Serine Protease Variants Encoded by Echis ocellatus Venom Gland cDNA: Cloning and Sequencing Analysis

Envenoming by Echis saw-scaled viper is the leading cause of death and morbidity in Africa due to snake bite. Despite its medical importance, there have been few investigations into the toxin composition of the venom of this viper. Here, we report the cloning of cDNA sequences encoding four groups or isoforms of the haemostasis-disruptive Serine protease proteins (SPs) from the venom glands of Echis ocellatus. All these SP sequences encoded the cysteine residues scaffold that form the 6-disulphide bonds responsible for the characteristic tertiary structure of venom serine proteases. All the Echis ocellatus EoSP groups showed varying degrees of sequence similarity to published viper venom SPs. However, these groups also showed marked intercluster sequence conservation across them which were significantly different from that of previously published viper SPs. Because viper venom SPs exhibit a high degree of sequence similarity and yet exert profoundly different effects on the mammalian haemostatic system, no attempt was made to assign functionality to the new Echis ocellatus EoSPs on the basis of sequence alone. The extraordinary level of interspecific and intergeneric sequence conservation exhibited by the Echis ocellatus EoSPs and analogous serine proteases from other viper species leads us to speculate that antibodies to representative molecules should neutralise (that we will exploit, by epidermal DNA immunization) the biological function of this important group of venom toxins in vipers that are distributed throughout Africa, the Middle East, and the Indian subcontinent

Neutralisation of Local Haemorrhage Induced by the Saw-Scaled Viper Echis carinatus sochureki

The objective of the study is to investigate the anti-snake venom activities of a local plant, Hibiscus aethiopicus L. The H. aethiopicus was dried and extracted with ethanol. Different assays were performed according to standard techniques, to evaluate the plant’s acute toxicity and its antivenom activities. The results of evaluating the systemic acute toxicity of the H. aethiopicus extract using “oral and intra-peritoneal” route were normal even at the highest dose (24 g/kg) tested. All guinea pigs (n=3) when treated with venoms E. c. sochureki (75 μg) alone induced acute skin haemorrhage. In contrast, all guinea pigs (n=18) treated with both venom and the plant extract at a concentration between 500 and 1000 mg/kg showed no signs of haemorrhage. Moreover, all guinea pigs (n=18) treated with venom and the plant extract below 400 mg/kg showed acute skin haemorrhage. All guinea pigs treated with venom E. c. sochureki (75 μg) alone induced acute skin haemorrhage after both 24 and 32 hours. In contrast, all guinea pigs treated with both venom and the plant extract (administered independently) at concentrations between 500 and 1000 mg/kg showed no signs of haemorrhage after 32 hours. However, after 24 hours all tested guinea pigs showed less inhibition (<60%) compared to that obtained after 32 hours. The outcome of this study reflects that the extract of H. aethiopicus plant may contain an endogenous inhibitor of venom induced local haemorrhage

Antimicrobial and antioxidant activities of the various extracts of Verbascum pinetorum Boiss. O. Kuntze (Scrophulariaceae)

Background and Objectives: The present study was performed to evaluate the in vitro antimicrobial and antioxidant properties of various extracts of Verbascum (V.) pinetorum, a member of Scrophulariaceae family. While the antimicrobial activity of various extracts of V. pinetorum was determined with agar-well diffusion method, the antioxidant activity was examined with two complementary test systems, namely 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging and beta-carotene/linoleic acid test systems

Activity guided isolation of chemical constituents from the biologically active methanol extract of Euphorbia schimperi C. Presl

In this study we investigated the chemical constituents of bioactive methanol extract of Euphorbia schimperi C. Presl. For this the methanol extract was fractionated into 20, 40, 60, 80% MeOH in CHCl3, and 100% MeOH fractions respectively by vacuum liquid chromatography. Excision wound surface of the animals were topically treated with these fractions at a dose of 100 mg/kg body weight for twenty days. Povidone-iodine ointment was used as a reference drug. Wound contraction measurement and period of epithelialization were used to assess the effect of fractions on wound repairing. The 100% MeOH fraction treated animals achieved significant (p < 0.001) value by showing 100% wound contraction and minimum period of epithelization (17.75±0.47) on the 20th day as compared to standard drug treated animals on the same day. The active 100% MeOH fraction was subjected to various chromatographic techniques led to the isolation of miquelianin (1), kaempferol 3-O-glucuronide (2) and quercitrin (3). Compounds (1-3) were isolated from this plant for the first time