Active Constituents from Drynaria fortunei Rhizomes on the Attenuation of Aβ(25-35)-Induced Axonal Atrophy

Metabolite profiling of Drynariae Rhizoma using 1H NMR and HPLC coupled with multivariate statistical analysis

Drynariae Rhizoma has been used to treat bone diseases and kidney deficiency in traditional medicine. Recently its aqueous extract was reported to enhance memory function. Although the Japanese standards for non-Pharmacopoeial crude drugs 2022 prescribed Drynaria roosii as the botanical origin, some counterfeits and both raw and stir-fired crude drugs are available in markets. To distinguish Drynariae Rhizoma derived from D. roosii appropriately from others and verify the validity of uses of stir-fried ones, 1H NMR-based metabolite profiling coupled with HPLC were performed. Raw samples derived from D. roosii contained naringin (1), neoeriocitrin (2), 5,7-dihydroxychromone-7-O-neohesperidoside (3), caffeic acid 4-O-β-D-glucoside (4), protocatechuic acid (5), trans-p-coumaric acid 4-O-β-D-glucoside (6), and kaempferol 3-O-α-L-rhamnoside 7-O-β-D-glucoside (8). Stir-fried samples were characterized by presence of 5-hydroxymethyl-2-furaldehyde (13), and were divided into two types; one possessing similar composition to raw samples (Type I) and another without above components except 5 (Type II). Quantitative analyses using qHNMR and HPLC, followed by principal component analysis demonstrated that the raw samples had higher contents of 1 (0.93-9.86 mg/g), 2 (0.74-7.59 mg/g), 3 (0.05-2.48 mg/g), 4 (0.27-2.51 mg/g), 6 (0.14-1.26 mg/g), and 8 (0.04-0.52 mg/g), and Type II had a higher content of 5 (0.84-1.32 mg/g). The counterfeit samples derived from Araiostegia divaricata var. formosana were characterized by higher content of ( -)-epicatechin 3-O-β-D-allopyranoside (10) (1.44-11.49 mg/g) without 1 and 2. These results suggested that Drynariae Rhizoma samples derived from other botanical origins and Type II stir-fried samples cannot substitute for D. roosii rhizome.

Digital Database of Absorption Spectra of Diverse Flavonoids Enables Structural Comparisons and Quantitative Evaluations

Flavonoids play diverse roles in plants, comprise a non-negligible fraction of net primary photosynthetic production, and impart beneficial effects in human health from a plant-based diet. Absorption spectroscopy is an essential tool for quantitation of flavonoids isolated from complex plant extracts. The absorption spectra of flavonoids typically consist of two major bands, band I (300-380 nm) and band II (240-295 nm), where the former engenders a yellow color; in some flavonoids the absorption tails to 400-450 nm. The absorption spectra of 177 flavonoids and analogues of natural or synthetic origin have been assembled, including molar absorption coefficients (109 from the literature, 68 measured here). The spectral data are in digital form and can be viewed and accessed at http://www.photochemcad.com. The database enables comparison of the absorption spectral features of 12 distinct types of flavonoids including flavan-3-ols (e.g., catechin, epigallocatechin), flavanones (e.g., hesperidin, naringin), 3-hydroxyflavanones (e.g., taxifolin, silybin), isoflavones (e.g., daidzein, genistein), flavones (e.g., diosmin, luteolin), and flavonols (e.g., fisetin, myricetin). The structural features that give rise to shifts in wavelength and intensity are delineated. The availability of digital absorption spectra for diverse flavonoids facilitates analysis and quantitation of these valuable plant secondary metabolites. Four examples are provided of calculations─multicomponent analysis, solar ultraviolet photoprotection, sun protection factor (SPF), and Förster resonance energy transfer (FRET)─for which the spectra and accompanying molar absorption coefficients are sine qua non.

The flavonoid profiles in the pulp of different pomelo (Citrus grandis L. Osbeck) and grapefruit (Citrus paradisi Mcfad) cultivars and their in vitro bioactivity

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Fourteen flavonoid compounds were detected in pomelo and grapefruit pulp.

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The flavonoid profiles in pomelo and grapefruit pulp had varietal difference.

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Flavonoids of pomelo and grapefruit showed strong cellular antioxidant activity.

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Flavonoids of pomelo and grapefruit are good inhibitors of pancreatic lipase.

Previous results indicated that the flavonoid profiles might have varietal differences in pomelo, but detailed information is unknown. We previously isolated 4 new flavonoids, cigranoside C, D, E, F, in Citrus grandis Shatianyu pulp. However, their distribution in different pomelo cultivars remains to be explored. Therefore, the flavonoid profiles and in vitro bioactivity of the pulp from 5 pomelo and 1 grapefruit cultivars commonly consumed in China were investigated. Fourteen flavonoids were identified, cigranoside C, D, E were detected in these pomelo and grapefruit. Naringin and cigranoside C were the major flavonoids in grapefruit, Guanximiyu-W, Guanximiyu-R and Liangpingyu, while melitidin and rhoifolin was the predominant flavonoid in Shatianyu and Yuhuanyu, respectively. Pomelo and grapefruit showed strong antioxidant activity, and were potent inhibitors of pancreatic lipase with IC₅₀ values of 11.4–72.6 mg fruit/mL except Shatianyu. Thus, pomelo and grapefruit are natural antioxidants and possess anti-obesity potential.

Potential Therapeutic Implications of Caffeic Acid in Cancer Signaling: Past, Present, and Future

Caffeic acid (CA) has been present in many herbs, vegetables, and fruits. CA is a bioactive compound and exhibits various health advantages that are linked with its anti-oxidant functions and implicated in the therapy and prevention of disease progression of inflammatory diseases and cancer. The anti-tumor action of CA is attributed to its pro-oxidant and anti-oxidant properties. CA’s mechanism of action involves preventing reactive oxygen species formation, diminishing the angiogenesis of cancer cells, enhancing the tumor cells’ DNA oxidation, and repressing MMP-2 and MMP-9. CA and its derivatives have been reported to exhibit anti-carcinogenic properties against many cancer types. CA has indicated low intestinal absorption, low oral bioavailability in rats, and pitiable permeability across Caco-2 cells. In the present review, we have illustrated CA’s therapeutic potential, pharmacokinetics, and characteristics. The pharmacological effects of CA, the emphasis on in vitro and in vivo studies, and the existing challenges and prospects of CA for cancer treatment and prevention are discussed in this review.

Potential Therapeutic Implications of Caffeic Acid in Cancer Signaling: Past, Present, and Future

Caffeic acid (CA) has been present in many herbs, vegetables, and fruits. CA is a bioactive compound and exhibits various health advantages that are linked with its anti-oxidant functions and implicated in the therapy and prevention of disease progression of inflammatory diseases and cancer. The anti-tumor action of CA is attributed to its pro-oxidant and anti-oxidant properties. CA’s mechanism of action involves preventing reactive oxygen species formation, diminishing the angiogenesis of cancer cells, enhancing the tumor cells’ DNA oxidation, and repressing MMP-2 and MMP-9. CA and its derivatives have been reported to exhibit anti-carcinogenic properties against many cancer types. CA has indicated low intestinal absorption, low oral bioavailability in rats, and pitiable permeability across Caco-2 cells. In the present review, we have illustrated CA’s therapeutic potential, pharmacokinetics, and characteristics. The pharmacological effects of CA, the emphasis onin vitro and in vivostudies, and the existing challenges and prospects of CA for cancer treatment and prevention are discussed in this review.

Tissue Distribution of Total Flavonoids Extracts of Drynariae Rhizoma in Young and Old Rats by UPLC-MS/MS Determination

Drynariae Rhizoma (Kunze ex Mett.) J. Sm. has been extensively used in China, Japan, and Korea to treat osteoporosis and tonify kidneys. A rapid and validated UPLC-MS/MS method for simultaneous determination of the seven analytes including neoeriocitrin, luteolin-7-O-β-D-glucoside, astragalin, naringin, eriodictyol, naringenin, and kaempferol in rats' various tissues (heart, liver, spleen, lung, kidney, stomach, brain, uterus, ovary, and small intestine) using quercetin as the internal standard (IS) was developed after oral administration of TFDR to rats. Tissues samples were retreated by protein precipitation with methanol. The chromatographic separation was performed using an ACQUITY UPLC™ BEH C₁₈ column (2.1 × 50 mm; 1.7 μm) at 35°C. The mobile phase consisted of 1% acetic acid in water as the aqueous phase (A) and 100% acetonitrile as the organic phase (B). All analytes and IS were quantified through electrospray ionization in positive ion multiple reaction monitoring (MRM) mode. MS transitions were m/z 597.5 ⟶ 289.2 for neoeriocitrin, m/z 449.1 ⟶ 287.1 for luteolin-7-O-β-D-glucoside, m/z 449.1 ⟶ 287.1 for astragalin, m/z 581.5 ⟶ 273.2 for naringin, m/z 289.2 ⟶ 153.1 for eriodictyol, m/z 273.2 ⟶ 153.1 for naringenin, m/z 287.1 ⟶ 153.1 for kaempferol, and m/z 303.2 ⟶ 153.1 for quercetin (IS). The mean extraction recovery of the seven analytes and IS in tissue samples at three levels of quality control (QC) samples ranged from 82.72% to 118.57%, and the RSD was ≤14.98%. The intraday and interday precision (RSD) were all less than 14.98%, and the accuracy (RE) ranged from -13.96% to 14.96%, which indicated that the present method was not an issue. Tissues distribution showed neoeriocitrin, luteolin-7-O-β-D-glucoside, astragalin, naringin, and naringenin could transfer across the blood-brain barrier, which may form the basis of TFDR entering the brain to play an anti-AD role. Compared with the 8-month-old rats, a higher concentration of naringin was found in the ovaries of the 18-month-old rats; this result indicated that it may regulate the autonomic nervous dysfunction of the cerebrospinal system through the hypothalamus-pituitary-ovary axis, thus playing an anti-AD role, but further research is needed. Naringenin, eriodictyol, and kaempferol have a higher concentration in the liver and kidney; this phenomenon may be related to the traditional Chinese medicine theory that there is a definite relationship between the liver and kidney meridian. These results provide reliable data support for further study of the pharmacological mechanism of TFDR, formulation of drug delivery schemes, and development of new Chinese medicines in the treatment of AD.

Prenylated Acylphloroglucinols from Hypericum jovis with Anti-inflammatory Potential

Thirteen prenylated acylphloroglucinols (1: -13: ), including 2 previously undescribed compounds (1: ) and (2: ), were isolated from Hypericum jovis. Their structures were elucidated by high-field NMR spectroscopy. The isolated prenylated acylphloroglucinols were evaluated for their anti-inflammatory effects in vitro through the reduction of the intercellular adhesion molecule 1 expression induced by TNF-α in the human microvascular endothelial cells 1 cell line. Compounds 3, 5, 6, 8,: and 12: significantly reduced intercellular adhesion molecule 1 expression in a concentration-dependent manner with IC₅₀ values of 16.9, 34.4, 4.0, 3.2, and 7.7 µM, respectively. In addition, compound 12: showed notable inhibitory activity on the formation of cyclooxygenase-1- and 12-lipoxygenase-derived inflammatory mediators in an ex vivo cyclooxygenase-lipoxygenase assay. Eleven further constituents were isolated (14: -24: ), including the rare quercetin 3-O-(2-O-acetyl)-arabinofuranoside (18: ).

Heterophyllin B, a cyclopeptide from Pseudostellaria heterophylla, enhances cognitive function via neurite outgrowth and synaptic plasticity

Neurite outgrowth-induced construction of neural circuits and networks is responsible for memory generalization, consolidation, and retrieval. In this study, we found that the traditional Chinese medicine Pseudostellaria heterophylla promoted neurite regrowth and enhanced cognitive function in normal mice. Further, we orally administered Pseudostellaria heterophylla water extracts (PHE) to ICR mice, and detected heterophyllin B (HET-B), an important cyclopeptide, in the plasma and cerebral cortex. We demonstrated that neurites were significantly elongated after coculturing with HET-B for 4 days. Next, the intraperitoneal injection of HET-B on seven consecutive days in 3-month-old ICR mice significantly enhanced the object recognition memory and object location memory than that in control. Immunohistochemical analysis indicated significantly increased β3-tubulin-positive neurite density, synaptophysin, and postsynaptic density 95 in the perirhinal cortex and hippocampus after administering HET-B. Furthermore, the concentration of neurotransmitters was measured using HPLC analysis; HET-B significantly increased five-levels of HT in the hippocampus, and decreased metabolites of dopamine, dihydroxyphenylacetic acid, and homovanillic acid, in the prefrontal cortex and hippocampus. Taken together, HET-B induces neurite elongation and neurotransmitter regulation and possibly enhances cognitive memory.

Structural elucidation of flavonoids from Shatianyu (Citrus grandis L. Osbeck) pulp and screening of key antioxidant components

The Citrus genus is a good source of dietary flavonoids, which have many health benefits. As a representative citrus fruit, the flavonoids composition in Shatianyu (Citrus grandis L. Osbeck) pulp remains to be investigated. In the present study, 11 flavonoids were isolated and identified from Shatianyu pulp flavonoid extracts (SPFEs). Among them, 4 flavonoids were previously undescribed and 2 flavonoids were firstly isolated from pummelo. The cellular antioxidant activity (CAA) and oxygen radical absorbance capacity (ORAC) of isolated compounds were evaluated. Naringin and rhoifolin showed the highest ORAC activity, and the presence of a 3-hydroxy-3-methylglutaryl or a 4'-glucose decreased the ORAC activity of flavonoids. The contribution of isolated flavonoids to the holistic antioxidant activity of SPFEs was determined by an online knockout method. Melitidin, bergamjuicin and naringin contributed most to ORAC activity, while bergamjuicin, melitidin and apigenin-4'-O-β-d-glucopyranosyl-7-O-α-l-rhamnopyranosyl-(1 → 2)-[6″-O-(3- hydroxy-3-methylgltaryl)]-β-d-glucopyranoside contributed most to CAA activity.

Chemometric Analyses for the Characterization of Raw and Stir-Frying Processed Drynariae Rhizoma Based on HPLC Fingerprints

The processing of traditional Chinese medicine (TCM) is a necessary practice and usually occurs before most herbs are prescribed. According to Chinese medicine theory, raw (RDR) and stir-frying processed (PDR) Drynariae Rhizoma have different clinical applications. The purpose of this study was to establish HPLC fingerprints coupled with chemometric methods to evaluate the differences between RDR and PDR. Multivariate chemometric methods were applied to analyze the obtained HPLC fingerprints, including hierarchical cluster analysis (HCA), principle components analysis (PCA), and partial least squares discriminant analysis (PLS-DA). The results indicated that RDR and PDR samples showed a clear classification of the two groups, and seven chemical markers having great contributions to the differentiation were screened out. The findings suggested that 5-hydroxymethyl-2-furaldehyde (5-HMF) with a variable importance in the project (VIP > 1) can be used to differentiate between RDR and PDR. Moreover, 5-HMF, naringin, and neoeriocitrin were determined to evaluate their contents in RDR and PDR. The chemometrics combined with the quantitative analysis based on HPLC fingerprint results indicated that stir-frying processing may change the contents and types of components in Drynariae Rhizoma. These changes are probably responsible for the various pharmacological effects of RDR and PDR.

Comprehensive off-line CCC × LC-DAD-MS separation of Cyclopia pubescens Eckl. & Zeyh. phenolic compounds and structural elucidation of isolated compounds

INTRODUCTION

The minor phenolic constituents of Cyclopia pubescens Eckl. & Zeyh. are unknown and one dimensional (1D) liquid chromatography (LC) is unable to provide sufficient separation.

METHODOLOGY

A two-dimensional (2D) LC method incorporating normal-phasehigh performance countercurrent chromatography (NP-HPCCC) in the first dimension (¹ D) and reversed-phase ultra-high-performance liquid chromatography (RP-UHPLC) as the second dimension (² D) was developed. The analytical HPCCC method was subsequently scaled up to semi-preparative mode and fractions pooled based on phenolic sub-groups. The phenolic compounds in selected fractions were subsequently isolated using RP-HPLC on a C₁₈ column. Isolated compounds were identified by nuclear magnetic resonance (NMR) spectroscopy. The absolute configurations of compounds were determined by optical rotation and electronic circular dichroism spectra. Sugars were identified by gas chromatography-mass spectrometry (GC-MS) analysis.

RESULTS

The comprehensive off-line 2D CCC × LC method gave a good spread of the phenolic compounds. Orthogonality calculated using both the convex hull and conditional entropy methods were 81%. High-resolution mass spectrometric fragmentation spectra obtained from a quadrupole-time-of-flight instrument and ultraviolet-visible (UV-vis) spectral data were used to (tentatively) identify 32 phenolic compounds from the analytical CCC fractions. Of the seven isolated compounds, (2S)-5-O-[α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranosyl]eriodictyol (3) and (2S)-5-O-[α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranosyl]-5,7,3',4'-tetrahydroxyflavan (4) were newly identified in all plants. The other isolated compounds were identified as (2S)-5-O-[α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranosyl]naringenin (1), R-neo-eriocitrin (2), 3-O-α-l-arabinopyranosyl-3,4-dihydroxybenzoic acid (5), 4-O-β-d-glucopyranosyl-Z-4-hydroxycinnamic acid (6) and 4-(4'-O-β-d-glucopyranosyl-4'-hydroxy-3'-methoxyphenyl)-2-butanone (7).

CONCLUSIONS

Among the 32 compounds (tentatively) identified, only six were previously identified in Cyclopia pubescens using 1D LC. Most of the isolated compounds were also identified for the first time in Cyclopia spp., improving the knowledge of the minor phenolic compounds of this genus.

Natural Products as Potential Anti-Alzheimer Agents

Medicinal plants have curative properties due to the presence of various complex chemical substances of different composition, which are found as secondary metabolites in one or more parts of the plant. The diverse secondary metabolites play an important role in the prevention and cure of various diseases including neurodegenerative diseases like Alzheimer's disease. Naturally occurring compounds such as flavonoids, polyphenols, alkaloids, and glycosides found in various parts of the plant and/or marine sources may potentially protect neurodegeneration as well as improve memory and cognitive function. Many natural compounds show anti-Alzheimer activity through specific pharmacological mechanisms like targeting β-amyloid, Beta-secretase 1 and Acetylcholinesterase. In this review, we have compiled more than 130 natural products with a broad diversity in the class of compounds, which were isolated from different sources showing anti- Alzheimer properties.

Chemical Constituents from the Aerial Parts of Elsholtzia ciliata and Their Protective Activities on Glutamate-Induced HT22 Cell Death

A new phenolic glucoside, (7E,9E)-3-hydroxyavenalumic acid-3-O-[6'-O-(E)-caffeoyl]-β-d-glucopyranoside (1), and three new acetylated flavone glycosides, acacetin-7-O-[β-d-glucopyranosyl(1″″→2″)-4‴-O-acetyl-α-l-rhamnopyranosyl(1‴→6″)]-β-d-glucopyranoside (3), acacetin-7-O-[6″″-O-acetyl-β-d-glucopyranosyl(1″″→2″)-3‴-O-acetyl-α-l-rhamnopyranosyl(1‴→6″)]-β-d-glucopyranoside (5), and acacetin-7-O-[3″″,6″″-di-O-acetyl-β-d-glucopyranosyl(1″″→2″)-4‴-O-acetyl-α-l-rhamnopyranosyl(1‴→6″)]-β-d-glucopyranoside (7), as well as 34 known compounds (2, 4, 6, and 8-38) were isolated from the aerial parts of Elsholtzia ciliata. The chemical structures of the new compounds were determined by spectroscopic/spectrometric data interpretation using NMR and HRESIMS. The neuroprotective effect of the isolated compounds was evaluated by a cell viability assay on HT22 murine hippocampal neuronal cells. Among them, 23 compounds, including new substances 1 and 3, exhibited neuroprotective effects against glutamate-induced HT22 cell death. In particular, compounds 2, 16, 17, 20, 22, 28, 29, and 31 presented potent neuroprotective effects with EC₅₀ values of 1.5-8.3 μM.

Phytochemical characteristics of bergamot oranges from the Ionian islands of Greece: A multi-analytical approach with emphasis in the distribution of neohesperidose flavanones

The present study describes the peculiar phytochemical characteristics of bergamots cultivated in distinct islands of the Ionian Sea. Ultrahigh-performance liquid chromatography high-resolution mass spectrometry (UHPLC-HRMS) supported by 1 and 2D NMR spectroscopy was used for unambiguous metabolic profiling of albedo, flavedo and juice samples. Profile differences were determined using a multi-analytical clustering approach based on high-performance thin-layer chromatography fingerprints and UHPLC-HRMS data. Finally, a validated HPLC method offering good precision (0.12-0.94%) and accuracy (95.25-103.93%) was proposed for the quantification of the major flavanones. A total of 37 secondary metabolites were characterized belonging to flavonoids, limonoids and coumarins. Their distribution was tissue-dependent and varied significantly from bergamots of other geographical locations. Surprisingly, neoeriocitrin was the major flavanone, reaching 1.69 ± 0.05 g/L in the juice and 5.24 ± 0.12 mg/g in albedo. This is the highest reported amount among Citrus species, rendering Ionian bergamots a promising candidate for novel functional products.

Natural Medicines and Their Underlying Mechanisms of Prevention and Recovery from Amyloid Β-Induced Axonal Degeneration in Alzheimer's Disease

In Alzheimer's disease (AD), amyloid β (Aβ) induces axonal degeneration, neuronal network disruption, and memory impairment. Although many candidate drugs to reduce Aβ have been clinically investigated, they failed to recover the memory function in AD patients. Reportedly, Aβ deposition occurred before the onset of AD. Once neuronal networks were disrupted by Aβ, they could hardly be recovered. Therefore, we speculated that only removal of Aβ was not enough for AD therapy, and prevention and recovery from neuronal network disruption were also needed. This review describes the challenges related to the condition of axons for AD therapy. We established novel in vitro models of Aβ-induced axonal degeneration. Using these models, we found that several traditional medicines and their constituents prevented or helped recover from Aβ-induced axonal degeneration. These drugs also prevented or helped recover from memory impairment in in vivo models of AD. One of these drugs ameliorated memory decline in AD patients in a clinical study. These results indicate that prevention and recovery from axonal degeneration are possible strategies for AD therapy.

Metabolomic analysis of Cyrtopodium glutiniferum extract by UHPLC-MS/MS and in vitro antiproliferative and genotoxicity assessment

ETHNOPHARMACOLOGICAL RELEVANCE

Extracts of orchids have been traditionally used as human phytotherapeutics. Cyrtopodium flavum, for example, due to the analgesic and anti-inflammatory properties, beside the capacity of heal skin lesions has been focus of research. Also Cyrtopodium glutiniferum, an orchid found in the Brazilian southeastern rainforest, is known to synthesize anti-inflammatory glucomannans in the pseudobulbs, as other potentially therapeutic compounds.

AIM OF THE STUDY

We have reported the first metabolomic analysis focused on the phenols expression of the neotropical orchid Cyrtopodium glutiniferum Raddi, besides free radical scavenging, anti-inflammatory and antiproliferative activities, and the genotoxicity properties of the aqueous extract.

MATERIAL AND METHODS

The metabolomics of C. glutiniferum aqueous extract was performed through UHPLC-MSⁿ acquisition. We have detected the scavenging potential of the extract using DPPH assay. The genotoxic potential was performed by Ames Test (0-5000 μg mL^-1) and micronucleous assay (0-5000 μg mL^-1) in RAW264.7 cells. The cytotoxic potential of the extract against RAW264.7 was tested by WST-1 assay (0-500 μg mL^-1). And after all, the RAW264.7 cells were treated with non-cytotoxic concentrations of C. glutiniferum (0-50 μg mL^-1) to evaluate the antiproliferative and anti-inflammatory potential, besides the mitochondrial activity.

RESULTS

From the 55 molecules identified, 45.5% belonged to the phenolic compounds database from Phenol Explorer, 29% to an in-house Orchidaceae molecules database, and 25.5% to both. Among the identified phenolic compounds, 18 subclasses were discriminated, being phenanthrenes the most abundant. Doses-dependent of C. glutiniferum extracts were able to induce DPPH free radicals scavenging and also to increase TA100 His⁺ revertants, in metabolic environment, showing mutagenicity just in the highest concentration, of 5 mg/plate. On Eukaryotic cell models, the extract also has induced dose-response and time-response cytotoxicity against RAW264.7 macrophages, mainly after 48 h and 72 h, even though the extract has not been able to induce the increase of micronucleated cells and mitotic index alteration on Micronucleus assay. The activation and proliferation of macrophages cultures were downregulated after 24 h and 48 h by the non-cytotoxic concentrations of the extract in a dose-dependent manner.

CONCLUSIONS

The Cyrtopodium glutiniferum metabolomics, anti-inflammatory and anti-proliferative properties observed in this study suggest a therapeutic efficacy of the orchid extract applied in folk medicine.

FA-97, a New Synthetic Caffeic Acid Phenethyl Ester Derivative, Protects against Oxidative Stress-Mediated Neuronal Cell Apoptosis and Scopolamine-Induced Cognitive Impairment by Activating Nrf2/HO-1 Signaling

Alzheimer's disease (AD) is an age-related neurodegenerative disorder with cognitive deficits, which is becoming markedly more common in the world. Currently, the exact cause of AD is still unclear, and no curative therapy is available for preventing or mitigating the disease progression. Caffeic acid phenethyl ester (CAPE), a natural phenolic compound derived from honeybee hive propolis, has been reported as a potential therapeutic agent against AD, while its application is limited due to the low water solubility and poor bioavailability. Here, caffeic acid phenethyl ester 4-O-glucoside (FA-97) is synthesized. We validate that FA-97 attenuates H₂O₂-induced apoptosis in SH-SY5Y and PC12 cells and suppresses H₂O₂-induced oxidative stress by inhibiting the ROS level, malondialdehyde (MDA) level, and protein carbonylation level, as well as induces cellular glutathione (GSH) and superoxide dismutase (SOD). Mechanistically, FA-97 promotes the nuclear translocation and transcriptional activity of Nrf2 associated with the upregulated expression of HO-1 and NQO-1. The prime importance of Nrf2 activation in the neuroprotective and antioxidant effects of FA-97 is verified by Nrf2 siRNA transfection. In addition, FA-97 prevents scopolamine- (SCOP-) induced learning and memory impairments in vivo via reducing neuronal apoptosis and protecting against cholinergic system dysfunction in the hippocampus and cortex. Moreover, the increased MDA level and low total antioxidant capacity in SCOP-treated mouse brains are reversed by FA-97, with the increased expression of HO-1, NQO-1, and nuclear Nrf2. In conclusion, FA-97 protects against oxidative stress-mediated neuronal cell apoptosis and SCOP-induced cognitive impairment by activating Nrf2/HO-1 signaling, which might be developed as a therapeutic drug for AD.

Anti-inflammatory glycosides from the roots of Paeonia intermedia C. A. Meyer

Three new phenolic glycosides, intermedia A-C (1-3), one new acyclic alcohol glycoside, intermedia D (4), together with 3 known glycosides (5-7), were isolated from the dried roots of Paeonia intermedia C. A. Meyer. Their structures were established by means of extensive spectroscopic analysis (HRESIMS, NMR). Compound 1 have a rare benzo[1,5]dioxepine skeleton. The bioassay results showed that compound 3 exhibited inhibitory activity against proinflammatory cytokines nitric oxide (NO) secretion in LPS-activated RAW264.7 cells with an IC₅₀ value of 85.76 ± 1.36 μM.

Memory Enhancement by Oral Administration of Extract of Eleutherococcus senticosus Leaves and Active Compounds Transferred in the Brain

The pharmacological properties of Eleutherococcus senticosus leaf have not been clarified although it is taken as a food item. In this study, the effects of water extract of Eleutherococcus senticosus leaves on memory function were investigated in normal mice. Oral administration of the extract for 17 days significantly enhanced object recognition memory. Compounds absorbed in blood and the brain after oral administration of the leaf extract were detected by LC-MS/MS analyses. Primarily detected compounds in plasma and the cerebral cortex were ciwujianoside C3, eleutheroside M, ciwujianoside B, and ciwujianoside A1. Pure compounds except for ciwujianoside A1 were administered orally for 17 days to normal mice. Ciwujianoside C3, eleutheroside M, and ciwujianoside B significantly enhanced object recognition memory. These results demonstrated that oral administration of the leaf extract of E. senticosus enhances memory function, and that active ingredients in the extract, such as ciwujianoside C3, eleutheroside M, and ciwujianoside B, were able to penetrate and work in the brain. Those three compounds as well as the leaf extract had dendrite extension activity against primary cultured cortical neurons. The effect might relate to memory enhancement.

Pharmacokinetics of Eight Flavonoids in Rats Assayed by UPLC-MS/MS after Oral Administration of Drynariae rhizoma Extract

As a traditional Chinese medicine, Drynariae rhizoma (Kunze ex Mett.) J. Sm. has been used to treat osteoporosis and bone resorption for 2500 years. Based on the previous study and literature references, flavonoids were proved to be the most abundant and main active compounds of Drynariae rhizoma for osteoporosis treatment. In order to make good and rational use of Drynariae rhizoma in future, a rapid, sensitive, and selective ultraperformance liquid chromatography-mass spectrometry (UPLC-MS/MS) method was developed to investigate the pharmacokinetics of eight main flavonoids in rat plasma after oral administration of the Drynariae rhizoma extract, including neoeriocitrin, luteolin-7-O-β-D-glucoside, astragalin, naringin, eriodictyol, luteolin, naringenin, and kaempferol. Plasma samples' pretreatment involved a solid-phase extraction column. The separation was performed on an ACQUITY UPLC^TM BEH C₁₈ column with a gradient mobile-phase system of acetonitrile and 1% acetic acid in water. The detection was performed using a triple quadrupole tandem mass spectrometer equipped with an electrospray ionization interface (ESI) by multiple reaction monitoring (MRM) in the positive ion mode. All calibration curves exhibited good linearity (r ² > 0.9990) over the measured ranges. The intraday and interday precisions (RSD) were within 13.87%, and the accuracy (RE) ranged from -14.57% to -0.25% at three quality control levels. Extraction recovery, matrix effect, and stability were satisfactory. The pharmacokinetic characteristics of the eight flavonoids of interest were clearly elucidated.

Anti-inflammatory and antioxidant activities of naringin isolated from Carissa carandas L.: In vitro and in vivo evidence

BACKGROUND

Carissa carandas L. is known in folk medicine for its anti-inflammatory and hepatoprotective activities. Meanwhile it is an evergreen shrub that constitutes a continuous source of leaves throughout the year.

HYPOTHESIS/PURPOSE

The leaves of Carissa carandas L. may be rich in compounds that can be used as safe anti-inflammatory and antioxidant remedies. The combined antioxidant and anti-inflammatory activities provoked the study of the hepatoprotective effects.

STUDY DESIGN

To isolate major constituents from the leaves of Carissa carandas L. and test their anti-inflammatory and antioxidant activities in-vivo and in-vitro.

METHODS

The leaves of Carissa carandas L. were extracted with 80% MeOH and then defatted with CHCl₃ to yield Carissa carandas defatted extract (CCDE). The extract was chemoprofiled using UPLC-MS/MS to stand for major constituents, then subjected to different chromatographic separation steps and naringin (NG) was isolated in a high yield. The anti-inflammatory activity of NG was investigated in-vivo by carrageenan induced hind rat paw edema model at two dose levels (50 and 25 mg/kg). The anti-inflammatory activity was also evaluated in-vitro by measuring its inhibitory effect on LPS induced release of NO from RAW 264.7 macrophages. The antioxidant activity was evaluated by superoxide and DPPH radical scavenging ability. The safety of NG was tested against primary rat hepatocytes. The hepatoprotective effect of CCDE was evaluated by detecting its effects on serum liver function markers and liver cell oxidative stress markers.

RESULTS

NG exhibited potent inhibition of inflammation as compared to indomethacin (20 mg/kg). NG inhibited LPS induced release of NO from macrophages (IC₅₀, 6.4 μM). NG showed significant antioxidant activity as it scavenged the superoxide radical (EC₉₀, 10.95 μM) and DPPH radical (EC₅₀, 11.2 μM). CCDE inhibited the elevation of the serum liver marker enzymes and increased GSH and decreased MDA contents in the liver homogenate. Liver histopathology supported the biochemical findings.

CONCLUSION

C. carandas has potent anti-inflammatory, antioxidant and hepatoprotective activities.

A Systematic Strategy for Discovering a Therapeutic Drug for Alzheimer's Disease and Its Target Molecule

Natural medicines are attractive sources of leading compounds that can be used as interventions for neurodegenerative disorders. The complexity of their chemical components and undetermined bio-metabolism have greatly hindered both the use of natural medicines and the identification of their active constituents. Here, we report a systematic strategy for evaluating the bioactive candidates in natural medicines used for Alzheimer's disease (AD). We found that Drynaria Rhizome could enhance memory function and ameliorate AD pathologies in 5XFAD mice. Biochemical analysis led to the identification of the bio-effective metabolites that are transferred to the brain, namely, naringenin and its glucuronides. To explore the mechanism of action, we combined the drug affinity responsive target stability with immunoprecipitation-liquid chromatography/mass spectrometry analysis, identifying the collapsin response mediator protein 2 protein as a target of naringenin. Our study indicates that biochemical analysis coupled with pharmacological methods can be used in the search for new targets for AD intervention.

New Age Therapy for Alzheimer's Disease by Neuronal Network Reconstruction

Alzheimer's disease (AD) is a recognized incurable neurodegenerative disorder. Clinically prescribed medicines for AD are expected to bring about only slight symptomatic improvement or a delay of its progression. Another strategy, amyloid β (Aβ) lowing agents, has not been successful at memory improvement. We have hypothesized that an improvement in cognitive function requires the construction of neuronal networks, including neurite regeneration and synapse formation; therefore, we have been exploring candidates for radical anti-AD drugs that can restore Aβ-induced neurite atrophy and memory impairment. Our studies found several promising drug candidates that may improve memory dysfunction in AD model mice. The main activity of these drugs is the restoration of damaged axons. Focusing on candidates based on the recovery of neurite atrophy in vitro certainly leads to positive effects on memory improvement also in vivo. This suggests that neuronal network reconstruction may importantly relate to functional recovery in the brain. When identifying the signaling mechanisms of exogenous compounds like natural medicine-derived constituents, molecules directly activated by the compound are hard to be identified. However, the drug affinity responsive target stability (DARTS) analysis may pave the way to an approach to determine the initial molecule of the signaling pathway. Exploring new drug candidates and clarifying their signaling pathways directly relating to neuronal network reconstruction may provide promising therapeutic strategies with which to overcome AD.

Effects of Oleanane-Type Triterpene Saponins from the Leaves of Eleutherococcus senticosus in an Axonal Outgrowth Assay

An aqueous extract of Eleutherococcus senticosus leaves exerted a beneficial effect in restoring the neurite outgrowth from Aβ25-35-induced degeneration using an axonal density assay. Subsequent bioassay-guided fractionation afforded seven new oleanane-type triterpene saponins, ezoukoginosides A-G (1-7), along with nine known analogues. The structures of 1-7 were elucidated through chemical and spectroscopic approaches, and their effects on restoring the neurite outgrowth from Aβ25-35-induced degeneration were investigated. The results revealed that hydrophilic oleanane-type saponins substituted with a free carboxylic acid, hydroxy, or formyl group in the aglycone, especially when the oxidation occurred at C-29, not only restrained Aβ25-35-induced degeneration but also restored axonal outgrowth significantly. Compounds 2 (-COOH at C-29) and 3 (-CH2OH at C-29) showed the most potent bioactivity among the isolates.