Hepatoprotective and antidiabetic effects of Pistacia lentiscus leaf and fruit extracts

Pistacia lentiscus (Anacardiaceae) is commonly used in folk medicine to treat various diseases. The aim of the present study was to evaluate the hepatoprotective and antioxidant activities of extracts of P. lentiscus leaves (PL) and fruits (PF) against experimentally induced liver damage. Furthermore, characterization of extracts was attempted by a spectroscopic methodology (Fourier transform infrared spectroscopy) and high-performance liquid chromatography with diode array detection analysis. A hepatoprotective potential against paracetamol [165 mg/kg body weight (b.w.)] toxicity was noticed in mice pretreated with the same dose of PL or PF extract (125 mg/kg b.w.) or a combination of both (PL/PF 63/63 mg/kg b.w.), as revealed by an analysis of biochemical parameters (alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase activities and total bilirubin). These results were confirmed by histological examination of the liver, which revealed significant protection against paracetamol-induced hepatic necrosis. Furthermore, PF extract exhibited a promising antidiabetic activity in streptozotocin-induced diabetic rats, similar to the reference drug glibenclamide (0.91 g/L), a result confirmed by in vitro inhibition of α-amylase. We demonstrated that the leaf crude extract showed the best effect in all tested methods, compared to its fruit counterpart, probably due to the presence of higher amounts of phenolic compounds, as determined by phytochemical and Fourier transform infrared spectroscopy analyses. Moreover, high-performance liquid chromatography with diode array detection led to the identification of six compounds for each part of the plant. Gallic acid, a characteristic compound of Pistacia species, was most abundant in leaves and fruits, while luteolin was detected for the first time in fruits. Obtained activities of P. lentiscus extracts may well be due, at least in part, to the presence of the above compounds.

The flavonol-enriched Cistus albidus chloroform extract possesses in vivo anti-inflammatory and anti-nociceptive activity

ETHNOPHARMACOLOGICAL RELEVANCE

Cistus albidus L. (Cistaceae) has been traditionally used to treat various inflammatory diseases, but no systematic studies on the anti-inflammatory and anti-nociceptive actions of C. albidus and its putative mechanism have been reported. We aimed to explore the anti-inflammatory and anti-nociceptive effects of this plant and to characterize its polyphenolic composition by liquid chromatography coupled to mass spectrometry (MS).

MATERIALS AND METHODS

A chloroform extract derived from C. albidus leaves was obtained by solid-liquid and liquid-liquid extraction. The tail immersion test and acetic-acid-induced writhing test were used to evaluate the anti-nociceptive action, while the experimental λ-carrageenan-induced paw edema model was used to test the anti-inflammatory action. Changes in cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) expression, as well as the role of mitogen-activated protein kinases (MAPKs) and the nuclear transcription factor kappa B (NF-kB) signaling pathways on lipopolysaccharide (LPS)-stimulated murine peritoneal macrophages were analyzed by western blotting. HPLC with diode array detection coupled to tandem mass spectrometry detection with electrospray ionization (HPLC-DAD-ESI-MS/MS) was performed to determine the phytochemical profile of the extract.

RESULTS

Significant anti-nociceptive activity was observed both in the tail immersion (59.63% reduction at 120min) and in the acetic acid (65.94% inhibition) tests at 100mg/kg. The extract (50mg/kg) exhibited a substantial reduction in paw edema (51.6%) and significantly inhibited nitrite generation (72.62%) without affecting cell viability of LPS-stimulated murine peritoneal macrophages. These results were concomitant with a down-regulation of the pro-inflammatory enzymes COX-2 and iNOS in extract-treated macrophages and a decrease in p38 MAPK phosphorylation. HPLC-DAD-ESI-MS/MS analysis revealed that flavonols such as kaempferol and quercetin derivatives were potentially responsible for such effects.

CONCLUSION

These results support the widespread use of C. albidus in popular medicine and indicate that this plant has therapeutic potential with analgesic and anti-inflammatory properties based on the presence of flavonol derivatives.

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.

Neuroprotective effects of Fraxinus angustifolia Vahl. bark extract against Alzheimer's disease

Alzheimer disease's (AD) is a neurodegenerative disease induced by amyloid-β (Aβ) aggregation and accumulation of neurotoxic metals in the brain. Fraxinus angustifolia Vahl. (Oleaceae) is a Mediterranean plant traditionally used to treat several human problems as nervous system problems. This study aimed to evaluate the neuroprotective effects of F. angustifolia Vahl. bark extract (FAB) in vitro and in vivo against Aβ-aggregation and aluminium induced-neurotoxicity in mice. FAB was characterized by colorimetric methods and its individual compounds were identified and quantified by LC-MS. First, the neuroprotective effect of FAB was evaluated against Aβ_25-35-aggregation where it was directly incubated with Aβ_25-35 and the kinetic of aggregation was measured by spectrophotometer at 200 nm. Then, the extract was tested against Aβ_25-35-induced cytotoxicity on PC12 cells and the cells viability was determined by MTT test. On the other hand, FAB (0.01-0.5 mg/mL) was tested against aluminium-activated lipid peroxidation in mice synaptosomal membranes, and in vivo against aluminium-caused neurotoxicity in male N.M.R.I. (Naval Medical Research Institute) mice; this test consisted of daily co-administration of the extract with Al for 60 days. At the end of the treatment, behavioral and memory tests (locomotor activity, black and white and Morris water maze tests) and histological analysis were realized. The identification and quantification of FAB phenolics revealed the presence of different phenolic classes with high concentration of phenylethanoids and hydroxycoumarins. FAB showed a high Aβ_25-35 anti-aggregative effect and a dose dependent protective effect on PC12 cells. The extract also demonstrated a significant inhibition of lipid peroxidation and was found to prevent the Al harmful effects where it significantly increased the locomotor activity, decreased the anxiety, improved memory and reduced histological alterations. In conclusion, FAB is rich of bioactive compounds that gave it the ability to inhibit Aβ-aggregation and Al-caused neurotoxicity in mice.

A novel flavonol glycoside and six derivatives of quercetin and kaempferol from Clematis flammula with antioxidant and anticancer potentials

Clematis flammula leaves are traditionally used in Algeria to treat rheumatoid arthritis. Our aim was to identify the main compounds in this plant in order to characterize its antioxidant and anticancer activities. A new flavonol compound, kaempferol 3-O-[(6-O- caffeoyl)- glucosyl(1 → 2)]-(6-Ocaffeoyl) glucoside-7-O-rhamnoside (6) along with six known flavonol molecules were isolated from an ethanolic extract of Clematis flammula leaves. The chemical structures of these flavonols were elucidated using NMR and high resolution-MS spectroscopies. Antioxidant activities of the extract were revealed through its elimination of superoxide radical (O2.-) produced enzymatically (49.7 ± 1.52% at 50 μg/ml) and non-enzymatically (34 ± 1.2% at 100 μg/ml), probably related to its inhibition of the xanthine oxidase form of the xanthine oxidoreductase (XOR) enzyme (25.05 ± 2.33 μg/mL at 100 μg/mL), but mostly to that of the NADH oxidase form of the enzyme (69.16 ± 4.0%). Cytotoxicity tests of the extract on human hepatoma cell line HepG2 and ovarian cancer cell lines A2780 and OVCAR3 were promising especially regarding A2780 cell line (IC50: 77.0 μg/mL), which was comparable to taxol (IC50:76.9 μg/mL).

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.