Effects of ginsenosides on rat jejunal contractility

Characteristics of ginsenoside Rd-induced effects on rat intestinal contractility with irritable bowel syndrome

Irritable bowel syndrome (IBS) is a very common refractory disease. Its exact pathophysiological mechanism is still unclear. Despite the availability of plentiful drugs to control IBS, most patients do not respond well. Ginsenoside Rd is one of the major active components of Panax ginseng, which has been verified to produce various pharmacological actions. However, the role of ginsenoside Rd in modulating smooth muscle contractility is still undefined. The aim of this study is to investigate the effects of ginsenoside Rd on intestinal contractility and related mechanisms in IBS.

Callicarpa nudiflora Hook. & Arn.: A comprehensive review of its phytochemistry and pharmacology

ETHNOPHARMALOGICAL RELEVANCE

Callicarpa nudiflora Hook. & Arn. is a perennial evergreen shrub or low arbor in the Genus Callicarpa. Its dried aerial parts are used as traditional Chinese herbal medicine, Luo-hua-zi-zhu (Callicarpa nudiflora), which has been widely used in anti-bacteria and anti-ulcer in China (Commission, 2015; Development, 1994; Ming-Sheng, 2008).

AIM OF THE STUDY

The present paper reviewed findings in phytochemistry and pharmacology of Callicarpa nudiflora.

METHODS

Chinese and English studies on Callicarpa nudiflora were collected from databases including Web of Science, SciFinder, PubMed, Elsevier, and CNKI (Chinese), and the phytochemical and pharmacological studies of Callicarpa nudiflora were reviewed.

RESULTS

A total of 300 small molecules, 173 of which are volatile oils, have been isolated from Callicarpa nudiflora. These small molecules could be divided into seven structural types - phenylpropanoids, flavonoids, triterpenes, diterpenes, iridoid glycosides, volatile oils, and other small molecules. Different types of compounds in Callicarpa nudiflora were summarized as follow: a) diterpenoid compounds can inhibit the generation of nitric oxide (NO) for exerting the function of anti-inflammation; b) triterpene compounds can play a role of anti-thrombus via inhibiting platelet aggregation and oleanane type and arbutane type pentacyclic triterpenes have the hepatoprotective activities; c) iridoid glycosides have cytotoxicity to tumor cells, and phenylpropanoids compounds have an antioxidant effect and could improve the function of memory. Our group further studied the antiviral activities of Callicarpa nudiflora finding that it has significant effects on RSV, EV71, COXB5, and HSV-1.

Wuda granule, a traditional Chinese herbal medicine, ameliorates postoperative ileus by anti-inflammatory action

BACKGROUND

Postoperative ileus (POI) is a temporary disturbance in gastrointestinal motility following surgery, and intestinal inflammatory response plays a critical role in the pathogenesis of POI. Wuda granule (WDG), a gastrointestinal prokinetic Chinese herbal medicine, is prescribed to promote recovery of gastrointestinal function after abdominal surgery. However, it has remained unclear whether WDG shows anti-inflammatory effects in POI. In the present study, we investigated the effects of WDG in a rat POI model and attempted to clarify the detailed mechanisms of action.

METHOD

Experimental POI was induced in adult male SD rats by intestinal manipulation (IM). WDG were orally administered after surgery at the same points (6 h, 12 h, 18 h, 24 h). Histological changes of mesenterium, levels of cytokines, and CD68 and iNOS expression were determined in rats treated or not with WDG. We also investigated the transcriptome profile of rats treated with WDG in a POI model.

RESULTS

Experimental POI in rats was characterized by a marked intestinal and systemic inflammatory response. WDG significantly inhibited the infiltration of neutrophils and macrophages, reduced the levels of IL-6, and CRP, and inhibited protein expressions of CD68 and iNOS in mesentery. Comparison analysis showed that there are 1432 differentially expressed genes (DEGs) between the POI and CON sample, whereas 331 DEGs between the WDG -treated sample and the POI group. And 16 DEGs were shared by the POI vs CON and WDG vs POI groups, among which 6 hub genes associated with immune system processes were identified and verified.

CONCLUSIONS

WDG treatment ameliorates the impaired gastrointestinal motility in the rat model of POI through inhibiting the inflammatory response of mesentery.

Bioactivities of serotonin transporter mediate antidepressant effects of Acorus tatarinowii Schott

ETHNOPHARMACOLOGICAL RELEVANCE

Acrorus tatarinowii Schott has been widely used in the treatments of neuropsychiatric and digestive disorders in clinical practices of traditional Chinese medicine for thousands of years. Both clinical and preclinical studies demonstrated antidepressant effects of A. tatarinowii. However, the possible action mechanisms of antidepressant effects of A. tatarinowii remain unraveled.

AIM OF THE STUDY

The present study aimed to investigate the roles of serotonin transporter (SERT) in antidepressant effects of A. tatarinowii.

MATERIALS AND METHODS

Antidepressant effects of water extract of A. tatarinowii were evaluated by forced swimming test (FST), tail suspension test (TST) and locomotor activity test. The water extract was analyzed by ultra high performance liquid chromatography (UPLC) method. Two major fractions of A. tatarinowii, petroleum ether extract and water extract after petroleum ether processed, were prepared and analyzed by UPLC method. Further, volatile oil extracted by ether extraction, solid phase micro-extraction (SPME) and hydro-distillation were compared and analyzed by gas chromatography-mass spectrometer (GC-MS) method. Finally, major constituents of water extract of A. tatarinowii were isolated by preparative high performance liquid chromatography (HPLC) and identified by extensive spectroscopic analyses. Effects of all of the above mentioned samples on SERT activity were tested by a high content assay (HCA).

RESULTS

Results of FST, TST and locomotor activity confirmed that water extract of A. tatarinowii significantly decreased mice immobility time but did not change mice locomotor activity. UPLC analysis results revealed that the water extract contained trace amount of β-asarone (0.0004206%) and α-asarone (0.0001918%). HCA results demonstrated that the water extract significantly enhanced SERT activity at 100 μg/mL. Further, GC-MS and UPLC analyses revealed that petroleum ether extract contained high content of β-asarone (45.63%) and α-asarone (12.50%). GC-MS analysis results demonstrated that the volatile oil extracted by ether extraction, SPME and hydro-distillation contained similar major components. HCA results verified that the petroleum ether extract significantly enhanced SERT activity at 1.56 μg/mL. Moreover, UPLC analysis of water extract after petroleum ether processed did not show any characteristic peaks. HCA results demonstrated that this extract significantly inhibited SERT activity at 50-100 μg/mL. Finally, phytochemistry investigation on the water extract of A. tatarinowii afforded seven constituents including veratric acid (9), anisic acid (7), 3,4,5-trimethoxybenzoic acid (3), trans-isoferulic acid (2), 2,4,5-trimethoxybenzoic acid (11), 4-hydroxybenzoic acid (6) and syringic acid (13). Their structures were established on the basis of nuclear magnetic resonance (NMR) and mass spectrometer (MS) data and comparative UPLC analyses. HCA results demonstrated the major components of the water extract of A. tatarinowii demonstrated SERT enhancement/inhibition activities.

CONCLUSIONS

This study first systematically demonstrated the roles of SERT activity in antidepressant effects of A. tatarinowii, including water extract, major fractions and main constituents. These results revealed that A. tatarinowii could regulate SERT activities in bidirectional ways.

Shen-ling-bai-zhu-san, a spleen-tonifying Chinese herbal formula, alleviates lactose-induced chronic diarrhea in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Shen-ling-bai-zhu-san (SLBZS) was firstly documented in ancient Chinese medical works "Tai Ping Hui Min He Ji Ju Fang" in Song-dynasty. It has been widely used for treating gastrointestinal disorders such as diarrhea with poor appetite for about 900 years. The present study is to observe the effects of SLBZS on high lactose diet-induced chronic diarrhea.

MATERIALS AND METHODS

Rats were subjected to a high lactose diet to induce chronic diarrhea, which were then administrated with SLBZS or smecta. General symptom, body weight, food consumption, water intake and fecal fluid content were recorded every day. The intestinal absorption function was determined by d-xylose uptake assay. The ultrastructures of intestine segments including jejunum, ileum, proximal and distal colon were observed by transmission electron microscopy. Additionally, sodium transport proteins including γ-epithelial sodium channel (ENAC-γ) and sodium/potassium-transporting ATPase subunit alpha-1 (ATP1A1) in distal colon were detected by immunohistochemistry and western blotting.

RESULTS

Diarrheal rats produced watery or loose, sticky feces, and presented inactiveness and grouping. A high lactose diet caused a significant decline in body weight, serum d-xylose level as well as food consumption rather than water intake. In contrast, general symptoms were improved to a certain extent and body weight loss was alleviated in the rats treated by SLBZS for one week. Fecal fluid content in diarrheal rats treated by SLBZS presented a gradual decrease trend with about 55% in the end, which was significantly less than the model group with about 81%. Meanwhile, SLBZS significantly improved the serum d-xylose level and reversed abnormal changes of tight junctions and microvilli in intestine. Additionally, SLBZS significantly modulated the abnormal expressions of ENAC-γ and ATP1A1 in distal colon of diarrheal rats.

CONCLUSIONS

These findings suggested that SLBZS exhibited ameliorating effects against lactose-induced diarrhea, which might be attributed to its modulations on intestinal absorption function as well as mucosal ultrastructure.

Anti-Inflammatory Response and Muscarinic Cholinergic Regulation during the Laxative Effect of Asparagus cochinchinensis in Loperamide-Induced Constipation of SD Rats

Several types of saponins and herbal plants containing saponins have been reported to have anti-inflammatory or laxative activities. To verify the therapeutic effects of saponin-enriched extracts of Asparagus cochinchinensis (SPA) on the anti-inflammatory response and on the cholinergic regulation in the gastrointestinal system, an alteration on the constipation phenotypes, on the inflammatory responses, and on the muscarinic cholinergic regulation were investigated in the transverse colons of Sprague Dawley (SD) rats with loperamide (Lop)-induced constipation after the treatment of SPA. Significant increases were observed on the total number of stools, the gastrointestinal transit, the thickness of the mucosal layer, the flat luminal surface, the number of paneth cells, and the lipid droplets in the Lop + SPA-treated group as compared to the Lop + Vehicle-treated group. SPA treatment induced the recovery of inflammatory cytokines (TNF-α, IL-1β) and IL-6), inflammatory mediators (NF-κB and iNOS), the total number of infiltered mast cells, and mucin secretion. Also, some similar improvements were observed on the levels of acetylcholine esterase (AChE) activity and on the phosphorylation of myosin light chains (MLC) as well as the expression of muscarinic acetylcholine receptors M2/M3 (mAChR M2/M3) and their mediators. The results presented herein provide the first strong evidence that SPA stimulates anti-inflammatory responses and the muscarinic cholinergic regulation when exerting its laxative effects in the chronic constipation of Lop-induced models.

Connection between Systemic Inflammation and Neuroinflammation Underlies Neuroprotective Mechanism of Several Phytochemicals in Neurodegenerative Diseases

Oxidative damage, mitochondrial dysfunction, and neuroinflammation are strongly implicated in the pathogenesis of neurodegenerative diseases including Alzheimer's disease (AD) and Parkinson's disease (PD), and a substantial portion of elderly population at risk of these diseases requires nutritional intervention to benefit health due to lack of clinically relevant drugs. To this end, anti-inflammatory mechanisms of several phytochemicals such as curcumin, resveratrol, propolis, polyunsaturated fatty acids (PUFAs), and ginsenosides have been extensively studied. However, correlation of the phytochemicals with neuroinflammation or brain nutrition is not fully considered, especially in their therapeutic mechanism for neuronal damage or dysfunction. In this article, we review the advance in antioxidative and anti-inflammatory effects of phytochemicals and discuss the potential communication with brain microenvironment by improved gastrointestinal function, enhanced systemic immunity, and neuroprotective outcomes. These data show that phytochemicals may modulate and suppress neuroinflammation of the brain by several approaches: (1) reducing systemic inflammation and infiltration via the blood-brain barrier (BBB), (2) direct permeation into the brain parenchyma leading to neuroprotection, (3) enhancing integrity of disrupted BBB, and (4) vagal reflex-mediated nutrition and protection by gastrointestinal function signaling to the brain. Therefore, many phytochemicals have multiple potential neuroprotective approaches contributing to therapeutic benefit for pathogenesis of neurodegenerative diseases, and development of strategies for preventing these diseases represents a considerable public health concern and socioeconomic burden.

Effects of Chinese herbal medicine Xiangbin prescription on gastrointestinal motility

AIM

To investigate the effects of Xiangbin prescription (XBP), a Chinese herbal concoction, on gastrointestinal motility.

METHODS

Forty healthy volunteers were recruited for this randomized controlled trial of XBP. Antroduodenojejunal manometry was used to monitor gastrointestinal motility in these subjects. After the subjects had fasted for at least 12 h, XBP (n = 30) or placebo (n = 10) was orally administrated and gastrointestinal motility was recorded for 4 h. Plasma motilin and ghrelin were measured by enzyme-linked immunosorbent assay.

RESULTS

Oral administration of XBP significantly increased the amplitude of duodenal contractions [19.5 (13.0-26.7) vs 16.9 (12.3-23.9), P < 0.05], jejunal contractions [18.3 (15.3-25.0) vs 15.4 (11.7-23.9), P < 0.01], and the motility index of duodenal contractions [522.0 (146.0-139.0) vs 281.0 (76.5-1006.0), P < 0.01] in phase II of the migratory motor complex (MMC), which subsequently initiated the MMC cycle [74.0 (30.0-118.0) vs 116.5 (24.0-219.0), P < 0.05], shortened the duration of phase I of the MMC [42.0 (0.0-90.0) vs 111.5 (42.0-171.0), P < 0.01], and lengthened the duration of phase II of the MMC [120 (21-240) vs 58 (16-170), P < 0.01] compared to the duration before XBP administration. There were significant differences in the amplitude of jejunal contractions [19.8 (14.0-30.0) vs 18.0 (13.0-28.5), P < 0.05], the motility index of duodenal contractions [236.0 (115.0-306.0) vs 195.0 (109.0-310.0), P < 0.05)], and jejunal contractions [214.0 (95.0-403.0) vs 178.0 (55.0-304.0), P < 0.01] in phase III of the MMC. Oral administration of XBP greatly increased plasma motilin (57.69 ± 9.03 vs 49.38 ± 8.63, P < 0.01) and ghrelin (279.20 ± 104.31 vs 238.73 ± 115.59, P < 0.01) concentrations compared to concentrations after oral administration of the placebo.

CONCLUSION

XBP can stimulate duodenal and jejunal motility and increase the concentrations of plasma motilin and ghrelin. The clinical applicability of XBP in treating GDIM deserves investigation.

In vitro and in vivo antioxidative and hepatoprotective activity of aqueous extract of Cortex Dictamni

AIM

To investigate the antioxidant and hepatoprotective effects of Cortex Dictamni aqueous extract (CDAE) in carbon tetrachloride (CCl₄)-induced liver damage in rats.

METHODS

The in vitro antioxidant effect of CDAE was investigated using α,α-diphenyl-β-picrylhydrazyl (DPPH), 2,2’-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), β-carotene bleaching, reducing power, and thiobarbituric acid reactive substance assays. A linoleic acid system, including ferric thiocyanate (FTC) and thiobarbituric acid (TBA) assays, was used to evaluate the inhibition of lipid peroxidation. The in vivo hepatoprotective and antioxidant effects of CDAE against CCl₄-induced liver damage were evaluated in Sprague-Dawley rats. Silymarin was used as a positive control. Liver damage was assessed by determining hepatic histopathology and liver marker enzymes in serum. Enzyme and non-enzyme antioxidant levels and lipid peroxide content were measured in the liver. Cytochrome P450 2E1 (CYP2E1) protein expression was measured via immunohistochemical staining. Nuclear factor E2-related factor (Nrf2), heme oxygenase-1 (HO-1), NAD(P)H quinine oxidoreductase 1 (NQO1), and γ-glutamylcysteine synthetase catalytic subunit (γ-GCSc) protein expression was measured by Western blot.

RESULTS

Our results showed that CDAE exhibited a strong antioxidant activity in vitro. CDAE scavenged DPPH and ABTS radicals in a dose-dependent manner. CDAE inhibited lipid peroxidation with a lipid peroxide inhibition rate of 40.6% ± 5.2%. In the FTC and TBA assays, CDAE significantly inhibited lipid peroxidation (P < 0.01). In vivo histopathological studies indicated that CCl₄-induced liver injury was alleviated following CDAE treatment in rats of both sexes. CDAE (160 and 320 mg/kg) significantly prevented CCl₄-induced elevations of alkaline phosphatase, glutamate pyruvate transaminase, aspartate aminotransferase, and total bilirubin levels in rats of both sexes (P < 0.05, 0.01, or 0.001). Moreover, CDAE restored the decreased activities of hepatic antioxidant enzymes, including superoxide dismutase, catalase, and glutathione peroxidase, as well as non-enzyme antioxidant glutathione, which were induced by CCl₄ treatment. CDAE significantly suppressed the up-regulation of CYP2E1 and promoted Nrf2, HO-1, NQO1, and γ-GCSc protein expression.

CONCLUSION

CDAE exhibits good antioxidant performance in vitro, with marked radical-scavenging and anti-lipid peroxidation activities. CDAE is effective in preventing CCl₄-induced hepatic damage in rats of both sexes. The hepatoprotective activity of CDAE may be attributable to its antioxidant activity, which may involve Keap1-Nrf2-mediated antioxidant regulation.