Lentiscus Extracts Research Articles

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.

Antiatherogenic effect of Pistacia lentiscus via GSH restoration and downregulation of CD36 mRNA expression

Pistacia lentiscus var. Chia (Anacardiaceae) grows almost exclusively on Chios Island, Greece, and gives a resinous exudate resin used for culinary purposes by Mediterranean people. We investigated the molecular mechanisms through which total polar extract of the resin inhibits oxidized low-density lipoprotein (oxLDL) cytotoxic effect on peripheral blood mononuclear cell (PBMC). Cells exposed to oxLDL underwent apoptosis and necrosis, dependent on the duration of exposure. When culturing cells with oxLDL and the polar extract concurrently, we observed inhibition of both the phenomena. Because under oxidative stress the pro-oxidant systems outbalance the antioxidant, potentially producing oxidative damage and ultimately leading to cell death, we measured the levels of intracellular antioxidant glutathione (GSH). Additionally, we measured CD36 expression, a class B scavenger receptor, on CD14-positive cells, as CD36 has been identified as the oxLDL receptor in macrophages and may play a pivotal role in atherosclerotic foam cell formation. oxLDL decreased GSH levels and upregulated CD36 expression. P. lentiscus extract restored GSH levels and downregulated CD36 expression, even at the mRNA level. In order to find out the biologically drastic constituents of the resin’s polar extract, fractions derived from RP-HPLC analysis were examined for their antioxidant effect on oxidatively stressed PBMC. The triterpenoid fraction revealed remarkable increase in intracellular GSH. We suggest GSH restoration and downregulation of CD36 mRNA expression as the pathways via which P. lentiscus triterpenes exert antioxidant/antiatherogenic effect. Additionally, our results provide strong evidence of the resin’s antiatherogenic effect; therefore it is credited with beneficial health aspects.