Wound healing potential of a formula based on Populus nigra L. flower buds extract with anti-inflammatory activity.

ETHNOPHARMACOLOGICAL RELEVANCE: Wound healing is a complex and dysnamic process supported by a myriad of cellular events that are tightly coordinated to repair efficiently damaged tissue. Populus nigra L. (Salicaceae) flower buds are traditionally used in the treatment of dermatitis, upper respiratory tract infections, rheumatism and wounds. AIM OF THE STUDY: The aim of this study was to assess the wound healing potential of black poplar ointment containing 10 or 20 % of Populus nigra ethanolic flower buds extract using the excision model in rats. MATERIALS AND METHODS: Two ointments (10 and 20 %) were prepared from Populus nigra flower buds ethanolic extract and topically applied on the area of excised skin of the rats for either 14 or 20 days. Morphological, macroscopic, histological and biochemical parameters were evaluated. RESULTS: The results showed that the extract contained high amounts of total phenols (89.5 ± 7.7 mg caffeic acid equivalent/g of extract) and hydrolysable tannins (142.05 ± 2.55 mg tannic acid equivalent/g of extract), in correlation with strong DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and beta-carotene bleaching with values of 96.31 ± 3.42 and 85.27 ± 1.79 %, respectively. Anti-inflammatory potential was illustrated by lipoxygenase and cyclooxygenase inhibition (52.80 ± 0.2 and 53.88 ± 2.55 %, respectively). Treatment with Populus nigra ointment (10 and 20 %) promoted wound contraction of 97.37 ± 1.19 and 97.28 ± 0.91 %, respectively. The antioxidant marker enzymes, catalase (0.10 ± 0.001; 0.08 ± 0.003 U/mg protein) and superoxide dismutase (363.34 ± 24.37; 317.82 ± 53.83 U/mg protein) activities in the granulation tissues were upgraded with respective treatments of 10 or 20 % ointment. Concurrently, the myeloperoxidase activity (2.21 ± 1.01; 2.13 ± 0.75 U/mg protein) was repressed, indicating anti-inflammatory potential, when compared to untreated, standard and excipient groups. Moreover, a significant increase in respective levels of hydroxyproline (p < 0.001) (28.05 ± 1.20; 25.29 ± 1.17 µg/mg tissue) and hexosamine (p < 0.05) (20.18 ± 1.21; 18.95 ± 1.98 µg/mg tissue) was triggered, reflecting a high regeneration of collagen in the scarred tissue. Histological examination of treated skin tissue revealed higher rates of re-epithelialization, lower neutrophils infiltration and re-vascularization in comparison to the control group. CONCLUSION: Given that the 10 % ointment was the optimal concentration, our findings offer an efficient drug formula for wound healing.

Pistacia lentiscus L. fruits showed promising antimutagenic and antigenotoxic activity using both in-vitro and in-vivo test systems.

Pistacia lentiscus L. is one of the most popular medicinal plants attributed to its beneficial properties on human health. However, few toxicogenetic studies have been carried out. Therefore, the aim of this study was to examine the potential genotoxic/antigenotoxic and mutagenic/antimutagenic properties of oil, ethyl acetate and ethanolic extracts of P. lentiscus L. fruits using in vitro the Ames and Umu assays, as well as in vivo micronucleus (MN) test. Extracts did not exert any significant mutagenic/genotoxic effects but provided protection against standard mutagenic and genotoxic agents including 2 nitrofluorene (2-NF) at 2.5 and 5 µg/ml; sodium azide at 5 and 10 µg/ml; 3-methylcholanthrene (3-MC) at 25 and 50 µg/ml; cyclophosphamide (CP) at 50 and 100 µg/ml; 4-nitroquinoline 1-oxide (4-NQO) at 0.05 µg/ml and 2-amino-anthracene (AA) at 0.2 µg/ml. Further, cytotoxicity and selectivity were examined on human hepatocarcinoma (HepG2), and MCF-7 breast cancer cell lines as well as a human normal-like fibroblast cell line (TelCOFS02MA) using MTT assay. Among all extracts, PF1 (ethanolic) showed the most significant selectivity index (SI) (HepG2:11.98; MCF7:4.83), which led to further investigations using an animal model. Oral administration of PF1 (125-1000 mg/kg b.w.) significantly decreased the number of micronucleated cells in CP -initiated (50 mg/kg b.w.) mice, while the number of micronucleated reticulocytes (MNRET), micronucleated polychromatic erythrocytes (MNPCE) or mitotic index (MI) were not markedly affected. Further, PF1 significantly enhanced catalase (CAT) and superoxide dismutase (SOD) activities in the livers and kidneys of these animals. The obtained results indicated the beneficial properties of P. lentiscus L. fruits for use in therapy against harmful effects of genotoxic and mutagenic agents. However, while promising it should be noted that the obtained results are preliminary and need to be confirmed prior to therapeutic use.

Antimutagenic, antigenotoxic and antiproliferative activities of Fraxinus angustifolia Vahl. leaves and stem bark extracts and their phytochemical composition.

In recent years, chronic degenerative diseases such as certain types of cancers, are becoming an evident issue. DNA damage has been for long recognized as a causal factor for cancer development because mutations or chromosomal aberrations affect oncogenes and tumor suppressor genes leading cells to malignant transformation and to the subsequent cancerous growth. Medicinal plants are often used for the prevention or treatment of various diseases with great scientific interest. Among the medicinal plants distributed in the Mediterranean region, Fraxinus angustifolia Vahl. has been used in traditional medicine for its remarkable curative properties. However, in spite of this popularity, little works have been performed on the activity so that further studies should be performed to investigate in depth the antimutagenic, antigenotoxic and antiproliferative activities of the plant. Thus, the present study was aimed to the evaluation of the potential antimutagenic, antigenotoxic and antiproliferative properties of leaves and stem bark extracts of this well-known tree. Antimutagenic activity was evaluated by Salmonella mutagenicity assay in Salmonella typhimurium TA98 and TA100 strains. The antigenotoxic potential was assessed by umu test in the strain of S. typhimurium TA1535/pSK1002. Antiproliferative activity was studied on human hepatoblastoma (HepG-2) and on breast adenocarcinoma (MCF-7) cell lines by MTT assay. Furthermore, the antiproliferative activity observed on cancer cells was compared with that on the human normal-like fibroblasts (TelCOFS02MA) and the selectivity index was calculated to understand if extracts were able to exert selective toxicity towards cancer cells. Moreover, phenolic compounds are plant substances with a large spectrum of biochemical activities with antioxidant, antimutagenic and anticarcinogenic effects. Based on the strong evidence of biological activities of phenolic compounds, the study was focused on the determination of total phenolics and flavonoids contents, and the phytochemical composition of the extracts assessed by LC/MS. The ethanol extracts of both leaves and stem barks showed significant from moderate to strong antimutagenic and antigenotoxic effects. In addition, selective cytotoxicity towards cancer cells was shown by ethanolic leaves extract and aqueous/chloroform leaves and stem bark extracts. The latter showed high levels of total phenolic contents among all the other extracts. Identified phenylethanoids (calceolariosides, verbascoside) and secoiridoids (oleuropein and ligstroside) could be responsible for the demonstrated broad spectrum of healthy properties.

Identification of bioactive compounds from Fraxinus angustifolia extracts with anti- NADH oxidase activity of bovine milk xanthine oxidoreductase.

Fraxinus angustifolia leaves and bark are used in traditional medicine against various inflammatory-related pathologies incumbent to reactive oxygen species (ROS) generation by the NADH oxidase activity of enzymes such as xanthine oxidoreductase (XOR). This study was designed to investigate the in vitro and in vivo inhibitory activities of this enzyme by Fraxinus angustifolia extracts. The leaf organic phase of ethyl acetate (LFA) and its bark aqueous counterpart (BFA) showed the strongest anti-NADH oxidase activity in vitro (IC50 = 38.51 and 42.04 µg mL-1, respectively). They consequently suppressed superoxide generation both enzymatically (53% and 19%, respectively) and nonenzymatically (34% and 19%, respectively). These results were corroborated in vivo, with high antiNADH oxidase potential of the leaves and bark extracts (75.32% and 51.32%, respectively) concomitant with moderate hypouricemic activities (36.84% and 38.59%, respectively). Bio-guided fractionation led to the identification, by LC-DAD-MS/MS, of esculin and calcelarioside in bark and kaempferol glucoside in leaves as the main compounds responsible for the anti-NADH oxidase activity of XOR. These results plead in favor of the use of F. angustifolia as a source of potentially interesting therapeutic substances.

Kinetic study on the inhibition of xanthine oxidase by extracts from two selected Algerian plants traditionally used for the treatment of inflammatory diseases.

In order to further understand and assess the validity of herbal medicine, we investigated the potential inhibitory effect of various extracts from Fraxinus angustifolia and Pistacia lentiscus, two plants used traditionally in Algeria against several inflammatory diseases such as rheumatism, arthritis, and gout, on purified bovine milk xanthine oxidase (XO) activity. The total phenolic contents of the leaves and bark of F. angustifolia and the leaves and seeds of P. lentiscus were estimated. P. lentiscus aqueous fractions from hexane and chloroform extractions and F. angustifolia aqueous fraction from ethyl acetate extraction inhibited XO activity by 72.74 +/- 2.63% (50% inhibitory concentration [IC(50)] = 27.52 microg/mL), 68.97 +/- 3.89% (IC(50) = 42.46 microg/mL) and 53.92 +/- 3.17% (IC(50) = 58.84 mmicroug/mL), respectively, at 100 microg/mL, compared to that of reference drug, allopurinol (98.18% [IC(50) = 6.34 microg/mL]). Moreover, at a concentration of 50 microg/mL, both P. lentiscus extracts showed inhibition rates higher than 50%. F. angustifolia leaf extracts showed only mild inhibition. Lineweaver-Burk analysis showed that the inhibitory activity exerted by F. angustifolia bark aqueous extract and P. lentiscus aqueous extracts is of mixed type, whereas the leaf extracts from F. angustifolia inhibited XO noncompetitively. Positive correlations were established between XO inhibition and total phenols (r = 0.89) and flavonoids (r = 0.93) for P. lentiscus and with total phenols (r = 0.72) and tannins (r = 0.54) for F. angustifolia. Our findings suggest that the therapeutic use of these plants may be due to the observed XO inhibition, thereby supporting their use in traditional folk medicine against inflammatory-related diseases, in particular, gout.