Effects of Two Fractions of Swietenia macrophylla and Catechin on Muscle Damage Induced by BothropsVenom and PLA₂.

Silvia Posada Arias,Tatiana Lobo-Echeverri,Stephen Hyslop,Berardo De Jesús Rodríguez,Vitelbinanúñez Rangel,Raphael Shezaro Ramos

doi:10.3390/toxins11010040

Abstract

Plant natural products can attenuate the myonecrosis caused by Bothrops snake venom and their phospholipases A2 (PLA2). In this study, we evaluated the effects of two fractions (F4 and F6) from Swietenia macrophylla and purified catechin on the muscle damage caused by a myotoxic PLA2 from Colombian Bothrops asper venom (BaColPLA2) in mice and by Bothrops marmoratus venom from Brazil in mouse phrenic nerve-diaphragm muscle (PND) preparations in vitro. Male mice were injected with PLA2 (50 µg) in the absence or presence of F4, F6, and catechin, in the gastrocnemius muscle and then killed 3, 7, 14, and 28 h later for histopathological analysis of myonecrosis, leukocyte infiltration, and the presence of collagen. Fractions F4 and F6 (500 µg) and catechin (90 µg) significantly reduced the extent of necrosis at all-time intervals. These two fractions and catechin also attenuated the leukocyte infiltration on day 3, as did catechin on day 14. There was medium-to-moderate collagen deposition in all groups up to day 7, but greater deposition on days 14 and 28 in the presence of F6 and catechin. Bothrops marmoratus venom (100 µg/mL) caused slight (~25%) muscle facilitation after 10 min and weak neuromuscular blockade (~64% decrease in contractile activity after a 120-min incubation). Pre-incubation of venom with F4 or F6 abolished the facilitation, whereas catechin, which was itself facilitatory, did not. All three fractions attenuated the venom-induced decrease in muscle contractions. These findings indicate that fractions and catechin from S. macrophylla can reduce the muscle damage caused by Bothrops venom and PLA2. These fractions or their components could be useful for treating venom-induced local damage.

Highlights

Snakebite is a major public health problem in tropical regions of the world, with ~5.5 million bites/year, of which around 400,000 lead to amputation and 20,000–125,000 result in death [1,2,3].Toxins 2019, 11, 40; doi:10.3390/toxins11010040 www.mdpi.com/journal/toxinsIn Colombia, data from the National Vigilance System (SIVIGILA) indicate that 4120 snakebites were reported in 2017, with an average of ~95 bites/week and a national incidence of 10.8 cases/100,000 inhabitants [4].The genus Bothrops is responsible for most venomous snakebites in SouthAmerica [5,6], including Colombia [7]
We examined the ability of two fractions of an S. macrophylla leaf extract and of catechin to attenuate the myonecrosis caused by a phospholipase A2 (PLA2) from Colombian B. asper venom in mouse gastrocnemius muscle and to prevent the neuromuscular action of Brazilian B. marmoratus venom in mouse isolated phrenic nerve-diaphragm preparations
The relative contribution of venom components to this damage varies and may differ in overall profile and severity when compared with the damage caused by whole venom [11]

Summary

Introduction

Snakebite is a major public health problem in tropical regions of the world, with ~5.5 million bites/year, of which around 400,000 lead to amputation and 20,000–125,000 result in death [1,2,3].Toxins 2019, 11, 40; doi:10.3390/toxins11010040 www.mdpi.com/journal/toxinsIn Colombia, data from the National Vigilance System (SIVIGILA) indicate that 4120 snakebites were reported in 2017, with an average of ~95 bites/week and a national incidence of 10.8 cases/100,000 inhabitants [4].The genus Bothrops (lancehead pit vipers) is responsible for most venomous snakebites in SouthAmerica [5,6], including Colombia [7]. In Colombia, data from the National Vigilance System (SIVIGILA) indicate that 4120 snakebites were reported in 2017, with an average of ~95 bites/week and a national incidence of 10.8 cases/. Myotoxicity is an important local effect of envenomation by Bothrops species and is mediated primarily by venom phospholipase A2 (PLA2 ) myotoxins that cause extensive damage to skeletal muscle [8]. These myotoxins produce pronounced edema that can increase the intra-compartmental pressure and compromise the blood flow, which leads to ischemia and necrosis [9]. The combined actions of ischemia and direct muscle damage contribute to the muscle necrosis associated with bites by Bothrops spp. [10]

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Conclusion