Pharmacological and analytical aspects of bergenin: a concise report

Computational approaches for lead compound discovery in dipeptidyl peptidase-4 inhibition using machine learning and molecular dynamics techniques

The prediction of possible lead compounds from already-known drugs that may present DPP-4 inhibition activity imply a advantage in the drug development in terms of time and cost to find alternative medicines for the treatment of Type 2 Diabetes Mellitus (T2DM). The inhibition of dipeptidyl peptidase-4 (DPP-4) has been one of the most explored strategies to develop potential drugs against this condition. A diverse dataset of molecules with known experimental inhibitory activity against DPP-4 was constructed and used to develop predictive models using different machine-learning algorithms. Model M36 is the most promising one based on the internal and external performance showing values of Q2CV = 0.813, and Q2EXT = 0.803. The applicability domain evaluation and Tropsha's analysis were conducted to validate M36, indicating its robustness and accuracy in predicting pIC50 values for organic molecules within the established domain. The physicochemical properties of the ligands, including electronegativity, polarizability, and van der Waals volume were relevant to predict the inhibition process. The model was then employed in the virtual screening of potential DPP4 inhibitors, finding 448 compounds from the DrugBank and 9 from DiaNat with potential inhibitory activity. Molecular docking and molecular dynamics simulations were used to get insight into the ligand-protein interaction. From the screening and the favorable molecular dynamic results, several compounds including Skimmin (pIC50 = 3.54, Binding energy = -8.86 kcal/mol), bergenin (pIC50 = 2.69, Binding energy = -13.90 kcal/mol), and DB07272 (pIC50 = 3.97, Binding energy = -25.28 kcal/mol) seem to be promising hits to be tested and optimized in the treatment of T2DM. This results imply a important reduction in cost and time on the application of this drugs because all the information about the its metabolism is already available.

Design and evaluation of nanostructured lipid carrier of Bergenin isolated from Pentaclethra macrophylla for anti-inflammatory effect on lipopolysaccharide-induced inflammatory responses in macrophages

Herein, we report the properties of nanostructured lipid carriers (NLCs) prepared with a gradient concentration of Bergenin (BGN) isolated from Pentaclethra macrophylla stem bark powder. A gradient concentration of BGN (BGN 0, 50, 100, 150, and 200 mg) was prepared in a 5 % lipid matrix consisting of Transcutol HP (75 %), Phospholipon 90H (15 %), and Gelucire 43/01 (10 %) to which a surfactant aqueous phase consisting of Tween 80, sorbitol, and sorbic acid was dissolved. The NLCs were evaluated by size, polydispersity index (PDI), zeta potential, Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), encapsulation efficiency, and in vitro drug release. The result shows polydispersed nanoparticles with high drug encapsulation (94.26-99.50 %). The nanoparticles were mostly spherical, but those from the 50 mg BGN batch were more cuboidal than spherical. The drug release was highest from the latter to the tune of 40 % compared to the pure BGN solution, which released about 15 % BGN. The anti-inflammatory activity of the BGN-NLC and total plant extract was studied on lipopolysaccharide (LPS)-inflamed macrophages. The cell study showed that BGN and plant extract had low cytotoxicity on macrophages and exhibited a dose-dependent anti-inflammatory effect on the LPS-induced inflammatory process in macrophages.

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.

Characteristics of the complete chloroplast genome of Saxifragaceae species Bergenia purpurascens (Hook. f. et Thoms.) Engl

Bergenia purpurascens (Hook. f. et Thoms.) Engl. is one species of traditional Chinese medicinal plant. This is the first publication of its complete chloroplast (cp) genome. The whole cp genome has 157,246 base pairs in length with 132 annotated genes, of which were 87 protein-coding genes, 37 tRNAs, and 8 rRNAs. According to the phylogenetic study, B. purpurascens and Bergenia scopulosa T. P. Wang. 1974 had a sister relationship. This genomic data and conclusions from B. purpurascens phylogenetic research will provide useful information and throw light on more in-depth investigations of the systematics and evolutionary patterns of Saxifragaceae.

Bergenin alleviates Diabetic Retinopathy in STZ-induced rats

Diabetic retinopathy (DR) is the key cause of blindness and visual impairment in diabetes patients around the world. The high levels of oxidative stress in diabetes patients cause diabetic retinopathy. In addition to being an antioxidant, Bergenin also works as an immunosuppressant, an anti-inflammatory, and anticarcinogenic against hepatocarcinoma. This study examined the effects of Bergenin on diabetic retinopathy rats, using Streptozotocin (STZ) intraperitoneally to induce diabetes in rats. The animals were divided into four groups (n = 6), including a normal control (Group I), diabetic control (Group II), Bergenin (25 mg/kg) (Group III), and metformin (350 mg/kg) (Group IV). As previously mentioned, each animal received treatment for 60 days. To induce DR, rats were administered STZ (60 mg/kg) intraperitoneally for 60 days. Standard methods were utilized to measure the body weight of rats, blood glucose levels. We measured lipid profiles (Triglycerides, cholesterol, LDL, and HDL), inflammatory markers, and antioxidant levels with their respective kits. Analysis of retinal tissue morphometry and MMP-9, VEGF, and MCP-1 levels in serum was performed. Our research examined the expression levels of target genes (TNF-α, IL-1β, and IL-6) using RT-PCR analysis. STZ-induced animals that were treated with Bergenin had less food intake, lower blood glucose, and improved body weight. Bergenin significantly suppressed levels of pro-inflammatory cytokines, cholesterol, TG, LDL, AI, MMP-9, VEGF, and MCP-1 and increased the level of HDL and antioxidant enzymes in STZ-induced DR rats. As well as increasing antioxidant levels, reducing retinal thickness, and increasing cell numbers, Bergenin also lessened DR remarkably. The results of this study demonstrated that Bergenin effectively inhibited STZ-induced DR in rats.

Comparative appraisal of in vitro biological profile and in vivo wound healing attributes of bergenin and Bergenia ciliata (Haw.) Sternb

ETHNOPHARMACOLOGICAL RELEVANCE

People of all ages experience injuries, whether mild or severe. The most available option to treat wounds as an alternative to allopathic care in both urban and rural populations is traditional medicine, which is mostly target inflammation. Bergenia ciliata (Haw.) Sternb rhizome and leaf powder are used in Ayurveda and local communities for various ailments including healing of wounds and burns. Owing to this property it is traditionally known as "Zakham-e-hayat" (wound healer).

AIM OF THE STUDY

In the present study, we compared biological activity and wound healing potential of B. ciliata rhizome (R) extract and bergenin, a glycoside isolated from B. ciliata.

MATERIALS AND METHODS

Reverse-phase high performance liquid chromatography (RP-HPLC) was performed to analyze polyphenols and bergenin in B. ciliata R extract. Samples were subjected to in vitro antioxidant assays including free radical scavenging, ferric chloride reducing power and total antioxidant capacity. Micro-broth dilution method, brine shrimp lethality assay and isolated RBC hemolysis assay were conducted to assess in vitro antibacterial and cytotoxic activities. Moreover, in vivo wound healing potential was determined by an excision wound model in mice.

RESULTS

RP-HPLC showed significant content of polyphenols and bergenin (6.05 ± 0.12 μg/mg) in B. ciliata R extract. Crude extract possesses higher overall antioxidant and antibacterial capacities than bergenin due to presence of multiple phytoconstituents in extract. Both samples showed low hemolytic activity indicating their safe profile. Furthermore, mice treated with B. ciliata R extract depicted substantial decrease in wound area (99.3%; p < 0.05) as compared to bergenin, which showed 88.8% of wound closure after 12 days of treatment. Additionally, both treatments reduced epithelization duration by 1.6- and 1.4-fold in B. ciliata R extract (12.0 ± 0.6 days) and bergenin (14.2 ± 0.8 days) treated mice, respectively. This was supported by histopathological examination that showed greater epithelization, fibroblast proliferation, collagen synthesis, and revascularization in mice treated with B. ciliata R.

CONCLUSION

Concisely, it is evident that B. ciliata R contains phytoconstituents in addition to bergenin, which potentiated wound healing activity of the extract. Hence, B. ciliata R is good source of compounds for treating wounds.

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.

Clinical Potential of Himalayan Herb Bergenia ligulata: An Evidence-Based Study

Herbal products have been used in traditional systems of medicine and by ethnic healers for ages to treat various diseases. Currently, it is estimated that about 80% of people worldwide use herbal traditional medicines against various ailments, partly due to easy accessibility and low cost, and the lower side effects they pose. Bergenia ligulata, a herb ranging from the Himalayas to the foothills, including the north-eastern states of India, has traditionally been used as a remedy against various diseases, most prominently kidney stones. The medicinal properties of B. ligulata have been attributed to bergenin, its most potent bioactive component. Apart from bergenin, the other compounds available in B. ligulata are arbutin, gallic acid, protocatechuic acid, chlorogenic acid, syringic acid, catechin, ferulic acid, afzelechin, paashaanolactone, caryophyllene, 1,8-cineole, β-eudesmol, stigmasterol, β-sitosterol, parasorbic acid, 3-methyl-2-buten-1-ol, phytol, terpinen-4-ol, tannic acid, isovalaric acid, avicularin, quercetin, reynoutrin, and sitoinoside I. This review summarizes various medicinal properties of the herb, along with providing deep insight into its bioactive molecules and their potential roles in the amelioration of human ailments. Additionally, the possible mechanism(s) of action of the herb's anti-urolithiatic, antioxidative, antipyretic, anti-diabetic, anti-inflammatory and hepatoprotective properties are discussed. This comprehensive documentation will help researchers to better understand the medicinal uses of the herb. Further studies on B. ligulata can lead to the discovery of new drug(s) and therapeutics for various ailments.

Anti-inflammatory properties of novel galloyl glucosides isolated from the Australian tropical plant Uromyrtus metrosideros

Two new galloyl glucosides, galloyl-lawsoniaside A (4) and uromyrtoside (6), were isolated from the polar fraction of Uromyrtus metrosideros leaf extract along with another four previously identified phytochemicals (1, 2, 3, and 5). The structures of these six compounds were characterised using low and high-resolution mass spectrometry (L/HRMS) and 1D and 2D Nuclear Magnetic Resonance (NMR) spectroscopy. These compounds were not toxic to human peripheral blood mononuclear cells (PBMCs) at 10 μg/mL over 24 h, yet showed significant in vitro suppression of proinflammatory cytokines involved in the pathogenesis of inflammatory bowel disease (IBD). Specifically, the release of interferon γ (IFN-γ), interleukin (IL)-17A, and IL-8 from phorbol myristate acetate/ionomycin (P/I) and anti-CD3/anti-CD28-activated cells were significantly suppressed by compounds 4 and 5. Interestingly, no effect on tumour necrosis factor (TNF) release was observed. These results show that the newly characterised compound 4 has promising cytokine suppressive properties, which could be further investigated as a candidate for IBD treatment.

Adsorptive removal of Acid Blue 113 using hydroxyapatite nanoadsorbents synthesized using Peltophorum pterocarpum pod extract

The present work reports the study on the green synthesis of hydroxyapatite (HAP) nanoadsorbents using Peltophorum pterocarpum pod extract. HAP nanoadsorbents were characterized by using FESEM, EDS, TEM, XRD, FTIR, XPS, and BET analyses. The results highlighted the high purity, needle-like aggregations, and crystalline nature of the prepared HAP nanoadsorbents. The surface area was determined as 40.04 m²/g possessing mesopores that can be related to the high adsorption efficiency of the HAP for the removal of a toxic dye, - Acid Blue 113 (AB 113) from water. Central Composite Design (CCD) was used for optimizing the adsorption process, which yielded 94.59% removal efficiency at the optimum conditions (dose: 0.5 g/L, AB 113 dye concentration: 25 ppm, agitation speed: 173 rpm, and adsorption time: 120 min). The adsorption kinetics followed the pseudo-second-order model (R²:0.9996) and the equilibrium data fitted well with the Freundlich isotherm (R²:0.9924). The thermodynamic parameters indicated that the adsorption of AB 113 was a spontaneous and exothermic process. The highest adsorption capacity was determined as 153.85 mg/g, which suggested the promising role of green HAP nanoadsorbents in environmental remediation applications.

Rivea hypocrateriformis (Desr.) Choisy: An Overview of Its Ethnomedicinal Uses, Phytochemistry, and Biological Activities and Prospective Research Directions

Rivea hypocrateriformis (Desr.) Choisy is a robust woody climbing shrub of the genus Rivea which is widely distributed in India, Nepal, Sri Lanka, Pakistan, Bangladesh, Myanmar, and Thailand. R. hypocrateriformis is a promising medicinal herb with a wide range of beneficial and health-promoting properties. Since the ancient times, it has been used as a traditional medicine to treat rheumatic pain, fever, urogenital problems, snake bites, cough, piles, malaria, and skin diseases. Aside from these traditional uses, its leaves and young shoots are also cooked and eaten as a vegetable and used for the preparation of bread with millet flour. This study extensively analyzes the available information on R. hypocrateriformis botanical characterization, distribution, traditional applications, phytochemistry, pharmacology, and toxicological properties. Phytochemical investigations of the plant has revealed the presence of highly valuable secondary metabolites including alkaloids, glycosides, coumarins, flavonoids, xanthones, stilbenes, and other organic compounds. Its crude extracts and isolated compounds have revealed anovulatory, antifertility, antiarthritic, antimicrobial, anticancer, antioxidant hepatoprotective, antilithiatic, and antimitotic potentials. This review of literature clearly identifies R. hypocrateriformis as a potent medicinal plant with remarkable healing and health-promoting properties. Further research directions into the bioactive extracts, clinical, and toxicological evaluations to assess the beneficial health-promoting properties of this promising herb are also discussed.

Design and Evaluation of pH-Sensitive Nanoformulation of Bergenin Isolated from Bergenia ciliata

The aim of the current study is extraction and isolation of bergenin from Bergenia ciliata and fabrication of pH-sensitive Eudragit^® L100 (EL100) polymeric nanoparticles (NP) to tackle limitations of solubility. Bergenin-loaded EL100 nanoparticles (BN-NP) were fabricated via nanoprecipitation and an experimental design was conducted for optimization. A reverse phase-high performance liquid chromatography (RP-HPLC) method was developed for the quantitation of bergenin. The optimized nanoformulation was characterized by its particle size, morphology, loading capacity, entrapment efficiency, drug-excipient interaction and crystallinity. An in vitro assay was executed to gauge the release potential of pH-sensitive nanoformulation. The mean particle size, zeta potential and polydispersity index (PDI) of the optimized nanoparticles were observed to be 86.17 ± 2.1 nm, -32.33 ± 5.53 mV and 0.30 ± 0.03, respectively. The morphological analysis confirmed the spherical nature of the nanoparticles. Drug loading capacity and entrapment efficiency were calculated to be 16 ± 0.34% and 84 ± 1.3%, respectively. Fourier transform infrared spectroscopy (FTIR) studies unfolded that no interaction was present between the drug and the excipients in the nanoformulation. Crystallography studies revealed that the crystalline nature of bergenin was changed to amorphous and the nanoformulation was stable for up to 3 months at 40 °C. The present study confirms that bergenin isolation can be scaled up from abundantly growing B. ciliata. Moreover, it could also be delivered by entrapment in stimuli-responsive polymer, preventing the loss of drug in healthy tissues.

Insights into the cytoprotective potential of Bergenia ligulata against oxalate-induced oxidative stress and epithelial-mesenchymal transition (EMT) via TGFβ1/p38MAPK pathway in human renal epithelial cells

Oxalate exposure to human renal epithelial cells triggers a vicious cycle of oxidative stress leading to cellular injury and deposition of calcium oxalate crystals on the injured cells. This results in further oxidative damage causing inflammation and loss of cell-cell adhesion factors, ultimately leading to irreparable kidney damage. However, these events can be attenuated or prevented by plants rich in antioxidants used in the traditional system of medicine for treatment of kidney stones. To delineate the mechanism by which Bergenia ligulata extract exerts its cytoprotective role in oxalate-induced injury we designed this study. Our results revealed that oxalate-injured HK2 cells cotreated with ethanolic extract of Bergenia ligulata displayed increased viability, reduced oxidative stress due to lowered production of intracellular reactive oxygen species (ROS) and decreased apoptosis. We also observed lowered markers of inflammation, along with increased expression of epithelial marker E-cadherin and decreased expression of mesenchymal markers Vimentin, F-actin, Transforming growth factor beta 1 (TGF-β1) and EMT-related proteins in renal tubular epithelial cells through immunocytochemistry, real-time PCR and western blotting. Our findings collectively suggest that by reducing oxidative stress, modulating crystal structure and preventing crystal-cell adhesion, B. ligulata inhibits the EMT pathway by downregulating the various mediators and thereby exerts its cytoprotective effect.

Biosynthetic potential of the endophytic fungus Helotiales sp. BL73 revealed via compound identification and genome mining

Endophytic fungi have been recognized as prolific producers of chemically diverse secondary metabolites. In this work, we describe a new representative of the order Helotiales isolated from the medicinal plant Bergenia pacumbis. Several bioactive secondary metabolites were produced by this Helotiales sp. BL 73 isolate grown on rice medium, including cochlioquinones and isofusidienols. Sequencing and analysis of the approx. 59 Mb genome revealed at least 77 secondary metabolite biosynthesis gene clusters, several of which could be associated with detected compounds or linked to previously reported molecules. Four terpene synthase genes identified in the BL73 genome were codon-optimized and expressed, together with farnesyl-, geranyl- and geranylgeranyl-pyrophosphate synthases, in Streptomyces spp. Analysis of recombinant strains revealed production of linalool and its oxidized form, terpenoids typically associated with plants, as well as a yet unidentified terpenoid. This study demonstrates the importance of a complex approach to the investigation of the biosynthetic potential of endophytic fungi using both conventional methods and genome mining. Importance Endophytic fungi represent as yet underexplored source of secondary metabolites, some of which may have industrial and medical applications. We isolated a slow-growing fungus belonging to the order Helotiales from the traditional medicinal plant Bergenia pacumbis and characterized its potential to biosynthesize secondary metabolites. We used both cultivation of the isolate with subsequent analysis of compounds produced, bioinformatics-based mining of the genome, and heterologous expression of several terpene synthase genes. Our study revealed enormous potential of this Helotiales isolate to produce structurally diverse natural products, including polyketides, non-ribosomally synthesized peptides, terpenoids and RiPPs. Identification of meroterpenoids and xanthones, along with establishing a link between these molecules and their putative biosynthetic genes sets a stage for investigation of the respective biosynthetic pathways. Heterologous production of terpenoids suggests that this approach can be used for the discovery of new compounds belonging to this chemical class using Streptomyces bacteria as hosts.

In Silico Analysis of Cissus rotundifolia Constituents as Human Neutrophil Elastase (HNE), Matrix Metalloproteinases (MMP 2 and MMP 9), and Tyrosinase Inhibitors

Cissus rotundifolia has been reported to possess various biological activities such as anti-diabetic, anti-fertility, anti-hyperlipidemic, anti-malarial, anti-osteoporotic, and anti-parasitic activities. Therefore in the present study, eleven selected constituents of Cissus rotundifolia which includes aconitic acid, astragalin, acteoside, aliospiroside A, beta amyrin, bergenin, formononetin, gallic acid, isovitexin, isoorientin, and isoquercitrin were studied on the docking behavior of human neutrophil elastase (HNE), matrix metalloproteinases (MMP 2 and MMP 9), and tyrosinase by using PatchDock method. Furthermore, molecular physicochemical, bioactivity score/drug-likeness, ADME (absorption, distribution, metabolism, and excretion), and toxicity analyses were also carried out using Molinspiration, Swiss ADME, and ProTox-II methods, respectively. The molecular physicochemical investigation showed that three ligands such as acteoside, aliospiroside A, and isoorientin have three violations for Lipinski's rule of five. Similarly, ADME analysis one ligand (formononetin) predicated to have high blood-brain barrier (BBB) permeability effect. The docking studies showed that isovitexin exhibited the highest atomic contact energy (-341.61 kcal/mol) for human neutrophil elastase (HNE), more over alliospiroside A has shown maximum atomic contact energy for both matrix metalloproteinases (MMP 2 [-618.00 kcal/mol] and MMP 9 [-634.73 kcal/mol]). Furthermore, isoquercitrin has exhibited the highest atomic contact energy (-145.70 kcal/mol) for tyrosinase. Thus, the present investigation outcome provides new knowledge in understanding eleven Cissus rotundifolia constituents as possible novel inhibitors against HNE, MMP 2, MMP 9, and tyrosinase.

Discovery of Natural Product Inspired 3-Phenyl-1H-isochromen-1-ones as Highly Potent Antioxidant and Antiplatelet Agents: Design, Synthesis, Biological Evaluation, SAR and in silico Studies

BACKGROUND

Several natural/synthetic molecules having structure similar to 1H-isochromen-1-ones have been reported to display promising antioxidants and platelet aggregation inhibitory activity. Isocoumarin (1H-2-benzopyran-1-one) skeleton, either whole or as a part of molecular framework, have been explored for their antioxidant or antiplatelet activities.

INTRODUCTION

Based on literature, a new prototype i.e., 3-phenyl-1H-isochromen-1-ones based compounds have been rationalized to possess both antioxidant as well as antiplatelet activities. Consequently, no reports are available regarding its inhibition either by cyclooxygenase-1 (COX-1) enzyme or by arachidonic acid (AA)-induced platelet aggregation. This prompted us to investigate 3-phenyl-1H-isochromen-1-ones towards antioxidant and antiplatelet agents.

METHODS

The goal of this work to identify new 3-phenyl-1H-isochromen-1-ones based compounds via synthesis of a series of analogues and performing in vitro antioxidant as well as AA-induced antiplatelet activities and then, identification of potent compounds by SAR and molecular docking studies.

RESULTS

Out of all synthesized 3-phenyl-1H-isochromen-1-ones analogues, five compounds showed 7-folds to 16-folds highly potent antioxidant activities than ascorbic acid. Altogether, ten 3-phenyl-1H-isochromen-1-one analogues displayed antioxidant activities in 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Almost, all the 3-phenyl-1H-isochromen-1-one analogues exhibited potent AA-induced antiplatelet activity; few of them displayed 7-folds more activity as compared to aspirin. Further, in silico analysis validated the wet results.

CONCLUSION

We disclose the first detailed study for the identification of 3-phenyl-1H-isochromen-1-one analogues as highly potent antioxidant as well as antiplatelet agents. The article describes the scaffold designing, synthesis, bioevaluation, structure-activity relationship and in silico studies of pharmaceutically privileged bioactive 3-phenyl-1H-isochromen-1-one class of heterocycles.

A Comprehensive Review about the Molecular Structure of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2): Insights into Natural Products against COVID-19

In 2019, the world suffered from the emergence of COVID-19 infection, one of the most difficult pandemics in recent history. Millions of confirmed deaths from this pandemic have been reported worldwide. This disaster was caused by SARS-CoV-2, which is the last discovered member of the family of Coronaviridae. Various studies have shown that natural compounds have effective antiviral properties against coronaviruses by inhibiting multiple viral targets, including spike proteins and viral enzymes. This review presents the classification and a detailed explanation of the SARS-CoV-2 molecular characteristics and structure-function relationships. We present all currently available crystal structures of different SARS-CoV-2 proteins and emphasized on the crystal structure of different virus proteins and the binding modes of their ligands. This review also discusses the various therapeutic approaches for COVID-19 treatment and available vaccinations. In addition, we highlight and compare the existing data about natural compounds extracted from algae, fungi, plants, and scorpion venom that were used as antiviral agents against SARS-CoV-2 infection. Moreover, we discuss the repurposing of select approved therapeutic agents that have been used in the treatment of other viruses.

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.

Endopleura uchi - A review about its nutritional compounds, biological activities and production market

Endopleura uchi (Huber) Cuatrec, known as uxi, is a native plant from the Amazon region, which has been used by locals for some pathology treatments. This review aimed to find the main uxi studies carried out in scientific literature. This compilation includes the biological activities that have been proven, parts of the plant that were exploited, as well as its nutritional properties. Uxi fruit has compounds, such as vitamins A and E, minerals, bioactive phenolic and organic acids, along with anti-inflammatory, antioxidant, antibacterial, antidiabetic, and anti-cholesterol actions. Some E. uchi extract activities have been reported, such as: α-glucosidase and cyclooxygenases (COX1/COX2) inhibitions, in addition to anti-bactericidal properties. The isocoumarin compound, bergenin is responsible for many of the reported biological activities of this species. E. uchi can be used for manufacturing products in food, pharmaceutical, and cosmetic industries, demonstrating its worth, regional economic growth, along the potential to dominate the worldwide market.

Residual Larvicidal Activity of Quinones against Aedes aegypti

The number of documented dengue cases has increased dramatically in recent years due to transmission through the Aedes aegypti mosquito bite. Vector control remains the most effective measure to protect against this and other arboviral diseases including Zika, chikungunya and (urban) yellow fever, with an established vaccine only available for yellow fever. Although the quinone class shows potential as leading compounds for larvicide development, limited information restricts the development of optimized structures and/or formulations. Thus, in this contribution we investigated the larvicidal and pupicidal activity of three quinone compounds isolated from a Connarus suberosus root wood ethyl acetate extract together with 28 quinones from other sources. Eight quinones demonstrated larvicidal activity, of which tectoquinone (4) proved to be the most active (LC50 1.1 µg/mL). The essential residual effect parameter of four of these quinones was evaluated in laboratory trials, with tectoquinone (4) and 2-ethylanthraquinone (7) presenting the most prolonged activity. In small-scale field residual tests, tectoquinone (4) caused 100% larvae mortality over 5 days, supporting its selection for formulation trials to develop a prototype larvicide to control Ae. aegypti.

Bergenia pacumbis from Nepal, an astonishing enzymes inhibitor

BACKGROUND

The Bergenia species are perennial herbs native to central Asia, and one of the most promising medicinal plants of the family Saxifragaceae which are popularly known as 'Pashanbheda'. The aim of this study was to evaluate antioxidant and α-amylase, α-glucosidase, lipase, tyrosinase, elastase, and cholinesterases inhibition potential of Bergenia pacumbis of Nepali origin collected from the Karnali region of Nepal.

METHODS

The sequential crude extracts were made in hexane, ethyl acetate, methanol, and water. Antioxidant activities were analyzed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. The α-amylase, α-glucosidase, lipase, tyrosinase, elastase, acetylcholinesterase, and butyrylcholinesterase inhibition were analyzed by the 3,5-Dinitrosalicylic acid (DNSA), p-Nitrophenyl-α-D-glucopyranoside (p-NPG), 4-nitrophenyl butyrate (p-NPB), l-3,4-dihydroxyphenylalanine (L-DOPA), N-Succinyl-Ala-Ala-p-nitroanilide (AAAPVN), acetylthiocholine, and butyrylcholine as a respective substrate. The major metabolites were identified by high performance liquid chromatography with electron spray ionization- quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS) profiling.

RESULTS

Our results revealed the great antioxidant ability of crude extract of B. pacumbis in ethyl acetate extract against both DPPH (IC50 = 30.14 ± 0.14 μg/mL) and ABTS (IC50 = 17.38 ± 1.12 μg/mL). However, the crude methanol extract of B. pacumbis showed the comparable enzymes inhibitions with standard drugs; α-amylase (IC50 = 14.03 ± 0.04 μg/mL), α-glucosidase (IC50 = 0.29 ± 0.00 μg/mL), lipase (IC50 = 67.26 ± 0.17 μg/mL), tyrosinase (IC50 = 58.25 ± 1.63 μg/mL), elastase (IC50 = 74.00 ± 3.03 μg/mL), acetylcholinesterase (IC50 = 31.52 ± 0.58 μg/mL), and butyrylcholinesterase (IC50 = 11.69 ± 0.14 μg/mL). On the basis of HPLC-ESI-QTOF-MS profiling of metabolites, we identified major compounds such as Bergenin, Catechin, Arbutin, Gallic acid, Protocatechuic acid, Syringic acid, Hyperoside, Afzelechin, Methyl gallate, Paashaanolactone, Astilbin, Quercetin, Kaempferol-7-O-glucoside, Diosmetin, Phloretin, and Morin in methanol extract which has reported beneficial bioactivities.

CONCLUSION

Our study provides a plethora of scientific evidence that the crude extracts of B. pacumbis from Nepalese origin in different extracting solvents have shown significant potential on inhibiting free radicals as well as enzymes involved in digestion, skin related problems, and neurological disorders compared with the commercially available drugs.

Anti-Inflammatory Activity of Miodesin™: Modulation of Inflammatory Markers and Epigenetic Evidence

PURPOSE

To investigate the effects of a combined herbal medicine Miodesin™ on the inflammatory response of key cells involved in the acute and chronic inflammatory processes as well as the possible epigenetic involvement.

METHODS

After the establishment of the IC50 dose, the chondrocyte, keratinocyte, and macrophage cell lines were pretreated for 2 hours with Miodesin™ (200 μg/mL) and stimulated with LPS (1 μg/mL) for 24 hours. The supernatant was used to measure the levels of cytokines (IL-1β, IL-6, IL-8, and TNF-α) and chemokines (CCL2, CCL3, and CCL5), and the cells were used to extract the mRNA for the transcription factor (NF-κβ), inflammatory enzymes (COX-1, COX-2, PLA2, and iNOS), and chemokines (CCL2, CCL3, and CCL5).

RESULTS

Miodesin™ inhibited the release of LPS-induced cytokines (IL-1β, IL-6, IL-8, and TNF-α; p < 0.01) and chemokines (CCL2, CCL3, and CCL5; p < 0.01) and the expression of the transcription factor (NF-κβ; p < 0.01), inflammatory enzymes (COX-1, COX-2, PLA2, iNOS; p < 0.01), and chemokines (CCL2, CCL3, and CCL5; p < 0.01). In addition, the evaluation of epigenetic mechanism revealed that Miodesin™ did not induce changes in DNA methylation, assuring the genetic safeness of the compound in terms of the inflammatory response.

CONCLUSIONS

Miodesin™ presents anti-inflammatory properties, inhibiting hyperactivation of chondrocytes, keratinocytes, and macrophages, involving epigenetics in such effects.

The phytochemical bergenin as an adjunct immunotherapy for tuberculosis in mice

The widespread availability and use of modern synthetic therapeutic agents have led to a massive decline in ethnomedical therapies. However, these synthetic agents often possess toxicity leading to various adverse effects. For instance, anti-tubercular treatment (ATT) is toxic, lengthy, and severely impairs host immunity, resulting in posttreatment vulnerability to reinfection and reactivation of tuberculosis (TB). Incomplete ATT enhances the risk for the generation of multidrug- or extensively drug-resistant (MDR or XDR, respectively) variants of Mycobacterium tuberculosis (M. tb), the TB-causing microbe. Therefore, a new therapeutic approach that minimizes these risks is urgently needed to combat this deadly disease and prevent future TB epidemics. Previously, we have shown that the phytochemical bergenin induces T helper 1 (Th1)- and Th17 cell-based protective immune responses and potently inhibits mycobacterial growth in a murine model of M. tb infection, suggesting bergenin as a potential adjunct agent to TB therapy. Here, we combined ATT therapy with bergenin and found that this combination reduces immune impairment and the length of treatment in mice. We observed that co-treatment with the anti-TB drug isoniazid and bergenin produces additive effects and significantly reduces bacterial loads compared with isoniazid treatment alone. The bergenin co-treatment also reduced isoniazid-induced immune impairment; promoted long-lasting, antigen-specific central memory T cell responses; and acted as a self-propelled vaccine. Of note, bergenin treatment significantly reduced the bacterial burden of a multidrug-resistant TB strain. These observations suggest that bergenin is a potent immunomodulatory agent that could be further explored as a potential adjunct to TB therapy.

African Herbal Remedies with Antioxidant Activity: A Potential Resource Base for Wound Treatment

The use of traditional herbal remedies as alternative medicine plays an important role in Africa since it forms part of primary health care for treatment of various medical conditions, including wounds. Although physiological levels of free radicals are essential to the healing process, they are known to partly contribute to wound chronicity when in excess. Consequently, antioxidant therapy has been shown to facilitate healing of such wounds. Also, a growing body of evidence suggests that, at least, part of the therapeutic value of herbals may be explained by their antioxidant activity. This paper reviews African herbal remedies with antioxidant activity with the aim of indicating potential resources for wound treatment. Firstly, herbals with identified antioxidant compounds and, secondly, herbals with proven antioxidant activity, but where the compound(s) responsible for the activity has not yet been identified, are listed. In the latter case it has been attempted to ascribe the activity to a compound known to be present in the plant family and/or species, where related activity has previously been documented for another genus of the species. Also, the tests employed to assess antioxidant activity and the potential caveats thereof during assessment are briefly commented on.

Linking traditional anti-ulcer use of rhizomes of Bergenia ciliata (Haw.) to its anti-Helicobacter pylori constituents

The rhizomes of Bergenia ciliata (B. ciliata, Family: Saxifragaceae) are widely used for treating gastric ulcers in folk medicine in Asia. It was hypothesized that anti-ulcer activity of B. ciliata is due to its anti-Helicobacter pylori (H. pylori) activity. The anti-H. pylori activity was investigated on six clinical bacterial isolates using agar well-diffusion and broth micro-dilution methods. The anti-H. pylori activity of amoxicillin (standard) was the highest (Zone of inhibition; ZI = 25 mm, minimum inhibitory concentration; MIC=0.125 µg/µL) whereas among all the extracts of the rhizomes, methanol extract showed the highest activity (ZI = 16 mm, MIC = 12.50 µg/µL). Bioassay guided isolation of methanol extract using chromatographic and crystallization techniques isolated bergenin (ZI = 21mm, MIC = 0.391µg/µL) as constituent responsible for anti-H. pylori activity. The present study describes for the first time anti-H. pylori activity and possible mechanism of anti-ulcer properties of rhizomes of B. ciliata.

Preventive effect of bergenin against the development of TNBS-induced acute colitis in rats is associated with inflammatory mediators inhibition and NLRP3/ASC inflammasome signaling pathways

Ulcerative colitis is an idiopathic inflammatory bowel disease characterized by intestinal inflammation; blocking this inflammatory process may be the key to the development of new naturally occurring anti-inflammatory drugs, with greater efficiency and lower side effects. The objective of this study is to explore the effects of bergenin (BG) in TNBS (2,4,6-trinitrobenzenesulfonic acid)-induced acute colitis model in rats in order to assist in the studies for the development of novel natural product therapies for inflammatory bowel disease. 48 Wistar rats were randomized into six groups: (i) Control and (ii) TNBS control; (iii) 5-ASA 100 mg/kg/day (iv) BG 12 mg/kg/day (v) BG 25 mg/kg/day and (vi) BG 50 mg/kg/day. Colitis was induced by instillation of TNBS. Colitis was evaluated by an independent observer who was blinded to the treatment. Our results revealed that bergenin decreased the macroscopic and microscopic damage signs of colitis, and reduced the degree of neutrophilic infiltration in the colon tissue; also, it was capable to down-regulate COX-2, iNOS, IkB-α, and pSTAT3 protein expression. Similarly, using a protocol for indirect ELISA quantification of cytokines, bergenin treatment reduced IL-1β, IFN-γ and IL-10 levels, and inhibited both canonical (IL-1) and non-canonical (IL-11) NLRP3/ASC inflammasome signaling pathways in TNBS-induced acute colitis. Conclusion: Our study has provided evidence that administration of bergenin reduced the damage caused by TNBS in an experimental model of acute colitis in rats, reduced levels of pro-inflammatory proteins and cytokines probably by modulation of pSTAT3 and NF-κB signaling and blocking canonical and non-canonical NLRP3/ASC inflammasome pathways.

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.

Factors Contributing to the Decline of Traditional Practices in Communities from the Gwallek-Kedar area, Kailash Sacred Landscape, Nepal

Traditional knowledge and practices are increasingly recognized in the resource conservation and management practices, however are declining in many parts of the world including Nepal. Studies on the inventory of traditional knowledge are available, albeit limited, and empirical analysis of factors contributing to the decline of traditional knowledge are negligible in Nepal. We thus initiated this study in the Nepal part of the Kailash Sacred Landscape to (i) document traditional knowledge and practices on agriculture, forest-based herbal remedy, and genetic resource conservation; and (ii) identify factors contributing to the decline of traditional practices in the communities. Data was collected during September-December 2015 through key informant interviews, focus group discussions, and households survey. The household survey data was used in binary logistic regression analysis to identify factors contributing to the decline of six key traditional practices. The study documented 56 types of traditional practices. The regressions showed that the age of the respondent, distance to the nearest forest, distance to the nearest motorable road, family members' ill health, and seasonal migration of the household members for jobs significantly influencing to the decline of the particular traditional practices, however, their effects vary within a practice and among the practices. The use of modern medicine, increasing road linkages, decreasing trend of plant resource availability, and agriculture intensification are responsible for the decline of the particular traditional practices. We recommend to recognize their significance in the governing socio-ecological systems and to link the traditional and scientific knowledge systems through policy formulations.

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.

Major bioactive phenolics in Bergenia species from the Indian Himalayan region: Method development, validation and quantitative estimation using UHPLC-QqQLIT-MS/MS

Bergenia species are important medicinal plants used in indigenous systems of medicine for their antilithiatic and diuretic properties. An ultra-high performance liquid chromatography coupled to hybrid linear ion trap triple quadrupole mass spectrometry (UHPLC-QqQLIT-MS/MS) method has been developed and validated for the estimation of quantitative variation of eight major bioactive phenolics in the rhizomes (150 samples) of four species of this herb, Bergenia (B. ciliata, B. ligulata, B. purpurascens and B. stracheyi). Chromatographic separation was obtained on a Waters ACQUITY UPLCTM BEH (ethylene bridged hybrid) C18 column with a mobile phase consisting of 0.1% (v/v) formic acid aqueous solution and acetonitrile under a gradient elution manner. A hybrid linear ion trap triple quadrupole mass spectrometer was operated in negative electrospray ionization mode with multiple reactions monitoring for detection and quantification of the eight compounds. The validated method demonstrated good linearity (r2 ≥ 0.9991), precision (RSD ≤ 1.87%) and accuracy (95.16-102.11%, RSD ≤ 1.83%) for all reference analytes. The quantitative results revealed that B. ligulata contains the highest amount of the major active marker-bergenin. The results also suggest that sensitive UHPLC-QqQLIT-MS/MS method, a sensitive, accurate and convenient one, could be helpful in identification of potential accession(s), rapid quality control and establishing authenticity of Bergenia species as raw material for pharmaceutical industries.

Medicinal importance, pharmacological activities, and analytical aspects of hispidulin: A concise report

Herbal medicines have been played an important role in the human civilization since very ancient time as a food, cloth, medicine and other aspects. Some of the important drugs in the modern medicine were derived from the natural sources such as aspirin, digitalis, quinine, vincristine, vinblastine etc. Hispidulin (4', 5, 7-trihydroxy-6-methoxyflavone) is a flavones derivative found in plant such as Grindelia argentina, Arrabidaea chica, Saussurea involucrate, Crossostephium chinense, Artemisia and Salvia species. Hispidulin have antioxidant, antifungal, anti-inflammatory, antimutagenic, and antineoplastic properties. So far, various analytical methods have been investigated and developed for detection of hispidulin in the plant materials. Productions of hispidulin through different tissue culture techniques have been also investigated. Present review summarized medicinal uses, pharmacological activities and analytical aspects of hispidulin. From the above mentioned aspects, we can conclude that, this review will be helpful to the researcher in the field of natural product for the development of novel molecule for the treatment of different disorders.

The Phytochemical Bergenin Enhances T Helper 1 Responses and Anti-Mycobacterial Immunity by Activating the MAP Kinase Pathway in Macrophages

Tuberculosis (TB) remains one of the greatest health concerns worldwide, which has hindered socioeconomic development in certain parts of the world for many centuries. Although current TB therapy, "Directly Observed Treatment Short-course," is effective, it is associated with unwanted side effects and the risk for the generation of drug-resistant organisms. The majority of infected individuals successfully confine the mycobacterial organisms and remain asymptotic unless immune responses are perturbed. Thus, host immunity can protect against TB and immunomodulation is therefore an attractive therapeutic option. Previous studies have shown that TNF-α and Nitric Oxide (NO) in conjunction with IFN-γ-producing T helper 1 (Th1) cells play critical roles in host protection against TB. Here, we show that bergenin, a phytochemical isolated from tender leaves of Shorea robusta, activates the MAP kinase and ERK pathways and induces TNF-α, NO and IL-12 production in infected macrophages. We further show that bergenin induces Th1 immune responses and potently inhibits bacillary growth in a murine model of Mycobacterium tuberculosis infection. These findings identify bergenin as a potential adjunct to TB therapy.

Astible Rivularis: Bioactive Compounds and Pharmacological Functions

Astilbe rivularis Buch. Ham., a rhizomatous perennial herb of the Saxifragaceae family, has been listed in rare species. In traditional medicine the plant has been used for the treatment of ulcer, bleeding during child birth, inflammation, body ache, diarrhea, and dysentery. This article reviews and analyses the traditional use, pharmacological activities of the corresponding bioactive compounds, and toxicological data on A. rivularis species. A. rivularis has been used across Indian subcontinent to treat various human ailments. Its extract consists of alkaloids, flavonoids, coumarins and glycosides. These extracts as well as isolated bioactive compounds demonstrated various biological activities including antimicrobial, anti-peptic ulcer, anti-inflammatory, and antioxidant activity. Toxicological studies of the extract on brine shrimp larvae demonstrated mild toxicity; however no acute toxicity in mice. Although the pharmacological effect of A. rivularis has been poorly explored, the available data validated its use in ethnomedicine. To reveal the cryptic therapeutic potential of the species, research should focus on identification and mechanistic studies of the bioactive compounds.

Isocoumarins, miraculous natural products blessed with diverse pharmacological activities

Isocoumarins are lactonic natural products abundant in microbes and higher plants. These are considered an amazing scaffold consecrated with more or less all types of pharmacological applications. This review is complementary to the earlier reviews and aims to focus the overlooked aspects of their fascinating chemistry with special emphasis on their classification and diverse biological activities with some SAR conclusions. The most recent available literature on the structural diversity and biological activity of these natural products has been reviewed.

Bergenin Content and Free Radical Scavenging Activity of Bergenia Extracts

Our research was focused on the evaluation of bergenin content and free radical scavenging activity of extracts prepared from three different species of Bergenia - B. crassifolia (L.) Fritsch., B. ciliata (Haw.) Sternb. and B. x ornata Stein. collected during different seasons. Using an HPLC method, the highest total amount of bergenin was revealed in the leaves of B. x ornata and B. crassifolia (4.9 - 5.1 mg.g−1). Free radical scavenging power was determined by two methods - FRAP and NADH. The best free radical scavengers were B. crassifolia (FRAP: 6.7 - 15.9 mg GAE.100g−1; NADH: 20.3 - 50.9%) and B. ornata (FRAP: 13.7 - 15.2 mg GAE.100g−1; NADH: 29.3 - 31.1%). The lowest content of bergenin and the weakest radical scavenger was B. ciliata (bergenin: 3.1 mg.g−1; FRAP: 5.5 - 11.0 mg GAE.100g−1; NADH: 23.2 - 25.6%). The presence of a large percentage of bergenin is responsible for the radical scavenging activity, as shown by the results from the FRAP and NADH assays. Significant, positive correlation was found between bergenin content and radical scavenging activity in both methods.

Evaluation of antioxidant and antiproliferative activity of Flueggea leucopyrus Willd (katupila)

BACKGROUND

Flueggea leucopyrus Willd is a shrub grown in many parts of the dry zones in Sri Lanka. The leaves of F. leucopyrus has been used for treating cancer in the traditional system of medicine in Sri Lanka. Hence, this study was performed to analyze the antioxidant and antiproliferative properties of the aqueous extract of the leaves of F. leucopyrus on HEp-2 cells.

METHOD

The aqueous extract of F. leucopyrus leaves (AEFLL) was freeze dried. Total phenolic content was assayed using Folin Ciocalteu reagent. Antioxidant activities of the extracts were evaluated using in vitro assays: inhibition of DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging and 2-deoxy-D-ribose degradation assay. Nitric oxide radical scavenging activity was determined by using Griess reagent. The MTT, LDH assays and protein synthesis were used to study antiproliferative and cytotoxic activities against the Hep-2 cell after 24 hour exposure. DNA fragmentation and microscopic examination of cells stained with a mixture of ethidium bromide/acridine orange were used to visualize apoptosis in HEp-2 cells treated with the AEFLL.

RESULTS

The total phenolic content of the extract was 22.15 ± 1.65 (w/w) % of gallic acid equivalent. The values for EC50 were 11.16 ± 0.37, 4.82 ± 1.82 and 23.77 ± 3.16 μg/mL for DPPH radical scavenging, nitric oxide radical scavenging activity and 2-deoxy-D-ribose degradation assay respectively. The EC50 with MTT and LDH assays were 506.8 ± 63.16 and 254.52 ± 42.92 μg/mL respectively. A dose dependent decrease in protein synthesis in HEp-2 cells was shown with an EC50 value of 305.84 ± 12.40 μg/mL. DNA fragmentation and ethidium bromide/acridine assays showed that the AEFLL induces apoptosis in HEp-2 cells. These results were in conformity with the morphological changes observed in the cells treated with the AEFLL. The brine shrimp bioassay showed that the AEFLL had no lethality over the concentration range of 50-500 μg/mL.

CONCLUSIONS

Aqueous extract of the leaves of F. leucopyrus extract demonstrated antioxidant activity in vitro. Further it showed antiproliferative properties and induced apoptosis in HEp-2 cells.

In vivo and in vitro antimalarial activity of bergenin

Malaria is a potentially life-threatening protozoal parasitic disease transmitted by female Anopheles mosquitoes. Drug therapy is currently the most widely used method for the control and treatment of this disease. Several plants were found to contain substances possessing antimalarial properties. In this study, we investigated the antimalarial activity of bergenin, a sesquiterpene lactone compound derived from Rodgersia aesculifolia Batal. The results indicated that bergenin effectively inhibited Plasmodium falciparum growth in vitro (IC50, 14.1 μg/ml, with ~100% inhibition at 50 μg/ml), without apparent cytotoxicity to erythrocytes or to mammalian HeLa and HepG2 cells. Bergenin exhibited less cytotoxic activity and the selectivity index (SI) was 887 and 1,355 for HeLa and HepG2 cells, respectively. The administration of bergenin to Plasmodium berghei-infected mice for 6 days significantly inhibited the growth of the parasites. Taken together, these findings provide evidence that bergenin may be a promising novel drug for antimalarial treatment.

LC-MS/MS determination and pharmacokinetic study of bergenin, the main bioactive component of Bergenia purpurascens after oral administration in rats

Bergenin, a C-glucoside of 4-O-methyl gallic acid from Bergenia purpurascens, is a naturally antitussive and expectorant agent. A rapid and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the determination of the active component-bergenin, in rat plasma after oral administration of aqueous B. purpurascens extract. The plasma samples were pretreated by protein precipitation with acetonitrile and chromatographic separation was achieved on a Diamonsil® C18 column (150 mm×4.6 mm, 5 μm) with isocratic elution using a mobile phase consisting of water-methanol (30:70, v/v) at a flow rate of 0.6 mL/min. The detection was accomplished by a triple-quadrupole tandem mass spectrometer in multiple-reaction monitoring (MRM) scanning via an electrospray ionization (ESI) source operating in the negative mode. The optimized mass transition ion-pairs (m/z) for quantitation were 327.3/192.0 for bergenin, and 431.1/311.1 for IS. The time for each analysis run was only 3.5 min between injections. The calibration curve exhibited good linearity (r2>0.99) over a range of 1.00-2000 ng/mL for bergenin. The lower limit of quantitation (LLOQ) was 1.00 ng/mL. The intra- and inter-day precisions were no more than 11.8%, and relative errors (RE) were within the range of 0.0-4.4%. The validated method was successfully applied to investigate the pharmacokinetics of bergenin after oral administration of B. purpurascens extract in rats.