Orange, red and purple barberries: Effect of in-vitro digestion on antioxidants and ACE inhibitors

Effect of Various Fruit Extracts on Angiotensin I-Converting Enzyme (ACE) and Kallikrein (KLK) Activities

Hypertension is one of the main risk factors for cardiovascular disease and causes widespread morbidity and mortality worldwide. The aim of this work was to screen the fruit with high angiotensin I-converting enzyme (ACE) inhibitory activity and kallikrein (KLK) promotion activity by three different extraction methods from 22 kinds of fruits. Results showed that the aqueous extracts of fresh kiwifruit significantly inhibited ACE activity (47.71%), whereas the KLK activity was also inhibited (4.56%). This indicated that the substances inhibiting ACE activity existed in kiwifruit might be small molecular substances such as polyphenols. The nonpolar substance existed in the ethanol extracts of grape inhibited ACE activity significantly. The enzymatic hydrolysates of red grape significantly promoted KLK activity, whereas its ethanol extracts significantly inhibited KLK activity. This results suggested that the components that lower blood pressure and raise blood pressure are generally presented in the same fruit, the former are mostly water-soluble substances, while the latter are generally alcohol-soluble substances. If certain or individual components can be isolated from edible fruits, they may significantly affect blood pressure in humans.

Fruits of Wild-Grown Shrubs for Health Nutrition

Cultivated fruits and berries, such as raspberries, strawberries, black currants, cherries, blueberries, are generally recognized sources of antioxidants, vitamins, minerals, and other substances beneficial to human health and well-being. However, there are also wild berries and fruits that are of undoubted interest as food products having valuable medicinal properties due to the presence of phenolic compounds, antioxidants, and vitamins. These fruits have a great potential to be used in functional food making. The present review is dedicated to fruits of wild-grown shrubs Bird cherry (Prunus padus L.), Rowan berry (Sorbus aucuparia L.), Guelder rose (Viburnum opulus L.), Black elderberry (Sambucus nigra L.), and Barberry (Berberis vulgaris L.) The chemical compositions of these wild berries are described as well as their effects on the improvement of human health proved by clinical trials and epidemiological studies. The possibilities of using the fruits of wild-grown shrubs in the preparation of functional foods and examples of their implementation for the manufacturing of dairy, bakery and meat products are considered.

Inhibitory effects of the anthocyanins from Lycium ruthenicum Murray on angiotensin-I-converting enzyme: in vitro and molecular docking studies

BACKGROUND

Lycium ruthenicum Murray (LRM), a perennial shrub plant belonging to the Solanaceae family, is rich in anthocyanins, which have anti-inflammatory, antioxidant, lipid-lowering, intestinal flora regulating, and other pharmacological qualities. This study was primarily aimed to investigate the inhibitory effect of different anthocyanin purities from LRM on angiotensin-I-converting enzyme (ACE) activity in vitro. Moreover, the inhibitory mechanism was further analyzed by molecular docking technology.

RESULTS

Two main anthocyanin isomers were identified by ultra-performance liquid chromatography-tandem mass spectrometry and proton/carbon-13 nuclear magnetic resonance, namely petunidin-3-O-[rhamnopyranosyl-(trans-p-coumaroyl)]-5-O-(β-d-glucopyranoside) (trans-Pt3R5G) and petunidin-3-O-[rhamnopyranosyl-(cis-p-coumaroyl)]-5-O-(β-d-glucopyranoside) (cis-Pt3R5G), with a molar ratio of 9:1. Three purification grades of Pt3R5G all showed excellent inhibitory effects on ACE, with the half maximal inhibitory concentration (IC50 ) values being 0.562, 0.421, and 0.106 mg·mL-1 . Increasing the purity may reduce the IC50 within a certain concentration range. An enzymatic kinetic experiment showed that the inhibitory effect of Pt3R5G on ACE was reversible and non-competitive: Pt3R5G and substrate were not in competition for the active sites of ACE. Molecular docking technology further revealed the possible mechanism was that Pt3R5G and ACE amino acid residues were interacting by hydrogen bonds to exert the inhibitory effect.

CONCLUSION

The results indicated that Pt3R5G from LRM was highly effective at inhibiting ACE activity in vitro, with the hydrogen bonds of Pt3R5G and ACE amino acid residues exerting the inhibition. As a potential plant-based ACE inhibitor, Pt3R5G can be used as a functional ingredient for antihypertensive effects. © 2023 Society of Chemical Industry.

Physicochemical properties, phenolic content and in vitro digestion profile of Chinese black rice (Oryza sativa L.)

Yangxian black rice, as one of the ancient Chinese black rice varieties, is widely planted in the Yangxian area of China. This study investigated the physicochemical properties, phenolic content and in vitro digestion profile of Chinese black rice under gradient milling treatment. The chemical composition, color, pasting and thermal properties of black rice with different milling degrees were comprehensively compared. In vitro digestion analysis indicated that cooked rice flour had higher rapidly digestible starch (RDS) and lower resistant starch (RS) contents compared with the uncooked one. Besides, all cooked black rice samples exhibited high predicted glycemic index (pGI) value and whole black rice showed a lower pGI than refined rice. The microstructure and the abundance of phenolic compounds in the solid matrix during different treatments or digestion stages were observed by CLSM. Furthermore, a total of 102 phenolic constituents were absolutely quantified by targeted metabolomics techniques. Methanol extraction and moderate cooking treatment contributed to the release of phenolic compounds from the solid matrix of whole black rice. Besides, compared to the gastric digestion stage, the transition in the intestinal environment caused a decrease in the majority of the analyzed polyphenols. Identifying the phenolic constituents was favorable for a better elucidation of the chemical basis of the function and nutritional value of Chinese black rice.

Optimization of Supercritical Carbon Dioxide Extraction of Polyphenols from Black Rosehip and Their Bioaccessibility Using an In Vitro Digestion/Caco-2 Cell Model

The fruits of Rosa pimpinellifolia are rich sources of (poly)phenols, however they are underutilized due to the limited information available. The influence of the pressure, temperature, and co-solvent concentration (aqueous ethanol) of the supercritical carbon dioxide extraction (SCO₂-aqEtOH) on the extraction yield, total phenolic-, total anthocyanin-, catechin-, cyanidin-3-O-glucoside contents, and total antioxidant activity of black rosehip was investigated simultaneously. The maximum obtained total phenolic and total anthocyanin contents under the optimized extraction conditions (280 bar, 60 °C and 25% ethanol, v/v) were 76.58 ± 4.25 mg gallic acid equivalent and 10.89 ± 1.56 mg cyanidin-3-O-glucoside equivalent per g of the dry fruits, respectively. The optimal extract obtained by SCO₂-aqEtOH was compared to two other extraction procedures: ultrasonication using ethanol as solvent (UA-EtOH) and pressurized hot water extraction (PH-H₂O). The bioaccessibility and cellular metabolism of the phenolic compounds in the different black rosehip extracts were assessed using an in vitro digestion coupled with a human intestinal Caco-2 cell model. The in vitro digestive stability and cellular uptake of the phenolic compounds had no significant difference among the different extraction methods. The results of this study confirm the efficiency of SCO₂-aqEtOH extraction for phenolic compounds and, in particular, for anthocyanins, and could be used to produce new functional food ingredients from black rosehip with high antioxidant power containing both hydrophilic and lipophilic compounds.

The effect of purple-black barberry (Berberis integerrima) on blood pressure in subjects with cardiovascular risk factors: a randomized controlled trial

ETHNOPHARMACOLOGICAL RELEVANCE

Berberis integerrima commonly known as "barberry" belongs to the Berberidaceae family and has been used as a medicinal plant in Iranian traditional medicine.

AIM OF THE STUDY

Our aim in this study was to investigate the effects of barberry consumption on blood pressure (BP).

MATERIALS AND METHODS

Eighty-four medicated hypertensive patients were selected and randomly allocated to barberry and placebo groups. The barberry group received 10 g/day dried purple-black barberry powder, once daily, for 2-months. Systolic, diastolic, and mean arterial BP was assessed through 24-h ambulatory BP monitoring before and after 2-month treatment. The estimation of sodium and potassium intake was done through measurement of sodium and potassium in 24-h urinary samples. Plasma and urinary nitrite, and nitrate (NOx) levels, as well as plasma angiotensin-converting enzyme (ACE) activity, were also determined.

RESULTS

Seventy-eight participants with an average age of 54.12 ± 10.32 years and BMI of 27.93 ± 2.22 kg/m² completed the study. There was no significant difference in body weight, physical activity, and the 24-h urinary sodium and potassium excretion between the two groups before and after the study. After adjusting for baseline values and changes in sodium intake, systolic, and mean arterial BP decreased significantly in the barberry group compared to the placebo group (p = 0.015 and p = 0.008, respectively). Plasma NOx levels and ACE activity were not different between the two groups, but urinary NOx was increased significantly in the barberry group compared to the placebo group (p = 0.008).

CONCLUSIONS

In patients treated with antihypertensive drugs, daily consumption of purple-black barberry can be effective in improving systolic BP control.

Inhibitory activities of grape bioactive compounds against enzymes linked with human diseases

A quest for identification of novel, safe and efficient natural compounds, as additives in the modern food and cosmetic industries, has been prompted by concerns about toxicity and side effects of synthetic products. Plant phenolic compounds are one of the most documented natural products due to their multifarious biological applications. Grape (Vitis vinifera) is an important source of phenolic compounds such as phenolic acids, tannins, quinones, coumarins and, most importantly, flavonoids/flavones. This review crisply encapsulates enzyme inhibitory activities of various grape polyphenols towards different key human-ailment-associated enzymes: xanthine oxidase (gout), tyrosinase (hyperpigmentation), α-amylase and α-glucosidase (diabetes mellitus), pancreatic lipase (obesity), cholinesterase (Alzheimer's disease), angiotensin i-converting enzymes (hypertension), α-synuclein (Parkinson's disease) and histone deacetylase (various diseases). The review also depicts the enzyme inhibitory mechanism of various grape polyphenols and briefly discusses their stature as potential therapeutic and drug development candidates. KEY POINTS: • Nineteen major bioactive polyphenols from the grape/grape products and their disease targets are presented • Sixty-two important polyphenols as enzyme inhibitors from grape/grape products are presented • A thorough description and graphical presentation of biological significance of polyphenols against various diseases.