Antioxidant Constituents of Cotoneaster melanocarpus Lodd

The Inhibition of α-Glucosidase, α-Amylase and Protein Glycation by Phenolic Extracts of Cotoneaster bullatus, Cotoneaster zabelii, and Cotoneaster integerrimus Leaves and Fruits: Focus on Anti-Hyperglycemic Activity and Kinetic Parameters

Cotoneaster species have gained significant importance in traditional Asian medicine for their ability to prevent and treat hyperglycemia and diabetes. Therefore, in this study, some aspects of the beneficial health effects of hydromethanolic extracts of C. bullatus, C. zabelii, and C. integerrimus leaves and fruits were evaluated, including their influence on α-glucosidase, α-amylase, and nonenzymatic protein glycation. The activity was investigated in relation to the polyphenolic profile of the extracts determined by UV-spectrophotometric and HPLC-PDA-fingerprint methods. It was revealed that all leaf and fruit extracts are a promising source of biological components (caffeic acid pseudodepsides, proanthocyanidins, and flavonols), and the leaf extracts of C. bullatus and C. zabelii contain the highest levels of polyphenols (316.3 and 337.6 mg/g in total, respectively). The leaf extracts were also the most effective inhibitors of digestive enzymes and nonenzymatic protein glycation. IC50 values of 8.6, 41.8, and 32.6 µg/mL were obtained for the most active leaf extract of C. bullatus (MBL) in the α-glucosidase, α-amylase, and glycation inhibition tests, respectively. In the kinetic study, MBL was displayed as a mixed-type inhibitor of both enzymes. The correlations between the polyphenol profiles and activity parameters (|r| > 0.72, p < 0.05) indicate a significant contribution of proanthocyanidins to the tested activity. These results support the traditional use of Cotoneaster leaves and fruits in diabetes and suggest their hydrophilic extracts be promising in functional applications.

Can Extracts from the Leaves and Fruits of the Cotoneaster Species Be Considered Promising Anti-Acne Agents?

This study aimed to evaluate the phenolic profile and biological activity of the extracts from the leaves and fruits of Cotoneaster nebrodensis and Cotoneaster roseus. Considering that miscellaneous species of Cotoneaster are thought to be healing in traditional Asian medicine, we assumed that this uninvestigated species may reveal significant therapeutic properties. Here, we report the simultaneous assessment of chemical composition as well as biological activities (antioxidant, anti-inflammatory, antibacterial, and cytotoxic properties) of tested species. Complementary LC-MS analysis revealed that polyphenols (especially flavonoids and proanthocyanidins) are the overriding phytochemicals with the greatest significance in tested biological activities. In vitro chemical tests considering biological activities revealed that obtained results showed different values depending on concentration, extraction solvent as well as phenolic content. Biological assays demonstrated that the investigated extracts possessed antibacterial properties and were not cytotoxic toward normal skin fibroblasts. Given the obtained results, we concluded that knowledge of the chemical composition and biological activities of investigated species are important to achieve a better understanding of the utilization of these plants in traditional medicine and be useful for further research in their application to treat various diseases, such as skin disorders.

The Anti-Acne Potential and Chemical Composition of Two Cultivated Cotoneaster Species

In light of current knowledge on the role of reactive oxygen species and other oxidants in skin diseases, it is clear that oxidative stress facilitates inflammation and is an important factor involved in skin diseases, i.e., acne. Taking into consideration the fact that some Cotoneaster plants are valuable curatives in skin diseases in traditional Asian medicine, we assumed that thus far untested species C. hsingshangensis and C. hissaricus may be a source of substances used in skin diseases. The aim of this study was to evaluate the antioxidant, anti-inflammatory, antimicrobial, and cytotoxic activities of their various extracts. LC-MS analysis revealed the presence of 47 compounds (flavonoids, phenolic acids, coumarins, sphingolipids, carbohydrates), while GC-MS procedure allowed for the identification of 42 constituents (sugar derivatives, phytosterols, fatty acids, and their esters). The diethyl ether fraction of C. hsingshangensis (CHs-2) exhibited great ability to scavenge free radicals and good capacity to inhibit cyclooxygenase-1, cyclooxygenase-2, lipoxygenase, and hyaluronidase. Moreover, it had the most promising power against microaerobic Gram-positive strains, and importantly, it was non-toxic toward normal skin fibroblasts. Taking into account the value of the calculated therapeutic index (>10), it is worth noting that CHs-2 can be subjected to in vivo study and constitutes a promising anti-acne agent.

An Overview of the Genus Cotoneaster (Rosaceae): Phytochemistry, Biological Activity, and Toxicology

Traditional herbal medicines have become a subject of global importance with both medical and economic implications. The regular consumption of herbal drugs has led to serious concerns regarding their quality, effectiveness, and safety. Thus, relevant scientific evidence has become an important criterion for the acceptance of traditional health claims. The genus Cotoneaster Medikus provides numerous species traditionally used in Asian medicine for the treatment of haemorrhoids, diabetes, and cardiovascular diseases. This review summarises the achievements of modern research on the Cotoneaster taxa, including ethnobotany, phytochemistry, pharmacology, and toxicology. To date, more than 90 compounds have been isolated or analytically identified in Cotoneaster leaves, fruits, flowers or twigs. These phytochemicals are categorised into flavonoids, procyanidins, phenolic acids, cotonefurans, cyanogenic glycosides, triterpenes, sterols, fatty acids, volatile compounds, and carbohydrates, and many of them are responsible for Cotoneaster pharmacological properties including antioxidant, anti-inflammatory, antimicrobial, antiparasitic, hepatoprotective, anti-diabetic or anti-dyslipidaemic activity. In order to ensure the safety of pharmaceutical applications, the potential toxicity of Cotoneaster extracts has also been investigated. In conclusion, this systematic review provides an important reference base for further study into the various medical applications of both the dry extracts and pure isolates of Cotoneaster species.

Contribution of Individual Polyphenols to Antioxidant Activity of Cotoneaster bullatus and Cotoneaster zabelii Leaves-Structural Relationships, Synergy Effects and Application for Quality Control

Cotoneaster plants are sources of traditional medicines and dietary products, with health benefits resulting from their phenolic contents and antioxidant activity. In this work, active markers of the leaves of C. bullatus and C. zabelii were characterized and evaluated in an integrated phytochemical and biological activity study. Based on UHPLC-PDA-ESI-MS³ analysis, twelve analytes were preselected from the constituents of the hydromethanolic leaf extracts, and two of them—caffeoylmalic acid and quercetin 3--O-β-d-(2″--O-β-d-xylopyranosyl)galactopyranoside (QPH)—were isolated for full identification (NMR spectroscopy: ¹H, ¹³C, COSY, HMBC, HMQC). All selected phenolics contributed to the antioxidant activity of the extracts, which was demonstrated in chemical in vitro tests (DPPH, FRAP, and TBARS) and in a biological model of human plasma exposed to oxidative/nitrative stress induced by peroxynitrite. This contribution was partly due to the synergy between individual polyphenols, evidenced by an isobolographic analysis of the interactions of (–)-epicatechin, chlorogenic acid, and QPH as representatives of three classes of Cotoneaster polyphenols. All twelve markers, including also neochlorogenic acid, cryptochlorogenic acid, procyanidin B2, procyanidin C1, rutin, hyperoside, isoquercitrin, and quercitrin, were thus applied as calibration standards, and a fast, accurate, reproducible, and fully validated RP-HPLC-PDA method for quality control and standardization of the target extracts was proposed.

Analysis of leaf flavonoid composition of some Iranian Cotoneaster Medik. (Rosaceae) species

The genus Cotoneaster consists of unarmed shrubs that naturally distributed in north parts of Iran. It is a problematic genus, and there are many discussions about its species number in Iran as well the World. Recently, M Khatamsaz has been listed 19 species of it in Iran. In the current research, we studied leaf flavonoid composition of seven Cotoneaster species from Iran. These species were harvested from the northern provinces of the country and their leaf ethanolic extracts were subjected to HPLC, for detection the types and amounts of their flavonoid compounds. We identified four flavonoid compounds: rutin, myricetin, quercetin, and kaempferol. The concentration of these flavonoids differed between the species, moreover amount of each flavonoid also varied among the studied species. All of them were registered in the studied species, except for myricetin, which was not observed in C. nummularius. The highest amount of flavonoids were detected in C. nummularius, while C. discolor had the lowest one. The evaluated species divided into four distinct group in UPGMA tree. According to CA-Joined plot, each group was characterized by species amount of flavonoid(s). All of evaluated species belonged to the same section of the genus, therefore our findings revealed that the flavonoid data were useful at sectional level for identification of the species.

Hyperoside protects against heart failure-induced liver fibrosis in rats

Heart failure (HF) is an end-stage of various serious cardiovascular diseases, which causes liver injury. Hyperoside has been reported to exert protective effect on liver injury and fibrosis. However, the role and related mechanisms of hyperoside in HF-induced liver fibrosis are still unclear. In the current study, we established a model of HF via aortocaval fistula (ACF) in rats in vivo. Hyperoside treatment in ACF rats increased cardiac output, the maximum peak rate of rise/fall in left ventricular pressure (+dP/dt, -dP/dt) and LV ejection fraction (LVEF), decreased LV end-systolic pressure (LVESP), LV end-diastolic pressure (LVEDP) and LV end-systolic volume (LVESV), and reduced heart weight/body weight ratio in a dose-dependent manner. Moreover, hyperoside could attenuate liver fibrosis and injury in ACF rats, as evidenced by reduction of fibrosis area and hydroxyproline content, amelioration of edema and degeneration of liver cell vacuoles, and inhibition of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) levels. Further, α-smooth-muscle actin (α-SMA), collagen I, profibrotic factor-connective tissue growth factor (CTGF), matrix metalloproteinase-2 (MMP2) and MMP9 levels were down-regulated in hyperoside-treated ACF rats. Additionally, hyperoside inhibited the activation of TGF-β1/Smad pathway. Finally, we confirmed that hyperoside suppressed TGF-β1-mediated hepatic stellate cell activation in vitro. Collectively, hyperoside showed a suppressive role in HF-induced liver fibrosis and injury.

Preventive effect of purgative manna on neonatal jaundice: A double blind randomized controlled clinical trial

ETHNOPHARMACOLOGICAL RELEVANCE

Cotoneaster nummularioides Pojark manna (Shir-e-Khesht) is popular in Persian medicine. Different effects of some Cotoneaster species manna include antibacterial, antioxidant, anticancer, and hepatoprotective effects, as well as bilirubin serum levels reduction. Cotoneaster species manna is used in many parts of Iran as a laxative and accelerates the passage of meconium. Neonatal jaundice has relatively costly and sometimes invasive therapeutic interventions, which its prevention from becoming severe cases can be a priority in neonatal medicine.

AIM OF THE STUDY

The aim of this study was to evaluate the effectiveness of an herbal product (Purgative Manna, native to Iran and Asian countries) in preventing severe cases of jaundice and reducing total bilirubin levels in neonates.

MATERIALS AND METHODS

This randomized double-blind controlled clinical trial included full-term babies. Four hundred and forty-five (445) eligible neonates were assigned to two groups using the block balanced randomization method; 222 neonates received the Purgative Manna product as drops, and 223 neonates received placebo drops. The neonates received a dose of 5 drops per kilogram of neonatal weight (divided into three doses per day) for three days. The treatment period was three days, and a 24-h (three times) examination was performed to measure the initial outcome of the trial (i.e., the total serum bilirubin level). The secondary outcomes of this trial were the need for hospitalization due to jaundice and/or phototherapy from 4 to 14 days after birth, the frequency of defecation within 24 h, and the triple complications of diarrhoea, dehydration symptoms, and abdominal colic.

RESULTS

In this study, 220 neonates in the Purgative Manna product group and 222 neonates in the placebo group completed their interventions within the predicted period of the study. At the end of study, the total bilirubin level in the Purgative Manna treated group was significantly lower than that of the placebo group. The difference between the mean total bilirubin levels of the two groups was approximately 2.1 mg/dl on the third day after treatment, with an effect size of 0.79 (95% CI: 0.06-0.98). The relative risk for reducing the need for hospitalization or phototherapy in the group treated with Purgative Manna drops was 0.26, compared with the placebo group. The risk of occurrence of severe jaundice or phototherapy in the Purgative Manna group was 75% lower than that of the placebo group. The median frequency of defecation in the intervention group at three time intervals in the first, second and third days after treatment was 1-2 times more than that of the comparison group (p < 0.001).

CONCLUSIONS

Meanwhile, considering the fact that one in every eight neonates who used the product avoided having a severe and high-risk case of jaundice or the need for phototherapy intervention (even through an exchange transfusion), the use of Purgative Manna drops can be recommended; however, further study is necessary.

Polyphenol-Rich Extracts from Cotoneaster Leaves Inhibit Pro-Inflammatory Enzymes and Protect Human Plasma Components against Oxidative Stress In Vitro

The present study investigated the phenolic profile and biological activity of dry extracts from leaves of C. bullatus, C. zabelii and C. integerrimus-traditional medicinal and dietary plants-and evaluated their potential in adjunctive therapy of cardiovascular diseases. Complementary UHPLC-PDA-ESI-MS³, HPLC-PDA-fingerprint, Folin-Ciocalteu, and n-butanol/HCl assays of the extracts derived by fractionated extraction confirmed that they are rich in structurally diverse polyphenols (47 analytes, content up to 650.8 mg GAE/g dw) with proanthocyanidins (83.3⁻358.2 mg CYE/g) dominating in C. bullatus and C. zabelii, and flavonoids (53.4⁻147.8 mg/g) in C. integerrimus. In chemical in vitro tests of pro-inflammatory enzymes (lipoxygenase, hyaluronidase) inhibition and antioxidant activity (DPPH, FRAP), the extracts effects were dose-, phenolic- and extraction solvent-dependent. The most promising polyphenolic extracts were demonstrated to be effective antioxidants in a biological model of human blood plasma-at in vivo-relevant levels (1⁻5 µg/mL) they normalized/enhanced the non-enzymatic antioxidant capacity of plasma and effectively prevented peroxynitrite-induced oxidative/nitrative damage of plasma proteins and lipids. As demonstrated in cytotoxicity tests, the extracts were safe-they did not affect viability of human peripheral blood mononuclear cells. In conclusion, Cotoneaster leaves may be useful in development of natural-based products, supporting the treatment of oxidative stress/inflammation-related chronic diseases, including cardiovascular disorders.

Phenolic Profile and Antioxidant Potential of Leaves from Selected Cotoneaster Medik. Species

The antioxidant efficiency of 70% aqueous methanolic extracts from the leaves of twelve selected Cotoneaster Medik. species was evaluated using four complementary in vitro tests based on SET- (single electron transfer) and HAT-type (hydrogen atom transfer) mechanisms (DPPH, FRAP, O₂(•-) and H₂O₂ scavenging assays). The samples exhibited the dose-dependent responses in all assays with activity parameters of EC50 = 18.5-34.5 µg/mL for DPPH; 0.9-3.8 mmol Fe(2+)/g for FRAP; SC50 = 27.7-74.8 µg/mL for O₂(•-); and SC50 = 29.0-91.3 µg/mL for H₂O₂. Significant linear correlations (|r| = 0.76-0.97, p < 0.01) between activity parameters and total contents of phenolics (5.2%-15.4% GAE) and proanthocyanidins (2.1%-15.0% CYE), with weak or no effects for chlorogenic acid isomers (0.69%-2.93%) and total flavonoids (0.28%-1.40%) suggested that among the listed polyphenols, proanthocyanidins are the most important determinants of the tested activity. UHPLC-PDA-ESI-QTOF-MS analyses led to detection of 34 polyphenols, of which 10 B-type procyanidins, 5 caffeoylquinic acids and 14 flavonoids were identified. After cluster analysis of the data matrix, the leaves of Cotoneaster zabelii, C. splendens, C. bullatus, C. divaricatus, C. hjelmqvistii and C. lucidus were selected as the most promising sources of natural antioxidants, exhibiting the highest phenolic levels and antioxidant capacities, and therefore the greatest potential for pharmaceutical applications.