Anticholinesterase and antioxidant activities of foliar extract from a tropical species: Psidium guajava L. (Myrtaceae) grown in Algeria

Abstract

Guava (Psidium guajava L.) is a fruit tree largely used in folk medicine in tropical and subtropical areas. This exotic species was introduced in a botanical garden in the northeast of Algeria in the 1950’s. The aim of this study is to estimate, for the first time, the antioxidant and anticholinesterase activities of chloroform, ethyl acetate and n-butanol extracts of P. guajava growing in Algeria. Six antioxidant assays were tested, results showed very important efficiency in free radical scavenging, reducing power and β-carotene bleaching of tested extracts. Values of IC50 or A0.5 of some samples were lower than those of standards. With regard to anticholinesterase activity, the inhibitory of both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) was investigated. The extracts exhibited interesting capacity to inhibit these enzymes with low values of IC50 and even less than that of galanthamine. These activities were correlated with total phenolic content which was more important compared to the one found in extracts from trees growing in tropical and subtropical region. This could be due to resistance and adaptation of P. guajava grown in Algeria. The data obtained suggest the use of bioactive compounds from P. guajava leaves as antioxidant and drugs for symptomatic treatment of Alzheimer disease.

Crystal Guava (Psidium guajava L. “Crystal”): Evaluation of In Vitro Antioxidant Capacities and Phytochemical Content

“…Previous research [ 6 – 12 ] reported that Psidium guajava had antioxidant capacity. There was no research concerning the antioxidant capacity of different extracts (n-hexane, ethyl acetate, and ethanol) of leaves and fruit from crystal guava (“ Psidium guajava L.”“crystal”) which is grown in Cianjur, West Java-Indonesia, using three methods (DPPH, CUPRAC, and FRAP).…”

“…Manikandan et al [ 8 ] showed that ethanol leaves extract had the highest antioxidant activity using the DPPH method than methanol and water extract, by Soxhlet extraction. The study by Bouchoukh et al [ 6 ] demonstrated that guava leaves from Algeria had the highest antioxidant activity in ethyl acetate extract, when compared to butanol and chloroform extracts, using the DPPH method, while with the CUPRAC method, the highest antioxidant activity was given by butanol [ 6 ]. The study by Ashraf et al [ 7 ] using guava from Pakistan showed that n-hexane leaves extract had the lowest antioxidant activity, compared to methanol and chloroform extracts, using DPPH and FRAP methods.…”

“…It was similar with the current study, as the TPC of ethanol extract (49.55 g·GAE/100 g) was also higher than ethyl acetate extract (8.49 g·GAE/100 g). In another research by Bouchoukh et al [ 6 ], it was figured that the TPC and TFC in ethyl acetate extract of guava that was cultivated in Algeria were 931.15 μ g GAE/mg and 269.57 μ g QE/mg, respectively. In this research, the TPC (8.49 g·GAE/100 g) and TFC (7.68 g·QE/100 g) of ethyl acetate leaves extract were lower than those in the previous research.…”

“…DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), CUPRAC (Cupric ion-Reducing Antioxidant Capacity), and FRAP (Ferric Reducing Antioxidant Power) methods could be applied to observe the antioxidant activity in many plant extracts [ 3 – 5 ]. Previous studies [ 6 – 12 ] exposed that DPPH, CUPRAC, and FRAP methods could evaluate antioxidant activities of Psidium guajava . The phenolic content in a plant might be linked with its antioxidative properties [ 6 ].…”

“…Previous studies [ 6 – 12 ] exposed that DPPH, CUPRAC, and FRAP methods could evaluate antioxidant activities of Psidium guajava . The phenolic content in a plant might be linked with its antioxidative properties [ 6 ]. Psidium guajava contained a phenolic compound [ 3 ] and flavonoids such as apigenin, quercetin, and morin in its leaves [ 13 ].…”