Isolation of Strong Antioxidants from Paeonia Officinalis Roots and Leaves and Evaluation of Their Bioactivities

A novel source of biologically active compounds - The leaves of Serbian herbaceous peonies

In order to gain further insight into how various extraction techniques (maceration, microwave-, and ultrasound-assisted extractions) affect the chemical profile and biological activities of leaf extracts from Paeonia tenuifolia L., Paeonia peregrina Mill., and Paeonia officinalis L., this research was performed. The targeted chemical characterization of the extracts was achieved using the Ultra-High-Performance-Liquid-Chromatography-Linear-Trap-Mass-Spectrometry OrbiTrap instrumental technique, while Fourier Transform Infrared Spectroscopy was conducted to investigate the structural properties of the examined leaf extracts. According to the results, the species P. officinalis, Božurna locality as the origin of the plant material, and microwave-assisted extraction produced the maximum polyphenol yield, (491.9 ± 2.7 mg gallic acid equivalent (GAE)/mL). The ethanolic extracts exhibited moderate antioxidant activity as evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) and phosphomolybdenum tests. With MIC values of 0.125 mg/mL, the leaf extracts produced by ultrasound-assisted extraction and maceration (Deliblato sands and Bogovo gumno) had the best antibacterial activity against Pseudomonas aeruginosa and Salmonella Typhimurium. Ultrasound-assisted extraction has proven to produce the most effective antimicrobial agents. Inhibitory potential towards glucosidase, amylase, cholinesterases, and tyrosinase was evaluated in enzyme inhibition assays and molecular docking simulations. Results show that leaves of P. tenuifolia L. obtained by ultrasound-assisted extraction had the highest acetylcholinesterase and butyrylcholinesterase inhibitory activity. Namely, the complexity of the polyphenol structures, the extraction method, the used locality, and the different mechanisms of the reactions between bioactives from leaf extracts and other components (free radicals, microorganisms, and enzymes) are the main factors that influence the results of the antioxidant tests, as well as the antibacterial and enzyme-inhibitory activities of the extracts. Hydroxymethyl-phenyl pentosyl-hexoside and acetyl-hydroxyphenyl-hexoside were the first time identified in the leaf extract of the Paeonia species. Due to their proven biological activities and the confirmed existence of bioactive compounds, leaf extracts may find use in foodstuffs, functional foods, and pharmaceutical products.

Anticonvulsant effects of Paeonia daurica subsp. macrophylla root extracts in pentylenetetrazol-induced seizure models in mice

INTRODUCTION

In the present study, anticonvulsant effects of aqueous extract (AE), hydro-alcoholic crude extract (HE), and its fractions (F-CHCl3, F-EtOAc, F-MeOH) of Paeonia daurica subsp. macrophylla (P. daurica ssp. macrophylla) root examined by using a pentylenetetrazol-induced model (PTZ) on mice.

METHODS

HE and its fractions as well as AE, in concentrations of (100, 200 and 400mg/kg), valproate (Val) (100 and 200mg/kg), and saline (negative control) (10mg/kg) were injected intraperitoneally (i.p.) 30min before PTZ (80mg/kg, i.p.). The time taken before the onset of myoclonic convulsions (MC), MC duration, time taken before the onset of generalized tonic-clonic seizures (GTCS), the duration of GTCS, and the percentage of GTCS and mortality protection recorded. The plant's anticonvulsant mechanisms were assessed using flumazenil (5mg/kg, i.p.) before AE (100, 200, and 400mg/kg, i.p.) injection. GraphPad Prism software was used to compare the differences between various treatment groups with one-way analysis of variance (ANOVA) followed by Tukey-Krammer multiple comparison tests.

RESULTS

All the plant samples except F-EtOAc significantly delayed the onset and decreased the duration of PTZ-induced MCS and GTCS, and significantly reduced the GTCS and mortality rate. Pretreatment with flumazenil diminished the significant anticonvulsant effects of AE against PTZ-induced seizures.

CONCLUSIONS

It can report that extract of P. daurica ssp. macrophylla might be a helpful guide for future studies in the treatment of epilepsy.

Genus Paeonia monoterpene glycosides: A systematic review on their pharmacological activities and molecular mechanisms

BACKGROUND

Genus Paeonia, which is the main source of Traditional Chinese Medicine (TCM) Paeoniae Radix Rubra (Chishao in Chinese), Paeoniae Radix Alba (Baishao in Chinese) and Moutan Cortex (Mudanpi in Chinese), is rich in active pharmaceutical ingredient such as monoterpenoid glycosides (MPGs). MPGs from Paeonia have extensive pharmacological effects, but the pharmacological effects and molecular mechanisms of MPGs has not been comprehensively reviewed.

PURPOSE

MPGs compounds are one of the main chemical components of the genus Paeonia, with a wide variety of compounds and strong pharmacological activities, and the structure of the mother nucleus-pinane skeleton is similar to that of a cage. The purpose of this review is to summarize the pharmacological activity and mechanism of action of MPGs from 2012 to 2023, providing reference direction for the development and utilization of Paeonia resources and preclinical research.

METHODS

Keywords and phrases are widely used in database searches, such as PubMed, Web of Science, Google Scholar and X-Mol to search for citations related to the new compounds, extensive pharmacological research and molecular mechanisms of MPGs compounds of genus Paeonia.

RESULTS

Modern research confirms that MPGs are the main compounds in Paeonia that exert pharmacological effects. MPGs with extensive pharmacological characteristics are mainly concentrated in two categories: paeoniflorin derivatives and albiflflorin derivatives among MPGs, which contains 32 compounds. Among them, 5 components including paeoniflorin, albiflorin, oxypaeoniflorin, 6'-O-galloylpaeoniflorin and paeoniflorigenone have been extensively studied, while the other 28 components have only been confirmed to have a certain degree of anti-inflammatory and anticomplementary effects. Studies of pharmacological effects are widely involved in nervous system, endocrine system, digestive system, immune system, etc., and some studies have identified clear mechanisms. MPGs exert pharmacological activity through multilateral mechanisms, including anti-inflammatory, antioxidant, inhibition of cell apoptosis, regulation of brain gut axis, regulation of gut microbiota and downregulation of mitochondrial apoptosis, etc. CONCLUSION: This systematic review delved into the pharmacological effects and related molecular mechanisms of MPGs. However, there are still some compounds in MPGs whose pharmacological effects and pharmacological mechanisms have not been clarified. In addition, extensive clinical randomized trials are needed to verify the efficacy and dosage of MPGs.

Comprehensive comparison of different parts of Paeonia ostii, a food-medicine plant, based on untargeted metabolomics, quantitative analysis, and bioactivity analysis

Introduction

Paeonia ostii T. Hong & J.X. Zhang (s.s.) (Chinese name, Fengdan) is a widely cultivated food-medicine plant in China, in which root bark, seed kernels, and flowers are utilized for their medicinal and edible values. However, other parts of the plant are not used efficiently, in part due to a poor understanding of their chemical composition and potential biological activity.

Methods

Untargeted ultra-performance liquid chromatography-quadrupole time of flight-mass spectrometry (UPLC-Q-TOF-MS) metabolomics was applied to characterize the metabolic profiles of 10 different parts of P. ostii.

Results and discussion

A total of 160 metabolites were alternatively identified definitely or tentatively, which were significantly different in various plant parts by multivariate statistical analysis. Quantitative analysis showed that underutilized plant parts also contain many active ingredients. Compared with the medicinal part of root bark, the root core part still contains a higher content of paeoniflorin (17.60 ± 0.06 mg/g) and PGG (15.50 ± 2.00 mg/g). Petals, as an edible part, contain high levels of quercitrin, and stamens have higher methyl gallate and PGG. Unexpectedly, the ovary has the highest content of methyl gallate and rather high levels of PGG (38.14 ± 1.27 mg/g), and it also contains surprisingly high concentrations of floralalbiflorin I. Paeoniflorin (38.68 ± 0.76 mg/g) is the most abundant in leaves, and the content is even higher than in the root bark. Branches are also rich in a variety of catechin derivatives and active ingredients such as hydrolyzable tannins. Seed kernels also contain fairly high levels of paeoniflorin and albiflorin. Fruit shells still contain a variety of components, although not at high levels. Seed coats, as by-products removed from peony seeds before oil extraction, have high contents of stilbenes, such as trans-gnetin H and suffruticosol B, showing significant potential for exploitation. Except for the seed kernels, extracts obtained from other parts exhibited good antioxidant activity in DPPH, ABTS, and ferric ion reducing antioxidant power (FRAP) assays (0.09-1.52 mmol TE/g). Five compounds (gallic acid, PGG, trans-resveratrol, kaempferol, and quercitrin) were important ingredients that contributed to their antioxidant activities. Furthermore, P. ostii seed cakes were first reported to possess agonistic activity toward CB1/CB2 receptors. This study provides a scientific basis for the further development and utilization of P. ostii plant resources.

Skin health properties of Paeonia lactiflora flower extracts and tyrosinase inhibitors and free radical scavengers identified by HPLC post-column bioactivity assays

Skin health is a major concern across the world. The Paeonia lactiflora Pall. flower (PLPF) is well-known in China as an edible ornamental flower, that has been traditionally prescribed for the treatment of irregular menstruation and dysmenorrhea. However, its chemical constituents and bioactivities have not been systematically stuided. This study tentatively identified 27 compounds in aqueous and ethanol extracts of PLPF using ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry, including four monoterpene glycosides, six phenols, six tannins, ten flavonoids and a hydroxycinnamic acid amide. Online antioxidant and tyrosinase inhibitor screening assays based on post-column bioactivity tests were used to screen for bioactive compounds in the extracts. Online and offline bioactivity assays showed that both extracts exhibited notable antioxidant properties against DPPH, ABTS, and FRAP, potent antiglycation capacity, and significant inhibition of tyrosinase, cyclooxygenase-2, and collagenase. Gallic acid derivatives were the main contributors to the antioxidant and antityrosinase capacity and may also inhibit cyclooxygenase-2 and collagenase, but they exhibited weak antiglycation capacity. The antiglycation effects may be due to the synergistic action of gallic acid and specific flavonoids. PLPF is a promising source of bioactive compounds for the development of natural skin health products.

Bioassay-Guided Fractionation with Antimalarial and Antimicrobial Activities of Paeonia officinalis

Bioassay-guided fractionation technique of roots of Paeonia officinalis led to isolation and structure elucidation of seven known compounds, including four monoterpene glycosides: lactiflorin (1), paeoniflorin (4), galloyl paeoniflorin (5), and (Z)-(1S,5R)-β-pinen-10-yl β-vicianoside (7); two phenolics: benzoic acid (2) and methyl gallate (3); and one sterol glycoside: β-sitosterol 3-O-β-D-glucopyranoside (6). The different fractions and the isolated compounds were evaluated for their antimicrobial and antimalarial activities. Fraction II and III showed antifungal activity against Candida neoformans with IC₅₀ values of 28.11 and 74.37 µg/mL, respectively, compared with the standard fluconazole (IC₅₀ = 4.68 µg/mL), and antibacterial potential against Pseudomonas aeruginosa (IC₅₀ = 20.27 and 24.82 µg/mL, respectively) and Klebsiella pneumoniae (IC₅₀ = 43.21 and 94.4 µg/mL, respectively), compared with the standard meropenem (IC₅₀ = 28.67 and 43.94 µg/mL, respectively). Compounds 3 and 5 showed antimalarial activity against Plasmodium falciparum D6 with IC₅₀ values of 1.57 and 4.72 µg/mL and P. falciparum W2 with IC₅₀ values of 0.61 and 2.91 µg/mL, respectively, compared with the standard chloroquine (IC₅₀ = 0.026 and 0.14 µg/mL, respectively).

Response surface optimization of enzymatic hydrolysis and ROS scavenging activity of silk sericin hydrolysates

CONTEXT

Sericin, a protein found in wastewater from the silk industry, was shown to contain a variety of biological activities, including antioxidant. The enzymatic conditions have been continuously modified to improve antioxidant effect and scavenging capacity against various free radicals of silk sericin protein.

OBJECTIVE

Variables in enzymatic reactions, including pH, temperature and enzyme/substrate ratio were analysed to discover the optimum conditions for antioxidant activity of sericin hydrolysates.

MATERIALS AND METHODS

Hydrolysis reaction catalysed by Alcalase^® was optimized through response surface methodology (RSM) in order to generate sericin hydrolysates possessing potency for % inhibition on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, ferric-reducing power and peroxyl scavenging capacity. Flow cytometry was performed to evaluate cellular ROS level in human HaCaT keratinocytes and melanin-generating MNT1 cells pre-treated either with 20 mg/mL RSM-optimized sericin hydrolysates or 5 mM N-acetyl cysteine (NAC) for 60 min prior exposure with 1 mM hydrogen peroxide (H₂O₂).

RESULTS

Among these three variables, response surface plots demonstrate the major role of temperature on scavenging capacity of sericin hydrolysates. Sericin hydrolysates prepared by using Alcalase^® at RSM-optimized condition (enzyme/substrate ratio: 1.5, pH: 7.5, temperature: 70 °C) possessed % inhibition against H₂O₂ at 99.11 ± 0.54% and 73.25 ± 8.32% in HaCaT and MNT1 cells, respectively, while pre-treatment with NAC indicated the % inhibition only at 30.26 ± 7.62% in HaCaT and 51.05 ± 7.14% in MNT1 cells.

DISCUSSION AND CONCLUSIONS

The acquired RSM information would be of benefit for further developing antioxidant peptide from diverse resources, especially the recycling of waste products from silk industry.

Isolation and Characterization of Galloylglucoses Effective against Multidrug-Resistant Strains of Escherichia coli and Klebsiella pneumoniae

The search for new antibiotics against multidrug-resistant (MDR), Gram-negative bacteria is crucial with respect to filling the antibiotics development pipeline, which is subject to a critical shortage of novel molecules. Screening of natural products is a promising approach for identifying antimicrobial compounds hosting a higher degree of novelty. Here, we report the isolation and characterization of four galloylglucoses active against different MDR strains of Escherichia coli and Klebsiella pneumoniae. A crude acetone extract was prepared from Paeonia officinalis Linnaeus leaves, and bioautography-guided isolation of active compounds from the extract was performed by liquid–liquid extraction, as well as open column, flash, and preparative chromatographic methods. Isolated active compounds were characterized and elucidated by a combination of spectroscopic and spectrometric techniques. In vitro antimicrobial susceptibility testing was carried out on E. coli and K. pneumoniae using 2 reference strains and 13 strains hosting a wide range of MDR phenotypes. Furthermore, in vivo antibacterial activities were assessed using Galleria mellonella larvae, and compounds 1,2,3,4,6-penta-O-galloyl-β-d-glucose, 3-O-digalloyl-1,2,4,6-tetra-O-galloyl-β-d-glucose, 6-O-digalloyl-1,2,3,4-tetra-O-galloyl-β-d-glucose, and 3,6-bis-O-digalloyl-1,2,4-tri-O-galloyl-β-d-glucose were isolated and characterized. They showed minimum inhibitory concentration (MIC) values in the range of 2–256 µg/mL across tested bacterial strains. These findings have added to the number of known galloylglucoses from P. officinalis and highlight their potential against MDR Gram-negative bacteria.

Antioxidant Activities of Bioactive Compounds Isolated from Rheum emodi Wall (Himalayan Rhubarb) Based on LC-DAD-ESI/MS and Preparative LC/MS System

Natural compounds are a good substitute for synthetic antioxidants. Attempts have been made to characterize the antioxidant capacity of natural resources (e.g., medicinal plants). Thus, the Rheum emodi Wall was evaluated using liquid chromatography with diode array detection and electrospray ionization-mass spectrometry. Three antioxidant compounds (i.e., myricitrin, myricetin-3-galloyl rhamnoside, and myricetin) were isolated, identified, and used to screen the antioxidant capacity of the new compounds. 2,2-Diphenyl-1-picrylhydrazyl, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and superoxide dismutase assay results are presented in the half-maximal inhibitory concentration values ranging 1.50∼28.46, 102.01∼137.55, and 4.06∼15.74 μg/mL, respectively. Myricetin had the highest antioxidant activity among the other compounds. A significantly positive correlation was noted between the ethyl acetate fraction and the antioxidant compound. In a partial least squares-discriminant analysis model, identified antioxidant compounds were shown to play a role in the structure of the compound and its contents based on the antioxidant activity. The study suggests that myricetin from R. emodi possesses the most potent antioxidant activity, and thus is the most efficient in extracting antioxidant contents.

In vitro evaluation of antioxidant activity and determination of total phenolic and flavonoids contents of ethanol-water extracts of Paeonia lactiflora and Calendula officinalis L. petals

In this study, the petals collected from peony hybrid Paeonia lactiflora "Bowl of beauty" and Calendula officinalis L. were extracted using ethanol-water mixture assisted with microwave and ultrasonic treatment. The isolation of Calendula officinalis L. essential oil was done by hydrodistillation as well. The total phenolic and flavonoids content in the extracts and oil were determined and their antioxidant activity was evaluated. The highest total phenolic content was found for the extracts of hybrid Paeonia lactiflora and Calendula officinalis L. obtained by ultrasound extraction (9.73 and 10.03 mg GA/mL RE, respectively), while the highest flavonoid content was obtained by microwave-assisted extraction (14.45 and 6.02 mg QE/mL RE, respectively). Antioxidant activity was assessed using standard antioxidant in vitro DPPH• and ABTS•+ assays. The highest antioxidant activity was obtained in DPPH• and ABTS•+ assay for the microwave-assisted extraction of hybrid Paeonia lactiflora (79% and 83%) and ultrasound-assisted extraction of Calendula officinalis L. (45% and 49%), respectively. In order to improve the antioxidative activity of both extract and essential oil the pectin films with gallic acid, using enzymatically assisted catalysis to attain covalent bonding to a carrier, were prepared. Optical microscopy and FTIR spectroscopy were used for the characterization of obtained materials. The films, with essential oil of Calendula officinalis L. and gallic acid, showed significantly increased percentage inhibition in DPPH• and ABTS•+ test (91% and 95%, respectively) after 10 minutes. The results, also, showed that all formulations of pectin biopolymer film, modified with gallic acid, can be successfully applied as a carrier for both types of ingredients.

Effect of Ustukhuddus Alavi, a multi-herbal product, on the cognitive performance of adolescent female students

ETHNOPHARMACOLOGICAL RELEVANCE

Ustukhuddus Alavi is a polyherbal formula which is introduced by Persian medicine scholars. It is traditionally used to treat brain disorders and is claimed to do so by preprocessing and cleansing the waste products from the brain. According to Persian medicine, the disposal of brain waste products is necessary for optimal cognitive performance.

AIM OF THE STUDY

Sustaining optimal cognitive performance is crucial for ideal quality of life and higher academic achievements in high school students. The objective of this study was to determine the effects of this multi-component herbal product on the cognitive performance and salivary cortisol levels of adolescent female students.

MATERIALS AND METHODS

The effect of a 6-week randomly assigned Ustukhuddus Alavi versus placebo administration on cognitive performance was assessed by the paced auditory serial addition test (PASAT) at the baseline and after the 3- and 6-week intake of Ustukhuddus Alavi or placebo and the one-month follow-up in 86 healthy female high school students in grades 10 and 11. Additionally, we measured the levels of salivary cortisol of the students pre- and post-intervention.

RESULTS

Significant mean difference between the Ustukhuddus Alavi and placebo groups in three of the paced auditory serial addition test (PASAT) subscales, namely mental health (p-value = 0.006), sustained attention (p-value = 0.001) and mental fatigue (p-value = 0.001), were observed after six weeks. We also found a significant difference between the mean salivary cortisol level of the two groups after the intervention (p-value = 0.047).

CONCLUSIONS

These findings reveal that the intake of the multi-ingredient herbal product Ustukhuddus Alavi for six weeks can be helpful for cognitive function and cortisol levels in female high school students. These positive effects seem to be related to the increase in sustained attention and the decrease in mental fatigue.

A Novel Strategy for Unveiling Spatial Distribution Pattern of Gallotannins in Paeonia rockii and Paeonia ostii Based on LC–QTRAP–MS

Gallotannins (GTs) are a series of hydrolyzable tannins with multiple health-promoting effects. In this study, an integrated liquid chromatography tandem mass spectrometry (LC–MS/MS) strategy was developed for unveiling the spatial distribution pattern of GTs in the emerging oilseed crops Paeonia rockii and P. ostii. According to the fragmentation behavior of the representative GT (1,2,3,4,6-penta-O-galloyl-β-D-glucose, PGG), the diagnostic neutral loss (NL) of 170 Da was chosen for the non-targeted screening of GT precursors. Simultaneously, the tandem mass spectrometry spectrum (MS/MS) information was acquired through an enhanced product ion (EPI) scan. Nine major GTs were identified in tree peony. To quantify the targeted GTs in different tissues of tree peony, we established a multiple reaction monitoring (MRM)–enhanced product ion (EPI)-based pseudo-targeted approach under the information-dependent acquisition (IDA) mode. The quantitative results show that the GT compounds were ubiquitous in tree peony plants with diverse structures. The typical GT PGG was mainly distributed in roots, leaves, and petals. This strategy can also be utilized for metabolite characterization and quantification in other substrates.

In vitro evaluation of antioxidative activities of the extracts of petals of Paeonia lactiflora and Calendula officinalis incorporated in the new forms of biobased carriers

In this study, the petals collected from peony hybrid Paeonia lactiflora "Bowl of Beauty" and Calendula officinalis L. were extracted using an ethanol-water mixture assisted with microwave and ultrasonic treatment. The isolation of Calendula officinalis L. essential oil was done by hydrodistillation as well. The total phenolic and flavonoids content in the extracts and oil were determined and their antioxidant activity was evaluated. The highest total phenolic content was found for the extracts of hybrid P. lactiflora and C. officinalis L. obtained by ultrasound extraction (83.16 and 114.47 mg GA/g, respectively), while the flavonoid content obtained by microwave-assisted extraction was relatively high (123.48 and 65.29 mg QE/g, respectively). The highest antioxidant activity was obtained in DPPH• and ABTS•+ assay for the microwave-assisted extraction of hybrid P. lactiflora (79% and 83%) and ultrasound-assisted extraction of C. officinalis L. (45% and 49%), respectively. To improve antioxidant activity of both types of examined analytes (extracts and essential oil), the pectin biopolymer film (as a carrier) was prepared in the process of enzymatically assisted catalysis. Optical microscopy and FTIR spectroscopy were used for the characterization of obtained materials. The films, with essential oil of C. officinalis L. and gallic acid, showed significantly increased percentage inhibition in DPPH• and ABTS•+ test (91% and 95%, respectively) after 10 minutes. The results, also, showed that all formulations of pectin biopolymer film, modified with gallic acid, can be successfully applied as a carrier for both types of ingredients.

Comprehensive metabolite profile of multi-bioactive extract from tree peony (Paeonia ostii and Paeonia rockii) fruits based on MS/MS molecular networking

Tree peony seed, traditionally used for edible oil production, is rich in α-linolenic acid. However, little attention is given to the fruit by-products during seed oil production. The present work aimed to comprehensively investigate the phytochemical constituents and multiple biological activities of different parts of tree peony fruits harvested from Paeonia ostii and Paeonia rockii. 130 metabolites were rapidly identified through UPLC-Triple-TOF-MS on the basis of MS/MS molecular networking. Metabolite quantification was performed through the targeted approach of HPLC-ESI-QQQ-MS. Eight chemical markers were screened via principal component analysis (PCA) for distinguishing species and tissues. Interestingly, two dominant compounds, paeoniflorin and trans-resveratrol, are specially localized in seed kernel and seed coat, respectively. Unexpectedly, the extracts of fruit pod and seed coat showed significantly stronger antioxidant, antibacterial, and anti-neuroinflammatory activities than seed kernel from both P. ostii and P. rockii. Our work demonstrated that tree peony fruit is promising natural source of bioactive components and provided its potential utilization in food and pharmaceutical industries.

Anticonvulsant effects of Paeonia daurica subsp. macrophylla root extracts in pentylenetetrazol-induced seizure models in mice

INTRODUCTION

In the present study, anticonvulsant effects of aqueous extract (AE), hydro-alcoholic crude extract (HE), and its fractions (F-CHCl3, F-EtOAc, F-MeOH) of Paeonia daurica subsp. macrophylla (P. daurica ssp. macrophylla) root examined by using a pentylenetetrazol-induced model (PTZ) on mice.

METHODS

HE and its fractions as well as AE, in concentrations of (100, 200 and 400mg/kg), valproate (Val) (100 and 200mg/kg), and saline (negative control) (10mg/kg) were injected intraperitoneally (i.p.) 30min before PTZ (80mg/kg, i.p.). The time taken before the onset of myoclonic convulsions (MC), MC duration, time taken before the onset of generalized tonic-clonic seizures (GTCS), the duration of GTCS, and the percentage of GTCS and mortality protection recorded. The plant's anticonvulsant mechanisms were assessed using flumazenil (5mg/kg, i.p.) before AE (100, 200, and 400mg/kg, i.p.) injection. GraphPad Prism software was used to compare the differences between various treatment groups with one-way analysis of variance (ANOVA) followed by Tukey-Krammer multiple comparison tests.

RESULTS

All the plant samples except F-EtOAc significantly delayed the onset and decreased the duration of PTZ-induced MCS and GTCS, and significantly reduced the GTCS and mortality rate. Pretreatment with flumazenil diminished the significant anticonvulsant effects of AE against PTZ-induced seizures.

CONCLUSIONS

It can report that extract of P. daurica ssp. macrophylla might be a helpful guide for future studies in the treatment of epilepsy.

Efficacy and tolerability of hydroalcoholic extract of Paeonia officinalis in children with intractable epilepsy: An open-label pilot study

Despite a wide range of medications available to control epilepsy, seizures in more than 30 % of patients remain uncontrolled. However, in traditional medicine, Paeonia officinalis (P. officinalis), a native perennial herb of Southern Europe and Western Asia, has been used for an anticonvulsant effect for over 2000 years globally. In an open-label pilot study implemented on 30 children with intractable epilepsy aged 1-14 years, the hydroalcoholic extract of P. officinalis was administered. This study's purpose was to assess the efficacy and tolerability of the P. officinalis extract as an adjunct therapy to a patient's antiseizure medications in reducing the frequency and duration of the seizures in childhood intractable epilepsy. The mean frequency of seizures decreased significantly during treatment with the P. officinalis extract (P < 0.05). At the end of the intervention, 62.5 % and 36.7 % of the patients showed a≥50 % and a≥75 % reduction in seizure frequency, respectively. Regarding safety and tolerability, no serious adverse events occurred during the trial, although restlessness was reported in one child and the other children who experienced constipation, stopped treatment. The results show that the P. officinalis root extract was well tolerated and has contributed to a significant improvement in seizure control in children with medically intractable epilepsy. This trial was registered with the Iranian Registry of Clinical Trials (www.irct.ir; registration number: IRCT20131125015533N2.

A comprehensive study of three species of Paeonia stem and leaf phytochemicals, and their antioxidant activities

ETHNOPHARMACOLOGICAL RELEVANCE

Paeonia plants have been widely used as traditional Chinese medicinal materials for more than 2,000 years in the treatment of cardiovascular, extravasated blood and female genital diseases; paeoniflorin and paeonol have been implicated as the plants' primary active ingredients.

AIM OF THE STUDY

Previous studies have been singularly focused on the chemical constituents and content variation of the Paeonia roots in the advancement of traditional Chinese medicine, with the plants' stems and leaves considered useless. This study aims to explore the chemical constituents, content variation, and antioxidant capacity in Paeonia stems and leaves for the future utilization of traditional Chinese medicine, given that current practices of digging and trade endanger Paeonia in the wild.

MATERIALS AND METHODS

Herein, secondary metabolites from the stems and leaves from six developmental stages of the annual growth cycle of Paeonia ostii T. Hong & J. X. Zhang, P. 'Hexie', and P. lactiflora Pall. were qualitatively and quantitatively analyzed via high-performance liquid chromatography with a diode array detector (HPLC-DAD) and high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS). Antioxidant capacity at each stage was also evaluated by various free radical scavenging assays.

RESULTS

A total of 24 metabolites were detected and identified, including 5 monoterpene glycosides, 4 tannins, 5 phenols, 9 flavonoids, and paeonol. Excepting paeonol and the phenols, the levels of each metabolite category were significantly higher in the leaves than the stems during all developmental stages. The paeoniflorin content in the P. ostii leaves was the highest during the first developmental stage and higher than the standards of the Chinese Pharmacopoeia, suggesting it to be the optimal harvesting stage for medicinal uses. Notably, the antioxidant capacity of the leaves was significantly greater than in the stems, particularly for the leaves of P. 'Hexie'.

CONCLUSION

Our study indicates that the leaves of P. 'Hexie' have the potential to be a worthy medicinal substitute to Paeonia roots due to their high monoterpene glycosides, phenols, and flavonoids as well as their strong antioxidant capacity. Further, this study provides a theoretical basis for the development and utilization of non-root Paeonia plant sections as medicinal plant resources.

Antioxidant and anticancer potentials of edible flowers: where do we stand?

Edible flowers are attracting special therapeutic attention and their administration is on the rise. Edible flowers play pivotal modulatory roles on oxidative stress and related interconnected apoptotic/inflammatory pathways toward the treatment of cancer. In this review, we highlighted the phytochemical content and therapeutic applications of edible flowers, as well as their modulatory potential on the oxidative stress pathways and apoptotic/inflammatory mediators, resulting in anticancer effects. Edible flowers are promising sources of phytochemicals (e.g., phenolic compounds, carotenoids, terpenoids) with several therapeutic effects. They possess anti-inflammatory, anti-diabetic, anti-microbial, anti-depressant, anxiolytic, anti-obesity, cardioprotective, and neuroprotective effects. Edible flowers potentially modulate oxidative stress by targeting erythroid nuclear transcription factor-2/extracellular signal-regulated kinase/mitogen-activated protein kinase (Nrf2/ERK/MAPK), reactive oxygen species (ROS), nitric oxide (NO), malondialdehyde (MDA) and antioxidant response elements (AREs). As the interconnected pathways to oxidative stress, inflammatory mediators, including tumor necrosis factor (TNF)-α, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), interleukins (ILs) as well as apoptotic pathways such as Bcl-2-associated X protein (Bax), Bcl-2, caspase and cytochrome C are critical targets of edible flowers in combating cancer. In this regard, edible flowers could play promising anticancer effects by targeting oxidative stress and downstream dysregulated pathways.

Antioxidant Activity in Rheum emodi Wall (Himalayan Rhubarb)

Using natural products as antioxidant agents has been beneficial to replace synthetic products. Efforts have been made to profile the antioxidant capacities of natural resources, such as medicinal plants. The polyphenol content of Himalayan rhubarb, Rheum emodi wall, was measured and the antioxidant activity was determined using DPPH and ABTS+ assay, and the oxidative stress was assessed using SOD enzymatic assay. Five different solvent fractions, n-hexane, n-butanol, ethyl acetate, dichloromethane, and water, were used for screening the antioxidant capacity in effort to determine the optimum extraction solvent. The total phenolic contents for R. emodi fractions ranged from 27.76 to 209.21 mg of gallic acid equivalents (GAE)/g of dry weight. DPPH and ABTS+ assay results are presented into IC50 values, ranged from 21.52 to 2448.79 μg/mL and 90.25 to 1718.05 μg/mL, respectively. The ethyl acetate fraction had the highest antioxidant activity among other fractions. Also, n-butanol and water fractions showed significantly lower IC50 values than the positive control in DPPH radical scavenging activity. The IC50 values of SOD assay of fractions ranged from 2.31 to 64.78 μg/mL. A similar result was observed with ethyl acetate fraction showing the highest SOD radical scavenging activity. The study suggests that the ethyl acetate fraction of R. emodi possess the strongest antioxidant activity, thus the most efficient in extracting antioxidant contents. Moreover, a highly significant correlation was shown between total polyphenol content and antioxidant activity screening assays. The compounds related to the antioxidant activity of R. emodi were identified to myricitrin, myricetin 3-galloyl rhamnoside, and myricetin, which have not been reported in studies about R. emodi before.

Genus Paeonia: A comprehensive review on traditional uses, phytochemistry, pharmacological activities, clinical application, and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Paeonia, which comprises approximately 52 shrubs or herbaceous perennials around the world, is the only genus of the Paeoniaceae and is pervasively distributed in Asia, southern Europe, and North America. Many species of the genus Paeonia have been used for centuries in ethnomedical medical systems.

AIM OF THE REVIEW

The present study aims to summarize the traditional uses, clinical applications, and toxicology of the genus Paeonia, to critically evaluate the state-of-the-art phytochemical and pharmacological studies of this genus published between 2011 and 2020, and to suggest directions for further in-depth research on Paeonia medicinal resources.

MATERIALS AND METHODS

Popular and widely used databases such as PubMed, Scopus, Science Direct, and Google Scholar were searched using the various search strings; from these searches, a number of citations related to the traditional uses, phytochemistry, biological activities, clinical application, and toxicology of the genus Paeonia were retrieved.

RESULTS

The use of 21 species, 2 subspecies, and 7 varieties of the genus Paeonia as traditional herbal remedies has been reported, and many ethnomedicinal uses, such as the treatment of hematemesis, blood stasis, dysmenorrhea, amenorrhea, epilepsy, spasms, and gastritis, have been recorded. The roots and root bark are the most frequently reported parts of the plants used in medicinal applications. In phytochemical investigations, 451 compounds have been isolated from Paeonia plants to date, which contains monoterpenoid glucosides, flavonoids, tannins, stilbenes, triterpenoids and steroids, and phenols. Studies of their pharmacological activities have revealed the antioxidant, anti-inflammatory, antitumour, antibacterial, antiviral, cardiovascular protective, and neuroprotective properties of the genus Paeonia. In particular, some bioactive extracts and compounds (total glucosides of peony (TGP), paeonol, and paeoniflorin) have been used as therapeutic drugs or tested in clinical trials. In addition to the "incompatibility" of the combined use of "shaoyao" and Veratrum nigrum L. roots in traditional Chinese medicine theory, Paeonia was considered to have no obvious toxicity based on the available toxicological tests.

CONCLUSION

A large number of phytochemical and pharmacological reports have indicated that Paeonia is an important medicinal herb resource, and some of its traditional uses including the treatment of inflammation and cardiovascular diseases and its use as a neuroprotective agent, have been partially confirmed through modern pharmacological studies. Monoterpenoid glucosides are the main active constituents. Although many compounds have been isolated from Paeonia plants, the biological activities of only a few of these compounds (paeoniflorin, paeonol, and TGP) have been extensively investigated. Some paeoniflorin structural analogues and resveratrol oligomers have been preliminarily studied. With the exception of several species (P. suffruticosa, P. ostii, P. lactiflora, and P. emodi) that are commonly used in folk medicine, many medicinal species within the genus do not receive adequate attention. Conducting phytochemical and pharmacological experiments on these species can provide new clues that may lead to the discovery of medicinal resources. It is necessary to identify the effective phytoconstituents of crude extracts of Paeonia that displayed pharmacological activities by bioactivity-guided isolation. In addition, comprehensive plant quality control, and toxicology and pharmacokinetic studies are needed in the future studies.

In vitro protective effects of Paeonia mascula subsp. hellenica callus extract on human keratinocytes

Natural ingredients have been used to improve the state of health in humans. The genus Paeonia has been studied only limited yet it’s reported to have many activities such as antioxidant and anti-inflammatory. To this context, here we focused on an endemic Paeonia species in Attica. This study aims to present the development of the Paeonia mascula subsp. hellenica callus extract and its pleiotropic bioactivity on human primary keratinocytes exploring its potential application as an active agent in skin-related products. This extract showed a high scavenging activity with high phenolic content and an interesting metabolic profile. At a molecular level, the study on the transcript accumulation of genes revealed that this extract exhibits in vitro skin-related protection properties by mediating mitochondrial energy, cell proliferation, immune and inflammatory response and positively regulates genes involved in epidermal and in stratum corneum function. Besides, the extract is proven not skin irritant on reconstructed human skin model. These findings indicate that the specific P. mascula subsp. hellenica extract possesses significant in vitro protection activity on human epidermis and provides new insights into its beneficial role in skin confirming that the advent of biotechnology contribution the past few decades.

Rapid screening and isolation of antioxidants from Eupatorium lindleyanum DC. using CCC target-guided by on-line HPLC-DPPH assay

Counter-current chromatography (CCC) target-guided by on-line HPLC with post-column DPPH assay was established for efficient screening and isolation of large amount of antioxidants from Eupatorium lindleyanum DC. On-line HPLC with post-column DPPH reaction was used to screen the antioxidants and optimize the biphasic solvent system of CCC, then the targeted peaks were purified using CCC. In the present study, three compounds, nepetin, cirsiliol and jaceosidin, were targeted and successively separated from n-butanol fraction of E. lindleyanum DC. by this strategy. All three compounds showed strong DPPH radical scavenging activity. These results confirmed that the strategy would be an efficient and effective method to isolate antioxidants from complex mixtures.