1. Venom from the Black Scorpion Heterometrus longimanus was found to exhibit a certain degree of anti-microbial property in our planned experiments. It was found that all dilutions of the venom (12.5% - 100%) was effective against all 4 species of bacteria tested, i.e S.aureus, E.coli, S.faecalis and B.subtilis. This was particularly interesting as S.aureus and B.subtilis are Gram-positive bacteria while E.coli and S.faecalis are Gram-negative bacteria. The Gram-positive bacteria have a significantly thicker peptidoglycan layer in their cell walls, while the Gram-negative bacteria have a complex outer layer consisting of endotoxin, lipoprotein and phospholipids. The venom proved to be able to inhibit and destroy both Gram-positive and Gram-negative bacteria, although Gram-negative bacteria have been known to be less susceptible to proteolytic enzymes than Gram-positive bacteria. (Cruickshank, Medical Microbiology) 2. As scorpion venom are one of the most powerful neurotoxins known to man (Karlsson 1937) and have been known to affect the important ion transfers, particularly sodium and potassium channels (Chalan 1975; Meves et al. 1982; Wang and Strichartz 1982, 1983; Hu et al. 1983; Simard et al. 1986), we suspect that the inhibitory action of the scorpion venom was due to the components in the venom that affected either : The osmotic pressure of the bacterial cells The transfer of ions in and out of the cells. 3. The venom was found to have no effect on fungi, in all doses. This might be due to the fact that fungi have a different cell structure from bacteria, and are more resistant to external factors than bacteria (which explains the fact that fungi can grow in places where some bacteria cannot). Fungi are also less dependent on the osmotic transfer of ions than bacteria are, as they are multi- celled organisms that carry out active diffusion. Therefore, if the venom were to affect their sodium or potassium channels, this might not have affected the fungi in any noticeable way. The cell walls are also much too thick to be affected by changes in osmotic pressure. 4. The scorpion venom showed a limited degree of inhibition on the yeasts, especially Yeast 1. Also, not all dilutions proved to be as effective : in Yeast 1, the 12.5% doses yielded only a meagre degree of inhibition, which is scientifically rejected as having "antimicrobial activities". The venom had an effect on S.cerevisiae to some extent. In overall, the venom was not as effective an yeast-inhibitor as compared to the bacteria.

Neuro-muscular tests

5. The results of the neuro-muscular tests conducted on the rat anococcygeus muscles suggested that H.longimanus venom affects the nervous system of animals. As the muscular contraction decreased readily after the venom was introduced into the organ bath, it shows that neural transmissions from the motor neuron to the muscle was affected. We therefore believe that the venom actually has an effect in blocking or inhibiting the neural transmissions in the nerve. In the experiments, we found out that the neural transmissions returned to normal after the H.longimanus venom was flushed out repeatedly from the organ bath, as the amplitude of contractions by the muscle after treatment and flushing was almost equal to that of before treatment. This suggests that the effect of H.longimanus venom on the nerve and muscle tissue is not permanently damaging, and the nerves return to normal after effective washing. We therefore believe that an organism injected with H.longimanus venom will be able to recover without any help as soon as the the venom was flushed out by bodily liquids such as plasma or when the venom is eventually broken down into other harmless substances by the liver. 6. However, Graph 5.2 showed that even after recovery, the contractions of the muscles did not return to 100% of the normal (compare interval 1 and interval Therefore we conclude that injection of crude venom into an organism may leave it weaker than before, but in time, full recovery is possible. 7. Therefore, venom was found to tense smooth muscle (rat anococcygeus muscle). This property might be valuable help in cases of open wounds or when arteries are cut, since the arterial walls are in fact layers of smooth muscle. If the muscles tense up after treatment with venom, constriction of the blood vessels will be liable to occur and therefore bleeding can be significantly reduced. 8. If the venom also causes a similar reaction on skeletal muscle, this will also be an added advantage since bleeding can also be decreased. The flow of blood in blood vessels is aided by the contractions of adjacent skeletal muscle. Therefore, if the skeletal muscles can too be made to become tense, the blood will likewise flow more slowly and bleeding will be reduced.

Effects of venom on open wounds.

9. From the first test to see the reaction of wounds that are treated with 25% crude venom, we found out that venom was able to clot the blood in the ears of the mice where an incision was made. As compared to an untreated ear and an ear with 0.9% saline solution applied on it, the ears with 25% venom applied on them had red patches within the ear, suggesting agglutination of blood. Therefore, we can conclude that venom contained some compound(s) that helped in the coagulation of blood. 10. The rapid coagulation of blood, seemingly triggered off by the application of venom on open wounds, would be an added advantage as bleeding will be inhibited in open wounds. 11. When the treated mice were compared, behavior-wise, to the untreated mice and those that were treated with 0.9% saline solution, it was found out that the treated mice did not exhibit any unusual behavior. Non of the odd behaviors associated with envenomation was observed, as when compared to results obtained from the second experiment involving injection of venom to test for behavior after envenomation. 12. In the second experiment, it was found out that mice, when injected with large doses (50% concentration, 100ul for intra-peritoneal injection and 20ul for intra-cervical injection)of crude H.longimanus venom, showed signs of behavioral unrest. When injected intra-peritoneally, the mice showed signs of itchiness, paralysis (especially that of the hind limbs), difficulty in breathing, and lastly death, which might occur after 20 minutes or so. 13. When injected intra-cranially, the mice died instantly. This suggests that the venom had been transported directly into the brain, and had affected the brain cells or damaged them. 14. From the intra-peritoneal injection, we can also conclude that the venom had broken the blood-brain barrier, and so had affected the brain and caused death eventually. The delay of mortality time as compared to that of intra-cranial injection points to the fact that the venom took some time to travel from the peritoneal cavity into the bloodstream before reaching the brain and breaking the blood-brain barrier. 15. When observed and interpreted as a whole, it can be seen that venom, when applied to a wound, did not cause any negative reaction in the mice. This means that most of the venom remained at the upper surface of the skin instead of entering the bloodstream, which will cause reactions such as those seen in the injection experiment.