Pharmacological characterization of cnidarian extracts from the Caribbean Sea: evaluation of anti-snake venom and antitumor properties

Abstract Background: Cnidarians produce toxins, which are composed of different polypeptides that induce pharmacological effects of biotechnological interest, such as antitumor, antiophidic and anti-clotting activities. This study aimed to evaluate toxicological activities and potential as antitumor and antiophidic agents contained in total extracts from five cnidarians: Millepora alcicornis, Stichodactyla helianthus, Plexaura homomalla, Bartholomea annulata and Condylactis gigantea (total and body wall). Methods: The cnidarian extracts were evaluated by electrophoresis and for their phospholipase, proteolytic, hemorrhagic, coagulant, fibrinogenolytic, neuromuscular blocking, muscle-damaging, edema-inducing and cytotoxic activities. Results: All cnidarian extracts showed indirect hemolytic activity, but only S. helianthus induced direct hemolysis and neurotoxic effect. However, the hydrolysis of NBD-PC, a PLA2 substrate, was presented only by the C gigantea (body wall) and S. helianthus. The extracts from P. homomalla and S. helianthus induced edema, while only C gigantea and S. helianthus showed intensified myotoxic activity. The proteolytic activity upon casein and fibrinogen was presented mainly by B. annulata extract and all were unable to induce hemorrhage or fibrinogen coagulation. Cnidarian extracts were able to neutralize clotting induced by Bothrops jararacussu snake venom, except M. alcicornis. All cnidarian extracts were able to inhibit hemorrhagic activity induced by Bothrops moojeni venom. Only the C. gigantea (body wall) inhibited thrombin-induced coagulation. All cnidarian extracts showed antitumor effect against Jurkat cells, of which C. gigantea (body wall) and S. helianthus were the most active; however, only C. gigantea (body wall) and M. alcicornis were active against B16F10 cells. Conclusion: The cnidarian extracts analyzed showed relevant in vitro inhibitory potential over the activities induced by Bothrops venoms; these results may contribute to elucidate the possible mechanisms of interaction between cnidarian extracts and snake venoms.

背景：刺胞动物（Cnidaria）可产生毒素，此类毒素由多种多肽构成，具备具有重要生物技术研究价值的药理活性，包括抗肿瘤、抗蛇毒及抗凝血活性。本研究旨在评估5种刺胞动物的总提取物（含各物种的整体提取物与体壁提取物）的毒理学活性，以及其作为抗肿瘤、抗蛇毒制剂的潜力，所涉物种分别为：Millepora alcicornis、Stichodactyla helianthus、Plexaura homomalla、Bartholomea annulata及Condylactis gigantea。

方法：通过电泳技术，对刺胞动物提取物的磷脂酶（phospholipase）活性、蛋白水解活性、出血活性、凝血活性、纤维蛋白原溶解（fibrinogenolytic）活性、神经肌肉阻滞（neuromuscular blocking）活性、肌肉损伤活性、水肿诱导活性及细胞毒性（cytotoxic）活性进行检测与评估。

结果：所有刺胞动物提取物均表现出间接溶血活性，但仅Stichodactyla helianthus可诱导直接溶血与神经毒性效应。不过，仅Condylactis gigantea（体壁提取物）与Stichodactyla helianthus可水解磷脂酶A2（PLA2）底物NBD-PC。Plexaura homomalla与Stichodactyla helianthus的提取物可诱导水肿形成，而仅Condylactis gigantea与Stichodactyla helianthus表现出增强的肌毒性活性。针对酪蛋白与纤维蛋白原的蛋白水解活性主要存在于Bartholomea annulata提取物中，且所有提取物均无法诱导出血反应或纤维蛋白原凝固。刺胞动物提取物可中和矛头蝮属（Bothrops）Bothrops jararacussu蛇毒诱导的凝血反应，但Millepora alcicornis提取物除外。所有刺胞动物提取物均可抑制矛头蝮属（Bothrops）Bothrops moojeni蛇毒诱导的出血活性。仅Condylactis gigantea（体壁提取物）可抑制凝血酶诱导的凝血反应。所有刺胞动物提取物均对Jurkat细胞表现出抗肿瘤效应，其中Condylactis gigantea（体壁提取物）与Stichodactyla helianthus的活性最强；但仅Condylactis gigantea（体壁提取物）与Millepora alcicornis对B16F10细胞具有细胞毒性活性。

结论：本研究所分析的刺胞动物提取物对矛头蝮属蛇毒诱导的生物学活性具有显著的体外抑制潜力；上述结果可为阐明刺胞动物提取物与蛇毒之间的潜在相互作用机制提供科学参考。