Immunomodulatory effect of bergenin and norbergenin against adjuvant-induced arthritis--a flow cytometric study

Exploring the underlying pharmacological, immunomodulatory, and anti-inflammatory mechanisms of phytochemicals against wounds: a molecular insight

BACKGROUND

Numerous cellular, humoral, and molecular processes are involved in the intricate process of wound healing.

PHARMACOLOGICAL RELEVANCE

Numerous bioactive substances, such as ß-sitosterol, tannic acid, gallic acid, protocatechuic acid, quercetin, ellagic acid, and pyrogallol, along with their pharmacokinetics and bioavailability, have been reviewed. These phytochemicals work together to promote angiogenesis, granulation, collagen synthesis, oxidative balance, extracellular matrix (ECM) formation, cell migration, proliferation, differentiation, and re-epithelialization during wound healing.

FINDINGS AND NOVELTY

To improve wound contraction, this review delves into how the application of each bioactive molecule mediates with the inflammatory, proliferative, and remodeling phases of wound healing to speed up the process. This review also reveals the underlying mechanisms of the phytochemicals against different stages of wound healing along with the differentiation of the in vitro evidence from the in vivo evidence There is growing interest in phytochemicals, or plant-derived compounds, due their potential health benefits. This calls for more scientific analysis and mechanistic research. The various pathways that these phytochemicals control/modulate to improve skin regeneration and wound healing are also briefly reviewed. The current review also elaborates the immunomodulatory modes of action of different phytochemicals during wound repair.

Palladium-catalyzed Suzuki-Miyaura cross-couplings of stable glycal boronates for robust synthesis of C-1 glycals

C-1 Glycals serve as pivotal intermediates in synthesizing diverse C-glycosyl compounds and natural products, necessitating the development of concise, efficient and user-friendly methods to obtain C-1 glycosides is essential. The Suzuki-Miyaura cross-coupling of glycal boronates is notable for its reliability and non-toxic nature, but glycal donor stability remains a challenge. Herein, we achieve a significant breakthrough by developing stable glycal boronates, effectively overcoming the stability issue in glycal-based Suzuki-Miyaura coupling. Leveraging the balanced reactivity and stability of our glycal boronates, we establish a robust palladium-catalyzed glycal-based Suzuki-Miyaura reaction, facilitating the formation of various C(sp2)-C(sp), C(sp2)-C(sp2), and C(sp2)-C(sp3) bonds under mild conditions. Notably, we expand upon this achievement by developing the DNA-compatible glycal-based cross-coupling reaction to synthesize various glycal-DNA conjugates. With its excellent reaction reactivity, stability, generality, and ease of handling, the method holds promise for widespread appication in the preparation of C-glycosyl compounds and natural products.

Therapeutic potential of Bergenin in the management of neurological-based diseases and disorders

Originally sourced from plants, Bergenin has been used as a medicinal compound in traditional medicine for centuries, and anecdotal reports suggest a wide range of therapeutic uses. Naturally-occurring and lab-synthesized Bergenin, as well as some of its related compounds, have been shown in in vivo and in vitro studies to alter activity of several enzymes and proteins critical in cellular functioning, including reelin, GSK-3β, Lingo-1, Ten-4, GP-43, Aβ 1-42, P-tau, SOD1,2, GPx, Glx1, NQO1, HO1, PPAR-ɣ, BDNF, VEGF, and STAT6. Additionally, Bergenin alters levels of several cytokines, such as IL-6, IL-1β, TNF-α, and TGF-β. Behavioral and cellular effects of Bergenin have been shown to involve PI3K/Akt, NF-κB, PKC, Nrf2, and Sirt1/FOXO3a pathways. These pathways, enzymes, and proteins have been shown to be important in normal neurological functioning, and/or dysfunctions in these pathways and proteins have been shown to be important in several neuro-based disorders or diseases, which suggests that Bergenin could be therapeutic in management of neuropsychiatric conditions or neurological disorders. In preclinical studies, Bergenin has been shown to be useful for the management of Alzheimer's disease, Parkinson's disease, anxiety, depression, addiction, epilepsy, insomnia, stroke, and potentially, state control. Our review aims to summarize current evidence supporting the conclusion that Bergenin could play a role in treating various neuro-based disorders and that future studies should be conducted to evaluate the mechanisms by which Bergenin could exert its therapeutic effects.

Anti-oxidative, anti-apoptotic, and anti-inflammatory activities of Connarus semidecandrus Jack ethanol extract in UVB-irradiated human keratinocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Connarus semidecandrus Jack (Family: connaraceae) is a medicinal plant known for its wide distribution throughout Southeast Asia. Renowned for its diverse therapeutic properties, it has been traditionally used for treating fever, skin irritation, and colic.

AIM OF THE STUDY

Numerous individuals suffer from skin issues, including wrinkles, hyperpigmentation, and inflammation, due to environmental factors. Although many drugs are available to treat skin problems, chemical drugs have many shortcomings and side effects. Therefore, natural products are attractive potential medicines for alleviating skin troubles. We recently showed that Connarus semidecandrus Jack ethanol extract (Cs-EE) has anti-alopecia potential. This paper aims to explore the potential skin-protective effects and underlying molecular mechanisms of Connarus semidecandrus Jack in UVB-induced human keratinocytes (HaCaT).

MATERIALS AND METHODS

Before utilization, Cs-EE was dissolved in dimethyl sulfoxide (DMSO) and was preserved at a temperature of -20 °C. The phytochemical constituents of Cs-EE were detected by gas chromatography-mass spectrometry analysis (GC-MS). Sequentially, HaCaT cells were exposed to varying concentrations of Cs-EE prior to ultraviolet B (UVB) irradiation. Evaluations of cellular responses in HaCaT cells, including assessments of cell viability, deoxyribonucleic acid (DNA) damage, and gene and protein expressions, were carried out. To explore the specific signaling pathway involved, we conducted a luciferase assay in addition to validating these pathways using Western blot analysis.

RESULTS

Nitric oxide (NO) and intracellular reactive oxygen species were decreased. Melanin production through the activation of melanocytes by α-melanocyte-stimulating hormone (MSH) was also inhibited by Cs-EE. Furthermore, the mRNA expression levels of key factors such as cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), MMP-1, MMP-3, and MMP-9 exhibited a remarkable decrease. In addition, the phosphorylation of TAK1 within the signaling cascade exhibited a decline, and the activities of the transcription factor AP-1 were decreased according to a luciferase reporter assay.

CONCLUSIONS

Taken together, these findings suggest that the anti-inflammatory, anti-aging, and anti-apoptotic effects of Cs-EE indicate the compound's potential usefulness as a natural component in pharmaceutical and cosmetic products.

Different Levels of Autophagy Activity in Mesenchymal Stem Cells Are Involved in the Progression of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is an age-related lung interstitial disease that occurs predominantly in people over 65 years of age and for which there is a lack of effective therapeutic agents. It has demonstrated that mesenchymal stem cells (MSCs) including alveolar epithelial cells (AECs) can perform repair functions. However, MSCs lose their repair functions due to their distinctive aging characteristics, eventually leading to the progression of IPF. Recent breakthroughs have revealed that the degree of autophagic activity influences the renewal and aging of MSCs and determines the prognosis of IPF. Autophagy is a lysosome-dependent pathway that mediates the degradation and recycling of intracellular material and is an efficient way to renew the nonnuclear (cytoplasmic) part of eukaryotic cells, which is essential for maintaining cellular homeostasis and is a potential target for regulating MSCs function. Therefore, this review focuses on the changes in autophagic activity of MSCs, clarifies the relationship between autophagy and health status of MSCs and the effect of autophagic activity on MSCs senescence and IPF, providing a theoretical basis for promoting the clinical application of MSCs.

The traditional uses, phytochemistry, pharmacology and toxicology of Bergenia purparescens: A review comments and suggestions

Bergenia purpurascens (B. purpurascens, Saxifragaceae) has been used to treat several diseases in different countries, such as lung diseases, stomach problems, rheumatic pains, boosting immunity etc. However, the information on phytochemistry, pharmacology and toxicology of this plant has rarely been comprehensively and critically reported. This paper aims to study and evaluate its therapeutic potential, including the traditional uses and all the latest information of phytochemistry, pharmacology and toxicology. The main components of this plant are phenols compounds and the characteristic substance is bergenin.The results about modern pharmacology have shown that its pharmacological effects include antibacterial, antiviral, cough relieving, anti-inflammatory and so on. In addition, it could inhibit diabetic neuropathy, restore insulin secretion, treat cancer, protect liver and prevent Alzheimer's disease (AD). Thus, its therapeutic fields may be cancer, diabetic and AD in the future. The information will help to further update and study pharmacologic effect and action mechanism of this herb, which is more widely, effectively, and safely used in clinic.

An outlook on the target-based molecular mechanism of phytoconstituents as immunomodulators

The immune system is one of the essential defense mechanisms. Immune system inadequacy increases the risk of infections and cancer diseases, whereas over-activation of the immune system causes allergies or autoimmune disorders. Immunomodulators have been used in the treatment of immune-related diseases. There is growing interest in using herbal medicines as multicomponent agents to modulate the complex immune system in immune-related diseases. Many therapeutic phytochemicals showed immunomodulatory effects by various mechanisms. This mechanism includes stimulation of lymphoid cell, phagocytosis, macrophage, and cellular immune function enhancement. In addition increased antigen-specific immunoglobulin production, total white cell count, and inhibition of TNF-α, IFN-γ, NF-kB, IL-2, IL-6, IL-1β, and other cytokines that influenced the immune system. This review aims to overview, widely investigated plant-derived phytoconstituents by targeting cells to modulate cellular and humoral immunity in in vivo and in vitro. However, further high-quality research is needed to confirm the clinical efficacy of plant-based immunomodulators.

Norbergenin prevents LPS-induced inflammatory responses in macrophages through inhibiting NFκB, MAPK and STAT3 activation and blocking metabolic reprogramming

Inflammation is thought to be a key cause of many chronic diseases and cancer. However, current therapeutic agents to control inflammation have limited long-term use potential due to various side-effects. This study aimed to examine the preventive effects of norbergenin, a constituent of traditional anti-inflammatory recipes, on LPS-induced proinflammatory signaling in macrophages and elucidate the underlying mechanisms by integrative metabolomics and shotgun label-free quantitative proteomics platforms. Using high-resolution mass spectrometry, we identified and quantified nearly 3000 proteins across all samples in each dataset. To interpret these datasets, we exploited the differentially expressed proteins and conducted statistical analyses. Accordingly, we found that LPS-induced production of NO, IL1β, TNFα, IL6 and iNOS in macrophages was alleviated by norbergenin via suppressed activation of TLR2 mediated NFκB, MAPKs and STAT3 signaling pathways. In addition, norbergenin was capable of overcoming LPS-triggered metabolic reprogramming in macrophages and restrained the facilitated glycolysis, promoted OXPHOS, and restored the aberrant metabolites within the TCA cycle. This is linked to its modulation of metabolic enzymes to support its anti-inflammatory activity. Thus, our results uncover that norbergenin regulates inflammatory signaling cascades and metabolic reprogramming in LPS stimulated macrophages to exert its anti-inflammatory potential.

Bergenia stracheyi extract-based hybrid hydrogels of biocompatible polymers with good adhesive, stretching, swelling, self-healing, antibacterial, and antioxidant properties

An ultra-stretchable, quickly self-healable, adhesive hydrogel with efficient anti-oxidant and anti-bacterial activities makes it potential wound dressing material, particularly in healing skin wounds. However, it is highly challenging to prepare such hydrogels with a facile and efficient material design. Given this, we opine the synthesis of medicinal plant Bergenia stracheyi extract-loaded hybrid hydrogels of biocompatible and biodegradable polymers like Gelatin, Hydroxypropyl cellulose, and Polyethylene glycol with acrylic acid via in situ free radical polymerization reaction. The selected plant extract is rich in phenols, flavonoids, and tannins and found to have important therapeutic benefits such as anti-ulcer, anti-Human Immunodeficiency Virus, anti-inflammatory, and burn wound healing effects. The polyphenolic compounds in the plant extract interacted strongly via hydrogen bonding with -OH, -NH₂, -COOH, and C-O-C groups of the macromolecules. The synthesized hydrogels were characterized by fourier transform infrared spectroscopy and rheology. The as-prepared hydrogels demonstrate ideal tissue adhesion, excellent stretchability, good mechanical strength, broad-band anti-bacterial capability, and efficient anti-oxidant properties, in addition to quick self-healing and moderate swelling properties. Thus, the aforementioned properties attract the potential use of these materials in the biomedical field.

Pathogenesis of rheumatoid arthritis and its treatment with anti-inflammatory natural products

Introduction Rheumatoid arthritis (RA) is a common autoimmune disease across the globe that is chronic and systemic as well. The disease is linked with autoantibodies and is inflammatory, eventually targeting several molecules along with certain modified self-epitopes. The disease majorly affects the joints of an individual. Rheumatoid arthritis is manifested clinically by polyarthritis linked with the dysfunction of the joints. This chiefly affects the synovial joint lining and is linked with progressive dysfunction, premature death, along with socioeconomic implications. The macrophage activation, along with the activation of certain defense cells, results in a response to self-epitopes that helps in providing a better understanding of the disease pathogenesis.  Material and methodology For this review article, papers have been retrieved and reviewed from database including PubMed, Scopus and Web of science. Relevant papers were taken fulfilling the criteria for writing this review article. Results This has resulted in the establishment of several new therapeutic techniques that serve as potential inhibitors of such cells. Researchers have gained an interest in understanding this disease to provide strategies for treatment in the last two decades. This also includes recognition followed by the treatment of the disease at its early stages. Various allopathic treatment approaches often have chronic and toxic teratogenic effects. However, to avoid this issue of toxicity followed by side effects, certain medicinal plants have been used in treating RA.  Conclusion Medicinal plants possess active phytoconstituents that entail antioxidants as well as anti-inflammatory properties, making them a helpful alternative to allopathic drugs that are often linked with highly toxic effects. This review paper entails a thorough discussion of the epidemiology, pathophysiology, diagnosis, and management of RA. The paper will also focus on the use of herbal plants in the treatment of the disease to avoid the side effects that generally occur in allopathic treatment.

Chemistry and Pharmacology of Bergenin or Its Derivatives: A Promising Molecule

Bergenin is a glycosidic derivative of trihydroxybenzoic acid that was discovered in 1880 by Garreau and Machelart from the rhizomes of the medicinal plant Bergenia crassifolia (currently: Saxifraga crassifolia—Saxifragaceae), though was later isolated from several other plant sources. Since its first report, it has aroused interest because it has several pharmacological activities, mainly antioxidant and anti-inflammatory. In addition to this, bergenin has shown potential antimalarial, antileishmanial, trypanocidal, antiviral, antibacterial, antifungal, antinociceptive, antiarthritic, antiulcerogenic, antidiabetic/antiobesity, antiarrhythmic, anticancer, hepatoprotective, neuroprotective and cardioprotective activities. Thus, this review aimed to describe the sources of isolation of bergenin and its in vitro and in vivo biological and pharmacological activities. Bergenin is distributed in many plant species (at least 112 species belonging to 34 families). Both its derivatives (natural and semisynthetic) and extracts with phytochemical proof of its highest concentration are well studied, and none of the studies showed cytotoxicity for healthy cells.

Unveiling major ethnopharmacological aspects of genus Diospyros in context to its chemical diversity: A comprehensive overview

Diospyros species (DS), "Ebenaceae," were known for their therapeutic uses in folk medicine since days of yore. Thereafter, scientific evidence related their health benefits to a myriad of chemical classes, for instance, naphthoquinones, flavonoids, tannins, coumarins, norbergenin derivatives, sterols, secoiridoids, sesquiterpenes, diterpenoids, triterpenoids, volatile organic compounds (VOCs), and carotenoids. The available literature showed that more than 200 compounds were isolated and identified via spectroscopic techniques. Many pharmacological activities of DS have been previously described, such as antioxidant, neuroprotective, antibacterial, antiviral, antiprotozoal, antifungal, antiinflammatory, analgesic, antipyretic and cosmeceutical, investigated, and confirmed through versatile in vitro and in vivo assays. Previous studies proved that genus Diospyros is a rich reservoir of valuable bioactive compounds. However, further comparative studies among its different species are recommended for more precise natural source-based drug discovery and clinical application. Accordingly, this review is to recall the chemical abundance and diversity among different members of genus Diospyros and their ethnopharmacological and pharmacological uses. PRACTICAL APPLICATIONS: Practically, providing sufficient background on both secondary metabolites divergence and pharmacological properties of genus Diospyros has many fruitful aspects. As demonstrated below, extracts and many isolated compounds have significant curative properties, which can lead to the discovery of pharmaceutically relevant alternative substitutes to conventional medicine. Consequently, molecular docking on various receptors can be applied. On the grounds, Naoxinqing tablets, a standardized herbal product containing D. kaki leaves extract, have been patented and recorded in Chinese Pharmacopeia as an approved Traditional Chinese Medicine (TCM) for the treatment of cerebro- and cardiovascular diseases, although the underlying mechanism remains under advisement. Moreover, the antimicrobial applications of DS are of considerable concern; since the widespread use of antibiotics resulted in different forms of bacterial resistance, hence, limiting and compromising effective treatment. In addition, as a result of contemporary rampant memory disorders, neuroprotective activities of different extracts of DS became of great emphasis.

Advances in plant-derived C-glycosides: Phytochemistry, bioactivities, and biotechnological production

C-glycosides represent a large group of natural products with a C-C bond between the aglycone and the sugar moiety. They exhibit great structural diversity, wide natural distribution, and significant biological activities. By the end of 2021, at least 754 C-glycosides and their derivatives have been isolated and characterized from plants. Thus far, 66 functional C-glycosyltransferases (CGTs) have been discovered from plants, and provide green and efficient approaches to synthesize C-glycosides. Herein, advances in plant-derived C-glycosides are comprehensively summarized from aspects of structural diversity and identification, bioactivities, and biotechnological production. New strategies to discover novel C-glycosides and CGTs, as well as the applications of biotechnological methods to produce C-glycosides in the future are also discussed.

Synthesis and biological evaluation of bergenin derivatives as new immunosuppressants

Bergenin, which is isolated from Bergenia species, exhibits various pharmacological properties. In the search for new types of immunosuppressants, a series of bergenin derivatives were designed and synthesized, and their immunosuppressive effects were evaluated by the CCK-8 assay. The experimental data demonstrated that compounds 7 and 13 showed the strongest inhibition effects on mouse splenocyte proliferation (IC₅₀ = 3.52 and 5.39 μM, respectively). Further studies revealed that the inhibitory effect may come from the suppression of both IFN-γ and IL-4 cytokines. Alkylated derivatives of bergenin with n-hexyl and n-heptyl on the two phenolic hydroxyl groups showed better inhibitory activities. The hydrophobicity of bergenin derivatives, the configuration of the 4-OH in bergenin, and the ability to form hydrogen bonds of the substituents on the C-4 position are important to the immunosuppressive activity. This work proved that the modifications of bergenin may represent a new route to the discovery of a new class of immunosuppressive agents.

Ethanol extract of Bergenia ciliata (Haw.) Sternb. (rhizome) impedes the propagation of the malaria parasite

ETHNOPHARMACOLOGICAL RELEVANCE

The increasing resistant cases even against artemisinin-based combination therapy have necessitated the need to develop new antimalarials. Phytomedicinal therapy is a benchmark for malaria in the Himalayan region. As the dialect and traditional variations have been seen along with this, usage of medicinal plant, its portion (shoot and root system) and mode of preparation also varies. There is no scientific evidence available for illustrating the antiplasmodial activity of the rhizomes of Bergenia ciliata (Saxifragaceae), which is known to be an antipyretic (fever akin to malaria), hepato-protective, and also for spleen enlargement.

AIM OF THE STUDY

The present study evaluates the antimalarial activity of ethanol extract of B. ciliata rhizomes (EREBC).

MATERIALS AND METHODS

HPTLC was performed to identify and quantify three marker compounds in EREBC. The in vitro antimalarial activity was evaluated by schizont maturation inhibition assay. MTT assay was employed to test the cytotoxicity of EREBC. Peter's 4-day test and Peters method was employed to discern the suppressive and preventive activity of the extract respectively.

RESULTS

HPTLC analysis revealed the presence of bergenin, epicatechin and gallic acid in the extract. EREBC exhibited considerable inhibition (IC₅₀ < 5 μg/mL) of schizont maturation of both RKL-9 and MRC-2 strains of P. falciparum. EREBC was non-toxic to both HeLa cells and normal dermal fibroblasts (CC₅₀ > 1000 μg/mL). The selectivity index was > 200 for both strains. Acute toxicity of EREBC was > 4 g/kg. EREBC exhibited considerable in vivo suppressive activity with 96.48% inhibition at 500 mg/kg in comparison to chloroquine (96.08%). The ED₅₀ of the extract was < 50 mg/kg. No mortality was evident in mice administered with different doses of EREBC (50-500 mg/kg) throughout the follow up period of 28 days. EREBC exhibited safety to liver and kidney function of mice as observed from biochemical analysis.

CONCLUSION

Overall, the study illustrates the marked efficacy and potential of EREBC as an antimalarial agent with bergenin, epicatechin and gallic acid its major constituents, which played a pivotal role in the generation of the immune response.

Bergenin - a biologically active scaffold: Nanotechnological perspectives

Bergenin, 4-O-methyl gallic acid glucoside, is a bioactive compound present in various plants belonging to different families. The present work compiles scattered information on pharmacology, structure activity relationship and nanotechnological aspects of bergenin, collected from various electronic databases such as Sci Finder, PubMed, Google scholar, etc. Bergenin has been reported to exhibit hepatoprotective, anti-inflammatory, anticancer, neuroprotective, antiviral and antimicrobial activities. Molecular docking studies have shown that isocoumarin pharmacophore of bergenin is essential for its bioactivities. Bergenin holds a great potential to be used as lead molecule and also as a therapeutic agent for development of more efficacious and safer semisynthetic derivatives. Nanotechnological concepts can be employed to overcome poor bioavailability of bergenin. Finally, it is concluded that bergenin can be emerged as clinically potential medicine in modern therapeutics.

Optimization of Ultrasound-Assisted Extraction via Sonotrode of Phenolic Compounds from Orange By-Products

Orange peel is the main by-product from orange juice industry. It is a known source of bioactive compounds, mostly phenolic compounds, and it has been widely studied for its healthy activities. Thus, this research focuses on the establishment of ultrasound-assisted extraction of phenolic compounds in orange peel using a sonotrode. For this purpose, a Box–Behnken design of 27 experiments was carried out with four independent factors—ratio ethanol/water (v/v), time (min), amplitude (%), and pulse (%). Quantitative analyses of phenolic compounds were performed and the antioxidant activity was measured by ABTS and DPPH methods. The validity of the experimental design was confirmed by ANOVA and the optimal sonotrode extraction conditions were obtained by response surface methodology (RSM). The extracts obtained in the established conditions were analyzed by High Performance Liquid Chromatography (HPLC) coupled to mass spectrometer detector and 74 polar compounds were identified. The highest phenolic content and antioxidant activity were obtained using 45/55 ethanol/water (v/v), 35 min, amplitude 90% (110 W), and pulse 100%. The established method allows an increment of phenolics recovery up to 60% higher than a conventional extraction. Moreover, the effect of drying on phenolic content was also evaluated.

Bergenin protects pancreatic beta cells against cytokine-induced apoptosis in INS-1E cells

Beta cell apoptosis induced by proinflammatory cytokines is one of the hallmarks of diabetes. Small molecules which can inhibit the cytokine-induced apoptosis could lead to new drug candidates that can be used in combination with existing therapeutic interventions against diabetes. The current study evaluated several effects of bergenin, an isocoumarin derivative, in beta cells in the presence of cytokines. These included (i) increase in beta cell viability (by measuring cellular ATP levels) (ii) suppression of beta cell apoptosis (by measuring caspase activity), (iii) improvement in beta cell function (by measuring glucose-stimulated insulin secretion), and (iv) improvement of beta cells mitochondrial physiological functions. The experiments were carried out using rat beta INS-1E cell line in the presence or absence of bergenin and a cocktail of proinflammatory cytokines (interleukin-1beta, tumor necrosis factor-alpha, and interferon- gamma) for 48 hr. Bergenin significantly inhibited beta cell apoptosis, as inferred from the reduction in the caspase-3 activity (IC50 = 7.29 ± 2.45 μM), and concurrently increased cellular ATP Levels (EC50 = 1.97 ± 0.47 μM). Bergenin also significantly enhanced insulin secretion (EC50 = 6.73 ± 2.15 μM) in INS-1E cells, presumably because of the decreased nitric oxide production (IC50 = 6.82 ± 2.83 μM). Bergenin restored mitochondrial membrane potential (EC50 = 2.27 ± 0.83 μM), decreased ROS production (IC50 = 14.63 ± 3.18 μM), and improved mitochondrial dehydrogenase activity (EC50 = 1.39 ± 0.62 μM). This study shows for the first time that bergenin protected beta cells from cytokine-induced apoptosis and restored insulin secretory function by virtue of its anti-inflammatory, antioxidant and anti-apoptotic properties. To sum up, the above mentioned data highlight bergenin as a promising anti-apoptotic agent in the context of diabetes.

Bergenia Genus: Traditional Uses, Phytochemistry and Pharmacology

Bergenia (Saxifragaceae) genus is native to central Asia and encompasses 32 known species. Among these, nine are of pharmacological relevance. In the Indian system of traditional medicine (Ayurveda), "Pashanabheda" (stone breaker) is an elite drug formulation obtained from the rhizomes of B. ligulata. Bergenia species also possess several other biological activities like diuretic, antidiabetic, antitussive, insecticidal, anti-inflammatory, antipyretic, anti-bradykinin, antiviral, antibacterial, antimalarial, hepatoprotective, antiulcer, anticancer, antioxidant, antiobesity, and adaptogenic. This review provides explicit information on the traditional uses, phytochemistry, and pharmacological significance of the genus Bergenia. The extant literature concerned was systematically collected from various databases, weblinks, blogs, books, and theses to select 174 references for detailed analysis. To date, 152 chemical constituents have been identified and characterized from the genus Bergenia that belong to the chemical classes of polyphenols, phenolic-glycosides, lactones, quinones, sterols, tannins, terpenes, and others. B. crassifolia alone possesses 104 bioactive compounds. Meticulous pharmacological and phytochemical studies on Bergenia species and its conservation could yield more reliable compounds and products of pharmacological significance for better healthcare.

Natural SIRT1 modifiers as promising therapeutic agents for improving diabetic wound healing

BACKGROUND

The occurrence of chronic wounds, account for significant suffering of diabetic people, together with increasing healthcare burden. The chronic wounds associated with diabetes do not undergo the normal healing process rather stagnate into chronic proinflammatory phase as well as declined fibroblast function and impaired cell migration.

HYPOTHESIS

SIRT1, which is the most studied isoform of the sirtuin family in mammals, has now emerged as a crucial target for improving diabetic wound healing. It is an NAD+ dependent deacetylase, originally characterized to deacetylate histone proteins leading to heterochromatin formation and gene silencing. It is now known to regulate a number of cellular processes like cell proliferation, division, senescence, apoptosis, DNA repair, and metabolism.

METHODOLOGY

The retrieval of potentially relevant studies was done by systematically searching of three databases (Google Scholar, Web of science and PubMed) in December 2019. The keywords used as search terms were related to SIRT1 and wound healing. The systematic search retrieved 649 papers that were potentially relevant and after selection procedure, 73 studies were included this review and discussed below.

RESULTS

Many SIRT1 activating compounds (SACs) were found protective and improve diabetic wound healing through regulation of inflammation, cell migration, oxidative stress response and formation of granulation tissue at the wound site.

CONCLUSIONS

However, contradictory reports describe the opposing role of SACs on the regulation of cell migration and cancer incidence. SACs are therefore subjected to intense research for understanding the mechanisms responsible for controlling cell migration and therefore possess prospective to enter the clinical arena in the foreseeable future.

Endopleura uchi (Huber) Cuatrec.: A medicinal plant for gynecological treatments - A reproductive toxicity assessment in zebrafish (Danio rerio)

ETHNOPHARMACOLOGICAL RELEVANCE

Endopleura uchi (Huber) Cuatrec is a plant species from the Brazilian Amazon. The barks of this tree are used in folk medicine - mainly as a decoction - for dyslipidemia, uterine infection, fibroids, polycystic ovary, menstrual disorders, as a contraceptive and abortive agent, among others. However, the data available about its developmental toxicity are still insufficient.

AIM OF THE STUDY

This study aimed to evaluate the reproductive toxicity and teratogenic effects in embryos from zebrafish treated with the hydroethanolic extract from the barks of Endopleura uchi (EEu).

MATERIALS AND METHODS

Both sexes of zebrafish (Danio rerio) were treated with EEu either through immersion (1.2, 2.5, and 5 mg/L) or orally (75, 200, and 500 mg/kg) over 21 consecutive days. Next, we assessed their fertility and gonads' histopathology; in their embryos were assessed teratogenesis, lethalities, and heart rate during daily observations (24, 48, 72, and 96 hpf).

RESULTS

The phytochemical analysis of EEu through HPLC/MS shows bergenin as the major compounds. After 21 days of treatment were detected minor histopathological changes in parental fishes, such as atretic oocytes, interstitial fibrosis, and decreased the percentage of early vitellogenic oocytes, but without impairing the reproduction of treated animals. However, in the embryos was observed significantly increased frequency of malformation in all the groups treated through immersion, and in the group treated orally with the highest concentration (500 mg/kg).

CONCLUSION

Based on the results, EEu caused no adverse effects in the progenitors on both treatments (immersion and oral). However, it was observed that the concentrations 1.2, 2.5, and 5 mg/L (immersion), and the dose 500 mg/kg (oral) caused malformations in the offspring (F1 generation). These results emphasize the need for attention when using preparations from E. uchi, mainly for pregnant women. Further studies are needed to compare its effects with the extract's primary compound (bergenin).

Hydroethanolic extract from Endopleura uchi (Huber) Cuatrecasas and its marker bergenin: Toxicological and pharmacokinetic studies in silico and in vivo on zebrafish

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E. uchi stem bark hydroethanolic extract in zebrafish.

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Evaluating the in silico pharmacokinetic and toxicological parameters.

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Behavioral, biochemical and histopathological changes was dose dependent.

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In silico bergenin and its metabolites showed high intestinal absorption.

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Bergenin inhibited CYP2C9, CYP3A4 and CYP2C19.

Endopleura uchi, is used for the treatment of inflammatory disease and related to the female reproductive tract. The aim of this study was to evaluate the acute toxicity of the Endopleura uchi stem bark hydroethanolic extract (EEu) in zebrafish, emphasizing the histopathological and biochemical parameters, as well as evaluating the in silico pharmacokinetic and toxicological parameters of the phytochemical/pharmacological marker, bergenin, as their metabolites. The animals were orally treated with EEu at a single dose of 75 mg/kg, 500 mg/kg, 1000 mg/kg and 3000 mg/kg. the oral LD₅₀ of the EEu higher to the dose of 3000 mg/kg. Behavioral, biochemical and histopathological changes were dose dependent. In silico pharmacokinetic predictions for bergenin and its metabolites showed moderate absorption in high human intestinal absorption (HIA) and Caco-2 models, reduced plasma protein binding, by low brain tissue binding and no P-glycoprotein (P-Gp) inhibition. Their metabolism is defined by the CYP450 enzyme, in addition to bergenin inhibition of CYP2C9, CYP3A4 and CYP2C19. In the bergenin and its metabolites in silico toxicity test it have been shown to cause carcinogenicity and a greater involvement of the bergenin with the CYP enzymes in the I and II hepatic and renal metabolism’s phases was observed. It is possible to suggest that the histopathological damages are involved with the interaction of this major compound and its metabolites at the level of the cellular-biochemical mechanisms which involve the absorption, metabolization and excretion of these possible prodrug and drug.

Effect of bergenin on RANKL-induced osteoclast differentiation in the presence of methylglyoxal

Methylglyoxal (MG), a highly reactive dicarbonyl compound, is a major precursor in the formation of advanced glycation end products, which are associated with diabetes-related diseases. Bergenin, an active constituent of plants of the genus Bergenia, exhibits multiple biological activities. This study evaluated the effect of bergenin on osteoclast differentiation and determined its mechanism of action. Bergenin reversed MG-inhibited tartrate-resistant acid phosphatase (TRAP) activity and decreased the bone resorption activity of osteoclasts. Quantitative RT-PCR revealed that bergenin decreased the expression of ERK1, Akt2, MMP-9, and OSTM1 genes in the presence of MG. Bergenin pretreatment yielded significant increases in intracellular calcium concentration, mitochondrial mass, mitochondrial membrane potential, and glyoxalase I reduced by MG. Additionally, bergenin decreased the formation of mitochondrial superoxide induced by MG. Detoxification of MG by bergenin may be a viable treatment for bone disorders in patients with diabetes.

Design, Synthesis and Antiproliferative Evaluation of Novel 1,2,4-Triazole/Schiff Base Hybrids with EGFR and B-RAF Inhibitory Activities

Background:

1,2,4-triazoles possess a broad spectrum of biological activities such as analgesic, antimicrobial, antitubercular, anti-inflammatory and antineoplastic activities. This heterocycle and their derivatives were included into a wide variety of therapeutically interesting drugs. Hence, it is of great interest to explore new 1,2,4-triazoles as cytotoxic agents targeting EGFR, B-Raf kinases.

Methods:

The final compounds 9a-b, 10a-b, 11a-b, 12a-b, 13a-b and 14a-f were prepared by refluxing a mixture of triazole 3a-b and 7a-d with the corresponding benzaldehyde derivatives 8a-d in absolute ethanol to afford the target final compounds in good yields. The newly synthesized triazole-containing compounds were assessed according to standard protocols for their in vitro antiproliferative activity against four human cancer cell lines including human pancreas cancer cell line (Panc-1), pancreatic carcinoma cells (PaCa-2), colon cancer cells (HT-29) and lung cancer cells (H-460) using the propidium iodide (PI) fluorescence assay. Compounds 9a and 13a were evaluated against EGFR, B-Raf and Tubulin anticancer targets.

Results:

Compounds 9a, 9b, 10a, 11a, 12a, 13a and 13b showed remarkable antiproliferative activity against the tested cell lines with IC50 range of 1.3-5.9µM. Compounds 9a and 13a with the least IC50 values in the anticancer screening assay were tested against three known anticancer targets including EGFR, B-Raf kinase and Tubulin. The results revealed that compound 13a showed the highest potency against B-Raf and EGFR kinases with IC50 = 0.7 and 1.9 µM, respectively.

Conclusion:

1,2,4-triazoles reported herein are potent EGFR, B-Raf inhibitors. These lead compounds will be subjected to more detailed mechanistic studies.

Bergenin Activates SIRT1 as a Novel Therapeutic Agent for Osteogenesis of Bone Mesenchymal Stem Cells

Bone mesenchymal stem cells (BMSCs) are important candidates for bone regeneration. The role of Bergenin, a C-glucoside of 4-O-methyl gallic acid obtained from the species, Bergenia, in BMSC osteogenesis has not yet been elucidated. We therefore investigated the effects of Bergenin on the osteogenesis of BMSCs and found that Bergenin enhanced osteoblast-specific markers and downregulated the adipocyte-specific markers in vitro. Furthermore, using a rat calvarial defect model, we found that Bergenin significantly improved bone healing, as determined by imaging and histological analyses. Moreover, it also upregulated SIRT1 expression. A SIRT1 inhibitor (EX 527) decreased the enhanced bone mineral formation caused by Bergenin. Taken together, these findings show that Bergenin accelerated the osteogenic differentiation of BMSCs, at least partly through the activation of SIRT1.

Bark Extract of the Amazonian Tree Endopleura uchi (Humiriaceae) Extends Lifespan and Enhances Stress Resistance in Caenorhabditis elegans

Endopleura uchi (Huber) Cuatrec (Humiriaceae), known as uxi or uxi-amarelo in Brazil, is an endemic tree of the Amazon forest. In traditional medicine, its stem bark is used to treat a variety of health disorders, including cancer, diabetes, arthritis, uterine inflammation, and gynecological infections. According to HPLC analysis, the main constituent of the bark extract is the polyphenol bergenin. In the current study, we demonstrate by in vitro and in vivo experiments the antioxidant potential of a water extract from the stem bark of E. uchi. When tested in the model organism Caenorhabditis elegans, the extract enhanced stress resistance via the DAF-16/FOXO pathway. Additionally, the extract promoted an increase in the lifespan of the worms independent from caloric restriction. It also attenuated the age-related muscle function decline and formation of polyQ40 plaques, as a model for Huntington's disease. Thus, these data support anti-aging and anti-oxidant properties of E. uchi, which has not yet been described. More studies are needed to assess the real benefits of E. uchi bark for human health and its toxicological profile.

Pharmacological effects of gallic acid in health and diseases: A mechanistic review

OBJECTIVES

Gallic acid is a natural phenolic compound found in several fruits and medicinal plants. It is reported to have several health-promoting effects. This review aims to summarize the pharmacological and biological activities of gallic acid in vitro and animal models to depict the pharmacological status of this compound for future studies.

MATERIALS AND METHODS

All relevant papers in the English language were collected up to June 2018. The keywords of gallic acid, antioxidant, anticancer, antimicrobial, gastrointestinal-, cardiovascular-, metabolic-, neuropsychological-, and miscellaneous- diseases were searched in Google Scholar, PubMed, and Scopus.

RESULTS

Several beneficial effects are reported for gallic acid, including antioxidant, anti-inflammatory, and antineoplastic properties. This compound has been reported to have therapeutic activities in gastrointestinal, neuropsychological, metabolic, and cardiovascular disorders.

CONCLUSION

Current evidence confirms the pharmacological and therapeutic interventions of gallic acid in multiple health complications; however, available data are limited to just cellular and animal studies. Future investigations are essential to further define the safety and therapeutic efficacy of gallic acid in humans.

Protective Effect of Bergenin against Cyclophosphamide-Induced Immunosuppression by Immunomodulatory Effect and Antioxidation in Balb/c Mice

In this study, the aim was to investigate the effect of bergenin on immune function and antioxidation in cyclophosphamide (Cy)-induced immunosuppressed mice. Firstly, we estimated its effect on immune organs. Histological analysis and indexes of immune organs showed that cyclophosphamide exhibited spleen and thymus injury compared with the normal control, which was alleviated by bergenin. Secondly, bergenin also enhanced the humoral immune function through increasing the level of IgM and IgG in serum. Thirdly, bergenin also enhanced the cellular immune function. The results indicate that bergenin increased peritoneal macrophage functions, the proliferation of T and B lymphocytes, NK and CTL cell activities, and T (CD4⁺ and CD8⁺) lymphocyte subsets. Besides, bergenin also had the ability to modulate the Th1/Th2 balance. Moreover, bergenin prevented the Cy-induced decrease in numbers of peripheral RBC, WBC and platelets, providing supportive evidence for their anti-leukopenia activities. Finally, bergenin also reversed the Cy-induced decrease in the total antioxidant capacity including activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px). In conclusion, bergenin protected against Cy-induced adverse reactions by enhancing humoral and cellular immune functions and augmenting antioxidative activity and could be considered as a potential immunomodulatory agent.

Bergenin: a computationally proven promising scaffold for novel galectin-3 inhibitors

Bergenin is a C-glycoside of 4-O-methylgallic acid that is isolated from medicinal plants such as Flueggea leucopyrus, Bergenia crassifolia, Mallotus philippensis, Corylopsis spicata, Caesalpinia digyna, Mallotus japonicus, and Sacoglottis gabonensis. Even though there appears to be ample evidence from South Asian traditional medicine that bergenin possesses strong anticancer activity, no comprehensive scientific study has been carried out to test its anticancer potency. Therefore, in this study, the potential mechanisms of action for bergenin's postulated anticancer activity were examined using computational techniques. Firstly, bergenin was tested for its toxicity as a drug candidate using in silico toxicity analysis. It was found that bergenin is nontoxic according to modern toxicity measures. The optimized structure of bergenin was obtained at the DFT-B3LYP/6-31G(d) level of theory. Potential biological targets of bergenin were identified using reverse docking calculations. Reverse docking results suggested that galectin-3 is a potential target of bergenin. Gelectin-3 is an enzyme that plays a major role in cell-cell adhesion, cell-matrix interactions, macrophage activation, angiogenesis, metastasis, and apoptosis in cancer, making it a popular target in anticancer drug design. Among the many potential biological targets predicted by reverse docking calculations, galectin-3 was selected as it complies with the primary objective of this study. The binding of bergenin to galectin-3 was studied by conventional forward docking calculations. Classical molecular dynamics (MD) simulations were used to study the stability of the galectin-3:bergenin complex. Docking calculations indicated that bergenin has the potential to effectively bind to the carbohydrate recognition domain (CRD) of galectin-3. As well as electrostatic and van der Waals interactions, a few strong hydrogen bonds were found to be involved in the binding of bergenin to galectin-3. There is also a plausible π-stacking interaction between the aromatic moiety of bergenin and the His158 residue at the binding site. A 50-ns MD simulation was carried out for the bergenin:galectin-3 complex in a cubic water box with periodic boundary conditions. The MD results showed that the bergenin:galectin-3 complex is highly stable and confirmed the veracity of the docking results, which suggested that bergenin potentially exerts an inhibitory effect on galectin-3. This study therefore sheds new light on the anticancer activity of bergenin and demonstrates that bergenin could potentially be used to develop more potent galectin-3 inhibitors. The study also provides scientific evidence supporting the use of bergenin-containing plants in cancer treatments in Eastern traditional medicine. Graphical abstract Bergenin in the galectin-3 binding site.

Stereoselective synthesis of sugar-fused (or 1,2-annulated) isochromans and isochromanones by using oxa-Pictet-Spengler reaction

A highly efficient stereoselective synthesis of sugar fused 1,2-annulated isochromans is reported by utilizing the oxa-Pictet-Spengler cyclization reaction. The process is found to be very general as both glucal and galactal derived C2-hydroxy-α-C-aryl glycosides lead to the target molecules in good yields. The utility of this strategy was extended to the synthesis of sugar fused isochromanones, which are bergenin type molecules.

Optimized Extract from Corylopsis coreana Uyeki (Hamamelidaceae) Flos Inhibits Osteoclast Differentiation

Osteoporosis is a metabolic disorder that decreases the stability against fractures of the spine, femur, and radius by weakening the strength and integrity of bones. Receptor activator of nuclear factor-kappa B ligand signaling ultimately activated nuclear factor-activated T cells c1, a major transcription factor for osteoclast formation. This study researched the effects of Corylopsis coreana (C. coreana) Uyeki flos extracts on the antiosteoclastic potential of macrophages and the phytochemicals contained therein. The alcoholic extract of C. coreana Uyeki flos inhibited the differentiation of osteoclast. We carried out the experiments of the pattern of differentiation of osteoclasts based on the alcoholic percentage of extracts. Among them, 80% alcoholic extract showed the highest inhibitory effect. The alcoholic extract was composed of phytochemicals such as bergenin, quercetin, and quercitrin. This extract inhibited not only mRNA expression levels of NFATc1, osteoclast-associated receptor (OSCAR), cathepsin K, and tartrate-resistant acid phosphatase (TRAP), but also the translational expression of NFATc1. The inhibitory effect for osteoclast differentiation of the alcoholic extract was confirmed using the resorption pit assay. This is the first scientific report of the antiosteoclastic effects of C. coreana Uyeki flos extract, which can be applied therapeutically for the treatment of osteoporosis.

Bergenin increases osteogenic differentiation and prevents methylglyoxal-induced cytotoxicity in MC3T3-E1 osteoblasts

Bergenin, an active component of plants in the genus Bergenia, has multiple biological activities, including anti-inflammatory and immunomodulatory properties. We investigated the effects of bergenin on MC3T3-E1 osteoblasts. Bergenin treatment significantly elevated collagen synthesis, alkaline phosphatase activity, osteocalcin synthesis, and mineralization in the cells (p < 0.05). Additionally, bergenin increased the ratio of osteoprotegerin to receptor activator of nuclear factor kappa-B ligand, and cyclophilin B release. Methylglyoxal (MG), a highly reactive dicarbonyl compound, is the major precursor in the formation of advanced glycation end products. Pretreatment of MC3T3-E1 cells with bergenin prevented MG-induced cell death. Furthermore, bergenin treatment significantly reduced the induction of activating transcription factor 6 and autophagy by MG. These results indicate that bergenin may have positive effects on critical osteoblastic cell functions.

Bergenin, Acting as an Agonist of PPARγ, Ameliorates Experimental Colitis in Mice through Improving Expression of SIRT1, and Therefore Inhibiting NF-κB-Mediated Macrophage Activation

Bergenin, isolated from the herb of Saxifraga stolonifera Curt. (Hu-Er-Cao), has anti-inflammatory, antitussive and wound healing activities. The aim of the present study was to identify the effect of bergenin on experimental colitis, and explored the related mechanisms. Our results showed that oral administration of bergenin remarkably alleviated disease symptoms of mice with dextran sulfate sodium (DSS)-induced colitis, evidenced by reduced DAI scores, shortening of colon length, MPO activity and pathologic abnormalities in colons. Bergenin obviously inhibited the mRNA and protein expressions of IL-6 and TNF-α in colon tissues, but not that of mucosal barrier-associated proteins occludin, E-cadherin and MUC-2. In vitro, bergenin significantly inhibited the expressions of IL-6 and TNF-α as well as nuclear translocation and DNA binding activity of NF-κB-p65 in lipopolysaccharide (LPS)-stimulated peritoneal macrophages and RAW264.7 cells, which was almost reversed by addition of PPARγ antagonist GW9662 and siPPARγ. Subsequently, bergenin was identified as a PPARγ agonist. It could enter into macrophages, bind with PPARγ, promote nuclear translocation and transcriptional activity of PPARγ, and increase mRNA expressions of CD36, LPL and ap2. In addition, bergenin significantly up-regulated expression of SIRT1, inhibited acetylation of NF-κB-p65 and increased association NF-κB-p65 and IκBα. Finally, the correlation between activation of PPARγ and attenuation of colitis, inhibition of IL-6 and TNF-α expressions, NF-κB-p65 acetylation and nuclear translocation, and up-regulation of SIRT1 expression by bergenin was validated in mice with DSS-induced colitis and/or LPS-stimulated macrophages. In summary, bergenin could ameliorate colitis in mice through inhibiting the activation of macrophages via regulating PPARγ/SIRT1/NF-κB-p65 pathway. The findings can provide evidence for the further development of bergenin as an anti-UC drug, and offer a paradigm for the recognization of anti-UC mechanisms of compound with similar structure occurring in traditional Chinese medicines.

Bergenin loaded gum xanthan stabilized silver nanoparticles suppress synovial inflammation through modulation of the immune response and oxidative stress in adjuvant induced arthritic rats

Bergenin (BG) is a naturally occurring C-glycoside with demonstrated anti-arthritic potential.

Evaluation of in vitro and in vivo antileishmanial potential of bergenin rich Bergenia ligulata (Wall.) Engl. root extract against visceral leishmaniasis in inbred BALB/c mice through immunomodulation

BACKGROUND

Medicinal plants with immunomodulatory properties can provide good alternative therapeutics for curing visceral leishmaniasis. Bergenia ligulata (Wall.) Engl. is an interesting plant with strong antioxidant, antimicrobial, immunomodulatory and hepatoprotective properties.

AIM

The present study was planned to determine the antileishmanial activity of plant extract by modulating the immune responses of inbred BALB/c mice.

METHODOLOGY

Bergenin, the principle active component of B. ligulata, was quantitated in crude extract by performing RP-HPLC. The therapeutic potential was assessed through in vitro antileishmanial activity and in mice model through parasite load, cytokine assays, IgG antibody levels, DTH responses, histopathology and biochemical enzyme assays.

RESULTS

B. ligulata showed the presence of glycosides, saponins, carbohydrates, tannins, flavonoids and bergenin which contributed to the antileishmanial activity of extract with IC50 of 22.70 μg/mL. Furthermore, the higher dose significantly reduced the parasite load by 95.56 %. The reduction was further associated with significant enhancement of IL-12 and IFN-γ levels in comparison to IL-10 and IL-4 cytokines. The switching towards Th1 type of immune response was also confirmed by elevated antibody levels of IgG2a isotype as compared to IgG1 as well as increased DTH responses. The histology of liver and kidney further complimented the non toxic nature of plant extract in addition to its negligible toxicity on HeLa cells.

CONCLUSIONS

The current study revealed the significant antileishmanial and immunomodulatory properties of this plant extract against murine visceral leishmaniasis. Further, the bioactive components will be explored to assess their efficacy for the development of safe and cost effective drug.

Glycosyl Cross-Coupling of Anomeric Nucleophiles: Scope, Mechanism, and Applications in the Synthesis of Aryl C-Glycosides

Stereoselective manipulations at the C1 anomeric position of saccharides are one of the central goals of preparative carbohydrate chemistry. Historically, the majority of reactions forming a bond with anomeric carbon has focused on reactions of nucleophiles with saccharide donors equipped with a leaving group. Here, we describe a novel approach to stereoselective synthesis of C-aryl glycosides capitalizing on the highly stereospecific reaction of anomeric nucleophiles. First, methods for the preparation of anomeric stannanes have been developed and optimized to afford both anomers of common saccharides in high anomeric selectivities. We established that oligosaccharide stannanes could be prepared from monosaccharide stannanes via O-glycosylation with Schmidt-type donors, glycal epoxides, or under dehydrative conditions with C1 alcohols. Second, we identified a general set of catalytic conditions with Pd₂(dba)₃ (2.5 mol%) and a bulky ligand (JackiePhos, 10 mol%) controlling the β-elimination pathway. We demonstrated that the glycosyl cross-coupling resulted in consistently high anomeric selectivities for both anomers with mono- and oligosaccharides, deoxysugars, saccharides with free hydroxyl groups, pyranose, and furanose substrates. The versatility of the glycosyl cross-coupling reaction was probed in the total synthesis of salmochelins (siderophores) and commercial anti-diabetic drugs (gliflozins). Combined experimental and computational studies revealed that the β-elimination pathway is suppressed for biphenyl-type ligands due to the shielding of Pd(II) by sterically demanding JackiePhos, whereas smaller ligands, which allow for the formation of a Pd-F complex, predominantly result in a glycal product. Similar steric effects account for the diminished rates of cross-couplings of 1,2-cis C1-stannanes with aryl halides. DFT calculations also revealed that the transmetalation occurs via a cyclic transition state with retention of configuration at the anomeric position. Taken together, facile access to both anomers of various glycoside nucleophiles, a broad reaction scope, and uniformly high transfer of anomeric configuration make the glycosyl cross-coupling reaction a practical tool for the synthesis of bioactive natural products, drug candidates, allowing for late-stage glycodiversification studies with small molecules and biologics.

Effects of bergenin on methylglyoxal-induced damage in osteoblastic MC3T3-E1 cells

Bergenin is the main chemical constituent of plants in the genus Bergenia, which are used in traditional medicines. Methylglyoxal (MG), a highly reactive dicarbonyl compound, is the major precursor for forming advanced glycation end products (AGEs). Pretreating MC3T3-E1 cells with bergenin prevented MG-induced protein adduct formation. Bergenin inhibited the MG-induced soluble receptor for AGE (sRAGE), interleukin, reactive oxygen species and mitochondrial superoxide production. Additionally bergenin increased glyoxalase I activity, glutathione, heme oxygenase-1 and nuclear factor erythroid 2-related factor 2 levels in the presence of MG. Pretreatment with bergenin before MG exposure reduced MG-induced mitochondrial dysfunction by preventing mitochondrial membrane potential dissipation, loss of adenosine triphosphate and reduced adenosine monophosphate-activated protein kinase. These results demonstrate that bergenin may prevent the development of diabetic osteopathy.

Antimicrobial and Anti-Inflammatory Effects of Ethanol Extract of Corylopsis coreana Uyeki Flos

Background:

Corylopsis coreana Uyeki (Hamamelidaceae) is a medicinal plant cultivated in Northeast Asia. Previously, we have reported that an ethanol extract of Corylopsis coreana Uyeki flos (ECCF) contains four active compounds with antioxidant activity.

Objective:

The aim of this study was to investigate the antimicrobial spectrum against infectious bacteria and anti-inflammatory effect of ECCF in a mouse model of acute local inflammation.

Materials and Methods:

In vitro antimicrobial susceptibility was evaluated using standard plate assay technique. Antimicrobial activities (minimum inhibitory concentration, MIC; μg/mL) were determined with the serial dilution method. In vivo anti-inflammatory activity was studied using a mouse model of carrageenan-induced air pouch inflammation.

Results:

The ECCF showed antimicrobial activities against general bacteria and drug-resistant bacteria including Staphylococcus aureus, Micrococcus luteus ATCC 9341, Mycrobacterium smegmatis ATCC 9341, Mycrobacterium smegmatis ATCC 9341, Salmonella typhimrium KCTC 1925, and nine methicillin-resistant Staphylococcus aureus strains, with MIC values ranging from 250 to 1000 μg/mL. In in vivo mouse model, inflammatory morphologic changes observed in the air pouch membrane were restored to its normal condition by the ECCF treatment. Moreover, the ECCF significantly reduced exudate volumes, protein contents, inflammatory cell counts, and pro-inflammatory cytokine levels in the exudates recovered from air pouches of the mouse model. Flavonoids in the ECCF were found to contain bergenin, quercitrin, and quercetin with reported anti-inflammatory activity via suppressing tumor necrosis factor-α production.

Conclusion:

To the best of our knowledge, this is the first report to demonstrate the antimicrobial and anti-inflammatory activities of ECCF. Our results suggest that the ECCF might potentially serve as an alternative or complementary medicine for treating inflammatory diseases caused by microbial infection.

SUMMARY

ECCF showed antimicrobial activity against infectious bacteria and multidrug-resistant strains.

ECCF exhibited anti-inflammatory activity in a carrageenan-induced air pouch mouse model.

ECCF contained several active constituents such as bergenin, quercitrin, and quercetin.

Abbreviations used:Corylopsis coreana CCF: Uyeki flos, ECCF: ethanol extract of CCF

The natural product bergenin ameliorates lipopolysaccharide-induced acute lung injury by inhibiting NF-kappaB activition

ETHNOPHARMACOLOGICAL RELEVANCE

Bergenin, an active constituent of the plants of the genus Bergenia, was reported to have anti-inflammatory effects in the treatment of chronic bronchitis and chronic gastritis clinically. However, its therapeutic effect on lipopolysaccharide (LPS)-induced acute lung injury (ALI) and its potential mechanisms of actions were still unknown.

AIM OF THIS STUDY

To evaluate the effect of bergenin on murine model of acute lung injury induced by LPS and also to explore its potential mechanisms.

MATERIALS AND METHODS

Half an hour and 12h after an intranasal inhalation of LPS, male BALB/c mice were treated with bergenin (50,100 and 200mg/kg) or dexamethasone (DEX, 5mg/kg) by gavage. Twenty-four hours after LPS exposure, the lung wet/dry ratio, histological changes, myeloperoxidase (MPO) in lung tissues, inflammatory cells (in BALF) and cytokines (in BALF and serum) were detected. Meanwhile, the protein expression of MyD88 and the phosphorylation of NF-κB p65 in lung tissue were analyzed using immunoblot analysis. Moreover, the nuclear translocation and the phosphorylation of NF-κB p65 in Raw264.7 cells were also analyzed. The viability of Raw264.7 cells was determined by MTT assay.

RESULTS

Results showed that bergenin significantly decreased pulmonary edema, improved histological changes and reduced MPO activity in lung tissues. Moreover, bergenin obviously decreased inflammatory cells, IL-1β and IL-6 production in BALF, as well as IL-1β, TNF-α and IL-6 production in serum of LPS-induced ALI mice. Furthermore, bergenin markedly inhibited LPS-induced NF-κB p65 phosphorylation, as well as the expression of MyD88 but not the expression of NF-κB p65 in lung tissues. Additionally, bergenin also significantly inhibited the nuclear translocation and the phosphorylation of NF-κB p65 stimulated by LPS in Raw264.7 cells.

CONCLUSIONS

These findings suggested that bergenin had a therapeutic effect on LPS-induced ALI by inhibiting NF-κB activition.

First Report on the Ethnopharmacological Uses of Medicinal Plants by Monpa Tribe from the Zemithang Region of Arunachal Pradesh, Eastern Himalayas, India

The Himalayas are well known for high diversity and ethnobotanical uses of the region’s medicinal plants. However, not all areas of the Himalayan regions are well studied. Studies on ethnobotanical uses of plants from the Eastern Himalayas are still lacking for many tribes. Past studies have primarily focused on listing plants’ vernacular names and their traditional medicinal uses. However, studies on traditional ethnopharmacological practices on medicine preparation by mixing multiple plant products of different species has not yet been reported in published literature from the state of Arunachal Pradesh, India, Eastern Himalayas. In this study, we are reporting for the first time the ethnopharmacological uses of 24 medicines and their procedures of preparation, as well as listing 53 plant species used for these medicines by the Monpa tribe. Such documentations are done first time in Arunachal Pradesh region of India as per our knowledge. Our research emphasizes the urgent need to document traditional medicine preparation procedures from local healers before traditional knowledge of tribal people living in remote locations are forgotten in a rapidly transforming country like India.