Evaluation of antimicrobial, cytotoxic, and hemolytic activities from venom of the spider Lasiodora sp.

This study characterized the protein/peptide profile of venom isolated from the spider Lasiodora sp. (Mygalomorphae, Theraphosidae) found in northeastern Brazil and determined its antimicrobial activity, toxicity against human cells, and hemolytic activity. Protein concentration of the Lasiodora sp. venom was 4.53 ± 0.38 mg/mL. SDS-PAGE showed proteins with molecular masses up to 75 kDa, some of which contained disulfide bridges. RP-HPLC analysis separate at least 12 peaks that were identified by mass spectrometry as peptides U1-theraphotoxin-Lp1a (lasiotoxin-1), U1-theraphotoxin-Lp1c (lasiotoxin-3), U3-theraphotoxin-Lsp1a (LTx5), and ω-theraphotoxin-Asp3a as well as the proteins phospholipase A2 (PLA2) and hyaluronidase. The crude venom exhibited bactericidal effect against Aeromonas sp., Bacillus subtilis, and Micrococcus luteus and fungicidal effect against Candida parapsilosis and Candida albicans. In addition, the venom exerted bacteriostatic effect against Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus and fungistatic effect against Candida tropicalis and Candida krusei. The minimum inhibitory (MIC), minimum bactericidal (MBC), and minimum fungicidal (MFC) concentrations ranged from 3.9 to 500 µg/mL. The Lasiodora sp. venom decreased the viability of human peripheral blood mononuclear cells (PBMCs) by 50%-90% at concentrations of 0.1, 1, 10, and 100 µg/mL, promoting apoptosis of these cells. On the other hand, the venom showed weak hemolytic activity against Mus musculus erythrocytes (EC50: 757 µg/mL). In conclusion, the Lasiodora sp. spider venom is a rich source of antimicrobial agents. Future studies will focus on identifying antimicrobial agents present in this venom and evaluating whether these agents contribute to its cytotoxic effects against PBMCs.

Ultrastructural characterization of the hemocytes of Lasiodora sp. (Koch, 1850) (Araneae: Theraphosidae).

This paper is the first descriptive review of hemolymph cell types in the circulation of the tarantula spider Lasiodora sp. These animals are more long-lived than other arthropods, and may live for approximately twenty years. Such remarkable longevity may result from a highly successful immune system, which in turn is directly correlated with hemocyte function. Since the literature on the genus Lasiodora sp. is limited, the main goal of the present study was to identify the different cell types by optical and transmission microscope. Six hemocyte types were characterized and called prohemocyte, granulocyte type I, granulocyte type II, spherulocyte, oenocytoid and plasmatocyte. Prohemocytes presented a large nucleus, elongated granulocytes type I showed the nucleus with the same cell format, elliptical granulocytes type II showed the central nucleus of identical shape, spherulocytes exhibited the nucleus filling almost the whole cell, oval oenocytoids showed eccentric nucleus and less dense cytoplasm, and irregular plasmatocytes showed a nucleus and no granules in cytoplasm. These polymorphic granulocytes presented a round, elongated, elliptical, oval or irregular profile with large and varied numbers of granules, except for plasmatocytes, that were agranular. Different densities and different concentrations of these granules were found at the periphery of the cell. The possible reasons and implications of differences and similarities between arthropods hemocytes are discussed. It can be concluded that there are six cell types in Lasiodora sp. This study is of the first step in the elucidation of the role these cells play in the circulatory and immune system in spiders.