Hippophae rhamnoides L. leaf extracts alleviate diabetic nephropathy via attenuation of advanced glycation end product-induced oxidative stress in db/db mice.

Diabetes mellitus leads to chronic complications, such as nephropathy. Diabetic complications are closely related to advanced glycation end products (AGEs). Excessive formation and accumulation of AGEs in diabetic renal diseases lead to excessive oxidative stress, resulting in chronic renal failure. The leaves of Hippophae rhamnoides L. (sea buckthorn leaves; SBL) show biological benefits, including antioxidant effects. This study aimed to evaluate the effect of SBL on kidney damage in db/db mice. The SBL extract was orally administered at 100 and 200 mg kg-1 for 12 weeks to db/db mice. Histological changes and the urine albumin/creatinine ratio were relieved, and the accumulation of AGEs in kidney glomeruli decreased following SBL treatment. Moreover, the SBL extract reduced the expression of AGEs, the receptor for AGEs, and NADPH oxidase 4, but upregulated glyoxalase 1 in the diabetic renal tissue. Urinary excretion levels and expression of 8-hydroxy-2'-deoxyguanosine as a biomarker of oxidative stress decreased after SBL treatment in the renal tissue. Furthermore, SBL attenuated oxidative stress in diabetic kidneys by reducing AGE accumulation, thereby ameliorating renal damage. Therefore, from these results, we infer that the SBL extract can act as a potential therapeutic agent for diabetic renal complications caused by AGEs.

Dried Loquat Fruit Extract Containing Chlorogenic Acid Prevents Depressive-like Behaviors Induced by Repeated Corticosteroid Injections in Mice.

Eriobotrya japonica (loquat tree) has been used in traditional medicine to treat respiratory ailments, inflammation, and skin diseases; however, its potential antidepressant-like effects have not been extensively investigated. In this study, we evaluated the antidepressant-like effects of E. japonica fruit extract (EJFE) in a mouse model of corticosterone (CORT)-induced depression. An HPLC analysis revealed that chlorogenic acid (CGA) is the major compound in EJFE. Male ICR mice (5weeks-old) were injected with CORT (40 mg/kg, intraperitoneally) once daily for 21 days to induce depressive-like behaviors. Various behavioral tests, including the open field test, rotarod test, elevated plus maze (EPM), passive avoidance test (PAT), tail suspension test (TST), and forced swim test (FST), were conducted 1 h after the oral administration of EJFE at different doses (30, 100, and 300 mg/kg) and CGA (30 mg/kg). High-dose EJFE and CGA significantly alleviated CORT-induced depressive-like behaviors, as indicated by the reduced immobility times in the TST and FST. A decrease in the step-through latency time in the PAT, without an effect on locomotor activity, suggested an improvement in cognitive function. Moreover, EJFE- and CGA-treated mice exhibited significantly reduced anxiety-like behaviors in the EPM. Our results imply the promising potential of EJFE containing CGA as a therapeutic candidate for depression.

Anti-obesity effects of red pepper (Capsicum annuum L.) leaf extract on 3T3-L1 preadipocytes and high fat diet-fed mice.

Patients with obesity mostly have metabolic syndrome and this can lead to multiple health problems. In the present study, we evaluated the anti-obesity effect of water-soluble red pepper (Capsicum annuum L.) leaf extract (PLE) on 3T3-L1 adipocytes and high-fat diet (HFD)-fed mice. The adipocyte lipid content was determined using Oil Red O staining, which revealed that 100 µg mL-1 PLE markedly reduced fat accumulation without affecting the cell viability. PLE exhibited high prebiotic activity scores by modulating probiotic strains, contributing to host health improvement. In vivo investigation in HFD-fed mice revealed that PLE supplementation significantly decreased the HFD-induced increases in the body weight, amount of white adipose tissue, and serum triglyceride, total cholesterol, leptin, and insulin levels. Consistent with its effects on reduced lipid droplet formation in the liver, PLE supplementation suppressed the expression of lipid synthesis-related proteins including SREBP-1, FAS, and PPAR-γ in the liver and increased that of PGC-1α, CPT1, and adiponectin in epididymal WAT. PLE treatment improved intestinal barrier function and inflammation and reduced harmful intestinal enzyme activities in the feces. Collectively, these results indicate that PLE inhibits fat accumulation in HFD-fed mice via the suppression of adipogenesis and lipogenesis, suggesting its potential in preventing obesity.

Syzygium aromaticum Reduces Diabetes-induced Glucotoxicity via the NRF2/Glo1 Pathway.

Advanced glycation end products and methylglyoxal are known to show increased levels in diabetic conditions and induce diverse metabolic disorders. However, the antiglycation ability of the bark of Syzygium aromaticum is not yet studied. In this study, we determined the inhibitory effects of S. aromaticum on AGE formation. Moreover, S. aromaticum showed breakage and inhibitory ability against the formation of AGE-collagen crosslinks. In SV40 MES13 cells, treatment with the S. aromaticum extract significantly ameliorated MG-induced oxidative stress as well as cytotoxicity. Furthermore, in the S. aromaticum extract-treated group, there was a reduction in levels of several diabetic markers, such as blood glucose, kidney weight, and urinary albumin to creatinine ratio in streptozotocin-induced diabetic rats. Treatment with the S. aromaticum extract significantly increased the expression of nuclear factor erythroid 2-related factor 2, a transcription factor involved in the expression of antioxidant enzymes. Moreover, the treatment significantly upregulated the expression of glyoxalase 1 and downregulated the expression of receptor for AGEs. These results suggest that the S. aromaticum extract might ameliorate diabetes-induced renal damage by inhibiting the AGE-induced glucotoxicity and oxidative stress through the Nrf2/Glo1 pathway.

Chemical constituents from the fruits of Schisandra sphenanthera and their cytotoxicity activity

Abstract Schisandra sphenanthera Rehder & E.H. Wilson, Schisandraceae, is well known as a type of traditional medicine for the treatment of hepatitis, diarrhea and insomnia in Asia. It was also reported to have antiviral and anti-HIV activities. Using various chromatographic resins and isolation techniques, a new lignan (1), erythro-4-(3,4-dimethoxyphenyl)-4-hydroxy-3-methylbutan-2yl-3,4-dimethoxybenzoate, along with fifteen known compounds, were isolated from fruits of S. sphenanthera. The structures of the compounds were identified by extensive spectroscopic and spectrometric methods including 1D and 2D NMR and MS data. All the isolated compounds were evaluated for their cytotoxicity activity against Hela, HepG2 and HCT-116 cells. Among them, compound schisanlactone C showed significant cytotoxicity activity.

Optimization of Extraction Conditions for Phenolic Acids from the Leaves of Melissa officinalis L. Using Response Surface Methodology.

BACKGROUND: Melissa officinalis L. is a well-known medicinal plant from the family Lamiaceae, which is distributed throughout Eastern Mediterranean region and Western Asia. OBJECTIVE: In this study, response surface methodology (RSM) was utilized to optimize the extraction conditions for bioactive compounds from the leaves of M. officinalis L. MATERIALS AND METHODS: A Box-Behnken design (BBD) was utilized to evaluate the effects of three independent variables, namely extraction temperature (°C), methanol concentration (%), and solvent-to-material ratio (mL/g) on the responses of the contents of caffeic acid and rosmarinic acid. RESULTS: Regression analysis showed a good fit of the experimental data. The optimal condition was obtained at extraction temperature 80.53°C, methanol concentration 29.89%, and solvent-to-material ratio 30 mL/g. CONCLUSION: These results indicate the suitability of the model employed and the successful application of RSM in optimizing the extraction conditions. This study may be useful for standardizing production quality, including improving the efficiency of large-scale extraction systems. SUMMARY: The optimum conditions for the extraction of major phenolic acids from the leaves of Melissa officinalis L. were determined using response surface methodologyBox-Behnken design was utilized to evaluate the effects of three independent variablesQuadratic polynomial model provided a satisfactory description of the experimental dataThe optimized condition for simultaneous maximum contents of caffeic acid and rosmarinic acid was determined. Abbreviations used: RSM: Response surface methodology, BBD: Box-Behnken design, CA: Caffeic acid, RA: Rosmarinic acid, HPLC: High-performance liquid chromatography.

Neuraminidase inhibitory activity by compounds isolated from aerial parts of Rhinacanthus nasutus.

Rhinacanthus nasutus (L.) Kurz (Acanthaceae) is known as traditional medicine for the treatment of various diseases, such as cancer, fungal infections, herpes virus infections and several types of skin diseases in South-East Asian countries. In this study, eight compounds 1-8 were isolated from the aerial parts of R. nasutus. The structures of compounds were determined by the spectroscopic methods, including 1D and 2D NMR. The isolated compounds were evaluated for neuraminidase inhibitory activity. Several lignans, 2,3-bis[(4-hydroxy-3,5-dimethoxyphenyl)methyl]-1,4-butanediol (5) and 8,8'-bisdihydrosiringenin glucoside (6), significantly inhibited neuraminidase activity, which was comparable to the positive controls, mangiferin and oseltamivir. In addition, a structure-based virtual screening against neuraminidase using bioactive components was demonstrated.

Two New Phenolic Glycosides from the Aerial Part of Dryopteris erythrosora.

BACKGROUND: Dryopteris erythrosora (D.C. Eaton) Kuntze is a species of fern in the family of Dryopteridaceae, which is distributed throughout East Asia. The genus Dryopteris has been used as traditional medicine, especially to treat hepatitis and protect liver. However, only few studies of chemical constituents of D. erythrosora have been conducted so far. OBJECTIVE: In this study, we investigated the phytochemical constituents of D. erythrosora. MATERIALS AND METHODS: The 80% methanol extract of the aerial part of D. erythrosora was used for the isolation of phenolic compounds. The isolated compounds were elucidated by various spectroscopic methods including nuclear magnetic resonance and mass spectrometry. RESULTS: The present phytochemical investigation on the aerial part of D. erythrosora led to the isolation of two new phenolic glycosides, 1 and 2, as well as nine known flavonoids including two flavones (3 and 4) and seven flavonols (5-11). CONCLUSION: In this study, two new phenolic glycosides together with nine known flavonoids were isolated from the aerial part of D. erythrosora. Among them, compounds 4, 8, and 11 were isolated for the first time in Dryopteridaceae family from the present investigation. These results helped us to enrich our understanding of the chemical constituents of D. erythrosora and to identify compounds 1 and 2 which could be potential chemotaxonomic markers for the species. SUMMARY: The genus Dryopteris has been used as traditional medicine, especially to treat hepatitis and protect liverTwo new phenolic glycosides were isolated from D. erythrosoraNine known flavonoids (3-11) were isolated from D. erythrosoraCompounds 4, 8, and 11 were isolated for the first time in Dryopteridaceae family. Abbreviations used: HPLC: High-performance liquid chromatography; Q-TOF LC/MS: Quadrupole-time-of-flight liquid chromatography/mass spectrometry; NMR: Nuclear magnetic resonance; TMS: Tetramethylsilane.

Phenolics and neolignans isolated from the fruits of Juglans mandshurica Maxim. and their effects on lipolysis in adipocytes.

Juglans mandshurica Maxim. (Juglandaceae) is a traditional folk medicine used for treatment of dermatosis and to relieve aches in Korea and China. In this study, eight compounds, along with six known compounds, were isolated from the fruit of J. mandshurica. Among the six known compounds, the absolute configuration of two compounds were determined. The structures of compounds were determined on the basis of extensive spectroscopic methods, including 1D and 2D NMR and CD spectroscopic data. All isolated compounds were tested for their lipolytic activities in differentiated adipocytes using C3H10T1/2 mouse embryonic fibroblasts. Among them, 2-(4-formyl-2-methoxyphenoxy)-propan-1,3-diol and 2-[4-(3-hydroxypropyl)-2-methoxyphenoxy]-1,3-propanediol exhibited the most potent lipolytic activities.

Flavonoids isolated from Lespedeza cuneata G. Don and their inhibitory effects on nitric oxide production in lipopolysaccharide-stimulated BV-2 microglia cells.

BACKGROUND: Lespedeza cuneata (Dum. Cours.) G. Don, a perennial legume native to Eastern Asia, has been used therapeutically in traditional Asian medicine to protect the function of liver, kidneys and lungs. However, its effect on inflammatory nitric oxide (NO) production and the active constituents have not yet been explored. OBJECTIVE: In this study, we investigated the phytochemical constituents of L. cuneata and evaluated their effect on NO production using lipopolysaccharide (LPS)-stimulated BV2 cells. MATERIALS AND METHODS: The 80% methanol extract of the aerial part of L. cuneata were used for the isolation of flavonoids. The isolated compounds were elucidated by various spectroscopic methods including nuclear magnetic resonance and mass spectrometry spectrometry. To evaluate the effect on inflammatory NO production, LPS-stimulated murine microglia BV-2 cells were used as a screening system. RESULTS: Nine flavonoids were isolated from the aerial parts of L. cuneata. Among the isolated flavonoids, compounds 4, 5, 7 and 9 are reported from the genus Lespedeza for the first time. Moreover, compounds 1 and 6 showed significant inhibitory effects on NO production in LPS-stimulated BV2 cells without cell toxicity. CONCLUSION: In this study, nine flavonoids were isolated from L. cuneata. Among the compounds, only 1 and 6, which have free hydroxyl groups at both C3 and C7 showed significant inhibitory activity on NO production in LPS-stimulated BV2 cells. These results suggested L. cuneata and its flavonoid constituents as possible candidate for the treatment of various inflammatory diseases.

Determination of saponins and flavonoids in ivy leaf extracts using HPLC-DAD.

A new method for the determination of six compounds, chlorogenic acid, rutin, nicotiflorin, hederacoside C, hederasaponin B and α-hederin, in ivy leaf extracts using high-performance liquid chromatography with diode array detector was developed. The chromatographic separation was performed on a YMC Hydrosphere C18 analytical column using a gradient elution of 0.1% phosphoric acid and acetonitrile. The method was validated in terms of specificity, linearity (r(2) > 0.9999), precision [relative standard deviation (RSD) < 0.36%] and accuracy (97.4-103.8%). The limit of detection and limit of quantification were <20.32 and 61.56 ng for all analytes, respectively. The tested compounds were found to be stable in the ivy leaf extract from 0 to 48 h, and the RSD value for each compound was <0.90%. The validated method was successfully applied to quantify all six compounds in a 30% ethanol ivy leaf extract and 13 ivy leaf extract products. The results showed that all the tested products satisfied the minimum requirement for the content of hederacoside C. However, there were some differences between the contents of other constituents.

Implication of the stereoisomers of ginsenoside derivatives in the antiproliferative effect of HSC-T6 cells.

Two ginsenoside derivatives (9, 10) along with 10 known ginsenosides (1-8, 11, and 12) were isolated from BST204, which is a crude ginseng extract fermented by enzyme and acid hydrolysis. The two ginsenosides were determined as 12ß,20(S),25-trihydroxydammara-3-O-ß-D-glucopyranoside (9) and 12ß,20(R),25-trihydroxydammara-3-O-ß-D-glucopyranoside (10). Compounds 1-12 were categorized into stereoisomeric pairs differentiated by R- or S-configuration at C-20, the number or position of sugar residues at C-3 or C-6, and the type of derivative at C-21. Their structure-activity relationship was evaluated by the cell viability assay using HSC-T6 cells. Results showed that 20(S) (3 > 4, 7 > 8, and 9 > 10), a 2-hydroxy-2-methylbutyl moiety at C-21 (3, 7 > 9), and the number of sugar residues at C-3 (3 > 7) significantly affected the antiproliferative activity on HSC-T6 cells. The inhibition of the cell proliferation of compound 3 was assessed by annexin-V/PI staining analysis using flow cytometry.