لخّصلي

Psidion guajava, a tree known for its medicinal properties, was studied in a botanical garden in Algeria. Extracts from the tree showed high levels of total phenolics and flavonoids, resulting in strong antioxidant activity, particularly in DPPH scavenging and CUPRAC assays. Furthermore, the extracts demonstrated an inhibitory effect on the enzymes acetylcholinesterase and butyrylcholinesterase, suggesting potential therapeutic use against Alzheimer's disease. This remarkable antioxidant activity is attributed to the abundance of phenolic compounds produced by the leaves, possibly due to the tree's adaptation to abiotic stress. Extracts with higher phenolic content exhibited greater antioxidant capacity, highlighting the importance of isolating these compounds for further research. Chromatographic analysis would be essential for identifying these bioactive molecules. The study suggests that cultivating P. guajava in Algeria could provide a source of natural drugs and anti-Alzheimer remedies, although further research on toxicity is necessary for safe usage.

Psidion guajava is a tree grown in tropical and sub- tropical regions where it is known for its medicinal prop- erties. Our pioneering study focuses on P. guajava which has grown in a botanical garden in Algeria. A high level of total phenolic and flavonoid content was found. Therefore, extracts manifested antioxidant activities which were greater than the standards in some assays, notably DPPH scaveng- ing and CUPRAC assays. The efficiency of P. guajava leaf extracts against Alzheimer's disease was also investigated by testing the inhibitory effect of the two enzymes acetyl- cholinesterase and butyrvlcholinesterase. Results revealed that P. guajava extracts had values of IC close and even lower than the standard. We suppose that this important antioxidant activity is caused by the abundance of phenolic compounds produced unduly by leaves of our P. guajava trees through its acclimation and developed resistance to abiotic stress by way of manufacturing secondary metab- olites. It should be noted that extracts with a high level of total phenolic content showed best antioxidant capacities As a perspective, ulterior study for isolation of those compounds could be realized. Chromatographic analysis

would be necessary to identify these molecules. This species must undergo greater cultivation in Algeria as its bioactive molecules can be used as drugs and as an anti-Alzheimer remedy, though necessarily with the testing of other effects. such as toxicity for safe use