Alzheimer’s disease (AD) is the leading cause of dementia, characterised by beta-amyloid plaques, neurofibrillary tangles, and oxidative stress. Iron is suspected to enhance disease progression, and chelation may be a potential treatment. We propose that Aloysia citrodora Paláu (AC), a plant in the Verbenaceae family, can act as a moderate chelator of iron. It may reduce the effect of iron on beta-amyloid 1-42 (Aβ1-42) aggregation. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to demonstrate that AC can interact with iron (II) and iron (III), the two most abundant forms of iron within the body. DPV was also used to characterise Aβ1-42 aggregation, and two main features were obtained. The first is the tyrosine peak (~0.6 V) decreased in magnitude over time, which is a sign of aggregation and folding. The other is a conglomerate of peaks at ~0 V, whose identity is unknown. Furthermore, iron (II) increased the rate of tyrosine peak depreciation, and the addition of AC negated this induced effect. This implied that iron (II) increases Aβ1-42 aggregation into higher order, and AC may be an effective countermeasure.

A single-center, randomized, double-blind, placebo-controlled clinical trial with two arms was conducted in 71 healthy subjects suffering from sleep disturbances, which were treated with a dietary supplement based on an extract of Aloysia citrodora (or Lippia citriodora, lemon verbena) (n = 33) for 90 days. Subjects in the placebo group (n = 38) received capsules of microcrystalline and maltodextrin with the same organoleptic properties. Between-group significant differences in favor of the experimental group were found in the visual analogue scale (VAS) score rating sleep quality; overall score, sleep latency and sleep efficiency of the Pittsburg Sleep Quality Index (PSQI); and sleep latency, sleep efficiency, wakefulness after sleep onset and duration of awakening assessed by actigraphy. Plasma nocturnal melatonin levels also increased significantly in the experimental group. Changes in anthropometric parameters and physical activity levels were not found. This study shows that the administration of a dietary supplement comprised lemon verbena administered for 3 months was associated with a significant improvement of sleep quality as compared with placebo in a population of healthy subjects with sleep problems. Improvements were also apparent at the mid-study visit after 45 days of supplementation.

Aflatoxin B1 (AFB1) is a mycotoxin considered as a potent carcinogenic for humans that contaminates a wide range of crops. Various strategies have been established to reduce or block the synthesis of AFB1 in food and feeds. The use of aqueous extracts derived from plants with high antioxidant activity has been a subject of study in recent years due to their efficacy in inhibiting AFB1. In this study, we assessed the effect of Aloysia citrodora aqueous extract on Aspergillus flavus growth and on AFB1 production. A bio-guided fractionation followed by High Performance Liquid Chromatography (HPLC) and Mass spectrometry analysis of active fraction were applied to identify the candidate molecules responsible for the dose-effect inhibition of AFB1 synthesis. Our results revealed that polyphenols are the molecules implicated in AFB1 inhibition, achieving almost a total inhibition of the toxin production (99%). We identified luteoline 7- diglucuronide as one of the main constituents in A. citrodora extract, and demonstrated that it is able to inhibit, by itself, AFB1 production by 57%. This is the first study demonstrating the anti-Aflatoxin B1 effect of this molecule, while other polyphenols surely intervene in A. citrodora anti-AFB1 activity.