Bioactivity, phytochemistry studies and subacute in vivo toxicity of ethanolic leaf extract of white mulberry (Morus alba linn.) in female mice

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional uses of Morus alba L. leaf extracts (MLE) have been reported for treating hyperglycaemia and diabetes. Phytochemical compounds in the leaves demonstrated the ability to enhance insulin sensitivity and β-cell secretory function, suggesting their potential value in reducing blood glucose and treating diabetes. However, the phytochemical constituents and safety of the herbal medicines need to be verified in each experimental field from different growing areas. Studies on the phytochemistry and toxicity of Morus alba leaves in Southeast Asia, especially in Brunei, have never been investigated.

AIM OF THE STUDY

This study aimed to investigate the bioactivity and phytochemistry of Morus alba ethanolic leaf extract from Brunei Darussalam and its subacute toxic effects in the Institute of Cancer Research (ICR) female mice.

MATERIALS AND METHODS

The phenolic yield and antioxidant of the extract were analysed. Meanwhile, liquid chromatography-mass spectrometry and high-performance liquid chromatography were utilised to determine the phenolic compound of the MLE. In the subacute toxicity study, twenty-five female mice were randomly divided into five groups: the control group, which received oral gavage of 5% dimethyl sulfoxide solvent (DMSO), and the MLE treatment group, which received the extract at a dose of 125, 250, 500 and 1000 mg/kg. Physiology, haematology, biochemistry, and histology were evaluated during the study.

RESULTS

Morus alba leaf depicted total phenolic 10.93 mg gallic acid equivalents (GAE)/g dry weight (DW), flavonoid 256.67 mg quercetin equivalents (QE)/g DW, and antioxidant bioactivity content of 602.03 IC50 μg/mL and 13.21 mg Fe2+/g DW. Twenty compounds in the Morus alba ethanolic leaf extract were identified, with chlorogenic acid (305.60 mg/100 g DW) as the primary compound. As for subacute toxicity in this study, neither mortality nor haematological changes were observed. On the other hand, administration of 500 and 1000 mg/kg MLE resulted in mild hepatocellular injury, as indicated by a significant (p < 0.05) increase in liver enzyme activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The histopathological score showed mild hepatocellular necrosis in administering 250, 500, and 1000 mg/kg of MLE. The parameters of renal injury were within normal limits, with the increase in eosinophilic cytoplasm observed in the histological scoring at 1000 mg/kg of MLE.

CONCLUSIONS

Morus alba leaf extract showed abundant polyphenols. In a study on subacute toxicity, MLE caused mild hepatotoxicity in mice. The toxic effect of the extract may be due to kaempferol and chlorogenic acid compounds. The 125 mg/kg MLE dose was safe with no adverse effects.

Neochlorogenic Acid Attenuates Hepatic Lipid Accumulation and Inflammation via Regulating miR-34a In Vitro

Neochlorogenic acid (5-Caffeoylquinic acid; 5-CQA), a major phenolic compound isolated from mulberry leaves, possesses anti-oxidative and anti-inflammatory effects. Although it modulates lipid metabolism, the molecular mechanism is unknown. Using an in-vitro model of nonalcoholic fatty liver disease (NAFLD) in which oleic acid (OA) induced lipid accumulation in HepG2 cells, we evaluated the alleviation effect of 5-CQA. We observed that 5-CQA improved OA-induced intracellular lipid accumulation by downregulating sterol regulatory element-binding protein 1 (SREBP1) and fatty acid synthase (FASN) expression, which regulates the fatty acid synthesis, as well as SREBP2 and HMG-CoA reductases (HMG-CoR) expressions, which regulate cholesterol synthesis. Treatment with 5-CQA also increased the expression of fatty acid β-oxidation enzymes. Remarkably, 5-CQA attenuated OA-induced miR-34a expression. A transfection assay with an miR-34a mimic or miR-34a inhibitor revealed that miR-34a suppressed Moreover, Sirtuin 1 (SIRT1) expression and inactivated 5’ adenosine monophosphate-activated protein kinase (AMPK). Our results suggest that 5-CQA alleviates lipid accumulation by downregulating miR-34a, leading to activation of the SIRT1/AMPK pathway.

A Review on Electrochemical Sensors and Biosensors Used in Chlorogenic Acid Electroanalysis

Chlorogenic acid (5-O-caffeoylquinic acid) is a phenolic compound from the hydroxycinnamic acid family. Epidemiological, biological, and biochemical studies concur to support the beneficial role of chlorogenic acid in human health, along with other dietary phenolic compounds. Thus, chlorogenic acid has been reported to exert inhibitory effects on carcinogenesis in the large intestine, liver, and tongue, and a protective action on oxidative stress in vivo, together with anti-inflammatory, antidiabetic and antihypertensive activities. It is also claimed to have antifungal, antibacterial and antiviral effects with relatively low toxicity and side effects, alongside properties that do not lead to antimicrobial resistance. Due to its importance, numerous methods for determining chlorogenic acid (CGA), as well as for its derivatives from coffee beans and other plants, were elaborated. The most frequently used methods are infrared spectroscopy, high performance liquid chromatography (HPLC), capillary electrophoresis, liquid chromatography-mass spectrometry and chemiluminescence. Although these methods proved to be efficient for quantifying CGA and its derived products, a number of deficiencies were identified: they are time consuming, laborious, and require expensive instruments. Therefore, electrochemical methods have been developed and used in the determination of CGA in different nutraceuticals or food products. The present review aims to present the main progresses and performance characteristics of electrochemical sensors and biosensors used to detect CGA, as it is reported in a high number of relevant scientific papers published mainly in the last decade.

Identification of phytochemicals and antioxidant activity of Premna microphylla Turcz. stem through UPLC-LTQ-Orbitrap-MS

Premna microphylla Turcz. is a commonly used traditional Chinese medicine totreatdysentery and appendicitis. Present study is focused to explore antioxidants and other compounds in the Premna microphylla Turcz. stem. Assessment of chemical composition was done with high sensitivity UPLC-LTQ-Orbitrap-MS and for Separation Thermo Hypersil Gold (100 mm × 2.1 mm, 1.9 µm) was used while electrospray ionization (ESI) was used for the mass spectrometry. 18 compounds were identified including Vitexin (1), Schaftoside (2), Vicenin-2 (3), Apigenin-6, 8-di-C-arabinoside (4), Apigenin-7-O-β-d-glucoside (5), Carnosic acid (6), Apigenin-8-C-β-d-xylopyranoside (7), Prostratin (8), Aurantio-obtusin-β-d-glucoside (9), Royleanone (10), 5-hydroxy-7,3',4'-Trimethoxy flavonols (11), 6-Hydroxy-5,6-dehydrosugiol (12), 14-deoxycoleon (13), Arucadiol (14), Obtusinone-B (15), Trehalose (16), Citric acid (17) and Betaine (18). Among these, 6 compounds including (6), (8), (9), (16), (17) and (18) were identified first time within this genus and plant. Study highlights the importance of Premna microphylla Turcz. stem extract for strong therapeutic potential against oxidation-related diseases.

Rapid Detection and Characterization of Steroidal Saponins in the Root of Asparagus cochinchinensis by High-Performance Liquid Chromatography Coupled to Electrospray Ionization and Quadrupole Time-of-Flight Mass Spectrometry

The dried root of Asparagus cochinchinensis (RAC) has been used as an important traditional Chinese medicine for a long time in China. Steroidal saponins (SSs) are considered to be the main active ingredients of this herb. However, the isolation and structural determination of SSs from RAC are time-consuming and laborious. For this reason, the development of new methods for the separation and characterization of SSs is highly desirable. In this study, a new high-performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS/MS) method with precursor ions and the corresponding fragment ions was developed for the identification of SSs in RAC. Finally, 30 SSs have been detected and identified, including 17 potential new compounds. This is the first systematic study of SSs in RAC by HPLC-ESI-QTOF-MS/MS method.