Anti-Inflammatory and Antioxidant Activity of Litsea glaucescens Kunth in Rodents, an Aztec Medicinal Plant Used in Pre-Columbian Times

TL;DR

This study shows that an extract from the leaves of Litsea glaucescens, an Aztec medicinal plant, has anti-inflammatory and antioxidant effects in mice.

Contribution

The study provides empirical evidence supporting the historical use of L. glaucescens as an anti-inflammatory agent and identifies potential active compounds like quercitrin and pinocembrin.

Findings

Methanolic extract of L. glaucescens reduced carrageenan-induced paw swelling and TPA-induced ear inflammation in mice.

The extract showed antioxidant activity and reduced myeloperoxidase activity, indicating anti-neutrophilic effects.

Flavonoid compounds like quercitrin and pinocembrin were identified as potential contributors to the observed effects.

Abstract

Background/Objectives: Litsea glaucescens Kunth, commonly known as “laurel,” is a tree native to Mexico. The Codex Cruz-Badiano, from 1552, described it as the main ingredient of a topical anti-inflammatory recipe. This study aims to determine whether L. glaucescens leaf extract can reduce experimental inflammation, supporting its use in Aztec medicine. Methods: Methanolic extracts and fractions from the leaves of L. glaucescens were analyzed using techniques such as normal and reverse-phase TLC, 1H-NMR, HPLC-UV, MS, and GC-MS. The anti-inflammatory systemic activity of this methanolic extract was evaluated in mice using carrageenan-induced paw inflammation and TPA-induced ear topical inflammation models. Myeloperoxidase activity, DPPH, and TBARS assays were performed. L. guatemalensis, a closely related species, served as a positive control, as its biological activity has been demonstrated. Results: Thin-layer chromatography analysis reveals flavonoid-type compounds in the methanolic extract of L. glaucescens leaves, and when it was fractionated, pinocembrin and quercitrin were the main compounds found. L. glaucescens in mice significantly reduced carrageenan-induced paw swelling and TPA-induced ear inflammation. A decrease in myeloperoxidase activity and an increase in antioxidant activity were observed. Conclusions: Methanolic extract from L. glaucescens, administered systematically, produced significant in vivo anti-edematous effects and in vitro, antioxidant and anti-infiltrative/anti-neutrophilic activities, qualitatively like those of L. guatemalensis. Quercitrin and pinocembrin could contribute to these actions. It is unclear which of the two plant species was used in pre-Columbian times; However, our results show that both species contain phytochemicals with anti-inflammatory properties, suggesting that the Aztecs recognized this medicinal property.

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