Potential Role and Mechanism of Mulberry Extract in Immune Modulation: Focus on Chemical Compositions, Mechanistic Insights, and Extraction Techniques

Mulberry is a rapidly growing plant that thrives in diverse climatic, topographical, and soil types, spanning temperature and temperate countries. Mulberry plants are valued as functional foods for their abundant chemical composition, serving as a significant reservoir of bioactive compounds like proteins, polysaccharides, phenolics, and flavonoids. Moreover, these compounds displayed potent antioxidant activity by scavenging free radicals, inhibiting reactive oxygen species generation, and restoring elevated nitric oxide production induced by LPS stimulation through the downregulation of inducible NO synthase expression. Active components like oxyresveratrol found in Morus demonstrated anti-inflammatory effects by inhibiting leukocyte migration through the MEK/ERK signaling pathway. Gallic and chlorogenic acids in mulberry leaves (ML) powder-modulated TNF, IL-6, and IRS1 proteins, improving various inflammatory conditions by immune system modulation. As we delve deeper into understanding its anti-inflammatory potential and how it works therapeutically, it is crucial to refine the extraction process to enhance the effectiveness of its bioactive elements. Recent advancements in extraction techniques, such as solid-liquid extraction, pressurized liquid extraction, superficial fluid extraction, microwave-assisted extraction, and ultrasonic-assisted extraction, are being explored. Among the extraction methods tested, including Soxhlet extraction, maceration, and ultrasound-assisted extraction (UAE), UAE demonstrated superior efficiency in extracting bioactive compounds from mulberry leaves. Overall, this comprehensive review sheds light on the potential of mulberry as a natural immunomodulatory agent and provides insights into its mechanisms of action for future research and therapeutic applications.

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.

The Effect of Maturity and Extraction Solvents on Bioactive Compounds and Antioxidant Activity of Mulberry (Morus alba) Fruits and Leaves

Cultivation location, maturity levels, and extraction solvents could affect the bioactive compounds and biological activities of mulberry (Morus alba Linnaeus). The lack of study on Malaysia-grown mulberry causes its underutilization. This study investigated the bioactive compound content and the antioxidant activity of Sabah-grown mulberry at two different maturity stages (fruits: red mature and black fully ripe; leaves: young and mature) extracted using 70% (v/v) methanol, 60% (v/v) ethanol, and 65% (v/v) acetone. Analyses showed that mulberry fruits demonstrated maturity-dependent increment (except UHPLC-DAD quantification), while the leaves revealed maturity-dependent reduction. Principal component analysis (PCA) displayed 65% (v/v) acetone black fully ripe fruits as the best phenolics and antioxidant sources. However, the 60% (v/v) ethanol black fully ripe fruits contained 20.08-68.43% higher total anthocyanins. Meanwhile, the 65% (v/v) acetone and 70% (v/v) methanol red mature fruits were higher in chlorogenic acid (27.53-47.12%) and rutin (31.42-35.92%) than other fruit extracts, respectively. For leaves, 65% (v/v) acetone young leaves were the best phenolics and antioxidant sources. However, the 60% (v/v) ethanol young leaves possessed greater chlorogenic acid (19.56-74.11%) than other leaf extracts. Overall, Malaysia-grown mulberry is rich in phenolics and antioxidants, suggesting its potential application in food and pharmaceutical products.

Bioavailability and Bioactivities of Polyphenols Eco Extracts from Coffee Grounds after In Vitro Digestion

Coffee grounds are a valuable source of bioactive compounds. In Romania, most of the amount obtained is lost through non-recovery; the rest is occasionally used as organic fertilizer. The coffee grounds were selected according to the roasting degree: blonde roasted (BR), medium roasted (MR), and dark roasted (DR). The study aimed to evaluate three extracts, obtained with a mixture of ethanol/water/acetic acid (50/49.5/0.5), depending on the roasting degree. The majority phenolic component, the antioxidant, and anti-inflammatory effect, as well as the role that gastrointestinal transit had on the bioavailability of bioactive compounds were determined. Chlorogenic acid was inversely proportional to the roasting degree. BR showed the best correlation between antioxidant and anti-inflammatory activities in vitro/in vivo. The antiproliferative capacity of the extracts determined an inhibitory effect on the tumor cells. Antimicrobial activities, relevant in the control of type 2 diabetes, were exerted through the inhibition of microbial strains (Escherichia coli). Following gastric digestion, BR demonstrated a maximum loss of 20% in the stomach. The recovery of coffee grounds depended on the pattern of functional compounds and the bioavailability of the main component, chlorogenic acid.