Analysis of Secretory Structures, Chemical Composition, and Anti-Inflammatory Properties of Allophylus edulis (A. St.-Hil., A. Juss. & Cambess.) Radlk Leaves.

Background/

Objectives

Allophylus edulis, known as "vacum", is popularly used in Brazil for treating inflammatory diseases, though no scientific evidence supports the anti-inflammatory activity of its leaf infusion. This study aimed to assess the chemical composition, antioxidant and anti-inflammatory properties of the lyophilized infusion (ILAE) of A. edulis leaves, as well as the pharmacological effects of its hydromethanolic fraction (HMf) and the isolated compound vitexin 2″-O-rhamnoside (AE-1). Histochemical analyses of the leaves and in silico toxicity prediction of AE-1 were also performed.

Methods

Fresh leaves were used for histochemical analysis and preparation of ILAE. The infusion was fractionated into n-hexane (Hf), ethyl acetate (EAf), and HMf fractions. Total phenols, flavonoids, flavonols, tannins, and antioxidant activity were determined by spectrophotometric methods. AE-1 was obtained from HMf through chromatographic methods and was evaluated by the ProTox model in relation to toxicity predictions (in silico). Anti-inflammatory effects of ILAE (3, 30, 100 mg/kg), HMf (3, 30 mg/kg), and AE-1 (3 mg/kg) were evaluated in carrageenan-induced paw edema, pleurisy, and CFA-induced inflammation in mice.

Results

ILAE and its fractions were rich in total phenols (≤177 mg GAE/g) and showed potent antioxidant activity. Histochemical analysis revealed leaf secretory structures. AE-1 showed no hepatotoxic, carcinogenic, mutagenic, or cytotoxic effects in silico. All doses of ILAE and HMf reduced edema, hyperalgesia, and leukocyte migration. ILAE (30 mg/kg), HMf (30 mg/kg), and AE-1 (3 mg/kg) reduced CFA-induced inflammatory responses.

Conclusions

ILAE contains polyphenolic compounds with antioxidant, anti-inflammatory, and antihyperalgesic properties, supporting the traditional use of A. edulis and its potential in inflammation-related therapies.