Mesbah Lahouel

Polyphenolic fraction of Algerian propolis protects rat kidney against acute oxidative stress induced by doxorubicin

We evaluated the effects of propolis extract on renal oxidative stress induced by doxorubicin throughout an analytical and pharmacological study of the eastern Algerian propolis using thin layer chromatography, ultra-violet-high-performance liquid chromatography) and gas chromatography-mass spectrometry. The pharmacological study was carried out in vivo on Wistar rat pre-treated with propolis extract 100 mg/kg/day for seven days. Doxorubicin at 10 mg/kg of body weight was administered intravenously on Day 7. Serum creatinine concentration, scavenging effect of flavonoids, lipid peroxidation and glutathione concentration were measured. Chemical analysis allowed identification and quantification of the phenolic compounds including pinostrombin chalcone (38.91%), galangin (18.95%), naringenin (14.27%), tectochrysin (25.09%), methoxychrysin (1.14%) and a prenylated coumarin compound suberosin (1.65%). The total flavonoid concentration in the propolis extract was 370 mg (quercetin equivalents QE) /g dry weight (QE/g DWPE). Propolis extract restored the renal functions and reduced the toxic effect of doxorubicin. These data show a protective effect of Algerian propolis extract against doxorubicin-induced oxidative stress.

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.

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.

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.

Oxidative stress in benign prostate hyperplasia

To assess the status of oxidative stress in benign prostate hyperplasia, a very common disease in older men which constitutes a public health problem in Jijel, prostate tissues were obtained by transvesical adenomectomy from 10 men with benign prostate hyperplasia. We measured the cytosolic levels of malondialdehyde (MDA) and glutathione (GSH) and cytosolic enzyme activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione S‐transferase. The development of benign prostate hyperplasia is accompanied by impaired oxidative status by increasing levels of MDA, depletion of GSH concentrations and a decrease in the activity of all the antioxidant enzymes studied. These results have allowed us to understand a part of the aetiology of benign prostate hyperplasia related to oxidative stress.

Ethanolic Extract of Algerian Propolis and Galangin Decreased Murine Melanoma T.

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.

Abstract 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.

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 β-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 ± 0.03 and 5.9 ± 0.04 pyrocatechol equivalents and quercetin equivalents, respectively. In β-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.

Toxicity assessment of Diclofenac and its biodegradation metabolites toward mice

Biodegradation of the anti-inflammatory drug Diclofenac (DCF) was studied using Enterobacter cloacae (D16) isolated from household compost. This isolate was able to eliminate 67.57% of DCF as sole carbon source after 48 h of incubation. Parallel to its disappearance, five metabolites were observed in microbial active samples which were suspected to be the DCF metabolites. GCMS showed a very similar spectrum of these metabolites with the MS spectrum of the parent compound. DCF Toxicity at different concentrations (toxic dose, therapeutic dose, and low dose) and its metabolites toxicity toward mice liver cells were evaluated. At toxic and therapeutic doses DCF had a negative effect on the oxidative stress parameters represented by a decrease in Reduced Glutathione reserve, lipid peroxidation and a disturbance of the liver detoxification enzymes (superoxide dismutase, Catalase, and glutathione S-transferase). In contrast, no effect was observed after treatment of animals with low dose and DCF biotransformation products.

Propolis Extract: A Potent Bacteria Efflux Pump Inhibitor

Abstract The research and development of specific, potent efflux pump inhibitors (EPIs) appears to be an important goal for the improved control of infectious diseases. In recent years, different classes of EPIs have been described and tested however, several of them causes side effects. Therefore, there is an increased need to search for new inhibitors. There have been no natural EPIs identified so far, so the natural bee product, propolis, that has attracted much attention in recent years for their biological and antimicrobial activities seems to be efficient for this purpose. The agar microdilution method, minimum inhibitory concentration (MIC) was implemented to evaluate the antibacterial activity of ethanolic extract of propolis (EEP) against various reference strains and against bacteria with efflux pumps and resistant microbes at concentrations ranged between 0.06 mg/ml to 8 mg/ml. Strong antibacterial activity was detected against Gram positive bacteria and Gram negative with an average MIC of 0.25 mg/ml. The combination of EEP with standard inhibitors of pumps efflux (EPIs) was more efficient against Escherichia coli and other strains with efflux pump. The present findings revealed that propolis extract inhibit the efflux pumps and so must be a promising source of new antimicrobial agents.