated the effects of artepillin C, an ingredient of Baccharis dracunculifolia, on adipogenesis and glucose uptake using 3T3-L1 cells. In PPARγ ligand-binding assays, artepillin C exhibited binding affinity toward PPARγ. Artepillin C dose-dependently enhanced adipocyte differentiation of 3T3-L1 cells. As a result of the artepillin C-induced adipocyte differentiation, the gene expression of PPARγ and its target genes, such as aP2, adiponectin and glucose transporter (GLUT) 4, was increased. These increases were abolished by cotreatment with GW9662, a PPARγ antagonist. In mature 3T3-L1 adipocytes, artepillin C significantly enhanced the basal and insulin-stimulated glucose uptake. These effects were decreased by cotreatment with a PI3K inhibitor. Although artepillin C had no effects on the insulin signaling cascade, artepillin C enhanced the expression and plasma membrane translocation of GLUT1 and GLUT4 in mature adipocytes. In conclusion, these findings suggest that artepillin C promotes adipocyte differentiation and glucose uptake in part by direct binding to PPARγ, which could be the basis of the pharmacological benefits of green propolis intake in reducing the risk of type 2 diabetes.

Inhibition of corneal neovascularization with propolis extract

Neovascularization of the normally avascular cornea is seen in many pathological conditions including trauma, corneal transplantation, inflammation and eye diseases. Various growth factors and proteinases are involved in corneal neovascularization. Data supporting a causal role for vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs) are extensive. Inhibition of angiogenesis is a main strategy for treating corneal neovascularization. Several findings have shown that corneal neovascularization can be reduced by using anti-VEGF and anti-MMPs agents. Efficacy of a propolis extract has been demonstrated for reducing angiogenesis in vitro and in vivo. Propolis extracts containing artepillin C and caffeic acid phenyl ester significantly reduced the number of newly formed vessels and expression of MMPs and VEGF production from various cells. So far, propolis extract is a potential candidate as an anti-angiogenic agent and can inhibit cell proliferation, migration and capillary tube formation. We hypothesize that topical application of propolis is potentially useful for inhibiting corneal neovascularization and restoration of corneal clarity.

Suppression of tumor-induced angiogenesis by Brazilian propolis: Major component artepillin C inhibits in vitro tube formation and endothelial cell proliferation

Propolis, a resinous substance collected by honeybees from various plant sources, possesses various physiological activities such as antitumor effects. We have previously shown that propolis of Brazilian origin was composed mainly of artepillin C and that its constituents were quite different from those of propolis of European origin. In this report, we examined an antiangiogenic effects of Brazilian propolis and investigated whether artepillin C was responsible for such effects. In an in vivo angiogenesis assay using ICR mice, we found that the ethanol extract of Brazilian propolis (EEBP) significantly reduced the number of newly formed vessels. EEBP also showed antiangiogenic effects in an in vitro tube formation assay. When compared with other constituents of EEBP, only artepillin C was found to significantly inhibit the tube formation of HUVECs in a concentration-dependent manner (3.13-50microg/ml). In addition, artepillin C significantly suppressed the proliferation of HUVECs in a concentration-dependent manner (3.13-50microg/ml). Furthermore, artepillin C significantly reduced the number of newly formed vessels in an in vivo angiogenesis assay. Judging from its antiangiogenic activity in vitro and in vivo, we concluded that artepillin C at least in part is responsible for the antiangiogenic activity of EEBP in vivo. Artepillin C may prove useful in the development of agents and foods with therapeutic or preventive activity against tumor angiogenesis.

Inhibition of doxorubicin-induced mutagenicity by Baccharis dracunculifolia

Baccharis dracunculifolia DC (Asteraceae), a native plant from Brazil, have been used as an antipyretic, stomachic and health tonic in Brazil. The objective of the present study was to investigate the potential mutagenic effect of B. dracunculifolia ethyl acetate extract (Bd-EAE) and its influence on the mutagenicity induced by the chemotherapeutic agent doxorubicin (DXR) using the rat bone marrow and peripheral blood micronucleus test. Wistar rats were divided into 10 treatment groups. Five groups received DXR (90 mg/kg body weight, b.w., intraperitoneally) to induce mutagenicity and three of these groups received a single oral dose of Bd-EAE at a concentration of 6, 12 or 24 mg/kg b.w. prior to DXR administration. A vehicle-treated control group and Bd-EAE control groups were also included. The results showed that Bd-EAE itself was not mutagenic, in the rat micronucleus assay. In animals treated with Bd-EAE and DXR, the number of MNPCEs was significantly decreased compared to animals receiving DXR alone. HPLC analysis of the extract obtained permitted the identification of the following phenolic compounds: caffeic acid, p-coumaric acid, aromadendrin-4'O-methyl ether, 3-prenyl-p-coumaric acid (drupanin), 3,5-diprenyl-p-coumaric acid (artepillin C) and baccharin. The putative antioxidant activity or the interference of one or more of the active compounds of Bd-EAE with mutagenic metabolic pathways may explain its effect on DXR mutagenicity.