Aqueous extract of Psidium guajava leaves: phenolic compounds and inhibitory potential on digestive enzymes

Abstract

Leaves of Psidium guajava L. (guava) have been widely used in the popular way for prevention and treatment of various diseases. Thus, the objective of this study was to evaluate the inhibitory potential of leaves aqueous extract from three cultivars of P. guajava (Pedro Sato, Paluma and Século XXI) on α-amylase, α-glycosidase, lipase, and trypsin enzymes, in the presence or not of simulated gastric fluid and to determine the content of phenolic compounds by high performance liquid chromatography. All cultivars presented the same composition in phenolic compounds, but in different proportions. The compounds identified are gallic acid, epigallocatechin gallate, syringic acid, o-coumaric acid, resveratrol, quercetin, and catechin (which was the major compound in all the cultivars evaluated). In the absence of simulated gastric fluid, it was observed different inhibitions exercised by the leaves aqueous extracts from three cultivars of P. guajava on each enzyme. In presence of simulated gastric fluid, all cultivars showed increase in the inhibition of lipase and α-glycosidase, and decrease in inhibition of α-amylase and trypsin enzymes. These results indicate that P. guajava leaves aqueous extracts from all cultivars evaluated possess potential of use as an adjuvant in the treatment of obesity and other dyslipidemias.

Nutritional properties, identification of phenolic compounds, and enzyme inhibitory activities of Feijoa sellowiana leaves

“…This strong anti‐lipase activity may be due to the high level of quercetin in our leaves’ extract. Similar enzymatic results were found by Simao, Marques, Marcussi, and Correa () in an aqueous extract of leaves of Psidium guajava (Myrtaceae). Those authors reported that the potential use of this plant as an adjuvant in the treatment of dyslipidemias and obesity, following its richness in catechin and quercetin.…”

“…This strong anti-lipase activity may be due to the high level of quercetin in our leaves' extract. Similar enzymatic results were found by Simao, Marques, Marcussi, and Correa (2017) in an aqueous extract of leaves of Psidium guajava (Myrtaceae). Those…”

Phytopharmacological Strategies in the Management of Type 2 Diabetes Mellitus

“…The study revealed that all cultivars showed the same phenolic composition but in different proportions, where catechin was the major compound in Paluma cultivar, epigallocatechin gallate, and revesterol in Pedro Sato and syringic acid, o-coumaric acid, and quercetin for Século XXI [43]. The enzyme inhibition occured in major proportion for Século XXI cultivar against alpha-amylase before the exposure to gastric fluid (14410.60 ± 38 inhibited enzyme unit in µmol·min −1 ·g −1 ) and Paluma against alpha-glucosidase before (28.82 ± 0.02 inhibited enzyme unit in µmol·min −1 ·g −1 ) and after exposure (2.59 ± 0.06 inhibited enzyme unit in µmol·min −1 ·g −1 ) [43]. Pedro Sato revealed the highest inhibitory effect against lipase before (36.45 ± 0.68 inhibited enzyme unit in µmol·min −1 ·g −1 ) and after exposure (43.33 ± 1.80 inhibited enzyme unit in µmol·min −1 ·g −1 ) [43].…”

“…Simão and colleagues tested the inhibitory potential of an aqueous extract from the leaves of three cultivars of Psidium guajava (guava) on α-amylase, α-glucosidase, lipase and trypsin enzymes. These studies were done in the presence or absence of simulated gastric fluid and the content of phenolic compounds was determined [43]. The study revealed that all cultivars showed the same phenolic composition but in different proportions, where catechin was the major compound in Paluma cultivar, epigallocatechin gallate, and revesterol in Pedro Sato and syringic acid, o-coumaric acid, and quercetin for Século XXI [43].…”

“…These studies were done in the presence or absence of simulated gastric fluid and the content of phenolic compounds was determined [43]. The study revealed that all cultivars showed the same phenolic composition but in different proportions, where catechin was the major compound in Paluma cultivar, epigallocatechin gallate, and revesterol in Pedro Sato and syringic acid, o-coumaric acid, and quercetin for Século XXI [43]. The enzyme inhibition occured in major proportion for Século XXI cultivar against alpha-amylase before the exposure to gastric fluid (14410.60 ± 38 inhibited enzyme unit in µmol·min −1 ·g −1 ) and Paluma against alpha-glucosidase before (28.82 ± 0.02 inhibited enzyme unit in µmol·min −1 ·g −1 ) and after exposure (2.59 ± 0.06 inhibited enzyme unit in µmol·min −1 ·g −1 ) [43].…”