Neurotoxic and cytotoxic peptides underlie the painful stings of the tree nettle Urtica ferox.

The stinging hairs of plants from the family Urticaceae inject compounds that inflict pain to deter herbivores. The sting of the New Zealand tree nettle (Urtica ferox) is among the most painful of these and can cause systemic symptoms that can even be life-threatening; however, the molecular species effecting this response have not been elucidated. Here we reveal that two classes of peptide toxin are responsible for the symptoms of U. ferox stings: Δ-Uf1a is a cytotoxic thionin that causes pain via disruption of cell membranes, while ß/δ-Uf2a defines a new class of neurotoxin that causes pain and systemic symptoms via modulation of voltage-gated sodium (NaV) channels. We demonstrate using whole-cell patch-clamp electrophysiology experiments that ß/δ-Uf2a is a potent modulator of human NaV1.5 (EC50: 55 nM), NaV1.6 (EC50: 0.86 nM), and NaV1.7 (EC50: 208 nM), where it shifts the activation threshold to more negative potentials and slows fast inactivation. We further found that both toxin classes are widespread among members of the Urticeae tribe within Urticaceae, suggesting that they are likely to be pain-causing agents underlying the stings of other Urtica species. Comparative analysis of nettles of Urtica, and the recently described pain-causing peptides from nettles of another genus, Dendrocnide, indicates that members of tribe Urticeae have developed a diverse arsenal of pain-causing peptides.

Recovery of Polyphenolic Compounds and Vitamins from the Stinging Nettle Leaves: Thermal and Behavior and Biological Activity of Obtained Extracts.

Stinging nettle (SN) is an extraordinary plant from the Urticaceae botanical family. It is well-known and widely used in food and folk medicine to treat different disorders and diseases. This article aimed to study the chemical composition of SN leaves extracts, i.e., polyphenolic compounds and vitamins B and C, because many studies ascribed high biological potency to these compounds and their significance in the human diet. Besides the chemical profile, the thermal properties of the extracts were studied. The results confirmed presence of many polyphenolic compounds and vitamins B and C. It also showed that the chemical profile closely correlated with the applied extraction technique. The thermal analysis showed that analyzed samples were thermally stable up to about 160 °C. Thermal degradation of samples UAE, MAE, and MAC took place in four steps, and sample SE in three steps. Altogether, results confirmed the presence of health-beneficial compounds in stinging nettle leaves and indicated the possible application of its extract in pharmaceutical and food industries as both a medicinal and food additive.

Phytochemical, Chemotaxonomic and Bioinformatics Study on Laportea bulbifera (Urticaceae).

Phytochemical investigation of the aerial part of Laportea bulbifera (Siebold & Zucc.) Wedd. (L. bulbifera) showed the isolation of seventeen compounds, including five flavonoids (1-4 and 6), one terpenoid (5), five phenolic acids (7-11), one coumarin (12), two steroids (13-14), and three alkaloids (15-17). Structure elucidations of these compounds were performed on the basis of extensive NMR experiments and compared with the published data in the references. It is remarkable that compounds (3-5) were firstly isolated from the Urticaceae family, compounds (3-8, 11 and 15-17) were firstly obtained from genus Laportea. Furthermore, the result of the chemotaxonomic significance discussion showed that compounds (2-4) may can be served as compound fingerprints to distinguish between species of L. bulbifera and genus Urtica, and what' more, we proposed a bold conjecture that isoflavones can distinguish between species of L. bulbifera and genus Urtica. At the same time, the molecular docking method was used to evaluate the inhibitory effect of these compounds on human steroid 5α-reductase 2 (SRD5α2). The results showed that compounds (1-4 and 6) had better expected effects than the positive drug finasteride can by effectively binding to the active sites of SRD5α2. This study assisted in the future phytochemical and chemotaxonomic research on genus Laportea. Simultaneously, this research provided the theoretical evidence for the application of L. bulbifera in treating benign prostatic hyperplasia (BPH).

[Active constituents of Urtica fissa in inhibition of benign prostatic hyperplasia].

The present study investigated the material basis of Urtica fissa for the inhibition of benign prostatic hyperplasia(BPH). The active fractions were screened, and the extracts of dichloromethane and ethyl acetate exhibited significantly inhibitory activities against 5α-reductase in vitro and BPH in model rats. The chemical constituents in the active fractions were systematically investigated, and 28 compounds were obtained, which were identified as lobechine methyl ester(1), dibutyl-O-phthalate(2), 1-monolinolein(3), epipinoresinol(4), 5-hydroxy-3,4-dimethyl-5-pentanyl-2(5H)-furanone(5), E-7,9-diene-11-methenyl palmitic acid(6), evofolin B(7), ficusal(8), threo-2,3-bis-(4-hydroxy-3-methoxyphenyl)-3-ethoxypropan-1-ol(9), α-viniferin(10),(9R,7E)-9-hydroxy-5,7-mengatigmadien-4-one-9-O-ß-D-glucopyranoside(11), indole-3-carboxaldehyde(12), p-hydroxy ethyl cinnamate(13), benzyl alcohol-O-ß-D-glucoside(14), L-methionine(15), 4-methoxyaniline(16), 6-aminopurine(17), 8'-acetyl oilvil(18), 4-methoxyl-8'-acetyl oilvil(19), vanillic acid(20), ß-hydroxypropiovanillone(21), 7-hydroxy-6-methoxycoumarin(22), p-hydroxybenzaldehyde(23), pinoresinol(24), erythro-1,2-bis-(4-hydroxy-3-methoxyphenyl)-1,3-propanediol(25), urticol(26), urticol-7-O-ß-D-glucopyranoside(27), and lobechine(28). Compounds 1-17 were isolated from U. fissa for the first time. Meanwhile, compound 1 was a new natural product. Compounds 10, 11, 19, 21, and 27 exhibited significant inhibitory effects on 5α-reductase.

[Potential pharmacodynamic substances of Laportea bulbifera in treatment of rheumatoid arthritis based on serum pharmacochemistry and pharmacology].

The present study investigated the pharmacodynamic material basis of Laportea bulbifera in the treatment of rheumatoid arthritis. Firstly, human rheumatoid arthritis fibroblast-like synoviocyte line MH7A was cultured in vitro and treated with tumor necrosis factor alpha(TNF-α, 50 ng·mL~(-1)). The proliferation and the levels of inflammatory cytokines such as prostaglandin E2(PGE2), interleukin-1ß(IL-1ß), and interleukin-6(IL-6) of the MH7A cells exposed to the serum containing L. bulbifera were determined to evaluate the anti-rheumatoid arthritis effects of the serum. Furthermore, the ultra-performance liquid chromatography tandem mass spectrometry fingerprints of the L. bulbifera crude extract, the drug-containing serum, and the drug-free serum were compared to identify the compounds newly generated in the serum after oral administration of the extract. According to the peak areas of common peaks and the results of anti-rheumatoid arthritis effect test, the active components were identified. The serum containing L. bulbifera significantly inhibited the proliferation of the MH7A cells activated by TNF-α and the expression of PGE2, IL-6, and IL-1ß. Thirty newly generated compounds were detected in the drug-containing serum. Among them, neochlorogenic acid, cryptochlorogenic acid, chlorogenic acid, rutin, isoquercitrin, luteoloside, kaempferol-3-O-rutinoside, and quercitrin were also present in the crude extract. Twelve characteristic peaks(3, 7, 8, 14, 18, 19, 21, 23, 24, m6, m7, and m15) were significantly correlated with the pharmaceutical effect. According to the correlations, neochlorogenic acid, cryptochlorogenic acid, and chlorogenic acid had great contributions to the anti-rheumatoid arthritis activity. This study preliminarily clarified the potential pharmacodynamic substances of L. bulbifera in the treatment of rheumatoid arthritis, which laid a theoretical and experimental foundation for further development and application of the medicinal plant.

Chemical Profiles and Pharmacological Properties with in Silico Studies on Elatostema papillosum Wedd.

The current study attempted, for the first time, to qualitatively and quantitatively determine the phytochemical components of Elatostema papillosum methanol extract and their biological activities. The present study represents an effort to correlate our previously reported biological activities with a computational study, including molecular docking, and ADME/T (absorption, distribution, metabolism, and excretion/toxicity) analyses, to identify the phytochemicals that are potentially responsible for the antioxidant, antidepressant, anxiolytic, analgesic, and anti-inflammatory activities of this plant. In the gas chromatography-mass spectroscopy analysis, a total of 24 compounds were identified, seven of which were documented as being bioactive based on their binding affinities. These seven were subjected to molecular docking studies that were correlated with the pharmacological outcomes. Additionally, the ADME/T properties of these compounds were evaluated to determine their drug-like properties and toxicity levels. The seven selected, isolated compounds displayed favorable binding affinities to potassium channels, human serotonin receptor, cyclooxygenase-1 (COX-1), COX-2, nuclear factor (NF)-κB, and human peroxiredoxin 5 receptor proteins. Phytol acetate, and terpene compounds identified in E. papillosum displayed strong predictive binding affinities towards the human serotonin receptor. Furthermore, 3-trifluoroacetoxypentadecane showed a significant binding affinity for the KcsA potassium channel. Eicosanal showed the highest predicted binding affinity towards the human peroxiredoxin 5 receptor. All of these findings support the observed in vivo antidepressant and anxiolytic effects and the in vitro antioxidant effects observed for this extract. The identified compounds from E. papillosum showed the lowest binding affinities towards COX-1, COX-2, and NF-κB receptors, which indicated the inconsequential impacts of this extract against the activities of these three proteins. Overall, E. papillosum appears to be bioactive and could represent a potential source for the development of alternative medicines; however, further analytical experiments remain necessary.

The anti-biofilm potential of triterpenoids isolated from Sarcochlamys pulcherrima (Roxb.) Gaud.

Formation of biofilm is the major cause of Pseudomonas aeruginosa associated pathological manifestations in the urinary tract, respiratory system, gastrointestinal tract, skin, soft tissues etc. Triterpenoid group of compounds have shown their potential in reducing planktonic and biofilm form of bacteria. Sarcochlamys pulcherrima (Roxb.) Gaud. is an ethnomedicinal plant traditionally used for its anti-microbial and anti-inflammatory property. In the present study two triterpenoids, have been isolated from this plant, characterised and evaluated for their antibacterial and antibiofilm potential against P. aeruginosa. Compounds were characterised as 2α, 3ß, 19α-trihydroxy-urs-12-ene-28-oic acid (Tormentic acid) and 2α, 3ß, 23-trihydroxyurs-12-ene-28-oic acid (23-hydroxycorosolic acid) through spectroscopic studies viz. infrared (IR), nuclear magnetic resonance (NMR) and mass spectroscopy (MS). Depolarization of bacterial membrane and zone of inhibition studies revealed that both the compounds inhibited the growth of planktonic bacteria. Compounds were also found to inhibit the formation of P. aeruginosa biofilm. Inhibition of biofilm found to be mediated through suppressed secretion of pyoverdin, protease and swarming motility of P. aeruginosa. Gene expression study, in silico binding analysis, in vivo bacterial load and tissue histology observations also supported the antibiofilm activity of both the compounds. In vitro and in vivo study showed that both compounds were non-toxic. The study has explored the antibacterial and antibiofilm effect of two triterpenes isolated for the first time from S. pulcherrima.

Spectrum-effect relationship of antioxidant and anti-inflammatory activities of Laportea bulbifera based on multivariate statistical analysis.

Laportea bulbifera, named Hong He Ma in Chinese, is a Chinese herbal medicine commonly used by the Miao nationality of China. In this study, 43 batches of L. bulbifera were collected from different origins in China. Ethanol, ethyl acetate and petroleum ether were used to prepare different extracts of the plant. UHPLC technique was used to establish the fingerprints, whereas DPPH assay and RAW264.7 inflammatory cell models were used to evaluate the antioxidant and anti-inflammatory activities, respectively. Moreover, the spectrum-effect relationship between relative peak area of common peaks and efficacy value was set up by multivariate statistical analysis. Furthermore, 10 batches were selected randomly for validation of those models. The results showed that ethyl acetate and petroleum ether extracts possess excellent antioxidant and anti-inflammatory activities, respectively. Peaks A6 and A7 demonstrated the greatest antioxidant activity, while peak A17 showed the strongest anti-inflammatory activity. After a verified experiment, the result was obtained and illustrated that the spectrum-effect relationship which we established could reliably infer antioxidant and anti-inflammatory compounds of the Chinese herbal medicine.

Himalayan Nettle Girardinia diversifolia as a Candidate Ingredient for Pharmaceutical and Nutraceutical Applications-Phytochemical Analysis and In Vitro Bioassays.

Girardinia diversifolia, also known as Himalayan nettle, is a perennial herb used in Nepal to make fiber as well as in traditional medicine for the treatment of several diseases. To date, phytochemical studies and biological assays on this plant are scarce. Thus, in the present work, the G. diversifolia extracts have been evaluated for their potential pharmaceutical, cosmetic and nutraceutical uses. For this purpose, detailed phytochemical analyses were performed, evidencing the presence of phytosterols, fatty acids, carotenoids, polyphenols and saponins. The most abundant secondary metabolites were ß- and γ-sitosterol (11 and 9% dw, respectively), and trans syringin (0.5 mg/g) was the most abundant phenolic. Fatty acids with an abundant portion of unsaturated derivatives (linoleic and linolenic acid at 22.0 and 9.7 mg/g respectively), vitamin C (2.9 mg/g) and vitamin B2 (0.12 mg/g) were also present. The antioxidant activity was moderate while a significant ability to inhibit acetylcholinesterase (AChE), butyrilcholinesterase (BuChE), tyrosinase, α-amylase and α-glucosidase was observed. A cytotoxic effect was observed on human ovarian, pancreatic and hepatic cancer cell lines. The effect in hepatocarcinoma cells was associated to a downregulation of the low-density lipoprotein receptor (LDLR), a pivotal regulator of cellular cholesterol homeostasis. These data show the potential usefulness of this species for possible applications in pharmaceuticals, nutraceuticals and cosmetics.

Pilea umbrosa ameliorate CCl4 induced hepatic injuries by regulating endoplasmic reticulum stress, pro-inflammatory and fibrosis genes in rat.

BACKGROUND: Pilea umbrosa (Urticaceae) is used by local communities (district Abbotabad) for liver disorders, as anticancer, in rheumatism and in skin disorders. METHODS: Methanol extract of P. umbrosa (PUM) was investigated for the presence of polyphenolic constituents by HPLC-DAD analysis. PUM (150 mg/kg and 300 mg/kg) was administered on alternate days for eight weeks in rats exposed with carbon tetrachloride (CCl4). Serum analysis was performed for liver function tests while in liver tissues level of antioxidant enzymes and biochemical markers were also studied. In addition, semi quantitative estimation of antioxidant genes, endoplasmic reticulum (ER) induced stress markers, pro-inflammatory cytokines and fibrosis related genes were carried out on liver tissues by RT-PCR analysis. Liver tissues were also studied for histopathological injuries. RESULTS: Level of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD), peroxidase (POD) and glutathione (GSH) decreased (p < 0.05) whereas level of thiobarbituric acid reactive substance (TBARS), H2O2 and nitrite increased in liver tissues of CCl4 treated rat. Likewise increase in the level of serum markers; alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP) and total bilirubin was observed. Moreover, CCl4 caused many fold increase in expression of ER stress markers; glucose regulated protein (GRP-78), x-box binding protein1-total (XBP-1 t), x-box binding protein1-unspliced (XBP-1 u) and x-box binding protein1-spliced (XBP-1 s). The level of inflammatory mediators such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) was aggregated whereas suppressed the level of antioxidant enzymes; γ-glutamylcysteine ligase (GCLC), protein disulfide isomerase (PDI) and nuclear erythroid 2 p45-related factor 2 (Nrf-2). Additionally, level of fibrosis markers; transforming growth factor-ß (TGF-ß), Smad-3 and collagen type 1 (Col1-α) increased with CCl4 induced liver toxicity. Histopathological scrutiny depicted damaged liver cells, neutrophils infiltration and dilated sinusoids in CCl4 intoxicated rats. PUM was enriched with rutin, catechin, caffeic acid and apigenin as evidenced by HPLC analysis. Simultaneous administration of PUM and CCl4 in rats retrieved the normal expression of these markers and prevented hepatic injuries. CONCLUSION: Collectively these results suggest that PUM constituted of strong antioxidant chemicals and could be a potential therapeutic agent for stress related liver disorders.

[Differences in intestinal absorption characteristics of Laportea bulbifera extract in normal and rheumatoid arthritis model rats by isolated everted intestine model].

This work aimed to investigate the intestinal absorption characteristics of Laportea bulbifera extract in normal and rheumatoid arthritis model rats. The contents of neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, rutin, kaempferol-3-O-rutinoside, galuteolin, quercetin and isoquercetin in intestinal absorption solution samples were detected by UPLC-MS/MS with 5.0 g·L~(-1) as the absorption concentration. The cumulative absorption(Q) and absorption rate constant(K_a) were calculated, and the absorption characteristics of different components of L. bulbifera in intestinal absorption solution of normal rats and rheumatoid arthritis rats were compared. The results showed that all the eight index components in the extract of L. bulbifera could be absorbed into the intestinal capsule, the cumulative absorption-time curve of each component showed an upward trend without saturation, and the correlation regression coefficient(R~2) was greater than 0.92, which is consistent with the zero-order absorption rate process. It was speculated that the possible absorption mode of each component was passive diffusion. In normal condition, the absorption of ileum was the best(except chlorogenic acid), and in pathological condition, duodenum was the best. The total absorption of 8 components in each intestinal segment of RA rats was better than that of normal rats, which speculated that rheumatoid arthritis may change the specific site of drug absorption. The experimental results showed that rheumatoid arthritis could change the intestinal absorption of the extract of L. bulbifera, and its mechanism needs further study.

Cytotoxic Alkaloids from Leaves of Pilea aff. martinii.

Two new phenanthroquinolizidine alkaloids (1: and 2: ) and a new piperidine derivative (3: ) were isolated from the leaves of Pilea aff. martinii together with 3 known alkaloids: julandine (4: ), cryptopleurine (5: ), and 1,3,6,6-tetramethyl-5,6,7,8-tetrahydro-isoquinolin-8-one (6: ). Their structures were determined by spectral data analyses including mass spectrometry and 2-dimensional nuclear magnetic resonance data. The absolute configurations of 1: -3: were established by comparison of their experimental circular dichroism data with the calculated electronic circular dichroism spectra. The isolated compounds were evaluated for their cytotoxicity against 4 cancer cell lines: KB (mouth epidermal carcinoma cells), HepG-2 (human liver hepatocellular carcinoma cells), LU-1 (human lung adenocarcinoma cells), and MCF-7 (human breast cancer cells). The new phenanthroquinolizidine pileamartine D (2: ) showed strong and selective proliferation inhibition toward KB and HepG-2 cells with IC50 values of 25 and 27 nM, respectively. Pileamartine C (1: ), julandine (4: ), and cryptopleurine (5: ) exhibited cytotoxicity against 4 tested cancer cell lines with IC50 values less than 1 µM.

Two new secolignans from the roots of Urtica fissa.

Two new secolignans, 3,4-trans-3-hydroxymethyl-4-[bis(4-hydroxy-3- methoxyphenyl)methyl]butyrolactone (1) and 3,4-trans-3-hydroxymethyl-4- [bis(3,4-dimethoxyphenyl)methyl]butyrolactone (2) have been isolated from the roots of Urtica fissa E.Pritz. Their structures were determined on the basis of spectroscopic methods, especially 1H NMR, 13C NMR, 2D NMR, and HR-ESI-MS. The inhibitory effects on N1 and N2, two subtypes of neuraminidases (NAs), of these two compounds were assayed.

New lignans from Urticae Fissae Herba.

Two new lignans named neourticol A (1) and neourticol B (2), together with seven known compounds (3-9), were isolated from Urticae Fissae Herba, a folk medicine for rheumatism arthritis in China. The active evaluation results showed that 1 and 2 possessed the potent anti-complement and anti-inflammatory activities.

[Rapid identification of constituents of Urtica hyperborea using UPLC-ESI-Q-TOF-MS/MS method].

This paper deals with the application of ultra-performance liquid chromatography tandem quadrupole time of flight mass spectrometry(UPLC-ESI-Q-TOF-MS/MS) method to rapidly determine and analyze the chemical constituents of methanol extract of Urtica hyperborea. We employed UPLC YMC-Triart C18(2. 1 mm×100 mm,1. 9 µm) column to UPLC analysis with acetonitrile-water(containing 0. 4% formic acid) in gradient as mobile phase. The flow rate was 0. 3 m L·min-1 gradient elution and column temperature was 30℃; the injection volume was 4 µL. ESI ion source was used to ensure the data collected in anegative ion mode. The chemical components of U. hyperborea were identified through retention time,exact relative molecular mass,cleavage fragments of MS/MS and reported data.The results indicated that a total of 31 compounds were identified,including 8 flavonoids,14 phenolic compounds,8 phenylpropanoids(4 coumarins and 4 lignans),and 1 steroidal compound,13 of which were confirmed by comparison. The UPLC-ESI-Q-TOF-MS/MS method could rapid identify the chemical components of U. hyperborea. The above compounds were discovered in U. hyperborea for the first time,which could provide theoretical foundation for further research on the basis of the pharmacodynamics of U. hyperborea.

[Study on effect of extract from Tibetan medicine Urtica hyperborean on anti-prostatic hyperplasia].

In this study,mouse models of benign prostatic hyperplasia induced by subcutaneous injection of testosterone propionate was used to investigate the therapeutic effect and mechanism of Urtica hyperborean( UW) extracts on prostate hyperplasia in mice. The effects of UW extracts on prostate index,serum epidermal growth factor( EGF) and dihydrotestosterone( DHT) in model mice were observed,and the EGF and anti-apoptotic factor( Bcl-2) mRNA expression levels were detected as well as pathological changes in prostate tissue. The results showed that the ethyl acetate extraction and alcohol soluble fraction of the UW could significantly reduce the prostate index,reduce the serum DHT and EGF levels( P<0. 01),and significantly decrease the EGF and Bcl-2 mRNA expression( P<0. 01),significantly improved the morphological structure of prostate tissue. The above results confirmed that ethyl acetate extract and alcohol-soluble parts of UW have a good preventive effect on mice prostatic hyperplasia model,and its mechanism may be to reduce androgen levels by regulating polypeptide growth factors and/or inhibiting cell hyperproliferation and promoting apoptosis. This study laid the foundation for the further research on UW.

Investigations of Phytochemical Constituents and Their Pharmacological Properties Isolated from the Genus Urtica: Critical Review and Analysis.

The genus Urtica belongs to the family Urticaceae. The plants of this genus are known as nettles or, quite often, as stinging nettles. These plants can be easily identified by the presence of stinging hairs. Urtica species have previously been used for various medicinal purposes. The history for the use of these plants for medicinal purposes starts from the Bronze Age (3000-2000 BC). Medicinally, the genus Urtica has been used to treat several disorders, such as cancer, rheumatoid arthritis, bronchitis, diarrhea, sprains, kidney stones, urinary tract infection, high blood pressure, hemorrhoids, flu, cough, fever, and ulcers. Scientific reports on the phytochemical analysis of this genus has so far revealed more than 123 compounds from this genus, including terpenoids, flavonoids, lignans, sterols, and polyphenols, have been isolated. Various biological activities have been exhibited by these compounds, such as antihypertensive, hepatoprotective, nephroprotective, antiurolithiatic, anthelmintic, diuretic, antinoceceptive, antidiabetic, antiviral, , and immunomodulatory. In this article, we mainly emphasize the phytochemical composition, therapeutic applications, and ethnopharmacological values of various species of genus Urtica.

Bioactive Pentacyclic Triterpenes from the Root Bark Extract of Myrianthus arboreus, a Species Used Traditionally to Treat Type-2 Diabetes.

Four new Δ12 ursene-type pentacyclic triterpenes containing the trans-feruloyl moiety (1-4), along with ursolic acid (5), were isolated from a Myrianthus arboreus root bark ethanol extract, after bioassay-guided subfractionation of its hexane fraction. The structures of 1-4 were established on the basis of the results of standard spectroscopic analytical methods (IR, HRESIMS, GC-MS, 1D and 2D NMR). The compounds 3ß- O- trans-feruloyl-2α,19α-dihydroxyurs-12-en-28-oic acid (1), 2α-acetoxy-3ß- O- trans-feruloyl-19α-hydroxyurs-12-en-28-oic acid (3), and 5 were determined to decrease the activity of hepatocellular glucose-6-phosphatase (G6Pase) and to activate glycogen synthase (GS). Their action on G6Pase activity implicated both Akt and AMPK activation. In addition, these compounds were determined to stimulate GS via the phosphorylation of glycogen synthase kinase-3. Compound 3 showed the most potent effect in modulating glucose homeostasis in liver cells. This is the first comprehensive report on novel phytochemical components of the root bark extract of M. arboreus based on the isolation of the principles responsible for its antidiabetic effects.

In vitro antioxidant and cholinesterase inhibitory activities of Elatostema papillosum leaves and correlation with their phytochemical profiles: a study relevant to the treatment of Alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD), one of the major causes of dementia, is an overwhelming neurodegenerative disease that particularly affects the brain, leading to memory loss and impairment of language and judgment capacity. The aim of the present study was to investigate the antioxidant and anticholinesterase properties of the leaves of Elatostema papillosum (EPL) and correlate with their phytochemical profiles, which are relevant to the treatment of AD. METHODS: The dried coarse powder of EPL was extracted with 80% methanol (EPL-M80) by cold extraction method. The resultant EPL-M80 was assessed for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity by the Ellman method. The antioxidant activity was determined by DPPH (1, 1-diphenyl-2-picrylhydrazyl) and hydroxyl radical scavenging assays. Quantitative phytochemical (phenolic and flavonoid contents) analysis of endogenous substances in EPL-M80 was performed by standard spectrophotometric methods. RESULTS: EPL-M80 significantly (p < 0.05) inhibited AChE and BChE activity with IC50 of 165.40 ± 4.01 and 213.81 ± 3.57 µg/mL, respectively in a dose-dependent manner. Additionally, EPL-M80 exhibited strong radical scavenging activity against DPPH (IC50 = 32.35 ± 0.68 µg/mL) and hydroxyl radical (IC50 = 19.67 ± 1.42 µg/mL) when compared to that of standards. EPL-M80 was found to be rich in phenolic (23.74 mg gallic acid equivalent/g of dry extract) and flavonoid (31.18 mg quercetin equivalent/g of dry extract) content. Furthermore, a positive correlation (p < 0.001) was observed between the total phenolics and antioxidant as well as the anticholinesterase potential. CONCLUSIONS: The marked inhibition of AChE and BChE, and potent antioxidant activity of the leaves of Elatostema papillosum highlight its potential to provide an effective treatment for AD.

Two new p-coumaroylated sesquiterpenoids from Pilea cavaleriei.

A new p-coumaroylated santalane-type sesquiterpenoid, 8-p-coumaroyl-α-santalene (1), a new p-coumaroylated oplopanane-type sesquiterpenoid, 8-ß-p-coumaroyl-oplopanone (2), and three known p-coumaroylated humulene-type sesquiterpenoids (3-5) were isolated from the ethanol extract of the whole herbs of Pilea cavaleriei. Their structures were elucidated based on the combination of 1D and 2D NMR and HRMS methods. Compound 2 was found to show anti-tuberculosis activity with MIC of 16 µg/ml.