Article

Antioxidant activity of maslinic acid, a triterpene derivative obtained from Olea europaea.

Planta Medica (Impact Factor: 2.34). 06/2003; 69(5):472-4. DOI: 10.1055/s-2003-39698
Source: PubMed

ABSTRACT We investigated the effect of maslinic acid (a triterpene derivative obtained from olive pomace), on the susceptibility of plasma or hepatocyte membranes to lipid peroxidation (LPO), induced respectively by the hydroxyl radical (OH*) generated by Fe2+/H2O2 ex vivo and by the system Fe3+/ascorbate in vitro; moreover, three groups of animals used in the plasma study were pretreated with CCl4 (to generate CCl3-*). Endogenous plasma lipoperoxide levels and susceptibility to LPO were decreased in rats treated with maslinic acid, after exposure to OH* by Fe2+/H2O2 (Fenton reaction). Co-incubation with maslinic acid prevented hepatocyte membrane LPO as shown by the reduction of TBARS. In conclusion, maslinic acid may offer some advantages in the resistance of oxidative stress in the animals.

1 Bookmark
 · 
196 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Maslinic acid (MA), the main pentacyclic triterpene of Olea europaea L. fruit, possesses a variety of pharmacological actions, including hypoglycemic, antioxidant, cardioprotective and antitumoral activities. Despite its importance, little is known about its effects on the cytochrome P450 (CYP) activity in both humans and animals. Therefore, the aim of this study was to investigate the effects of MA on the CYP 1A2, 2C9/11, 2D1/6, 2E1 and 3A2/4 activities by human and rat liver microsomes and specific CYP isoforms. In humans, MA only weakly inhibited CYP3A4 activity in human liver microsomes and specific CYP3A4 isoform with IC50 value at 46.1 μM and 62.3 μM, respectively. In rats, MA also exhibited weak inhibition on CYP2C11, CYP2E1 and CYP3A2 activities with IC50 values more than 100 μM. Enzyme kinetic studies showed that the MA was not only a competitive inhibitor of CYP3A4 in humans, but also a competitive inhibitor of CYP2C11 and 3A2 in rats, with Ki of 18.4 μM, 98.7 μM and 66.3 μM, respectively. Moreover, the presence of hydroxyl group at C-2 position of triterpenic acid in MA compared with oleanolic acid could magnify its competitive inhibition on human CYP3A4 activity. The relatively high Ki values of MA would have a low potential to cause the possible toxicity and drug interactions involving CYP enzymes, thus suggesting a sufficient safety for its putative use as a nutraceutical taken together with drugs.
    Phytomedicine 01/2014; 22(1). DOI:10.1016/j.phymed.2014.10.003 · 2.88 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Introduction: Pittosporum phylliraeoides is an endemic Australian plant historically used as a medicinal agent by indigenous Australians. P. phylliraeoides solvent extracts were tested for antibacterial and antifungal activities and toxicity in vitro. Results: All extracts displayed antibacterial activity in the disc diffusion assay. The methanol and hexane extracts demonstrated the broadest specificity, inhibiting the growth of 4 of the 14 bacteria tested (28.6%). The water, ethyl acetate, and chloroform extracts inhibited the growth of 2 (14.3%), 3 (21.4%), and 3 (21.4%) of the 14 bacteria tested respectively. P. phylliraeoides methanolic extract was also effective as an antifungal agent, inhibiting the growth of a nystatin resistant strain of Aspergillus niger. It did not affect the growth of Candida albicans. All extracts were more effective at inhibiting the growth of Gram-negative bacteria than Gram-positive bacteria. Indeed, only the methanol and hexane extracts were capable of inhibiting the growth of any of the Grampositive bacteria, inhibiting the growth of only 1 of the 4 (25%) Gram-positive bacteria tested each. All P. phylliraeoides extracts displayed low toxicity in the Artemia franciscana bioassay. The only significant increase in mortality above that of the control was seen for the ethyl acetate, chloroform and hexane extracts, although even these extracts displayed low toxicity, inducing less than 50% mortality at 72 h. Conclusions: The low toxicity of the P. phylliraeoides extracts and their inhibitory bioactivity against bacteria and fungi validate Australian Aboriginal usage of P. phylliraeoides and indicates its medicinal potential.
    10/2011; 1(2):8-17.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Maslinic acid is a pentacyclic triterpene found in a variety of natural sources, ranging from herbal remedies used in traditional Asian medicine to edible vegetables and fruits present in the Mediterranean diet. In recent years, several studies have proved that maslinic acid exerts a wide range of biological activities, i.e. antitumor, antidiabetic, antioxidant, cardioprotective, neuroprotective, antiparasitic and growth-stimulating. Experimental models used for the assessment of maslinic acid effects include established cell lines, which have been often used to elucidate the underlying mechanisms of action, and also animal models of different disorders, which have confirmed the effects of the triterpene in vivo. Overall, and supported by the lack of adverse effects in mice, the results provide evidence of the potential of maslinic acid as a nutraceutical, not only for health promotion, but also as a therapeutic adjuvant in the treatment of several disorders.
    Molecules 08/2014; 19(8):11538-11559. DOI:10.3390/molecules190811538 · 2.10 Impact Factor