Anti-inflammatory activity of beta-sitosterol evaluated in mice.

Study of the anti-inflammatory, immunological and antioxidant activity of beta-sitosterol in murine models.

Abstract

Introduction: Phytosterols are chemicals found in various plant foods such as seeds, vegetables and fruits; these compounds are consumed by humans naturally or as components of vegetable oils or their derived products (industrialized). More than 44 phytosterols have been identified, being beta-sitosterol (BS), campesterol and stigmasterol the most abundant of the group. The chemical structure of BS resembles cholesterol except for the presence of an ethyl group at carbon 24 of its side chain. BS is a compound that has demonstrated several potentially useful activities for human health; it participates in the conversion of linoleic acid to polyunsaturated fatty acids, a process that is essential for the transformation of omega-6 fatty acids, prostaglandins and leukotrienes, compounds that are involved in improving the response of the immune system, as well as the reduction of thromboembolic disorders and the decrease in the amount of inflammatory metabolites. This chemical has been proposed as one of the active ingredients with therapeutic activities in hypercholesterolemia, inflammation, modulation of the immune response, and in the treatment of cancer, among others.

Objective: The objective of this study was to determine the anti-inflammatory and antioxidant potential of BS, its ability to stimulate lymphocyte proliferation in mice, and its ability to scavenge free radicals in vitro.

Methodology: The evaluation was performed in batches of CD3 mice. The following methods were applied to carry out the study objective. Two methods based on the passive reverse Arthus reaction: the paw edema assay and the rat pleurisy assay; as well as two methods related to nonspecific acute inflammation: the mouse ear edema assay and the mouse myeloperoxidase activity assay. The diphenylpicrylhydrazyl (DPPH) antioxidation technique was used to evaluate antioxidant activity.

Results: The results obtained in all tests established a significant anti-inflammatory potential of BS. In the rat paw edema test, we found an inhibitory effect ranging from 50-70%; in the rat pleurisy assay, our findings regarding pleural exudate volume showed a 46% reduction, as well as a low neutrophil count of 20% with respect to the level of the control group. In the mouse ear edema assay, we found an average inflammatory inhibition of 75%, and regarding myeloprooxidase activity, the results showed a dose-dependent inhibition induced by BS. In the 2,2-diphenyl-1-picryl hydrazyl radical analysis, the compound demonstrated the ability to scavenge free radicals in a concentration-dependent manner of up to 78.12% using 250 μg/ml.

Conclusions: Our research established trhee relevant biological activities of BS that demonstrate its anti-inflammatory, immunostimulant, antioxidant potential. We determined a potent anti-inflammatory capacity of BS in specific and non-specific types of acute inflammation in rodents, which places it as a highly useful prospect in inflammation, so new studies are required to assess its application in humans.