Nine phenylethanoid glycosides from Magnolia officinalis var. biloba fruits and their protective effects against free radical-induced oxidative damage

Response Surface Methodology in Optimising the Extraction of Polyphenolic Antioxidants from Flower Buds of Magnolia × soulangeana Soul.-Bod. var. 'Lennei' and Their Detailed Qualitative and Quantitative Profiling

A response surface methodology (RSM) with a central composite design (CCD) was developed to predict and apply the best ultrasound-assisted extraction (UAE) conditions, including the extraction time, the composition of aqueous-ethanolic extractants, and the solvent-to-plant-material ratio, for obtaining the highest yields of different types of polyphenolic components from the dried flower buds of Magnolia × soulangeana Soul.-Bod. var. 'Lennei' (MSL). The novel approach in the RSM procedure resulted from the simultaneous optimisation of UAE conditions to obtain extracts with the highest antioxidant and antiradical potential (examined as dependent variables), using appropriate spectrophotometric assays, with Folin-Ciocâlteu and 2,2-diphenyl-1-picrylhydrazyl reagents, respectively. The use of 66.8% (V/V) ethanol as the extraction solvent during the 55.2 min extraction protocol and the ratio of extractant volume to herbal substance of 46.8 mL/g gave the highest total yield of bioactive antioxidant phenolics in the extract obtained. For this herbal preparation, a qualitative and quantitative analysis was performed using combined chromatographic (LC), spectroscopic (PDA), and tandem mass spectrometric (ESI-QToF-MS/MS) techniques. A detailed phytochemical profiling, conducted for the first time, documented substantial amounts of various polyphenolic antioxidants, especially phenylethanoids and flavonoids, in the MSL flower buds. Their average total content exceeded 30.3 and 36.5 mg/g dry weight, respectively.

The Potential of Magnolia spp. in the Production of Alternative Pest Control Substances

The irrational use of synthetic pesticides in agriculture has had negative impacts on ecosystems and contributed to environmental pollution. Botanical pesticides offer a clean biotechnological alternative to meet the agricultural challenges posed by pests and arthropods. This article proposes the use of fruit structures (fruit, peel, seed, and sarcotesta) of several Magnolia species as biopesticides. The potential of extracts, essential oils, and secondary metabolites of these structures for pest control is described. From 11 Magnolia species, 277 natural compounds were obtained, 68.7% of which were terpenoids, phenolic compounds, and alkaloids. Finally, the importance of a correct management of Magnolia species to ensure their sustainable use and conservation is stressed.

Disruption of Bacterial Thiol-Dependent Redox Homeostasis by Magnolol and Honokiol as an Antibacterial Strategy

Some traditional Chinese medicines (TCMs) possess various redox-regulation properties, but whether the redox regulation contributes to antibacterial mechanisms is not known. Here, ginger juice processed Magnoliae officinalis cortex (GMOC) was found to show strong antibacterial activities against some Gram-positive bacteria, but not Gram-negative bacteria including E. coli, while the redox-related transcription factor oxyR deficient E. coli mutant was sensitive to GMOC. In addition, GMOC and its main ingredients, magnolol and honokiol, exhibited inhibitory effects on the bacterial thioredoxin (Trx) system, a major thiol-dependent disulfide reductase system in bacteria. The effects of magnolol and honokiol on cellular redox homeostasis were further verified by elevation of the intracellular ROS levels. The therapeutic efficacies of GMOC, magnolol and honokiol were further verified in S. aureus-caused mild and acute peritonitis mouse models. Treatments with GMOC, magnolol and honokiol significantly reduced the bacterial load, and effectively protected the mice from S. aureus-caused peritonitis infections. Meanwhile, magnolol and honokiol produced synergistic effects when used in combination with several classic antibiotics. These results strongly suggest that some TCMs may exert their therapeutic effects via targeting the bacterial thiol-dependent redox system.

Identification of the target protein and molecular mechanism of honokiol in anti-inflammatory action

BACKGROUND

Searching the targets of natural products is very important for drug discovery and elucidating the mechanism of drug action and disease. Honokiol (HK), as the major active component of Magnolia officinalis Rehder & E.H.Wilson, has been widely used in medicine and cosmetics. Among its bioactivities, its anti-inflammatory activity is particularly impressive. However, the target protein of HK in anti-inflammatory action and its regulatory mechanism are unclear.

PURPOSE

Here, we identified the target protein and molecular mechanism of the anti- inflammatory action of HK.

METHODS

First, an LPS-induced septic shock model and DSS-induced ulcerative colitis model were used to assess the anti-inflammatory efficacy of HK. Second, the drug affinity responsive target stability, proteomics analysis, thermal shift assays and cellular thermal shift assays were used to identify and validate the target of HK. Finally, western blot, ELISA, LDH immunofluorescence staining, shRNA and LC/MS for L-leucine analysis were performed to determine the mechanism of the anti-inflammatory action of HK.

RESULTS

This study revealed that HK significantly alleviated LPS-induced septic shock and DSS-induced ulcerative colitis in vivo, suggesting that HK has significant anti-inflammatory activity. HK treatment dramatically reduced IL-1β release and caspase-1 activation at different time points, showing that HK could inhibit both NLRP3 inflammasome priming and activation processes in cells. HK also suppressed adaptor apoptosis speck-like protein oligomerization. Mechanistically, SLC3A2 was identified as a direct target of HK in THP-1 cells. HK downregulated SLC3A2 expression by promoting its degradation via proteasome-mediated proteolysis. Further study demonstrated that HK triggered SLC3A2 to suppress NLRP3 inflammasome activation by significantly reducing the content of L-leucine transported into cells and lysosomes to block the mTORC1 pathway.

CONCLUSIONS

Our work identified HK as a promising anti-inflammatory drug candidate through the SLC3A2/L-leucine/mTORC1/NLRP3 pathways.

The glucotoxicity protecting effect of honokiol in human hepatocytes via directly activating AMPK

Introduction

Sustained hyperglycemia causes glucotoxicity, which has been regarded as a contributor to hepatocyte damage in type 2 diabetes (T2D) and its metabolic comorbidities. Honokiol is a natural biphenolic component derived from the dietary supplement Magnolia officinalis extract. This study aimed to investigate the effects of honokiol on glucose metabolism disorders and oxidative stress in hepatocytes and the underlying mechanisms.

Methods

HepG2 cells were treated with glucosamines (18 mM) to induce glucotoxicity as a diabetic complication model in vitro.

Results and discussion

Honokiol significantly increased glucose consumption, elevated 2-NBDG uptake, and promoted GLUT2 translocation to the plasma membrane in glucosamine-treated HepG2 cells, indicating that honokiol ameliorates glucose metabolism disorders. Furthermore, glucosamine-induced ROS accumulation and loss of mitochondrial membrane potential were markedly reduced by honokiol, suggesting that honokiol alleviated glucotoxicity-induced oxidative stress. These effects were largely abolished by compound C, an AMPK inhibitor, suggesting an AMPK activation-dependent manner of honokiol function in promoting glucose metabolism and mitigating oxidative stress. Molecular docking results revealed that honokiol could interact with the amino acid residues (His151, Arg152, Lys243, Arg70, Lys170, and His298) in the active site of AMPK. These findings provide new insights into the antidiabetic effect of honokiol, which may be a promising agent for the prevention and treatment of T2D and associated metabolic comorbidities.

Plants and their Bioactive Compounds as a Possible Treatment for Traumatic Brain Injury-Induced Multi-Organ Dysfunction Syndrome

BACKGROUND & OBJECTIVE

Traumatic brain injury is an outcome of the physical or mechanical impact of external forces on the brain. Thus, the silent epidemic has complex pathophysiology affecting the brain along with extracranial or systemic complications in more than one organ system, including the heart, lungs, liver, kidney, gastrointestinal and endocrine system. which is referred to as Multi-Organ Dysfunction Syndrome. It is driven by three interconnected mechanisms such as systemic hyperinflammation, paroxysmal sympathetic hyperactivity, and immunosuppression-induced sepsis. These multifaceted pathologies accelerate the risk of mortality in clinical settings by interfering with the functions of distant organs through hypertension, cardiac arrhythmias, acute lung injury, neurogenic pulmonary edema, reduced gastrointestinal motility, Cushing ulcers, acute liver failure, acute kidney injury, coagulopathy, endocrine dysfunction, and many other impairments. The pharmaceutical treatment approach for this is highly specific in its mode of action and linked to a variety of side effects, including hallucinations, seizures, anaphylaxis, teeth, bone staining, etc. Therefore, alternative natural medicine treatments are widely accepted due to their broad complementary or synergistic effects on the physiological system with minor side effects.

CONCLUSION

This review is a compilation of the possible mechanisms behind the occurrence of multiorgan dysfunction and reported medicinal plants with organoprotective activity that have not been yet explored against traumatic brain injury and thereby, highlighting the marked possibilities of their effectiveness in the management of multiorgan dysfunction. As a result, we attempted to respond to the hypothesis against the usage of medicinal plants to treat neurodegenerative diseases.

New oligomeric neolignans from the leaves of Magnolia officinalis var. biloba

Six new oligomeric neolignans including two trimeric neolignans (1 and 2) and four dimeric neolignans (3-6) were isolated from the leaves of Magnolia officinalis var. biloba. Their structures were determined based on HR-ESIMS and NMR data, as well as electronic circular dichroism (ECD) calculations. Compound 1 is formed from two obovatol moieties directly linked to an aromatic ring of the remaining obovatol moiety, which is an unprecedented type of linkage between monomers. All isolates were assessed for their inhibitory effects on NO production in LPS-stimulated RAW 264.7 macrophage cells. Compounds 1 and 3 showed significantly inhibitory activities with IC₅₀ values of 6.04 and 3.26 μmol·L^-1, respectively.

Novel oligomeric neolignans with PTP1B inhibitory activity from the bark of Magnolia officinalis var. biloba

The barks of Magnolia officinalis var. biloba, Magnoliae cortex, have been used as traditional Chinese medicines for several centuries. In this study, phytochemical investigation of M. officinalis var. biloba bark extract afforded five pairs of novel enantiomeric oligomeric neolignans, (±)-mooligomers A-E (1-5). (±)-1 and (±)-2 were two diastereomeric pairs of enantiomers with six C6-C3 subunits, and (±)-4 was a pair of previously unreported tetrameric neolignans bearing eight C6-C3 subunits. (±)-5 is the first example of a naturally occurring trilignan featuring an eight-membered ring with a magnolol moiety. The absolute configurations of (±)-1-(±)-5 were elucidated on the basis of HRESIMS, 1D and 2D NMR spectroscopy and electronic circular dichroism (ECD) calculations. Among the compounds tested for their PTP1B inhibitory activities, (±)-2, (±)-4 and (±)-5 displayed significant PTP1B inhibitory activities with IC₅₀ values of 0.14-2.10 μM. Furthermore, a Molecular docking simulation of PTP1B and active compounds [(±)-2, (±)-4 and (±)-5] exhibited that these active compounds possess low binding affinities ranging from - 5.9 to - 7.7 kcal/mol.

Therapeutic potential of phenylethanoid glycosides: A systematic review

Phenylethanoid glycosides (PhGs) are generally water-soluble phenolic compounds that occur in many medicinal plants. Until June 2020, more than 572 PhGs have been isolated and identified. PhGs possess antibacterial, anticancer, antidiabetic, anti-inflammatory, antiobesity, antioxidant, antiviral, and neuroprotective properties. Despite these promising benefits, PhGs have failed to fulfill their therapeutic applications due to their poor bioavailability. The attempts to understand their metabolic pathways to improve their bioavailability are investigated. In this review article, we will first summarize the number of PhGs compounds which is not accurate in the literature. The latest information on the biological activities, structure-activity relationships, mechanisms, and especially the clinical applications of PhGs will be reviewed. The bioavailability of PhGs will be summarized and factors leading to the low bioavailability will be analyzed. Recent advances in methods such as bioenhancers and nanotechnology to improve the bioavailability of PhGs are also summarized. The existing scientific gaps of PhGs in knowledge are also discussed, highlighting research directions in the future.

Magnolia officinalis and Its Honokiol and Magnolol Constituents Inhibit Human Norovirus Surrogates

Norovirus is a major cause of foodborne disease and nonbacterial gastroenteritis globally. This study evaluated the antiviral effects of Magnolia officinalis extract and its honokiol and magnolol constituents against human norovirus surrogates, murine norovirus (MNV) and feline calicivirus (FCV) in vitro, and in model food systems. Pretreatment or cotreatment of M. officinalis extract at 1 mg/mL reduced MNV and FCV titers by 0.6-1.8 log. Honokiol and magnolol, which are the major polyphenols in the extract, showed significant antiviral effects against MNV and FCV. The virus-infected cells that were treated with M. officinalis extract exhibited significantly increased glutathione levels (p < 0.05). The extract, honokiol, and magnolol revealed ferric ion-reducing and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities in a dose-dependent manner. Furthermore, MNV and FCV titers were reduced by >1.6 log or to undetectable levels in apple, orange, and plum juices and by 0.9 and 1.6 log in milk, respectively, when they were treated with the extract at 5 mg/mL. Therefore, the present study suggests that M. officinalis extract can be used as an antiviral food material to control norovirus foodborne diseases.

A randomized controlled pilot study of the effectiveness of magnolia tea on alleviating depression in postnatal women

The magnolia tea has been used in traditional oriental medicine for multiple purposes including sleep aid. Postpartum depression is a mental illness that adversely affects the health and well-being of many families with newborns. Given the known effectiveness and relative safety, herein we aimed to investigate whether magnolia tea has a palliative effect on postpartum depression. The qualified participants were randomly assigned to the intervention group or the control group. The participants in the intervention group drunk magnolia tea, while the control group received regular postpartum care only. The outcome variables including Postpartum Sleep Quality Scale (PSQS), Edinburgh Postnatal Depression Scale (EPDS), and Postpartum Fatigue Scale (PFS) were assessed and compared. In comparison with the control group, the intervention group demonstrated significant difference for physical-symptom-related sleep inefficiency (PSQS Factor 2) at 3 weeks post-test (t = -2.10, p = .03). The comparison results also revealed significant differences for PFS at both 3 weeks post-test (t = -2.02, p = .04) and 6 weeks post-test (t = -1.99, p = .04). Further, magnolia tea intervention significantly alleviated the symptoms of depression, reflected by the EPDS scores at 3 weeks post-test (t = -2.38, p = .02) and 6 weeks post-test (t = -2.13, p = .02). Our trial results suggested that drinking single-ingredient magnolia tea for a 3-week duration has positive effects on postpartum women. Magnolia tea is recommended as a supplementary approach to ameliorate sleep quality of postpartum women, while alleviating their symptoms of depression.

Delivery of phytochemicals by liposome cargos: recent progress, challenges and opportunities

Bio-availability is a major concern in delivery of dietary phytochemicals for better bio-efficacy. The reduced bio-availability of food bioactive compounds is evident due to degradation during human digestion process which involves liberation, absorption, distribution, metabolism and elimination. The bio-efficacy of any nutrient can be increased by increasing bio-availability. Different technologies are available for engineered efficient delivery systems; still many challenges remain with advancement of delivery systems. The ease of preparedness and adaptability of liposomes has resulted in wide-range of applicability and acceptability in scientific field, especially as delivery vehicles. In view, of properties like biocompatibility and biodegradability, liposomes have been modified with different usable methodologies for delivery of phytochemicals. The aim of this review is to abridge liposomes, methods of preparation, their application as delivery cargo in dietary phytochemicals, result of using different preparation techniques on properties.

A review of the phytochemistry and pharmacological activities of Magnoliae officinalis cortex

ETHNOPHARMACOLOGICAL RELEVANCE

Magnoliae Officinalis Cortex (the dried bark of Magnolia officinalis), a widely used traditional Chinese medicine, is also known as 'Houpo' (Chinese: ). Magnoliae Officinalis Cortex has a wide range of pharmacological effects and has been used to treat conditions such as abdominal distention, vomiting, diarrhea, food accumulation, Qi stagnation, constipation, phlegm and fluid retention and cough resulting from asthma.

AIMS OF THE REVIEW

The present paper reviews advances in research relating to the botany, ethnopharmacology, phytochemistry, pharmacology and toxicology of Magnoliae Officinalis Cortex. Prospects for future investigation and application of this herb are also discussed.

MATERIALS AND METHODS

Information on Magnoliae Officinalis Cortex was obtained from published materials, including ancient and modern books; PhD and MSc dissertations; monographs on medicinal plants; the pharmacopoeia of different countries and electronic databases, such as SCI finder, PubMed, Web of Science, ACS, Science Direct, Wiley, Springer, Taylor, AGRIS, Europe PMC, EBSCO host, CNKI, WanFang DATA, J-STAGE and Google Scholar.

RESULTS

More than 200 chemical compounds have been isolated from Magnoliae Officinalis Cortex, including lignans, phenylethanoid glycosides, phenolic glycosides, alkaloids, steroids and essential oils. The plant has been reported to have pharmacological effects on the digestive system, nervous system and cardiovascular and cerebrovascular systems, as well as antibacterial, anti-tumour, analgesic, anti-inflammatory and anti-oxidative effects.

CONCLUSIONS

Magnoliae Officinalis Cortex is an essential traditional Chinese medicine with pharmacological activities that mainly affect the digestive system, nervous system and cardiovascular and cerebrovascular systems. This review summarises its botany, ethnopharmacology, phytochemistry, pharmacology and toxicology. These information suggest that we should focus on the development of new drugs related to Magnoliae Officinalis Cortex, including specific constituents, so that Magnoliae Officinalis Cortex can exert greater therapeutic potential. Meanwhile, it is important to pay attention to the rational use of Magnolia resources, avoiding over-harvesting which could lead to lack of resources. We should also pursue research on Magnolia substitutes and develop resources such as Magnoliae Officinalis Flos and Magnolia Leaf.

Purification of 3, 4-dihydroxyphenylethyl alcohol glycoside from Sargentodoxa cuneata (Oliv.) Rehd. et Wils. and its protective effects against DSS-induced colitis

Sargentodoxa cuneata is a tropical plant used in traditional Chinese medicine to treat intestinal inflammation. In this study, 3, 4-dihydroxyphenylethyl alcohol glycoside (DAG) was purified from the stem of S. cuneata using macroporous resins and its bioactivity was also investigated. The adsorption/desorption of DAG on macroporous resins was investigated systematically. HPD300 resin was selected as the most suitable medium for DAG purification. Further dynamic absorption/desorption experiments on the HPD300 column were conducted to obtain the optimal parameters. To obtain more than 95% DAG, a second stage procedure was developed to purify the DAG using SiliaSphere C18 with 8% v/v acetonitrile through elution at low pressure. Further investigation showed that DAG pretreatment significantly reversed the shortening of colon length, the increase in the disease activity index (DAI) scores and histological damage in the colon. Moreover, DAG greatly increased SOD and GPx activities, significantly decreased MPO and MDA activities and reduced the levels of pro-inflammatory cytokines in the colon. Free radical scavenging activities of DAG were assessed using DPPH, with an IC50 value of 17.03 ug/mL. Additionally, DAG suppressed ROS and proinflammatory cytokine production in LPS-stimulated RAW 264.7 macrophages by suppressing activation of the ERK1/2 and NF-κB pathways. The results were indicative of the antioxidant and anti-inflammatory properties of DAG. When viewed together, these findings indicated that DAG can be used to expand future pharmacological research and to potentially treat colitis.

Saccharomyces cerevisiae Hog1 MAP kinase pathway is activated in response to honokiol exposure

AIM

The goal of the study was to investigate the cellular tolerance mechanism in response to honokiol exposure.

METHODS AND RESULTS

The broth microdilution method was employed to test the sensitivity of different Saccharomyces cerevisiae strains to honokiol. Intracellular levels of reactive oxygen species (ROSs) were determined by DCFH-DA staining. The phosphorylation of Hog1 was evaluated by Western blot analysis. The mRNA expressions of genes involved in the Ras-cyclic AMP (cAMP) pathway were analysed by real-time reverse transcription polymerase chain reaction. We found that the sod1▵ mutant was hypersensitive to honokiol and produced more ROS compared with wild-type and sod2▵ cells. Hog1 was phosphorylated in response to honokiol exposure and deletion of HOG1 increased the sensitivity to honokiol. The expressions of genes involved in the Ras-cAMP pathway were down-regulated after honokiol exposure; exogenous cAMP significantly reduced the phosphorylation of Hog1, although the level was higher than the control level.

CONCLUSIONS

In addition to SOD1, the Ras-cAMP cascade and Hog1 MAP kinase pathway is essential for protecting against honokiol-induced oxidative stress.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results provide insight into the understanding of the action mechanism of honokiol.

Total phenylethanoid glycosides and magnoloside IafromMagnolia officinalisvar.bilobafruits inhibit ultraviolet B-induced phototoxicity and inflammation through MAPK/NF-κB signaling pathways

Magnolia officinalisvar.bilobais used as a traditional medicine in China and as a food additive in the United Kingdom and the European Union.