Characteristics of hemolytic activity induced by skin secretions of the frog Kaloula pulchra hainana

Abstract

BackgroundThe hemolytic activity of skin secretions obtained by stimulating the frog Kaloula pulchra hainana with diethyl ether was tested using human, cattle, rabbit, and chicken erythrocytes. The skin secretions had a significant concentration-dependent hemolytic effect on erythrocytes. The hemolytic activity of the skin secretions was studied in the presence of osmotic protectants (polyethylene glycols and carbohydrates), cations (Mg2+, Ca2+, Ba2+, Cu2+, and K+), or antioxidants (ascorbic acid, reduced glutathione, and cysteine).ResultsDepending on their molecular mass, osmotic protectants effectively inhibited hemolysis. The inhibition of skin hemolysis was observed after treatment with polyethylene glycols (1000, 3400, and 6000 Da). Among divalent cations, only 1 mM Cu2+ markedly inhibited hemolytic activity. Antioxidant compounds slightly reduced the hemolytic activity.ConclusionsThe results suggested that skin secretions of K. pulchra hainana induce a pore-forming mechanism to form pores with a diameter of 1.36-2.0 nm rather than causing oxidative damage to the erythrocyte membrane.

Gruesome twosome kukri rippers: Oligodon formosanus (Günther, 1872) and O. fasciolatus (Günther, 1864) eat Kaloula pulchra Gray, 1831 either by eviscerating or swallowing whole

“…Kaloula pulchra can exude highly sticky secretions which are likely used to deter some predators (Evans and Brodie 1994;Hasan et al 2014;Purkayastha 2015;Niyomwan et al 2019). Wei et al (2013) observed that skin secretions of K. pulchra hainana induce erythrocyte haemolysis by means of a pore-forming mechanism in the bilayer lipid membrane. Furthermore, it is known that K. pulchra can swell its bulky body, by inflating the lungs like a balloon, as an anti-predator mechanism (Hasan et al 2014;Purkayastha 2015;Niyomwan et al 2019).…”

Identification and characterization of gastrointestinal hormone immunoreactive cells in the skin and parotoids of Chinese toad Bufo gargarizans

“…Amphibian skin and its secretion contain a wide variety of bioactive substances with various functions, which are the guarantee of amphibian's survival, and they are also a large drug storehouse yet to be developed [1]. Interestingly, numerous biogenic amines and biologically active peptides primarily found in the brain and gastrointestinal (GI) tract are also distributed in amphibian skins.…”