Effects of low molecular constituents from Aloe vera gel on oxidative metabolism and cytotoxic and bactericidal activities of human neutrophils

Int J Immunopharmacol. 1990;12(4):427-34. doi: 10.1016/0192-0561(90)90026-j.


In traditional South-East Asian medicine the therapeutic value of the parenchymous leaf-gel of Aloe vera for inflammatory-based diseases is well-reputed. The aim of this study is to investigate at which level gel-constituents exert their activity. We show here that low -Mr constituents of an aqueous gel-extract inhibit the release of reactive oxygen species (ROS) by PMA-stimulated human PMN. The compounds inhibit the ROS-dependent extracellular effects of PMN such as lysis of red blood cells. The capacity of the PMN to phagocytose and kill micro-organisms at the intracellular level is not affected. The inhibitory activity of the low-Mr compounds is most pronounced in the PMA-induced ROS production, but is significantly antagonized by the Ca-ionophore A23187. It is shown that the inhibitory effect of the low-Mr compounds is the indirect result of the diminished availability of intracellular free Ca-ions.

MeSH terms

  • Aloe*
  • Calcimycin / pharmacology
  • Calcium / metabolism
  • Candida albicans / immunology
  • Cytotoxicity, Immunologic / drug effects
  • Gels
  • Humans
  • Hydrogen Peroxide / metabolism
  • In Vitro Techniques
  • Molecular Weight
  • Neutrophils / drug effects*
  • Neutrophils / immunology
  • Neutrophils / metabolism
  • Oxygen Consumption
  • Phagocytosis / drug effects
  • Plant Extracts / antagonists & inhibitors
  • Plant Extracts / pharmacology*
  • Plants, Medicinal*
  • Staphylococcus aureus / immunology
  • Superoxides / metabolism


  • Gels
  • Plant Extracts
  • Superoxides
  • Calcimycin
  • Hydrogen Peroxide
  • Calcium