In the development of
new drugs taking something from nature and modifying it has been successful
tactic employed by medicinal chemists for years. Now with the use of venom, researchers are turning once- discarded drug candidates into
usable drugs.
Venom is a form of toxin secreted by some animals (e.g.
scorpion, bee, snake e.tc) for the purpose of defending or causing harm to
another. Off course we all know that venom can harm and kill human. However in
low doses, venom will not affect normal cells while it may affect cancer cells,
since cancer cells are most sensitive to e.g. modulation of various channels
much needed for the very fast cellular division. Once such substance with
anti-cancer potential is the cardiac glycoside Bufalin extracted from toad skin which is inhibiting a relevant ion channel for cancer cells i.e. the sodium-
potassium exchange channel.
Scorpion venom has been gaining interest as a source of new
drugs, it contains a mixture of biological chemicals called peptides. Some of
which are known to trigger cell death by forming proes in biological
membranes.. cell death can be useful if we are able to target say tumor cells to
auto-destruct.
Investigation carried out by specialist of the Faculty of chemistry at the university of Colima (UCOL), who have identified peptides(amino
acids molecules) that destroy cancer cells in vitro.
This toxins can have very potent effects. For instance one particular small peptide known as TsAP-1, isolated from the Brazillian yellow scorpion (Tityus serrulatus) has both anti-microbial and anti cancerproperties.
Laura Leticia ValdezVelazquez, Head of research, said that when the toxin, derived from scorpion
venom, invades channels in the cells with this disease it produces cellular
damage until killing them.
“Centruroides tecomanus species is one of the most poisonous scorpion found in colima and we have identified a highly selective group of peptides, which indicates that they could specifically bind to cancer cells and cause their deaths” she indicates.”
Diluted venom from blue scorpions from cuba, has been used
to fight cancer for long time now by tens of thousands of patients. Though still
in research phase, many patients report that tumors have disappeared upon
taking the venom.
Mechanism of action
Kills cancer cells by ion modulation:
A major anticancer action of scorpion venom is based on Chlorotoxin (CTX). This peptide found in the venom blocks small-conductance chloride channels that are highly relevant in some cancers for migration and invasion of healthy cells. It has been shown that chlorotoxin has the ability to interact with chloride channels in membrane protein in e.g glioma cells preventing trans-membrane chlorides fluxes .Inhibits Metastasis:
Chlorotoxin can also bind to MMP-2 (Matrix metalloproteinase), a surface protein over-expressed in highly invasive tumours. the MMP proteins are involves in the breakdown of extracellular matrix in normal physiological processes such as embryonic development, reproduction and tissue remodelling, as well as in disease processes such as arthritis and metastasis.
Although the research is at a primary stage, this indicates the use of venom from scorpions used against cancer. Experts have been observing in Labortory animals that the presence of such toxins releases dopamine, and often effective drugs have been discovered but not commerialised due to delivery of the drugs.
Reference:
Chlorotoxin: a helpful natural scorpion peptide to diagnose glioma and fight tumour invasion
Chlorotoxin is a small 36 amino- acid peptide identified from the venom of the scorpion Leiurus quinquestriatus, Initially, Chlorotoxin was used as pharmacological tool to characterize chloride channels.
