Purification and characterization of a phospholipase A2 isoenzyme isolated from Lachesis muta snake venom.
ABSTRACT A new phospholipase A2 (PLA2) isoenzyme was isolated from Lachesis muta crude venom, and was named LM-PLA2-II. This enzyme was purified by gel filtration on a Sephacryl S-200 HR column followed by reverse-phase chromatography on a C2/C18 column. LM-PLA2-II consists of a single polypeptide chain with an apparent molecular mass of 18 kDa and an isoelectric point at pH 5.4. The amino terminal sequence of the enzyme revealed a high degree of homology with other PLA2s from several sources. LM-PLA2-II has a high indirect hemolytic activity and a potent inhibitory effect on platelet aggregation induced by ADP and collagen. It also produces a significant paw edema reaction in rats. The edematous response in rats was abolished by pretreatment with either indomethacin or dexamethasone, suggesting the involvement of cyclo-oxygenase. Pretreatment of LM-PLA2-II with p-bromophenacyl bromide abolished all of these actions, clearly indicating that the biological activities, including the edematogenic effect, are dependent entirely on its enzymatic activity.
Article: Comparative analysis of viperidae venoms antibacterial profile: a short communication for proteomics.[show abstract] [hide abstract]
ABSTRACT: Bacterial infections involving multidrug-resistant strains are one of the ten leading causes of death and an important health problem in need for new antibacterial sources and agents. Herein, we tested and compared four snake venoms (Agkistrodon rhodostoma, Bothrops jararaca, B. atrox and Lachesis muta) against 10 Gram-positive and Gram-negative drug-resistant clinical bacteria strains to identify them as new sources of potential antibacterial molecules. Our data revealed that, as efficient as some antibiotics currently on the market (minimal inhibitory concentration (MIC) = 1-32 μg mL(-1)), A. rhodostoma and B. atrox venoms were active against Staphylococcus epidermidis and Enterococcus faecalis (MIC = 4.5 μg mL(-1)), while B. jararaca inhibited S. aureus growth (MIC = 13 μg ml(-1)). As genomic and proteomic technologies are improving and developing rapidly, our results suggested that A. rhodostoma, B. atrox and B. jararaca venoms and glands are feasible sources for searching antimicrobial prototypes for future design new antibiotics against drug-resistant clinical bacteria. They also point to an additional perspective to fully identify the pharmacological potential of these venoms by using different techniques.Evidence-based Complementary and Alternative Medicine 10/2008; 2011:960267. · 4.77 Impact Factor
Article: Interactions of PLA2-s from Vipera lebetina, Vipera berus berus and Naja naja oxiana Venom with Platelets, Bacterial and Cancer Cells.[show abstract] [hide abstract]
ABSTRACT: Secretory phospholipasesA(2) (sPLA(2)s) form a large family of structurally related enzymes widespread in nature. Herein, we studied the inhibitory effects of sPLA(2)s from Vipera lebetina (VLPLA(2)), Vipera berus berus (VBBPLA(2)), and Naja naja oxiana (NNOPLA(2)) venoms on (i) human platelets, (ii) four different bacterial strains (gram-negative Escherichia coli and Vibrio fischeri; gram-positive Staphylococcus aureus and Bacillus subtilis) and (iii) five types of cancer cells (PC-3, LNCaP, MCF-7, K-562 and B16-F10) in vitro. sPLA(2)s inhibited collagen-induced platelet aggregation: VBBPLA(2) IC(50) = 0.054, VLPLA(2) IC(50) = 0.072, NNOPLA(2) IC(50) = 0.814 μM. p-Bromophenacylbromide-inhibited sPLA(2) had no inhibitory action on platelets. 36.17 μM VBBPLA(2 )completely inhibited the growth of gram-positive Bacillus subtilis whereas no growth inhibition was observed towards gram-negative Escherichia coli. The inhibitory action of sPLA(2)s (~0.7 μM and ~7 μM) towards cancer cells depended on both venom and cell type. VBBPLA(2 )(7.2 μM) inhibited significantly the viability of K-562 cells and the cell death appeared apoptotic. The sPLA(2)s exhibited no inhibitory effect towards LNCaP cells and some effect (8%-20%) towards other cells. Thus, already sub-μM concentrations of sPLA(2)s inhibited collagen-induced platelet aggregation and from the current suite of studied svPLA(2)s and test cells, VBBPLA(2) was the most growth inhibitory towards Bacillus subtilis and K-562 cells.Toxins. 01/2013; 5(2):203-23.
Article: WITHDRAWN: Antiophidian properties of a dolastane diterpene isolated from the marine brown alga Canistrocarpus cervicornis.[show abstract] [hide abstract]
ABSTRACT: The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.bionut.2011.06.021. The duplicate article has therefore been withdrawn.Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie 10/2010; · 2.24 Impact Factor