Anti-Neuroinflammatory Effects of Arecae pericarpium on LPS-Stimulated BV2 Cells.

Arecae pericarpium (AP), the fruit peel of the betel palm, is a traditional Oriental herbal medicine. AP is used to treat various diseases and conditions, such as ascites, edema, and urinary retention, in traditional Korean medicine. Recent studies have demonstrated its anti-obesity and antibacterial effects; however, its anti-neuroinflammatory effects have not yet been reported. Therefore, we investigated the anti-neuroinflammatory effects of AP on lipopolysaccharide (LPS)-stimulated mouse microglia in this study. To determine the anti-neuroinflammatory effects of AP on BV2 microglial cells, we examined the production of nitric oxide (NO) using Griess assay and assessed the mRNA expression levels of inflammatory mediators, such as inducible NO synthase (iNOS) and cyclooxygenase (COX)-2, and pro-inflammatory cytokines, such as interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α, using a real-time reverse transcription-polymerase chain reaction. Furthermore, we determined the levels of mitogen-activated protein kinases and IκBα via Western blotting to understand the regulating mechanisms of AP. AP treatment decreased NO production in LPS-stimulated BV2 cells. Additionally, AP suppressed the expression of iNOS and COX-2 and the production of pro-inflammatory cytokines. AP also inhibited the activation of p38 and nuclear factor-kappa B (NF-κB) in LPS-stimulated BV2 cells. Therefore, AP exerts anti-neuroinflammatory effects via inactivation of the p38 and NF-κB pathways.

The Neuroprotective Effects of Arecae Pericarpium against Glutamate-Induced HT22 Cell Cytotoxicity.

Arecae Pericarpium has been found to exert anti-migraine, antidepressant, and antioxidative effects. However, the mechanisms involved are unclear. This study explored the possibility that Arecae Pericarpium ethanol extract (APE) exerts neuroprotective effects against oxidative stress-induced neuronal cell death. Since glutamate excitotoxicity has been implicated in the pathogenesis and development of several neurodegenerative disorders, we explored the mechanisms of action of APE on oxidative stress-induced by glutamate. Our results revealed that pretreatment with APE prevents glutamate-induced HT22 cell death. APE also reduced both the levels of intracellular reactive oxygen species and the apoptosis of cells, while maintaining glutamate-induced mitochondrial membrane potentials. Western blotting showed that pretreatment with APE facilitates the upregulation of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) phosphorylation; the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf-2); and the production of antioxidant enzymes, including catalase, glutamate-cysteine ligase catalytic subunits, NAD(P)H quinone oxidoreductase 1, and heme oxygenase (HO)-1. The administration of LY294002, a PI3K/Akt inhibitor, attenuated the neuroprotective effects of APE on oxidative stress-induced neuronal cell damage. This allowed us to infer that the protective effects of APE on oxidative damage to cells can be attributed to the PI3K/Akt-mediated Nrf-2/HO-1 signaling pathway.

Arecae pericarpium water extract alleviates chronic pancreatitis by deactivating pancreatic stellate cells.

Chronic pancreatitis (CP) is a chronic inflammatory disease of the pancreas with irreversible morphological changes. Arecae pericarpium (ARP), known to improve gastrointestinal disorders, has not yet been reported to inhibit fibrosis in CP. Therefore, we investigated the beneficial effects of ARP on cerulein-induced CP. Cerulein (50 µg/kg) was administered intraperitoneally to mice every hour, six times a day, four times a week for a total of 3 weeks to induce CP. To ascertain the prophylactic effects of ARP, ARP water extract (50, 100, or 200 mg/kg) or saline was administered intraperitoneally 1 h before the onset of CP. To determine the therapeutic effects of ARP, ARP water extract (200 mg/kg) or saline was administered for a total of 1 week or 2 weeks, starting 2 weeks or 1 week after the onset of CP. The pancreas was collected immediately for histological analysis. Additionally, to determine the effectiveness and mechanism of ARP in alleviating pancreatic fibrosis, pancreatic stellate cells (PSCs) were isolated. ARP treatment considerably improved glandular atrophy and inflammation and repressed collagen deposition in the pancreas. Furthermore, ARP water extract inhibited extracellular matrix (ECM) constituents such as alpha-smooth muscle actin (α-SMA), collagen I, and fibronectin 1 (FN1) in pancreatic tissue and PSCs. ARP also suppressed transforming growth factor-ß (TGF-ß) signaling by inhibiting Smad2 phosphorylation. Our study suggests that ARP exhibits anti-fibrotic effects in cerulein-induced CP by inhibiting TGF-ß/Smad signaling.

Arecae pericarpium extract induces porcine lower-esophageal-sphincter contraction via muscarinic receptors.

BACKGROUND: Gastroesophageal reflux disease (GERD) is associated with lower esophageal sphincter (LES) incompetence. In some patients, GERD is refractory to acid reduction therapy which is the main treatment for GERD. So far, medications that can increase LES tone are few. Arecae pericarpium (A. pericarpium) is a medication in Traditional Chinese Medicine known to promote intestinal motility. METHODS: We investigated the effect of A. pericarpium extracts on porcine LES motility. In addition, we used tetrodotoxin (TTX) and atropine to study the underlying mechanism of A. pericarpium extracts-induced contractions of LES. RESULTS: The results of this study showed that A. pericarpium extracts and their main active ingredient, arecoline, can induce the contractions of porcine LES sling and clasp muscles in a dose-response manner. TTX did not have an inhibitory effect on the contractions induced by A. pericarpium extracts and arecoline in LES. However, atropine significantly inhibited A. pericarpium extracts- and arecoline-induced contractions of LES. CONCLUSION: A. pericarpium extracts can induce the contractions of porcine LES in a dose dependent manner, possibly through muscarinic receptors, and hence, may be worth developing as an alternative therapy for GERD.

[Comparative study on contents of four alkaloids in homologous herbal medicines--Arecae Pericarpium and Arecae Semen].

To establish a high performance liquid chromatography (HPLC) method for simultaneous determination of four alkaloids(arecoline， guvacoline， arecaidine， and guvacine) in Arecae Pericarpium (AP) and Arecae Semen (AS), and compare the contents of these four alkaloids between different medicinal parts. The chromatographic conditions were as follows:Welch SCX（4.6 mm×250 mm， 5 µm）column, with acetonitrile-0.2% phosphoric acid solution (adjusted to pH 3.85-3.90 with ammonium hydroxide) at 50:50 as the mobile phase, at a flow rate of 0.5 mL·min⁻¹. The column temperature was set at 35 °C, and the detection wavelength was 215 nm. The results of content determination in 7 batches of AS and 10 batches of AP showed that, the contents of 4 alkaloids in AS (arecaidine 0.020%-0.045%, guvacine 0.031%-0.086%, arecoline 0.194%-0.346%, and guvacoline 0.065%-0.094%) were generally higher than those in AP (arecaidine 0.10%-0.032%, guvacine 0.006%-0.029% arecoline 0.00%-0.070%, and guvacoline 0.00%-0.020%), and most of the APs had no arecoline and arecaidine at all in fruit peel. The above results indicated that different alkaloids can be used to distinguish the different medicinal parts of Arera catechu. Arecoline， guvacoline， arecaidine， and guvacine can be used as the quality control markers of AS, while for AP, only arecaidine and guvacine were needed.

Comparative study on contents of four alkaloids in homologous herbal medicines--Arecae Pericarpium and Arecae Semen / 中国中药杂志

To establish a high performance liquid chromatography (HPLC) method for simultaneous determination of four alkaloids(arecoline， guvacoline， arecaidine， and guvacine) in Arecae Pericarpium (AP) and Arecae Semen (AS), and compare the contents of these four alkaloids between different medicinal parts. The chromatographic conditions were as follows:Welch SCX（4.6 mm×250 mm， 5 μm）column, with acetonitrile-0.2% phosphoric acid solution (adjusted to pH 3.85-3.90 with ammonium hydroxide) at 50:50 as the mobile phase, at a flow rate of 0.5 mL·min⁻¹. The column temperature was set at 35 °C, and the detection wavelength was 215 nm. The results of content determination in 7 batches of AS and 10 batches of AP showed that, the contents of 4 alkaloids in AS (arecaidine 0.020%-0.045%, guvacine 0.031%-0.086%, arecoline 0.194%-0.346%, and guvacoline 0.065%-0.094%) were generally higher than those in AP (arecaidine 0.10%-0.032%, guvacine 0.006%-0.029% arecoline 0.00%-0.070%, and guvacoline 0.00%-0.020%), and most of the APs had no arecoline and arecaidine at all in fruit peel. The above results indicated that different alkaloids can be used to distinguish the different medicinal parts of Arera catechu. Arecoline， guvacoline， arecaidine， and guvacine can be used as the quality control markers of AS, while for AP, only arecaidine and guvacine were needed.

Bioassay-Guided Isolation and Identification of Compounds from Arecae Pericarpium with Anti-inflammatory, Anti-oxidative, and Melanogenesis Inhibition Activities

This study describes the anti-inflammatory, anti-oxidant, and melanogenesis inhibition activities of methanol extract and various organic solvent fractions of Arecae Pericarpium. We examined the inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 cells, 1,1-diphenyl-2-picrylhydrazine (DPPH) scavenging activity, mushroom tyrosinase inhibition activity and melanin contents. The study showed that, among all tested fractions, methylene chloride fraction showed the strongest inhibition of LPS-induced NO production in RAW 264.7 cells (IC₅₀ value 8.89 µg/mL) and DPPH radical scavenging activity (EC₅₀ value 21.39 µg/mL). Methylene chloride and ethyl acetate fractions similarly inhibited mushroom tyrosinase activity. Methanol extract exhibited strongest reduction of melanin content in B16F10 melanoma cells. Based on the bioactivity assay results, methylene chloride and ethyl acetate fractions were further separated. Eight phenolic compounds were isolated, which are dimeric syringol (1), catechol (2), 4-hydroxybenzaldehyde (3), vanillin (4), 4-hydroxyacetophenone (5), apocynin (6), protocatechuic acid (7) and 4-hydroxybenzoic acid (8). Among the isolated compounds tested, catechol showed the strongest inhibition of LPS-induced NO production in RAW 264.7 cells. Catechol also showed the concentration-dependent NF-κB inhibition activity. Arecae Pericarpium might have potentials to be developed as anti-inflammatory agent or dermatological product for skin-whitening agent.

HPLC determination of arecoline in Arecae Pericarpium from different habitats / 中国药学杂志

OBJECTIVE: To establish a quantitative determination method for arecoline in Arecae Pericarpium. METHODS: The determination was performed on thermo-biobasic SCX column (4.6 mm×250 mm, 5 μm) with mobile phase consisting of acetonitrile-phosphoric acid solution (55;45). The flow rate was 1.0 mL·min-1, the column temperature was 30°C, and the detection wavelength was 215 nm. RESULTS: The method had good linear relationship for arecoline hydrobromide in the range of 5.2-83.2 μg·mL-1 (r=0.9991). The average recovery (n=9) was 98.8% for arecoline hydrobromide. CONCLUSION: The method is simple, accurate and specific. It provides a reliable way for evaluating the quality of Arecae Pericarpium.