Persicaria hydropiper (L.) Delarbre: A review on traditional uses, bioactive chemical constituents and pharmacological and toxicological activities

The genus Polygonum: An updated comprehensive review of its ethnomedicinal, phytochemical, pharmacological activities, toxicology, and phytopharmaceutical formulation

Polygonum is a plant genus that includes annual and perennial species and is found at various temperatures, from northern temperate regions to tropical and subtropical areas. The genus Polygonum has been used for centuries for various disorders, including hypertension, intestinal and stomach pain, dysuria, jaundice, toothaches, skin allergies, hemorrhoids, cardiac disorders, kidney stones, hemostasis, hyperglycemia, and others. Various databases, including Google Scholar, Scifinder, ScienceDirect, PubMed, Scopus, ResearchGate, and Web of Science, were utilized to collect pertinent scientific literature data. According to bibliographic studies, the Polygonum genus possesses various compounds from different families, including phenolic acids (gallic acid, caffeic acid, quinic acid, p-coumaric acid, ferulic acid, protocatechuic acid, chlorogenic acid, and many other compounds), flavonoids (quercetin, catechin, epicatechin, quercitrin, kaempferol, myricetin, etc.), tannins, stilbenes (polydatin and resveratrol), terpenes (α-pinene, β-caryophyllene and β-caryophyllene oxide, bisabolene, β-farnesene, etc.), fatty acids (decanoic acid, lauric acid, linoleic acid, oleic acid, palmitic acid, stearic acid, dodecanoic acid), polysaccharides, and others. Various chemical and biological activities (in vitro and in vivo), such as antioxidant, antimicrobial, anticancer, antitumor, anti-inflammatory, antidiabetic, antiparasitic, hepatoprotective, neuropharmacological, gastroprotective, diuretic, antipyretic, and others, have been described in several biological studies involving this species. An updated summary of Polygonum species and their ethnomedicinal, phytochemical, toxicological, pharmacological, and phytopharmaceutical formulations is necessary. Considering the numerous potentialities of the Polygonum species and their wide-ranging use, it is extremely essential to provide knowledge by compiling the accessible literature to identify the topics of intense investigation and the main gaps to better design future studies. The objective of this review is to give readers a better understanding, greater comprehension, and in-depth knowledge of the genus Polygonum's traditional applications, phytochemistry, pharmacology, toxicological features, and galenic formulation. Several species of this genus have been detailed in this review, including those that were frequently used in traditional medicine (P. minus, P. aviculare, P. hydropiper, P. cuspidatum, and P. multiflorum) and many of the genus' therapeutic species, like P. equisetiforme, which do not get enough attention.

A neutral polysaccharide from Persicaria hydropiper (L.) Spach ameliorates lipopolysaccharide-induced intestinal barrier injury via regulating the gut microbiota and modulating AKT/PI3K/mTOR and MAPK signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Persicaria hydropiper (L.) Spach, a herb that is prevalent across Asia and Europe, finds utility as both a culinary ingredient and medicinal herb. In China, P. hydropiper decoction is commonly employed to alleviate dysentery, gastroenteritis, and diarrhea symptoms.

AIM OF THE STUDY

To assess the effects of a neutral polysaccharide from P. hydropiper (PHP) on the intestinal barrier (IB) injury induced by lipopolysaccharide (LPS) in mice, and elucidate the molecular mechanisms involved.

MATERIALS AND METHODS

PHP was extracted from dried P. hydropiper herb using hot water extraction, followed by ethanol precipitation. The extract underwent successive isolation and purification steps involving anion-exchange and gel filtration chromatography. The primary structure of PHP was determined using Fourier-transformed infrared spectroscopy, ion chromatography, gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) spectroscopy. Male BALB/c mice were randomly assigned to control (CON), model (MOD), berberine hydrochloride (BBR), and PHP (20, 40 and 80 mg/kg) groups. Histopathological changes in jejunal tissues were assessed through hematoxylin and eosin (HE) staining. The expression levels of proteins and genes involved in AKT/PI3K/mTOR and MAPK signaling pathways were evaluated using qRT-PCR and Western blotting, respectively. The composition and abundance of the gut microbiota in mice were analyzed using high-throughput 16S rRNA gene sequencing. Additionally, the concentrations of short-chain fatty acids (SCFAs) were determined using GC-MS.

RESULTS

The main components of PHP included arabinose, galactose, and glucose (molar ratio = 1.00:5.52:11.39). The backbone of PHP consisted of →4)-Glcp-(1→, →4,6)-Glcp-(1→, →4)-Galp-(1→, →4,6)-Galp-(1→. The branched chains primarily consisted of 5)-Araf-(1→ residues, which were attached to the backbone through →6)-Glcp-(1→ and →6)-Galp-(1→ at the 6-position. Histological analysis demonstrated that PHP exhibited a mitigating effect on intestinal damage induced by LPS. PHP could markedly reduce the mRNA levels of PI3K, AKT, mTOR, p70 S6K, Ras, Raf1, MEK1/2, p38, ERK1/2, and JNK, while downregulating the protein levels of p-mTOR, p-PI3K, p-AKT, p-p38, p-ERK, and p-JNK. PHP also modulated the diversities and abundances of the gut microbiota, resulting in an increase in the abundances of Lactobacillaceae, Anaerovoracaceae, Lachnospiraceae, Eggerthellaceae, and Desulfovibrionaceae and a decrease in the abundances of Muribaculaceae, Prevotellaceae, and Rikenellaceae. Additionally, PHP significantly increased the content of various SCFAs.

CONCLUSION

PHP emerges as a pivotal factor in the repair of IB injury by virtue of its ability to regulate the gut microbiota, elevate SCFA levels, and inhibit the MAPK and AKT/PI3K/mTOR pathways. It is worth noting that the therapeutic effect of high-dose PHP was remarkably significant, surpassing even the positive control of berberine hydrochloride.

Neuroprotective potentials of Lead phytochemicals against Alzheimer's disease with focus on oxidative stress-mediated signaling pathways: Pharmacokinetic challenges, target specificity, clinical trials and future perspectives

BACKGROUND

Alzheimer's diseases (AD) and dementia are among the highly prevalent neurological disorders characterized by deposition of beta amyloid (Aβ) plaques, dense deposits of highly phosphorylated tau proteins, insufficiency of acetylcholine (ACh) and imbalance in glutamatergic system. Patients typically experience cognitive, behavioral alterations and are unable to perform their routine activities. Evidence also suggests that inflammatory processes including excessive microglia activation, high expression of inflammatory cytokines and release of free radicals. Thus, targeting inflammatory pathways beside other targets might be the key factors to control- disease symptoms and progression.

PURPOSE

This review is aimed to highlight the mechanisms and pathways involved in the neuroprotective potentials of lead phytochemicals. Further to provide updates regarding challenges associated with their use and their progress into clinical trials as potential lead compounds.

METHODS

Most recent scientific literature on pre-clinical and clinical data published in quality journals especially on the lead phytochemicals including curcumin, catechins, quercetin, resveratrol, genistein and apigenin was collected using SciFinder, PubMed, Google Scholar, Web of Science, JSTOR, EBSCO, Scopus and other related web sources.

RESULTS

Literature review indicated that the drug discovery against AD is insufficient and only few drugs are clinically approved which have limited efficacy. Among the therapeutic options, natural products have got tremendous attraction owing to their molecular diversity, their safety and efficacy. Research suggest that natural products can delay the disease onset, reduce its progression and regenerate the damage via their anti-amyloid, anti-inflammatory and antioxidant potentials. These agents regulate the pathways involved in the release of neurotrophins which are implicated in neuronal survival and function. Highly potential lead phytochemicals including curcumin, catechins, quercetin, resveratrol, genistein and apigenin regulate neuroprotective signaling pathways implicated in neurotrophins-mediated activation of tropomyosin receptor kinase (Trk) and p75 neurotrophins receptor (p75NTR) family receptors.

CONCLUSIONS

Phytochemicals especially phenolic compounds were identified as highly potential molecules which ameliorate oxidative stress induced neurodegeneration, reduce Aβ load and inhibit vital enzymes. Yet their clinical efficacy and bioavailability are the major challenges which need further interventions for more effective therapeutic outcomes.

In-depth in-vitro and in-vivo anti-diabetic evaluations of Fagonia cretica mediated biosynthesized selenium nanoparticles

Therapeutic moieties derived from medicinal plants as well as plants-based ecofriendly processes for producing selenium nanoparticles have shown great promise in the management of type 2 diabetes mellitus (T2DM). The current study was aimed to assess the anti-diabetic potentials of Fagonia cretica mediated biogenic selenium nanoparticles (FcSeNPs) using in-vitro and in-vivo approaches. The bio-synthesized FcSeNPs were characterized using various techniques including UV-VIS spectrophotometry and FTIR analysis. The in-vitro efficacy of FcSeNPs were assessed against α-glucosidase, α-amylase enzymes as well as the anti-radical studies were performed using DPPH and ABTS free radicals scavenging assays. For in-vivo studies, 20 Male Balb/C albino-mice were randomly divided into 4 groups (n = 5) including normal group, disease group (Diabetic group with no treatment), control group and treatment group (Diabetic group treated with FcSeNPs). Further, biochemistry markers including pancreas, liver, kidney and lipid profile were assessed for all treatment groups. The FcSeNPs exhibited a dose-dependent inhibition against α-amylase and α-glucosidase at 62-1000 µg mL^-1 concentration with IC₅₀ values of 92 and 100 µg mL^-1 respectively. In antioxidant experiments, the FcSeNPs demonstrated significant radicals scavenging effect against DPPH and ABTS radicals. In STZ-induced diabetic mice, a considerable decline in blood glucose level was observed after treatment with FcSeNPs. Anti-hyperglycemic effect of FcSeNPs treated animals were high (105 ± 3.22**) as compared to standard drug (128.6 ± 2.73** mg dL^-1). Biochemical investigations revealed that all biochemical parameters for pancreas, liver function, renal function panel and lipid profile were significantly lowered in FcSeNPs treated animals. Our findings indicate a preliminary multi-target efficacy for FcSeNPs against type-2 diabetes and thus warrant further detailed studies.

Monitoring the curing efficiency of a plant-based green engineered additive on caprine skin: a spectroscopic and chemometric novel approach

Environmental sustainability in industrial processing is one of the most fundamental requirements for sustainable development. The leather industry is known for its vast environmental pollution. But, green engineering may occur a paradigm shift in this sector. Plant-based goatskins curing is a cutting-edge green technology that holds the concept of pollution reduction through prevention on the upper stream of leather processing. The successful and rapid monitoring of the efficiency of this technology is the foremost demand for mass-level applications. In this study, ATR-FTIR spectroscopy was employed to monitor this technology's efficiency using a plant Polygonum hydropiper. Chemometrics was also applied to extract information from spectral data leading to an understanding of the inherent effect of studying preservatives on goatskins collagen chemistry. 10% plant-paste +5% NaCl, 10% plant-paste +10% NaCl, and 15% plant-paste +5% NaCl on goatskin were assessed by ATR-FTIR on 0th, 10th, and 30th days of preservation. The Spectral peak fitting (R² = 0.99) area of amide I and II of collagen peptide bands revealed 2.73 to 1.33 times more structural suitability of studied goatskins than the control. Principal component analysis and Hierarchical cluster analysis showed that, after 30 days of curing, 15% paste +5% salt-rubbed goatskin collagen matrix significantly (around 50%) interacted with P. hydropiper. The interaction was superficial, as it happened before the opening up of collagen fibers. In conclusion, ATR-FTIR spectroscopy with Chemometrics can be an effective tool in evaluating the efficiency of goatskin curing and understanding the entire effect on collagen chemistry quickly.

Natural products derived steroids as potential anti-leishmanial agents; disease prevalence, underlying mechanisms and future perspectives

Leishmaniasis is a vector-borne infection caused by protozoan parasites from the genus leishmania and is among the most neglected tropical diseases. It is highly prevalent disease, affecting about 350 million population worldwide. Only limited number of anti-leishmanial agents are approved for clinical use till now and they are associated with side effects and have limited efficacy. Subsequently, natural products based discovery of more safe and effective drugs against leishmania is under scientific consideration. Various studies reported the efficacy of natural products against intracellular and extracellular forms of leishmania species. This work is aimed to evaluate current literature focused on the anti-leihmanial efficacy of steroidal moieties from natural products and their mechanism of action. Compounds including steroidal saponins, steroidal alkaloids and phytosterols were found to exhibit considerable anti-leishmanial efficacy. For instance, steroidal saponin, (25R)-spirost-5-en-3b-ol,3-O-α-rhamnopyranosyl-(1 → 4)-α-rhamnopyranosyl-(1 → 4)-[a-rhamnopyranosyl-(1 → 2)]-glucopyranoside isolated from A. paradoxum has completely eradicated Leishmania major promastigotes at 50 µg mL-1 dose. Spirostanic saponins isolated from Solanum paniculatum L. were effective against Leishmania amazonensis promastigotes. Turgidosterones isolated from Panicum turgidum exhibited high leishmanicidal potentials against Leishmania donovani promastigotes with IC50 of 4.95-8.03 µg mL-1 and even better activity against amastigotes exhibiting an IC50 of 4.50-9.29 µg mL-1. Likewise, racemoside-A from Asparagus racemosus was found effective against an antimonial sensitive (AG83) and antimonial resistant (GE1F8R) strains of the L. donovani. Moreover, steroidal alkaloids including hookerianamide-1, hookerianamide-H, hookerianamide-J, hookerianamide-K, dehydrosarsalignone, vagenine-A, sarcovagine-C, holaphylline, saracodine, holamine, 15-α hydroxyholamine, holacurtin, N-desmethyl holacurtine and elasticine has exhibited time and dose-dependent efficacy against various strains of leishmania. β-sitosterol was found active against multiple strains of leishmania. These compounds mainly exhibit their therapeutic efficacy via liberation of ROS, mitochondrial depolarization, morphological and ultra-structural changes, accumulation of lipid droplets, depletion of non-protein thiols and triggering apoptotic pathways. In conclusion, leishmaniasis is a major health problem in many countries. Plants-derived steroids moieties have reveled efficacy against leishmaniasis and is a source of lead compounds. Further detailed molecular studies are warranted for the discovery of more effective and safe anti-leishmanial drugs.

HPLC-DAD-MS3 fingerprints of phenolics of selected Polygonum taxa and their chemometric analysis

Many Polygonaceae taxa such as Bistorta officinalis, Persicaria amphibia, Persicaria hydropiper, Persicaria lapathifolia, Persicaria maculosa, Persicaria mitis, Polygonum aviculare occur naturally in the entire territory of Poland and are also common in other European countries. Many of these species are also utilised as medicinal plants. In this manuscript we establish the phytochemical profiles of selected taxa from the Polygonaceae focusing on phenolics. Additionally, we try to find chemophenetic markers for the species investigated. Compounds were detected and characterised based on HPLC-DAD-MS data, quantified, and furtherly analysed using multivariate analyses. Chemophenetic markers were identified also considering previous literature.

In-silico evaluations of the isolated phytosterols from polygonum hydropiper L against BACE1 and MAO drug targets

Our previous anti-Alzheimer's studies on crude extracts, essential oils and isolated compounds including β-sitostrol from Polygonum hydropiper L, motivated us for further studies against beta amyloid cleaving enzyme 1 (BACE1) and monoamine oxidases (MAO-A), (MAO-B) enzymes. Before performing detailed studies on the compounds using animal models and immunohistochemistry, molecular docking study was performed against three vital enzymes implicated in several neurological disorders including Alzheimer's disease (AD), Parkinson's disease (PD), depression and anxiety to predict their inhibitory potential against important enzymes. Beta amyloid cleaving enzyme 1 (BACE1) is important enzyme that catalyze pathological amyloidogenic pathway of processing amyloid precursor proteins to form neurotoxic amyloid plaques. Subsequently, BACE1 inhibitors are considered an important tool in the management of AD. MAOs have been categorized in two well-known groups MAO-A and MAO-B, based on their differential affinity for various monoamines substrates. MAO-A has more affinity for norepinephrine and 5-HT, whereas, MAO-B mainly catalyze the breakdown of dopamine and 2-phenylathylamine (PEA) and other monoamines. Subsequently, they have divergent behavioral outcomes and play a significant role in pathophysiology of several neurodegenerative disorders like AD, depression, drug abuse, migraines, schizophrenia, Attention Deficit Disorder (ADD) and Parkinson's disease (PD). Molecular docking was carried out to predict the binding modes of β-sitosterol and stigmasterol in the binding pockets of BACE1 (beta-sectretase 1) and MAO (monoamine oxidase A, B) enzymes. The 3 D structure of BACE1 (PDB ID: 2QP8), MAO A (PDB ID: 2ZPX) and MAO B (PDB ID: 2XFN) were downloaded from protein databank. The 3 D structures were then subjected to protonation and energy minimization using default parameters of MOE. Three dimensional structures of β-sitosterol and stigmasterol were built by using Molecular Builder Module program implemented in MOE and saved as a (.mdb) file for molecular docking. Subsequently, the energy of both the compounds were minimized up to 0.05 Gradient using MMFF 94 s force field implemented in MOE. Both the compounds were docked into the active site of proteins using the Triangular Matching docking method (default) and 10 different conformations for each compound were generated. To obtain minimum energy structures the ligands were allowed to be flexible during docking. At the end of docking, the predicted ligand-protein complexes were analyzed for molecular interactions. Overall the docking results showed that these compounds showed good interaction with active site residues of BACE1 as compare to MAO-A and MAO-B. Furthermore, β-sitosterol showed good interaction with BACE1 as compare to stigmasterol.Communicated by Ramaswamy H. Sarma.

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.

Bio-intervention phyto-based material for raw goatskin preservation: a cleaner-sustainable approach

The regular practice of using sodium chloride to preserve raw animal skin triggers increasing salinity and total dissolved solids (TDS) in the surface and groundwater during rehydration soaking operations. The process disrupts the lives of animals, plants, and human beings. This paper is focused on the phyto-based short-term preservation of goatskin to reduce salinity in tannery soaking operations. The indigenous Persicaria hydropiper leaf was investigated to assess the preservation of animal skin to diminish salinity and TDS of tannery soaking wastewater. Methanol-extracted leaf was characterized by GC-MS and FTIR for chemical composition analysis and affiliated functional groups. Fresh goatskins were preserved at the preliminary, laboratory, and pilot-scale scenarios to establish the best possible mixture and monitor the moisture and nitrogen content, shrinkage temperature, microorganism analysis, and pollution load at each level. The processed leathers derived from the preserved skins with an optimal mixture of 10% leaf paste with 8% salt and conventional 50% salt were tested for their physical strength. Finally, the modification in fiber structure due to the varieties of preserving chemicals was evaluated through a scanning electron microscope (SEM) and detected insignificant variation of leather fibers. The findings reported in this study can be applied to the industrial level and remove certain amounts of salinity and TDS from tannery soaking wastewater.

Antioxidant, Enzyme Inhibitory, and Molecular Docking Approaches to the Antidiabetic Potentials of Bioactive Compounds from Persicaria hydropiper L

Introduction

Natural products are among the most useful sources for the discovery of new drugs against various diseases. Keeping in view the ethnobotanical relevance ethnopharmacological significance of Polygonaceae family in diabetes, the current study was designed to isolate pure compounds from Persicaria hydropiper L. leaves and evaluate their in vitro and in silico antidiabetic potentials.

Methods

Six compounds were isolated from the chloroform-ethyl acetate fractions using gravity column chromatography and were subjected to structure elucidation process. Structures were confirmed using ¹H-NMR, ¹³C-NMR, and mass spectrometry techniques. Isolated phytochemicals were subjected to in vitro antidiabetic studies, including α-glucosidase, α-amylase inhibition, and DPPH, and ABTS antioxidant studies. Furthermore, the in silico binding mode of these compounds in the target enzymes was elucidated via MOE-Dock software.

Results

The isolated compounds revealed concentration-dependent inhibitions against α-glucosidase enzyme. Ph-1 and Ph-2 were most potent with 81.84 and 78.79% enzyme inhibitions at 1000 µg·mL⁻¹, respectively. Ph-1 and Ph-2 exhibited IC₅₀s of 85 and 170 µg·mL⁻¹ correspondingly. Likewise, test compounds showed considerable α-amylase inhibitions with Ph-1 and Ph-2 being the most potent. Tested compounds exhibited considerable antioxidant potentials in both DPPH and ABTS assays. Molecular simulation studies also revealed top-ranked confirmations for the majority of the compounds in the target enzymes. Highest observed potent compound was Ph-1 with docking score of −12.4286 and formed eight hydrogen bonds and three H-pi linkages with the Asp 68, Phe 157, Phe 177, Asn 241, Glu 276, His 279, Phe 300, Glu 304, Ser 308, Pro 309, Phe 310, Asp 349, and Arg 439 residues of α-glucosidase binding packets. Asp 68, Glu 276, Asp 349, and Arg 439 formed polar bonds with the 3-ethyl-2-methylpentane moiety of the ligand.

Conclusions

The isolated compounds exhibited considerable antioxidant and inhibitory potentials against vital enzymes implicated in T2DM. The docking scores of the compounds revealed that they exhibit affinity for binding with target ligands. The enzyme inhibition and antioxidant potential of the compounds might contribute to the hypoglycemic effects of the plant and need further studies.

Phytochemical Analysis, α-Glucosidase and Amylase Inhibitory, and Molecular Docking Studies on Persicaria hydropiper L. Leaves Essential Oils

Objective

Medicinal plants and essentials oils are well known for diverse biological activities including antidiabetic potential. This study was designed to isolate essential oils from the leaves of Persicaria hydropiper L. (P. hydropiper), perform its phytochemical analysis, and explore its in vitro antidiabetic effects.

Materials and Methods

P. hydropiper leaves essential oils (Ph.Los) were extracted using a hydrodistillation apparatus and were subjected to phytochemical analysis using the gas chromatography mass spectrometry (GC-MS) technique. Ph.Lo was tested against two vital enzymes including α-glucosidase and α-amylase which are important targets in type-2 diabetes. The identified compounds were tested using in silico approaches for their binding affinities against the enzyme targets using MOE-Dock software.

Results

GC-MS analysis revealed the presence of 141 compounds among which dihydro-alpha-ionone, cis-geranylacetone, α-bulnesene, nerolidol, β-caryophyllene epoxide, and decahydronaphthalene were the most abundant compounds. Ph.Lo exhibited considerable inhibitory potential against α-glucosidase enzyme with 70% inhibition at 1000 μg mL⁻¹ which was the highest tested concentration. The inhibitory activity of positive control acarbose was 77.30 ± 0.61% at the same tested concentration. Ph.Lo and acarbose exhibited IC₅₀ of 170 and 18 µg mL⁻¹ correspondingly. Furthermore, dose-dependent inhibitions were observed for Ph.Lo against α-amylase enzyme with an IC₅₀ of 890 μg mL⁻¹. The top-ranked docking conformation was observed for β-caryophyllene epoxide with a docking score of -8.3182 against α-glucosidase, and it has established seven hydrogen bonds and one H-pi interaction at the active site residues (Phe 177, Glu 276, Arg 312, Asp 349, Gln 350, Asp 408, and Arg 439). Majority of the identified compounds fit well in the binding pocket of Tyr 62, Asp 197, Glu 233, Asp 300, His 305, and Ala 307 active residues of α-amylase. β-Caryophyllene epoxide was found to be the most active inhibitor with a docking score of -8.3050 and formed five hydrogen bonds at the active site residues of α-amylase. Asp 197, Glu 233, and Asp 300 active residues were observed to be making polar interactions with the ligand.

Conclusions

The current study revealed that Ph.Lo is rich in bioactive metabolites which might contribute to its enzyme inhibitory potential. Inhibition of these enzymes is the key target in reducing postprandial hyperglycemia. However, further detailed in vivo studies are required for their biological and therapeutic activities.

HPLC-DAD phenolics analysis, α-glucosidase, α-amylase inhibitory, molecular docking and nutritional profiles of Persicaria hydropiper L

BACKGROUND

Natural phenolic compounds and Phenolics-rich medicinal plants are also of great interest in the management of diabetes. The current study was aimed to analyze phenolics in P. hydropiepr L extracts via HPLC-DAD analysis and assess their anti-diabetic potentials using in-vitro and in-silico approaches.

METHODS

Plant crude methanolic extract (Ph.Cme) was evaluated for the presence of phenolic compounds using HPLC-DAD analysis. Subsequently, samples including crude (Ph.Cr), hexane (Ph.Hex), chloroform (Ph.Chf), ethyl acetate (Ph.EtAc), butanol (Ph.Bt), aqueous (Ph.Aq) and saponins (Ph.Sp) were tested for α-glucsidase and α-amylase inhibitory potentials and identified compounds were docked against these target enzymes using Molecular Operating Environment (MOE) software. Fractions were also analyzed for the nutritional contents and acute toxicity was performed in animals.

RESULTS

In HPLC-DAD analysis of Ph.Cme, 24 compounds were indentfied and quantified. Among these, Kaemferol-3-(p-coumaroyl-diglucoside)-7-glucoside (275.4 mg g- 1), p-Coumaroylhexose-4-hexoside (96.5 mg g- 1), Quercetin-3-glucoronide (76.0 mg g- 1), 4-Caffeoylquinic acid (58.1 mg g- 1), Quercetin (57.9 mg g- 1), 5,7,3'-Trihydroxy-3,6,4',5'-tetramethoxyflavone (55.5 mg g- 1), 5-Feruloylquinic acid (45.8 mg g- 1), Cyanidin-3-glucoside (26.8 mg g- 1), Delphinidin-3-glucoside (24 mg g- 1), Quercetin-3-hexoside (20.7 mg g- 1) were highly abundant compounds. In α-glucosidase inhibition assay, Ph.Sp were most effective with IC50 value of 100 μg mL-1. Likewise in α-amylase inhibition assay, Ph.Chf, Ph.Sp and Ph.Cme were most potent fractions displayed IC50 values of 90, 100 and 200 μg mL-1 respectively. Docking with the α-glucosidase enzyme revealed top ranked conformations for majority of the compounds with Kaemferol-3-(p-coumaroyl-diglucoside)-7-glucoside as the most active compound with docking score of - 19.80899, forming 14 hydrogen bonds, two pi-H and two pi-pi linkages with the Tyr 71, Phe 158, Phe 177, Gln 181, Arg 212, Asp 214, Glu 276, Phe 300, Val 303, Tyr 344, Asp 349, Gln 350, Arg 439, and Asp 408 residues of the enzyme. Likewise, docking with α-amylase revealed that most of the compounds are well accommodated in the active site residues (Trp 59, Tyr 62, Thr 163, Leu 165, Arg 195, Asp 197, Glu 240, Asp 300, His 305, Asp 356) of the enzyme and Cyanidin-3-rutinoside displayed most active compound with docking score of - 15.03757.

CONCLUSIONS

Phytochemical studies revealed the presence of highly valuable phenolic compounds, which might be responsible for the anti-diabetic potentials of the plant samples.

Cytotoxicity, anti-angiogenic, anti-tumor and molecular docking studies on phytochemicals isolated from Polygonum hydropiper L

BACKGROUND

According to the recent global cancer statistics, breast cancer is the leading cause of deaths among women with 2.3 million new cases globally. Likewise, cervical cancer is also among the leading causes of mortality among women. Polygonum hydropiper is traditionally known for its cytotoxic effects and several bioactive cytotoxic compounds were isolated from it. This study was aimed to isolate potential anticancer compounds from its most potent fractions and evaluate their anticancer potentials.

METHODS

Based on our earlier studies, active fractions including chloroform and ethyl acetate were subjected to column chromatography for isolation of compounds. Chemical structures of isolated compounds were confirmed via 1H NMR, 13C NMR, mass spectrometry. Purified compounds were tested for cytotoxicity against breast cancer cells (MCF-7), cervical cancer cells (HeLA) and NIH/3T3 fibroblasts cells cultures using MTT assy. Anti-angiogenic potentials of isolated compounds were evaluated via chorioallantoic membrane assay. Anti-tumor studies were done using Agrobacterium tumefaciens induced potato tumor assay. Furthermore, to understand the binding modes of Isolated compounds, molecular docking was performed against EGFR, HER2 and VEGFR using MOE as docking software.

RESULTS

Two bioactive compounds PH-1 (4-methyl-5-oxo-tetrahydrofuran-3-yl acetate) and PH-2 (methyl 4-hydroxy-3-methoxybenzoate) were purified from the active fractions. In cytotoxicity studies, PH-1 exhibited highest cytotoxicity against HeLA cells with 87.50% lethality at 1 mgmL-1 concentration and LD50 of 60 µgmL-1. Likewise, PH-2 showed 82.33% cytotoxicity against HeLA cells with LD50 of 160 µgmL-1. Similarly, PH-1 and PH-2 exhibited LD50 of 170 and 380 µgmL-1 respectively. Moreover, PH-1 and PH-2 were also very potent cytotoxic compounds against NIH/3T3 cells with 81.45 and 85.55% cytotoxicity at 1 mgL-1 concentration and LD50 of 140 and 58 µgL-1 respectively. Isolated compounds exhibited considerable anti-angiogenic potentials with IC50 of 340 and 500 µgL-1 respectively for PH-1 and PH-2. In anti-tumor assay, PH-1 and PH-2 exhibited 81.15 and 76.09% inhibitions with LD50 of 340 and 550 µgL-1 respectively. Both compounds selectively binds with EGFR and HER2 receptors with low binding energies. Both compounds exhibited stronger interactions with VEGFR through binding pocket residues Lys868, Val916 and Asp1046.

CONCLUSIONS

Both compounds cause considerable cytotoxicity against cancer cells. The anti-angiogenic and anti-tumor results suggests additional tumor suppressive properties. Docking analysis suggests that these compound not only has the ability to bind to EGFR and HER2 but also equally binds to VEGFR and may act as potential anti-angiogenic agents.

Prospective Application of Two New Pyridine-Based Zinc (II) Amide Carboxylate in Management of Alzheimer's Disease: Synthesis, Characterization, Computational and in vitro Approaches

Background

Alzheimer’s disease (AD) is a neurodegenerative illness described predominantly by dementia. Even though Alzheimer’s disease has been known for over a century, its origin remains a mystery, and researchers are exploring many therapy options, including the cholinesterase technique. A decreased acetylcholine ACh neurotransmitter level is believed to be among the important factors in the progression of Alzheimer’s disease.

Methods

In continuation of synthesizing potential anti-Alzheimer agents and known appreciative pharmacological potential of amide-containing compounds, this study presents the synthesis of two novel amide-based transition metal zinc (II) complexes, AAZ7 and AAZ8, attached with a heterocyclic pyridine ring, which was synthesized and characterized by Fourier transform infrared spectroscopy (FT-IR), elemental analysis, ¹H_NMR, and ¹³C_NMR. FT-IR spectroscopic records showed the development of bidentate ligand as Δν value was decreased in both complexes when compared with the free ligand. Both of the synthesized complexes were analyzed for acetylcholinesterase and butyrylcholinesterase inhibitory potential along with the antioxidizing activity.

Results

Importantly, the complex of AAZ8 exhibited more potent activity giving IC₅₀ values of 14 µg/mL and 18µg/mL as AChE and BChE cholinesterase inhibitors, respectively, when compared with standard positive control galantamine. Interestingly, AAZ8 also displayed promising antioxidant potential by showing IC₅₀ values of 35 µg/mL for DPPH and 29 µg/mL for ABTS in comparison with positive control ascorbic acid.

Conclusion

Herein, we report two new amide carboxylate zinc (II) complexes which were potentially analyzed for various biological applications like acetylcholinesterase (AChE), butyrylcholinesterase (BChE) inhibitory potentials, and antioxidant assays. Computational docking studies also simulated results to understand the interactions. Additionally, thermodynamic parameters utilizing molecular dynamic simulation were performed to determine the ligand protein stability and flexibility that supported the results. Studies have shown that these compounds have the potential to be good anti-Alzheimer candidates for future studies due to inhibition of cholinesterase enzymes and display of free radical scavenging potential against DPPH as well as ABTS free radicals.

Neuroprotective Studies on Polygonum hydropiper L. Essential Oils Using Transgenic Animal Models

Polygonum hydropiper L. and related species are reported to possess neuroprotective potentials. In an attempt to validate its anti-Alzheimer's potentials, leaf oils (Ph. Lo) were extensively evaluated in this study against several in vitro and in vivo models of Alzheimer's disease. The Ph. Lo were tested against pathological targets of Alzheimer's diseases (ADs). The in vitro and in vivo assays were done for cholinesterase inhibition, anti-radical properties and cognitive assessments using transgenic animal models. In preliminary cholinesterase inhibition assays, Ph. Lo were more active against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzthiazoline)-6-sulfonic acid (ABTS), and hydrogen peroxide (H2O2) radicals. Subsequently, Ph. Lo was evaluated for its effects on special memory, exploratory behavior, and coordination using shallow water maze (SWM), Y-maze, open filed, and balance beam tests. Animal pre-genotyping was done via polymerase chain reaction (PCR) to confirm amyloid precursor protein (APP) transgene, and after completion of drug therapy, brain homogenates from the cortex and hippocampus were evaluated for cholinesterase and free radical studies. In SWM task, disease control animals treated with 10 mg/kg of Ph. Lo for 5 days exhibited significant improvement in cognitive performance indicated by low escape times on 5th day compared with normal animals. In the Y-maze test, transgenic animals showed higher spontaneous alternation behavior than disease control animals and standard control group animals. Ph. Lo therapy has improved the exploratory behavior and declined anxiety behavior in diseased animals as accessed via open field test. Ph. Lo administration significantly augmented the motor and coordination abilities of transgenic animals when compared to other groups of animals and declined AChE, BChE activities as well as free radicals load in the cortex and hippocampus tissues. Based on our finding, it is concluded that Ph. Lo exhibit significant neuroprotective potentials preliminary due to their anti-radicals and cholinesterase inhibitory activities. Ph. Lo need further detailed studies as potential aromatherapy against neurodegenerative disorders.

Antiviral and Antinematodal potentials of chitosan: Review

For many years, chemical pesticides have been performed to control different pests and diseases and this may be due to their broad spectrum of action, easy of application and the relatively low cost. But these chemicals have environmental risks, thus alternative control agents are needed. Chitosan is one of the novel suggested solutions to reduce the economic losses associated with chemical pesticides. Chitosan is naturally-occurring compound, as well as safe and biodegradable which obtained from certain natural sources. Chitosan have unique properties which help to control viruses, bacteria, fungi, insects, plant nematodes and other pests locally and systemically.

Phenolic Fingerprinting, Antioxidant, and Deterrent Potentials of Persicaria maculosa Extracts

Persicaria maculosa (Polygonaceae) (known as lady’s thumb) is an annual morphologically variable weed that is widely distributed in Chile. The purpose of this study was to investigate the antifeedant potential of methanolic (MeOH), ethanolic (EtOH), and dichloromethane (DCM) extracts from the aerial parts of this plant collected in the Valparaíso and Curicó provinces (Chile) and relate this activity to the antioxidant capacity and the presence of phenolic compounds in the extracts. A phenolic profile based on HPLC-ESI-MS/MS allowed the identification of 26 phenolic compounds, most of them glycosyl derivatives of isorhamnetin, quercetin, and kaempferol. In addition, the total phenolic content (TP), total flavonoids (TF), and antioxidant activity measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide anion scavenging (O₂⁻), ferric-reducing antioxidant power (FRAP), and cupric-reducing antioxidant capacity (CUPRAC) of the extracts are reported. The antifeedant potentials of the plant extracts were tested against Epilachna paenulata, Pseudaletia adultera, Macrosiphum euphorbiae, and Diaphorina citri insects for the first time. The activity against the aphid M. euphorbiae was significant for the DCM extracts of plants from Valparaíso and Curicó (settling % = 23% ± 4% and 23% ± 5%, respectively). The antifeedant activities against the beetle E. paenulata and the lepidoptera P. adultera were significant for Valparaíso extracts, especially when tested against E. Paenulata (IFP = 1.0 ± 0.0). Finally, the MeOH and EtOH extracts from Valparaíso plants reduced the diet consumption of the psilid D. citri (p < 0.05). The results showed that P. maculosa is a good source of flavonoids with some antioxidant capacities and has potential interest as botanical eco-friendly alternative with deterrent activity.