GC-MS based metabolic profile and toxicological evaluation of three Algerian propolis.

This study aimed to investigate the chemical composition and toxicity of methanolic extracts of three Algerian propolis collected from Oum el Bouaghi (MEPO), El Harrouch (MEPH) and Collo (MEPC) regions. The chemical profile was characterised by GC-MS. The toxicity of the extracts was tested using brine shrimp model. The GC-MS analysis revealed the presence of ferulic acid (23.8%), pinostrobin chalcone (15.8%) and α-eudesmol (11.3%) as major compounds in MEPO, pinostrobin chalcone (22.2%), 9-octadecenoic acid, methyl ester, (E)- (17.4%), and γ-gurjunenepoxide-(2) (11.7%) were the most abundant components in MEPH, whereas MEPC was dominated by 1-heptatriacotanol (17.8%), pinostrobin chalcone (14.7%), totarol (13.7%) and 9-octadecenoic acid, methyl ester, (E)- (13.0%). The brine shrimp lethality test indicated that the extracts had moderate toxicity in which MEPC exhibited the highest activity with LC50 of 201.61 ± 7.27 µg/mL. All extracts showed no toxicity at 25 µg/mL concentration and below.

Effect of probiotic supplementation on oxidative stress markers in rats with diclofenac-induced hepatotoxicity.

In this study, we have investigated the effect of an antioxidant probiotic pretreatment toward an overdose of diclofenac in rats (100 mg/kg bw). Rats were treated daily with the probiotic Streptococcus salivarius St.sa (109 CFU) during seven successive days and then received a single treatment with diclofenac overdose in distilled water. Liver transaminases (alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase), histology, glutathione (GSH) and malondialdehyde (MDA) level were investigated. In addition, both antioxidant enzyme activity and its mRNA gene expression were studied to evaluate diclofenac hepatotoxicity. The results indicated that probiotic pretreatment reduced diclofenac-induced hepatotoxicity through enhancement of the studied hepatic markers and regulation of antioxidant enzyme expression and activity. These findings indicate that the probiotic pretreatment protects rat liver against the oxidative stress induced by diclofenac overdose.

Myocardial protection by propolis during prolonged hypothermic preservation.

Oxidative stress is involved in the pathogenesis of ischemia-reperfusion during myocardial transplantation. Therefore, graft preservation solutions may be improved by supplementation with antioxidants to minimize graft dysfunction caused by cold ischemic injury. Propolis is a polyphenol-rich substance which has an important antioxidant activity. The protective effect of propolis against oxidative stress induced by prolonged cold preservation of heart was investigated. Mice were subjected to a hypothermic model of ischemia in which hearts were preserved for 24 h at 4 °C in Krebs-Hensleit (KH) solution in the absence or presence of propolis concentrations (50, 150 and 250 µg/ml). Levels of released Lactate dehydrogenase (LDH), Creatine phosphokinase (CPK) and Troponine-I (Trop I) were assessed in the preservation solution and histological assessement of heart ischemia injuries was performed. Oxidative stress biomarkers malondialdehyde (MDA) and advanced oxidation protein products (AOPP) and antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were assessed in cardiac tissue. Mitochondria were isolated from stored hearts and production of reactive oxygen species (ROS) was tested. Propolis supplementation protected efficiently hearts during preservation by reducing significantly levels of lipids and proteins oxidation and restoring activities of antioxidant enzymes. Also, propolis preserved tissue integrity altered by hypothermic ischemia in a concentration-dependent manner. Propolis reduced significantly the rate of H2O2 produced by mitochondrial respiration, the best antioxidant effect being obtained at the highest propolis concentration (250 µg/ml). Algerian propolis is a non-temperature sensitive scavenger that protects heart from oxidative damage induced by prolonged hypothermic ischemia.

Ethanolic extract of Algerian propolis decreases androgen receptor transcriptional activity in cultured LNCaP cells.

Antiandrogens have a peculiar place in the treatment of metastatic prostate cancer by blocking the androgen receptor (AR). Unfortunately, aggressive tumors could rapidly develop into a castration resistant state. It is therefore essential to look for new molecules that are more effective, affecting not only the androgen signaling and with minimum undesirable effects. Natural products are an interesting source of new therapeutics, especially for cancer therapy as 70% of them have botanical origin. Based on an ethnobotany screening, we evaluated the effects of ethanolic extract of propolis (EEP) from Algeria on LNCaP cells. Results pointed out that EEP reduces the survival of LNCaP cells with an IC50 of 0.04 mg/ml, induces the apoptosis and blocks the cell cycle at G0/G1 phase. Interestingly, EEP decreased the accumulation of AR suggesting some anti-androgen activity. Indeed, secreted amount of the androgen target protein PSA was decreased when LNCaP cells were incubated with EEP, starting after 4 h of treatment. This anti-androgen activity was also shown on the androgen target genes Fkbp5 and Sgk1. Finally, the capacity of EEP to block AR functioning was demonstrated in transient transfections with human AR and the reporter gene ARE-tk-Luc. Propolis antagonizes the induction of the luciferase activity induced by the natural androgen DHT (10-8M) or the synthetic AR agonist R1881 (10-7M). Altogether, these results highlight the potential pharmacological effects of EEP in future treatments of prostate cancer.

Reversing Multidrug Resistance in Chemo-resistant Human Lung Adenocarcinoma (A549/DOX) Cells by Algerian Propolis Through Direct Inhibiting the P-gp Efflux-pump, G0/G1 Cell Cycle Arrest and Apoptosis Induction.

BACKGROUND: Lung cancer is one of the most common malignancies with the highest incidence and mortality rate worldwide. Multidrug Resistance (MDR) continues to pose a major challenge for the clinicians and pharmacologists to effectively treat this disease. A new approach using natural substances with moderate or low cytotoxic properties become a promising hope for reversing multidrug resistance due to pgp- overexpression. OBJECTIVE: This study aims to explore the efficacy of Algerian propolis in reversing multidrug resistance and sensitizing chemo-resistant lung cancer cells (A549/DOX) to chemotherapy with DOX. METHODS: Resistant lung adenocarcinoma A549/DOX cell line was developed and used as in vitro model for MDR. Cell viability, Annexin V-PI apoptosis assay and cell cycle progression were tested to evaluate the reversal effect of propolis alone or in combination with DOX. Caspases 3, 8 and 9 assays were conducted to determine the type of apoptotic pathway. To investigate the mechanisms of MDR reversal agents, intracellular accumulation of DOX and P-gp-pump activity were investigated. RESULTS: Our results showed that the obtained chemo-resistant cells were 13-fold more resistant to DOX than the parental A549 cells. Propolis showed dramatically cell growth inhibition on A549/DOX cells (The IC50 was 50.44± 0.07µg/ml). The killing effect of propolis was due to G0/G1 cell cycle arrest and apoptosis induction. After 24hours treatment, propolis at 100 µg/ml caused cells accumulation in G0/G1 phase and increased with 50, 65-fold the percentage of apoptotic population sub-G. Annexin V-PI assay showed that propolis induces apoptosis with 53.57-fold at 100 µg/ml. It induced intrinsic apoptotic pathway by increasing caspase-3 (22.15-fold) and caspase-9 (16.73-fold) activities. The direct approach to investigate the mechanisms of reversal agents is to detect the accumulation of P-gp substrates in resistant cells. Our results indicated that resistant cells poorly accumulated Doxorubicin and rhodamine 123 (7-fold lower) when compared to parental A549 cells, suggesting that chemo-resistant cells overexpress P-gp which pump DOX out of cells. Propolis inhibited in a concentration-dependent manner, the pgp efflux-pump, enhancing thereby the intracellular level of DOX with 5.48- fold against 3.33 fold obtained with verapamil, the conventional P-gp inhibitor. CONCLUSION: Taken together, Algerian propolis reverses multidrug resistance in resistant human lung adenocarcinoma cells through direct inhibiting the transport function of pgp-pump resulting in enhancing intracellular DOX-accumulation, G0/G1 cell cycle arrest and apoptosis induction. Thus, propolis could be developed as a chemotherapeutic agent for reversing multidrug resistance.

Chemical composition, antioxidant, anticholinesterase, antimicrobial and antibiofilm activities of essential oil and methanolic extract of Anthemis stiparum subsp. sabulicola (Pomel) Oberpr.

Anthemis species are traditionally used to treat infectious and inflammatory processes, among others clinical disturbances. In the current study, the chemical composition, the total phenolic and flavonoid contents, the antioxidant, anticholinesterase, antimicrobial, and antibiofilm activities of Anthemis stiparum subsp. sabulicola aerial parts methanolic extract (As-ME) and essential oil (As-EO) were investigated. The chemical composition of As-EO was established by GC-MS and GC-FID. Total phenolic and flavonoid contents of As-ME were spectrophotometrically determined. Diphenyl-1-picrylhydrazyl (DPPH●) radical scavenging, cupric reducing antioxidant capacity (CUPRAC) and ß-carotene bleaching assays were applied to evaluate the antioxidant potential. The anticholinesterase activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes were carried out spectrophotometrically. The antimicrobial activity was assessed by Minimal Inhibitory Concentration (MIC) using broth microdilution method against 7 ATCC® bacterial and one ATCC® yeast reference strains. The antibiofilm effect was determined quantifying the percentage of adhesion inhibition. GC-MS and GC-FID identified 72 compounds (99.02%), being As-EO predominantly constituted by germacrene D (11.13%), t-cadinol (11.01%), camphor (6.73%), spathulenol (6.50%) and isoamyl salicylate (6.45%). The total phenolic and flavonoid contents of As-ME were 13.6 ±â€¯0.03 and 5.9 ±â€¯0.04 pyrocatechol equivalents and quercetin equivalents, respectively. In ß-carotene-linoleic acid assay, As-ME showed the best lipid peroxidation inhibition activity with an IC50 = 9.96 µg/mL followed by As-EO with an IC50 = 619.98 µg/mL. In contrast, in DPPH assay, As-ME and As-EO showed moderate to low activity with an IC50 = 92.69 µg/mL for As-ME and 917.69 µg/mL for As-EO. While in CUPRAC assay, As-EO and As-ME indicated a less to moderate reducing activity. As-ME inhibited AChE (IC50 = 490.46 µg/mL) and BChE (IC50 = 142.07 µg/mL), while As-EO was inactive against AChE and revealed a discreet inhibitory action against BChE (IC50 = 212.14 µg/mL). As-ME displayed better antimicrobial activity than As-EO, being active against Staphylococcus aureus (ATCC® 25923) and Bacillus subtilis (ATCC® 6633), with MIC of 1.56 mg/mL. An expressive fungal adhesion inhibition (80.02%) on Candida albicans (ATCC® 10239) was detected with As-ME at 6.25 mg/mL. These results showed that A. stiparum subsp. sabulicola is a natural source of active compounds with antibiotic and antibiofilm effects against S. aureus and B. subtilis, and C. albicans, respectively, and also presents antioxidant and anticholinesterase properties.

Antiproliferative and Antioxidant Activities of Two Extracts of the Plant Species Euphorbia dendroides L.

Background: These days, the desire for naturally occurring antioxidants has significantly increased, especially for use in foodstuffs, cosmetics, and pharmaceutical products, to replace synthetic antioxidants that are regularly constrained due to their carcinogenicity. Methods: The study in hand aimed to appraise the antioxidant effect of two Euphorbia dendroides extracts using reducing power, anti-peroxidation, and DPPH (1,1 Diphenyl 2 Pycril Hydrazil) scavenging essays, in addition to the anticancer activity against two tumor cell lines, namely C6 (rat brain tumor)cells, and Hela (human uterus carcinoma)cell lines. Results: The results indicated that the ethyl acetate extract exhibited antiradical activity of 29.49%, higher than that of n-butanol extract (18.06%) at 100 µg/mL but much lower than that of gallic acid (78.21%).The ethyl acetate extract exhibits better reducing capacity and lipid peroxidation inhibitory activity compared to n-butanol extract but less than all tested standards. Moreover, the ethyl acetate extract was found to have an antiproliferative activity of more than 5-FU (5-fluoro-Uracil) against C6 cells at 250 µg/mL with IC50 and IC75 of 113.97, 119.49 µg/mL, respectively, and good cytotoxic activity against the Hela cell lines at the same concentration. The HPLC-TOF-MS (high performance liquid chromatography-Time-of-flight-Mass Spectrometry) analyses exposed the presence of various compounds, among which Gallic and Chlorogenic acids functioned as major compounds. Conclusions: The two extracts exhibited moderate anticancer abilities and behaved somewhat as average antioxidant agents. Based on the total phenolics and flavonoids contents, as well as HPLC results, it could be concluded that antiproliferative and antioxidant activities depend upon the content of different phenolics and flavonoids.

Algerian Propolis Potentiates Doxorubicin Mediated Anticancer Effect Against Human Pancreatic PANC-1 Cancer Cell Line through Cell Cycle Arrest, Apoptosis Induction and P-Glycoprotein Inhibition.

BACKGROUND: Pancreatic cancer is one of the most aggressive and lethal cancers, with poor prognosis and high resistance to current chemotherapeutic agents. Therefore, new therapeutic strategies and targets are underscored. Propolis has been reported to exhibit a broad spectrum of biological activities including anticancer activity. OBJECTIVE: This study was carried out to assess the possible efficacy of Algerian propolis on the antitumor effect of doxorubicin on human pancreatic cancer cell line (PANC-1). METHODS: Modifications in cell viability, apoptosis and cell cycle progression, Pgp activity and intracellular accumulation of DOX were monitored to study the synergistic effect of Algerian propolis on the antitumor effects of DOX in PANC-1 cell line. RESULTS: Both propolis and its combination with doxorubicin inhibited cell growth in a dose-dependent manner by inducing cell cycle arrest and apoptosis. In the presence of 100 µg/ml of propolis, the IC50 of DOX against PANC-1 cells decreased by 10.9-fold. Propolis combined with DOX increased after 48h, the number of cells in the G0G1 phase with dramatical increase in sub-G1 phase to reach 47% of total cells, corresponding to an increase of senescence or apoptotic state of the cells. Dead cell assay with annexinV/PI staining demonstrated that propolis and propolis-DOX treatment resulted in a remarkable induction of apoptosis as detected by flow cytometry. It was interesting to note that propolis at its 5IC50 was found as the most potent inducer of apoptosis. Our finding revealed that induced apoptosis in our conditions was caspase-3 and caspase-9 dependent. Flow cytometry showed that propolis increased the accumulation of doxorubicin within PANC-1 cells. Moreover, fluorescent intensity detection revealed that propolis remarkably increased the retention of rhodamine-123, 7- fold compared to 3-fold of verapamil, the most effective P-gp inhibitor. CONCLUSION: In conclusion, propolis sensitize pancreatic cancer cells to DOX via enhancing the intracellular retention of DOX due to blocking the efflux activity of P-gp pump, inducing cell cycle arrest and increasing apoptosis, finding that improuve the synergism of antitumor effect of Algerian propolis and DOX in pancreatic cancer cell line. Therefore, Algerian propolis may be an effective agent in a combined treatment with doxorubicin for increased therapeutic efficacy against pancreatic cancer.

Dual effect of Algerian propolis on lung cancer: antitumor and chemopreventive effects involving antioxidant activity

Abstract The purpose of our study was to divulge the antiproliferative effect of an ethanolic extract of Algerian propolis (EEP) in the human lung adenocarcinoma cell line (A549) and reveal the chemopreventive role against benzo(a)pyrene-induced lung carcinogenesis in albino Wistar rats. Cytotoxicity of EEP was evaluated using the MTT assay and cell adhesion in A549 cells. Moreover, rats were given 25 mg/kg of propolis for 5 days before induction of experimental lung cancer by a single intraperitoneal dose of 200 mg/kg benzo(a)pyrene. Body weight, lung weight, lipid peroxidation, marker enzymes, and enzymatic and non-enzymatic antioxidants were estimated. The EEP demonstrated an inhibitory effect on proliferation of A549 at 24 and 72 hours in a dose-dependent manner and blocked adhesion of the cells by fibrinogen. Moreover, EEP reduced the oxidative stress generated by benzo(a)pyrene. The pre-treatment showed that enzymatic and non-enzymatic antioxidants increased and lipid peroxidation decreased. A histological analysis further supported these findings and showed a decrease in the number of side effects. These results are particularly important for both clinical applications of propolis and the possibility for its use as a potential chemotherapeutic agent.

Biological properties of propolis extracts: Something new from an ancient product.

Natural products are an interesting source of new therapeutics, especially for cancer therapy as 70% of them have botany origin. Propolis, a resinous mixture that honey bees collect and transform from tree buds, sap flows, or other botanical sources, has been used by ethnobotany and traditional practitioners as early in Egypt as 3000 BCE. Enriched in flavonoids, phenol acids and terpene derivatives, propolis has been widely used for its antibacterial, antifungal and anti-inflammatory properties. Even though it is a challenge to standardize propolis composition, chemical analyses have pointed out interesting molecules that also present anti-oxidant and anti-proliferative properties that are of interest in the field of anti-cancer therapy. This review describes the various geographical origins and compositions of propolis, and analyzes how the main compounds of propolis could modulate cell signaling. A focus is made on the putative use of propolis in prostate cancer.

Ferulenol, a Sesquiterpene Coumarin, Induce Apoptosis via Mitochondrial Dysregulation in Lung Cancer Induced by Benzo[a]pyrene: Involvement of Bcl2 Protein.

BACKGROUND: Ferulenol, a sesquiterpene coumarin, was extracted from "Ferula vesceritensis" and possesses pro-oxidative and anticancer effects in different types of cancer. OBJECTIVE: The objective of this study is to determine whether ferulenol has an anticancer effect by regulation the Bcl2 protein expression in lung cancer induced by benzo[a]pyrene in Wistar rats. METHODS: Rats in group 1 have received, intraperitoneally, olive oil and considered as controls, animals of group 2 were treated with 100 mg/kg of benzo[a]pyrene intraperitoneally in order to induce lung cancer for 24 weeks, the 3rd groups of rats received the ferulenol 50 mg/kg intraperitoneally after 24 weeks of administration of benzo[a]pyrene and the last group, the rats were treated with ferulenol alone 50 mg/kg. RESULTS: Treatment with ferulenol significantly increased the rate of lipid peroxidation and decrease enzymatic (CAT and GST) and non-enzymatic (GSH) anti-oxidants in benzo[a]pyrene induced lung cancer. Anticancer efficacy of ferulenol was evaluated by down-regulation of Bcl2 protein and up-regulation of Bax protein, Therefore, ferulenol can alter the functionality of lung mitochondria by increasing the production of superoxide anion and mitochondrial swelling. CONCLUSION: Together, our results depict that ferulenol can be used as pro-oxidant and chemotherapeutic agent against lung cancer.

Remote loading of doxorubicin into liposomes by transmembrane pH gradient to reduce toxicity toward H9c2 cells.

The use of doxorubicin (DOX) is limited by its dose-dependent cardiotoxicity. Entrapped DOX in liposome has been shown to reduce cardiotoxicity. Results showed that about 92% of the total drug was encapsulated in liposome. The release experiments showed a weak DOX leakage in both culture medium and in PBS, more than 98% and 90% of the encapsulated DOX respectively was still retained in liposomes after 24 h of incubation. When the release experiments were carried out in phosphate buffer pH5.3, the leakage of DOX from liposomes reached 37% after 24 h of incubation. Evaluation of cellular uptake of the liposomal DOX indicated the possible endocytosis of liposomes because the majority of visible fluorescence of DOX was mainly in the cytoplasm, whereas the nuclear compartment showed a weak intensity. When using unloaded fluorescent-liposomes, the fluorescence was absent in nuclei suggests that liposomes cannot cross the nuclear membrane. MTT assay and measurement of LDH release suggest that necrosis is the form of cellular death predominates in H9c2 cells exposed to high doses of DOX, while for weak doses apoptosis could be the predominate form. Entrapped DOX reduced significantly DOX toxicity after 3 and 6 h of incubation, but after 20 h entrapped DOX is more toxic than free one.

Ethanolic Extract of Algerian Propolis and Galangin Decreased Murine Melanoma Tumor Progression in Mice

Melanoma is the more dangerous skin cancer, and metastatic melanoma still carries poor prognosis. Despite recent therapeutic advances, prolonged survival remains rare and research is still required. Propolis extracts from many countries have attracted a great deal of attention for their biological properties. We here investigated the ability of an ethanolic extract of Algerian propolis (EEP) to control melanoma tumour growth when given to mice bearing B16F1melanoma tumour either as preventive or as therapeutic treatment. EEP given after tumour occurrence increased mice survival (+30%) and reduced tumour growth (-75%). This was associated with a decrease of the Mitotic Index (-75%) and of Ki-67 (-50%) expression. When given either before or both before and after tumour occurrence, EEP reduced tumour growth but without prolonging mice life. Isolation of B16F1 melanoma cells from resected tumour showed that preventive and curative EEP treatments reduced invasiveness by 55% and 40% respectively compared to control. Galangin, one of the most abundant flavonoids in propolis, significantly reduced the number of melanoma cells in vitro and induced autophagy/apoptosis dose dependently. In conclusion, we showed that EEP reduced melanoma tumour progression/dissemination and could extend mice lifespan when used as therapeutic treatment. Then, EEP may help patients with melanoma when used as a complementary therapy to classical treatment for which autophagy is not contraindicated.

Protective effects of probiotic Lactobacillus plantarum BJ0021 on liver and kidney oxidative stress and apoptosis induced by endosulfan in pregnant rats.

Endosulfan (EDS) is one of the most widely organochlorine insecticide used in many parts of the world, although it is currently banned or severely restricted in use in some countries. EDS causes a variety of negative effects in non-target species including humans. Therefore, the aim of the present study was to investigate the possible protective effects of Lactobacillus plantarum BJ0021 on toxicity, oxidative stress, and apoptosis induced by EDS intoxication on liver and kidneys of pregnant rats. This pesticide induced a significant increase in total cholesterol, alanine-amino transferase (ALAT), aspartate-amino transferase (ASAT), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), urea and creatinine in serum, while urinary urea and creatinine were lower than those of the control group. In the liver and kidney, lipid peroxidation increased significantly, the antioxidant levels, such as superoxide dismutase (SOD) and catalase (CAT) were markedly depressed and TdT-mediated dUTP-biotin Nick End Labeling (TUNEL) revealed more apoptotic cells. In contrast, co-administration of L. plantarum BJ0021 to EDS-treated animals ameliorated most of these biochemical parameters, but the activity of antioxidant enzymes (SOD, CAT) did not modify and the number of apoptotic nuclei remained significantly raised in kidney compared to control. In conclusion, the administration of L. plantarum BJ0021 decreased apoptosis and might play a protective role in reducing toxicity of EDS in pregnant rats.

Protective effects of probiotic Lactobacillus plantarum BJ0021 on liver and kidney oxidative stress and apoptosis induced by endosulfan in pregnant rats.

Endosulfan (EDS) is one of the most widely organochlorine insecticide used in many parts of the world, although it is currently banned or severely restricted in use in some countries. EDS causes a variety of negative effects in non-target species including humans. Therefore, the aim of the present study was to investigate the possible protective effects of Lactobacillus plantarum BJ0021 on toxicity, oxidative stress, and apoptosis induced by EDS intoxication on liver and kidneys of pregnant rats. This pesticide induced a significant increase in total cholesterol, alanine-amino transferase (ALAT), aspartate-amino transferase (ASAT), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), urea and creatinine in serum, while urinary urea and creatinine were lower than those of the control group. In the liver and kidney, lipid peroxidation increased significantly, the antioxidant levels, such as superoxide dismutase (SOD) and catalase (CAT) were markedly depressed and TdT-mediated dUTP-biotin Nick End Labeling (TUNEL) revealed more apoptotic cells. In contrast, co-administration of L. plantarum BJ0021 to EDS-treated animals ameliorated most of these biochemical parameters, but the activity of antioxidant enzymes (SOD, CAT) did not modify and the number of apoptotic nuclei remained significantly raised in kidney compared to control. In conclusion, the administration of L. plantarum BJ0021 decreased apoptosis and might play a protective role in reducing toxicity of EDS in pregnant rats.

Inhibition of stromelysin-1 by caffeic acid derivatives from a propolis sample from Algeria.

Stromelysin-1 (matrix metalloproteinase-3: MMP-3) occupies a central position in collagenolytic and elastolytic cascades, leading to cutaneous intrinsic and extrinsic aging. We screened extracts of a propolis sample from Algeria with the aim to isolate compounds able to selectively inhibit this enzyme. A butanolic extract (B (3)) of the investigated propolis sample was found to potently inhibit MMP-3 activity (IC (50) = 0.15 ± 0.03 µg/mL), with no or only weak activity on other MMPs. This fraction also inhibited plasmin amidolytic activity (IC (50) = 0.05 µg/mL) and impeded plasmin-mediated proMMP-3 activation. B (3) was fractionated by HPLC, and one compound, characterized by NMR and mass spectroscopy and not previously identified in propolis, i.e., (+)-chicoric acid, displayed potent IN VITRO MMP-3 inhibitory activity (IC (50) = 6.3 × 10 (-7) M). In addition, both caffeic acid and (+)-chicoric acid methyl ester present in fraction B (3) significantly inhibited UVA-mediated MMP-3 upregulation by fibroblasts.

Efficiency of propolis extract against mitochondrial stress induced by antineoplasic agents (doxorubicin and vinblastin) in rats.

To assess the oxidative stress and mitochondrial dysfunction associated with disease, toxic process and aging, in vivo and in vitro preventive effect of propolis extract against mitochondrial oxidative stress induced by two anticancer drugs (doxorubicin and vinblastin) have been investigated in female wistar rat using liver and heart mitochondria. The results show that doxorubicin and vinblastin altered mitochondrial functions as observed by a decrease in respiratory control value, an activation of swelling and overproduction of superoxide anion. Myocardial tissue from doxorubicin treated rats showed a marked increase in malondialdehyde production, a depletion of reduced glutathione contents and an inhibition of catalase and superoxide dismutase activities. Similar results were also observed in liver tissue. Pretreatment of rats with propolis extract (100 mg/kg/day po) (10(-4) M ip) administered 4 days prior to doxorubicin (20 mg/kg) and/or vinblastin (2 mg/kg) injection, substantially reduced the peroxidative damage in myocardium and hepatic tissues and markedly restored the tissues catalase and SOD activities. The results strongly suggest that propolis extract protects heart and liver tissues from oxidative stress by protecting the mitochondria.

Ferulenol specifically inhibits succinate ubiquinone reductase at the level of the ubiquinone cycle.

The natural compound ferulenol, a sesquiterpene prenylated coumarin derivative, was purified from Ferula vesceritensis and its mitochondrial effects were studied. Ferulenol caused inhibition of oxidative phoshorylation. At low concentrations, ferulenol inhibited ATP synthesis by inhibition of the adenine nucleotide translocase without limitation of mitochondrial respiration. At higher concentrations, ferulenol inhibited oxygen consumption. Ferulenol caused specific inhibition of succinate ubiquinone reductase without altering succinate dehydrogenase activity of the complex II. This inhibition results from a limitation of electron transfers initiated by the reduction of ubiquinone to ubiquinol in the ubiquinone cycle. This original mechanism of action makes ferulenol a useful tool to study the physiological role and the mechanism of electron transfer in the complex II. In addition, these data provide an additional mechanism by which ferulenol may alter cell function and demonstrate that mitochondrial dysfunction is an important determinant in Ferula plant toxicity.

The interaction of new plant flavonoids with rat liver mitochondria: relation between the anti- and pro-oxydant effect and flavonoids concentration.

Flavonoids are polyphenols derivatives of plant origin that possesses a broad range of pharmacological properties, including protection of cells and tissues against the deleterious effects of reactive oxygen species. Their antioxidant activity results from scavenging of free radicals and other oxidizing intermediates, from the chelation of iron or copper ions and from inhibition of oxidases. But a number of studies have found both anti and prooxidant effects for many of these compounds. These reasons prompted us to investigate whether flavonoids compounds alone or combined flavonoids had antioxidant, free radical scavenger and antiapoptotic properties. The investigation was carried in vitro using rat hepatic mitochondria. Respiratory control ratio (RCR), oxygen consumption, adenosine tri phosphate (ATP) synthesis, scavenging action, enzymatic activities of involved complexes, superoxide anion and the release of cytochrome C were measured to assess the mechanisms of action of these drugs. Our data showed that the decrease of RCR induced by high concentrations (0.1 mM and 0.01 mM) of all flavonoids tested was due to a common inhibition of oxidative phosphorylation (State 4) and activation of state 3. At the opposite mitochondrial swelling was slightly induced only by low concentrations (10(-8) and 10(-9) M) of the flavonoids. They had no effects on the mitochondrial complexes (I to V) activity. Furthermore the mitochondrial membrane potential was not affected by any flavonoids. The effect of flavonoids on superoxide anion generation was variable. All the flavonoids studied acted between 10(-4) M and 10(-6) M with no effects at lower concentrations. These effects were similar on lipid peroxidation (malondialdehyde [MDA] levels). We remarked a concentration-dependent in the effect of flavonoids since they acted as antioxidant and also as uncoupler at high concentrations, which is a risk for the cells. We conclude that flavonoids extracted from algerian plants have some protecting effects against oxidative stress by protecting the mitochondria.