Fruits, seeds and leaves of guabijuzeiro (Myrcianthes pungens (O. Berg) D. Legrand): characteristics, uses and health benefits.

Native fruit trees have potential for use in the food and pharmaceutical industries, which is widely used in folk medicine. Guabiju, known as guabijuzeiro (Myrcianthes pungens (O. Berg) D. Legrand) is a perennial tree that belongs to the family Myrtaceae, occurring in Brazil from São Paulo to Rio Grande do Sul, and other countries like Uruguay, Bolivia, Paraguay and Argentina. This species demonstrates great commercial potential regarding the consumption of its fresh fruit or industrialized. Due to its importance is necessary to develop studies aimed at characterization (phenotypic, propagative, reproductive, chemical and nutritional), uses and applications. However, the available information has never been systematized and in this sense the objective of this review is to compile information about the species to guide further research. Regarding morphology, the guabijuzeiro is a semi-deciduous tree species, with propagation is carried out mainly through seeds and vegetative. Regarding reproductive aspects, there is a lack of studies that assess the mode of reproduction. The fruit can be consumed fresh or processed as ice cream, juice, freeze-dried or dehydrated. It is sweet and slightly acidic, low in calories, high in carbohydrates, essential fatty acids, calcium and potassium. Both the fruit, the seed and the leaves have high levels of bioactive compounds and high antioxidant capacity. The fruit pulp stands out for its carotenoids and phenolic compounds and the peel is rich in anthocyanins, especially in the mature phase, in addition to terpenoids. M. pungens has antimicrobial effects, gastroprotective activity and is promising in the prevention of neurodegenerative diseases and against the side effects of cisplatin, an anticancer agent. Finally, there is a need for further studies with this species, mainly in the characterization of the leaves, uses and applications of the fruit.

Probiotic Yogurt Supplemented with Lactococcus lactis R7 and Red Guava Extract: Bioaccessibility of Phenolic Compounds and Influence in Antioxidant Activity and Action of Alpha-amylase and Alpha-glucosidase Enzymes.

The industry has increasingly explored the development of foods with functional properties, where supplementation with probiotics and bioactive compounds has gained prominence. In this context, the study aimed to evaluate the influence of in vitro biological digestion on the content of phenolic compounds, antioxidant activity, and inhibition of α-amylase and α-glucosidase activities of probiotic yogurt supplemented with the lactic acid bacteria Lactococcus lactis R7 and red guava extract (Psidium cattleianum). A yogurt containing L. lactis R7 (0.1%) and red guava extract (4%) was characterized for the content of phenolic compounds, antioxidant activity, and potential for inhibition of digestive enzymes after a simulated in vitro digestion process. After digestion, the caffeic and hydroxybenzoic acids remained, and sinapic acid only in the last digestive phase. Antioxidant activity decreased during digestion by 28.93, 53.60, and 27.97% for DPPH, nitric oxide and hydroxyl radicals, respectively, and the inhibition of the α-amylase enzyme decreased only 4.01% after the digestion process. α-glucosidase was more efficient in intestinal digestion, demonstrating an increase of almost 50% in probiotic yogurt with red guava extract before digestion. Possibly, the phenolics change their conformation during digestion, generating new compounds, reducing antioxidant activity, and increasing the inhibitory activity of α-glucosidase digestive enzymes. It was concluded that the probiotic yogurt formulation supplemented with red guava extract could interfere with the concentration of phenolic compounds and the formation of new compounds, suggesting a positive and effective inhibition of the digestive enzymes, even after the digestive process.

Chemical Composition, Antioxidant Potential, and Blood Glucose Lowering Effect of Aqueous Extract and Essential Oil of Thymus Serrulatus Hochst. Ex Benth.

Thymus serrulatus, an endemic plant of Ethiopia, is traditionally used to cure various diseases and as a food ingredient. In the Ethiopian folk medicine, the decoction is orally taken as a remedy to treat diabetes and high blood pressure. The purpose of the present study was to evaluate the antioxidant and antihyperglycemic effects of the aqueous extract and of the essential oil of Thymus serrulatus. The chemical composition of the aqueous extract was determined by LC-MS and the essential oil was characterized by GC-MS analysis. Radical scavenging assays, namely scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH•), hydroxyl (•OH), and nitric oxide (•NO), were used as a first approach to screen the potential antioxidant abilities of the samples. Alpha-amylase and α-glucosidase inhibitory studies were also employed to evaluate the in vitro antihyperglycemic potential of the plant. The in vivo blood glucose lowering effect of the extracts was assessed using hypoglycemic activity and the oral glucose tolerance test in normal and in streptozotocin induced diabetic mice. When compared to the aqueous extract, the essential oil showed superior radical scavenging activity, particularly for •NO, as well as greater inhibitory potency against α-amylase and α-glucosidase (IC50 = 0.01 mg/ml and 0.11 mg/ml, respectively). Both tested samples showed a statistically significant antihyperglycemic effect. The aqueous extract at 600 mg/kg exerted maximum antihyperglycemic activity (44.14%), followed by the essential oil (30.82%). Body weight and glucose tolerance parameters were also improved by the samples both in normal and diabetic mice. The findings of this study support the hypothesis that aqueous extract and essential oil of T. serrulatus are promising therapeutic agents.