Traditional Siddha Medical literature claim that washing of the leaf with water for 7 times can reduce concentration of bitter latex from
the gel which might be beneficial in healing of gastric ulcer. A scientific study has been published recently which was carried out by a Medical Pharmacologist from Kathmandu University School of Medical Sciences, Nepal. This is one of the best study in which author has cited Siddha literature. Our wishes to the author team.  "Ulcer protective action is improved by washing fresh Aloe vera gel: a comparative study with unwashed gel in indomethacin and ethanol induced ulcers in rats"   http://ijpcs.net/sites/default/files/10.5530ijpcs.5.3.4.pdf
http://ijpcs.net/article/160