Isolation and Characterization of a Novel Flavonoid Possessing a 4,2″-Glycosidic Linkage from Green Mature Acerola (Malpighia emarginataDC.) Fruit

Comparative metabolomic and transcriptomic analyses revealed the differential accumulation of secondary metabolites during the ripening process of acerola cherry (Malpighia emarginata) fruit

BACKGROUND

Acerola cherry is a famous functional fruit containing plentiful antioxidants and other nutrients. However, studies on the variations among nutrients during the ripening process of acerola fruit are scare.

RESULTS

Comparative metabolomic and transcriptomic analyses were performed and identified 31 331 unigenes and 1896 annotated metabolite features in acerola cherry fruit. K Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that several antioxidant and nutrient-related metabolic pathways, such as the flavonoids, vitamins, carotenoids, amino acids, and fatty acids metabolic pathways, were significantly changed during the ripening process. The metabolites related to the vitamin, carotenoid, and fatty acid metabolic pathways were downregulated during the ripening process. Several flavonoid biosynthesis-related genes (including dihydroflavonol 4-reductase, chalcone synthase, flavanone 3-hydroxylase, and anthocyanidin synthase), were significantly upregulated, suggesting their essential functions in the accumulation of flavonoids in mature fruit.

CONCLUSION

Most of the vitamin and carotenoid metabolism-related metabolites significantly accumulated in immature fruit, suggesting that immature acerola fruit is a good material for the extraction of vitamins and carotenoids. For macronutrients, most of the amino acids accumulated in mature fruit and most of the fatty acids greatly accumulated in immature fruit. Our data revealed the differential accumulation of antioxidants and nutrients during the ripening process of acerola cherry fruit. © 2021 Society of Chemical Industry.

Metabolic profiling and in vivo hepatoprotective activity of Malpighia glabra L. leaves

Although Malpighia glabra Linn. fruits are well studied for their nutritional and medicinal prominence; little attention has been given to the leaves. Our study intends to investigate the leaves metabolic profile using Q-TOF LC/MS/MS (Quadrupole-Time-of-Flight-Liquid-Chromatography-Mass-Spectrometry), and to explore their in vivo hepatoprotective activity in rats using CCL₄ -induced hepatic damage model and silymarin as standard. Fifty metabolites were characterized, belonging to different classes; coumarins (capensine, daphnoretin, and scopoletin), flavonoids (mainly quercetin and apigenin glycosides), phenolic acids (cinnamic acid and quinic acid derivatives) and amino acids (adenosine, homoisoleucine, and phenylalanine).These compounds are detected in the leaves for the first time. The hepatoprotective activity at three doses (200, 400, and 800 mg/kg) was investigated. The dose of 800 mg/Kg showed the highest hepatoprotective effect as it reduced the elevated serum levels of ALT, AST, NO, and TNF-α liver content by 26, 24, 23, and 42%, respectively, it also remarkably increased the serum level of catalase by 102%. All the tested doses showed higher reduction in serum level of TNF-α compared to silymarin which suggests their strong anti-inflammatory potential. M. glabra leaves are revealed to be a rich source of secondary metabolites and proved to possess significant hepatoprotective potential. PRACTICAL APPLICATIONS: The performed analyses in this study shows the richness of Malpighia glabra Linn. leaves in a plethora of beneficial and safe phytochemicals which are well-known to have a pivotal role in protection against different diseases including liver disorders. The carried-out investigations were done using Q-TOF LC/MS/MS analysis which is a reliable technique for the determination, characterization and identification of bioactive metabolites; in addition to evaluation of the hepatoprotective effect of the leaves. Therefore, this study may emphasize that Malpighia glabra Linn. leaves may have the same nutritional and medicinal importance as its fruits, and they could be incorporated into pharmaceuticals and foods instead of discarding them.

Metabolomic analysis of acerola cherry (Malpighia emarginata) fruit during ripening development via UPLC-Q-TOF and contribution to the antioxidant activity

Acerola cherry (Malpighia emarginata D.C.) is a tropical fruit of great economic and nutritional value due to its high content of vitamin C. However, there is little information available about which ripening stage of Acerola cherry can provide the best nutrients. In the current study, the chemical variation at two developmental stages (immature and mature) were investigated by metabolic profiling, and the biological properties of Acerola cherry and its antioxidant assays at four developmental stages were measured, respectively. Through comprehensive metabolites analysis via ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry system (UPLC-QTOF), 1896 annotated metabolite features were obtained, and 133 metabolites were finally identified according to the MS/MS fragments compared with these standards in in-house database. Statistically differences in the levels of amino acids, flavonoids, lipids, terpenoids and ascorbic acids were found between mature and immature fruits. Interestingly, most of differential accumulated amino acids, flavonoids, lipids, and terpenoids predominantly accumulated in the mature fruits and ascorbic acid predominantly accumulated in the immature fruits. On the other hand, their antioxidant activities were compared. The alcoholic extract of immature acerola fruit possessed better scavenging ability of DPPH and ABTS than the mature one. The well correlations were found between the antioxidant potential with its content of ascorbic acid (r = 0.9803 and 0.9897, respectively). In conclusion, Acerola cherry showed very different metabolite profile and antioxidant activities during the fruit ripening development. The maturity of Acerola cherry has to be considered when it is being used for health food products.

Acerola, an untapped functional superfruit: a review on latest frontiers

Acerola (Malpighia emarginata DC.) is one of the richest natural sources of ascorbic acid and contains a plethora of phytonutrients like carotenoids phenolics, anthocyanins, and flavonoids. There is an upsurge of interest in this fruit among the scientific community and pharmaceutical companies over the last few years. The fruit contains an exorbitant amount of ascorbic acid in the range of 1500-4500 mg/100 g, which is around 50-100 times than that of orange or lemon. Having a reservoir of phytonutrients, the fruit exhibits high antioxidant capacity and several interesting biofunctional properties like skin whitening effect, anti-aging and multidrug resistant reversal activity. Countries like Brazil, realizing the potential of the fruit have started to exploit it commercially and have established a structured agro-industrial based market. In spite of possessing an enriched nutrient profile with potent "functional food" appeal, acerola is underutilized in large part of the globe and demands greater attention. A comprehensive literature analysis was carried out with reference to the latest frontiers on the compositional characteristics of the fruit. Emphasis has been given on newer dimensions of functional aspects of ascorbic acid and allied work and pectin and pectin methylesterase. The range of nutraceutical phytonutrients present in acerola and their biofunctional properties has been discussed. Recent advances in the value addition of the fruit highlighting the use of techniques like filtration, encapsulation, ultrasound, sonication, etc. are also elaborated. Furthermore, the potential use of acerola pulp in edible films and waste utilization for development of valuable byproducts has been highlighted.

Superfruits: Phytochemicals, antioxidant efficacies, and health effects - A comprehensive review

The term "superfruit" has gained increasing usage and attention recently with the marketing strategy to promote the extraordinary health benefits of some exotic fruits, which may not have worldwide popularity. This has led to many studies with the identification and quantification of various groups of phytochemicals. This contribution discusses phytochemical compositions, antioxidant efficacies, and potential health benefits of the main superfruits such as açai, acerola, camu-camu, goji berry, jaboticaba, jambolão, maqui, noni, and pitanga. Novel product formulations, safety aspects, and future perspectives of these superfruits have also been covered. Research findings from the existing literature published within the last 10 years have been compiled and summarized. These superfruits having numerous phytochemicals (phenolic acids, flavonoids, proanthocyanidins, iridoids, coumarins, hydrolysable tannins, carotenoids, and anthocyanins) together with their corresponding antioxidant activities, have increasingly been utilized. Hence, these superfruits can be considered as a valuable source of functional foods due to the phytochemical compositions and their corresponding antioxidant activities. The phytochemicals from superfruits are bioaccessible and bioavailable in humans with promising health benefits. More well-designed human explorative studies are needed to validate the health benefits of these superfruits.

α-glucosidase inhibitors from plants: A natural approach to treat diabetes

Diabetes is a common metabolic disease characterized by abnormally high plasma glucose levels, leading to major complications, such as diabetic neuropathy, retinopathy, and cardiovascular diseases. One of the effective managements of diabetes mellitus, in particular, non-insulin-dependent diabetes mellitus (NIDDM) to decrease postprandial hyperglycemia, is to retard the absorption of glucose by inhibition of carbohydrate hydrolyzing enzymes, such as α-glucosidase and α-amylase, in the digestive organs. α-Glucosidase is the key enzyme catalyzing the final step in the digestive process of carbohydrates. Hence, α-glucosidase inhibitors can retard the liberation of d-glucose from dietary complex carbohydrates and delay glucose absorption, resulting in reduced postprandial plasma glucose levels and suppression of postprandial hyperglycemia. In recent years, many efforts have been made to identify effective α-glucosidase inhibitors from natural sources in order to develop a physiologic functional food or lead compounds for use against diabetes. Many α-glucosidase inhibitors that are phytoconstituents, such as flavonoids, alkaloids, terpenoids,anthocyanins, glycosides, phenolic compounds, and so on, have been isolated from plants. In the present review, we focus on the constituents isolated from different plants having α-glucosidase inhibitory potency along with IC50 values.

Antigenotoxicity and antioxidant activity of Acerola fruit (Malpighia glabra L.) at two stages of ripeness

Genotoxic and antigenotoxic effects of acerola fruit at two stages of ripeness were investigated using mice blood cells. The results show that no ripeness stage of acerola extracts presented any genotoxic potential to damage DNA (Comet assay) or cytotoxicity (MTT assay). When antigenotoxic activity was analyzed, unripe fruit presented higher DNA protection than ripe fruit (red color) extract. The antioxidant capacity of substances also showed that unripe samples inhibit the free radical DPPH more significantly than the ripe ones. The results about determination of compounds made using HPLC showed that unripe acerola presents higher levels of vitamin C as compared to ripe acerola. Thus, vitamin C and the complex mixture of nutrients of Malpighia glabra L., and especially its ripeness stages, influenced the interaction of the fruit extract with the DNA. Acerola is usually consumed when ripe (red fruit), although it is the green fruit (unripe) that has higher potential as beneficial to DNA, protecting it against oxidative stress.

Evaluation of glycemic and lipid profile of offspring of diabetic Wistar rats treated with Malpighia emarginata juice

Knowing that maternal diabetes is related to hyperglycemia and fetal hyperinsulinemia, which affect the lipid metabolism, the aim of this study was to evaluate the effects of Malpighia emarginata (acerola) juice on the glycemic and lipid profile of offspring of diabetic and nondiabetic Wistar rats. The adult offspring of non-diabetic dams and of dams with severe streptozotocin-induced diabetes were divided into groups: G1, offspring (of control dams) treated with water, G2, offspring (of diabetic dams) treated with water, G3, male offspring (of control dams) treated with acerola juice, and G4, male offspring (of diabetic dams) treated with acerola juice. The offspring of diabetic dams treated with acerola juice showed significantly decreased levels of glucose, cholesterol, triglycerides, and increased HDL-c. The use of acerola juice is a potential strategy to aid in the prevention of DM and dyslipidemia and its complications or to act as an auxiliary in the treatment of these diseases.

Evaluation of functional stability and batch-to-batch reproducibility of a Castanea sativa leaf extract with antioxidant activity

A growing body of evidence suggests that free radicals are generated by UV irradiation being responsible for skin injury. In this regard, the topical use of formulations composed of plant extracts with antioxidant activity could represent a useful strategy for the prevention of photoaging and oxidative-stress-mediated diseases. The aim of this study was to assess the reproducibility of the extraction method and the functional stability of a Castanea sativa leaf extract in view of its application as topical antioxidant. Measurements of 1,1-diphenyl-2-picryl hydrazyl (DPPH) scavenging activity, total phenols (measured by the Folin Ciocalteu assay) and phenolic composition (high-performance liquid chromatography unit coupled to a UV detector) were carried out on three different batches. The influence of pH and temperature on the extract's DPPH scavenging activity was assessed in aqueous and glyceric solutions (0.025% w/v) over a 3-month period. Minor differences were found between the three extract batches for all the evaluated parameters, and therefore the reproducibility of the extraction method can be inferred. pH presented a great influence in the extract functional stability. Major antioxidant activity decrease was found at pH 7.1, while lower changes were observed at pH 5. Glyceric solutions were stable throughout the test period. At 40 degrees C and pH 5, a marked decrease of activity was observed. Again, glyceric solutions were the most stable, even at 40 degrees C. Proper selection of pH and solvent is mandatory to ensure the stability of the studied extract after being incorporated in semisolid forms. In view of these results, glycerine is proposed as the best vehicle for topical formulations incorporating C. sativa leaf extract, which should have a pH around 5.