Activation of M3 muscarinic receptor and Ca²⁺ influx by crude fraction from Crotonis Fructus in isolated rabbit jejunum

Croton tiglium L. seeds ameliorate loperamide-induced constipation via regulating gastrointestinal hormones and gut microbiota before and after processing

ETHNOPHARMACOLOGICAL RELEVANCE

Crotonis Fructus (CF), the seeds of Croton tiglium L., have been commonly used in the treatment of constipation for more than two thousand years in traditional Chinese medicine (TCM). CF needs to be processed before clinical use and Crotonis Semen Pulveratum (CP) is the processed cream of CF, which could reduce the drastic purgative action and gastrointestinal damages. However, the mechanism of CF and CP in the treatment of constipation is still unclear.

AIM OF THE STUDY

This study was to evaluate the effects of CF and CP on loperamide-induced constipation and the underlying mechanism.

MATERIALS AND METHODS

The chemical compositions of CF and CP were analyzed by UPLC-Q-TOF-MS. Constipated mouse model was established by loperamide (9.6 mg/kg, b.w., i.g.) for two weeks. After successful modeling, the mice were treated with CF or CP (45.5 and 136.5 mg/kg, b.w., i.g.) once a day for seven days. The physiological status, defecation indices, defecation time, and intestinal propulsion rate in mice were measured. Histopathologic examination and serum biochemical parameters were further estimated. 16S rDNA gene sequencing was carried out to characterize the effects of CF and CP on intestinal microbiome structure. Spearman correlation analysis was also performed to explore the association between gut microbiotic abundance and serum indices.

RESULTS

The results verified the therapeutic effects of CF and CP on loperamide-induced constipation. CF and CP could significantly ameliorate the reduction of fecal number, fecal weight, fecal water content, and intestinal propulsion rate in mice with constipation, and the first stool defecation time was also obviously reduced. Moreover, CF and CP could regulate the secretion of gastrointestinal hormones and inflammatory factors induced by constipation. Histopathologic examination showed that CP was superior to CF in relieving pathological injury and inflammatory cell infiltration. According to 16S rDNA sequencing, CF and CP treatment could improve gut microbiota disturbance in mice with constipation and the abundance of opportunistic pathogens such as Parabacteroides, Parasutterella and Bacillus remarkably declined, while the levels of beneficial bacterial such as Candidatus_Arthromitus significantly increased. Besides, CP may play a better role in correcting the intestinal flora disorder than CF, which was more obvious in the high-dose group. In addition, phytochemical analysis revealed the presence of diterpenoids and alkaloids in CF and CP.

CONCLUSIONS

CF and CP could ameliorate loperamide-induced constipation by regulating gastrointestinal hormones secretion, reducing the levels of inflammatory cytokines and improving the disturbance of gut microbiota. Moreover, CP was superior to CF in the enrichment of beneficial bacteria and reduction of harmful bacteria and histopathological damage induced by constipation, which may be related to the changes in the species and content of diterpenoids after processing. The study provides new evidence for the processing mechanism and clinical application of CF and CP.

Botany, traditional uses, phytochemistry, pharmacological and toxicological effects of Croton tiglium Linn.: a comprehensive review

OBJECTIVES

Croton tiglium Linn. (Euphorbiaceae) is an ancient medicinal plant that has been used for a long time, which is widely distributed in tropical and subtropical regions. And it is widely used for defecation, induced labour, treatment of gastrointestinal diseases, headache, as well as rheumatoid arthritis.

KEY FINDINGS

Approximately 150 compounds have been isolated and identified from the seeds, stems, leaves and branches of C. tiglium, including fatty acids, terpenoids, alkaloids, the plants proteins and other types of components. Based on a wide range of biological properties, C. tiglium has a wide range of pharmacological effects, such as antitumor, anti-HIV, analgesic, anti-inflammatory and antibacterial effects.

SUMMARY

The review aims to provide a critical and comprehensive evaluation of the botany, phytochemistry, pharmacology and toxicity of C. tiglium, with a vision for promoting further pharmaceutical research to explore its complete potential for better clinical application. The tigliane diterpenoids have been the most studied compounds isolated from C. tiglium, which showing a variety of biological activities, but there is insufficient evidence to explain the mechanism of action. In addition, C. tiglium may have potential toxic effects, and it is necessary to reduce the toxic effects to ensure the safety of clinical medication, which may promote the discovery and development of new drugs.

Differential suppression of delayed-rectifier and inwardly rectifier K+ currents by a group of ent-kaurane-type diterpenoids from Croton tonkinensis, in microglial cells

Croton is an extensive flowering plant genus in the spurge family, Euphorbiaceae. Three croton compounds with the common ent-kaurane skeleton were purified from Croton tonkinensis. By using patch-clamp recording technique, we thoroughly examined the effect of a group of croton compounds, croton-01 (ent-18-acetoxy-7α-hydroxykaur-16-en-15-one), croton-02 (ent-7α,14β-dihydroxykaur-16-en-15-one), and croton-03 (ent-1β-acetoxy-7α,14β-dihydroxykaur-16-en-15-one), on the membrane current in SM826 and BV2 microglial cells. Although neither voltage-gated Na⁺ nor Ca²⁺ currents were present in these cells, both delayed-rectifier K⁺ outward (I_K(DR)) and inwardly rectifying K⁺ currents (I_K(IR)) were readily detected. Croton-03 differentially caused inhibition of I_K(DR) or I_K(IR) in a concentration-dependent manner. According to a minimal scheme, the shortening of the time constant in either the I_K(DR)-related block or I_K(IR) caused by different concentrations of croton-03 was quantitatively estimated with a dissociation constant of 6.45 and 29.5 μM, respectively. In SM826 cells differentiated with β-amyloid, inhibitory action on these K⁺ currents remained unaltered. In ultraviolet C-irradiated cells, the magnitude of I_K(IR) was still decreased by addition of croton-03. Therefore, our study suggests that these ent-kaurane diterpenoids ought to somehow act on the cellular mechanisms by which they influence the functional activities of microglial cells.

Natural Antispasmodics: Source, Stereochemical Configuration, and Biological Activity

Natural products with antispasmodic activity have been used in traditional medicine to alleviate different illnesses since the remote past. We searched the literature and compiled the antispasmodic activity of 248 natural compounds isolated from terrestrial plants. In this review, we summarized all the natural products reported with antispasmodic activity until the end of 2017. We also provided chemical information about their extraction as well as the model used to test their activities. Results showed that members of the Lamiaceae and Asteraceae families had the highest number of isolated compounds with antispasmodic activity. Moreover, monoterpenoids, flavonoids, triterpenes, and alkaloids were the chemical groups with the highest number of antispasmodic compounds. Lastly, a structural comparison of natural versus synthetic compounds was discussed.

Plants Producing Ribosome-Inactivating Proteins in Traditional Medicine

Ribosome-inactivating proteins (RIPs) are enzymes that deadenylate nucleic acids and are broadly distributed in the plant kingdom. Many plants that contain RIPs are listed in the pharmacopoeias of folk medicine all over the world, mostly because of their toxicity. This review analyses the position occupied in traditional medicine by plants from which RIPs have been isolated. The overview starts from the antique age of the Mediterranean area with ancient Egypt, followed by the Greek and Roman classic period. Then, the ancient oriental civilizations of China and India are evaluated. More recently, Unani medicine and European folk medicine are examined. Finally, the African and American folk medicines are taken into consideration. In conclusion, a list of RIP-expressing plants, which have been used in folk medicine, is provided with the geographical distribution and the prescriptions that are recommended by traditional healers. Some final considerations are provided on the present utilization of such herbal treatments, both in developing and developed countries, often in the absence of scientific validation. The most promising prospect for the medicinal use of RIP-expressing plants is the conjugation of purified RIPs to antibodies that recognise tumour antigens for cancer therapy.

Effects of traditional Chinese herbal medicine San-Huang-Xie-Xin-Tang on gastrointestinal motility in mice

AIM: To investigate the effects of San-Huang-Xie-Xin-Tang (SHXXT), a herbal product used in traditional Chinese medicine, on gastrointestinal (GI) motility in mice.

METHODS: The in vivo effects of SHXXT on GI motility were investigated by measuring the intestinal transit rates (ITRs) using Evans blue in normal mice and in mice with experimentally induced GI motility dysfunction (GMD).

RESULTS: In normal ICR mice, ITRs were significantly and dose-dependently increased by SHXXT (0.1-1 g/kg). GMD was induced by injecting acetic acid or streptozotocin intraperitoneally. The ITRs of GMD mice were significantly reduced compared to normal mice, and these reductions were significantly and dose-dependently inhibited by SHXXT (0.1-1 g/kg).

CONCLUSION: These results suggest that SHXXT is a novel candidate for the development of a prokinetic agent that may prevent or alleviate GMD.

Crotonis Fructus and Its Constituent, Croton Oil, Stimulate Lipolysis in OP9 Adipocytes

Introduction. Crotonis fructus (CF) is the mature fruit of Croton tiglium L. and has been used for the treatment of gastrointestinal disturbance in Asia. It is well known that the main component of CF is croton oil (CO). The present study is to investigate the effects of CF extracts (CFE) and CO on lipolysis in OP9 adipocytes. Methods. Glycerol release to the culture supernatants was used as a marker of adipocyte lipolysis. Results. Treatment with various concentrations of CFE and CO stimulates glycerol release in a dose-dependent manner. The increase in glycerol release by CFE is more potent than isoproterenol, which is a β-adrenergic agonist as a positive control in our system. The increased lipolysis by CFE and CO was accompanied by an increase of phosphorylated hormone sensitive lipase (pHSL) but not nonphosphorylated HSL protein and mRNA. Pretreatment with H89, which is a protein kinase A inhibitor, significantly abolished the CFE- and CO-induced glycerol release in OP9 adipocytes. These results suggest that CFE and CO may be a candidate for the development of a lipolysis-stimulating agent in adipocytes.

The influence of compatibility of traditional Chinese medicine on the pharmacokinetic of main components in Fructus aurantii

ETHNOPHARMACOLOGICAL RELEVANCE

Fructus Aurantii is one of the commonly used traditional Chinese medicines and the compatibility of Fructus Aurantii, Radix et Rhizoma Rhei and Semen Crotonis Pulveratum were the main components in a Chinese traditional patent medicine Weichang'an pill. Naringin and neohesperidin are two main flavonoid glycosides in the extract of Fructus Aurantii. The pharmacokinetics of naringin and neohesperidin, as the main marker constituents were analysis by a simple and accurate method.

MATERIALS AND METHODS

In the present study, pharmacokinetic differences of two flavonoid glycosides were detected after oral administration of the extract of single herb and different compatibility of Fructus Aurantii, Radix et Rhizoma Rhei and Semen Crotonis Pulveratum which at doses of approximately 700 mg/kg naringin and 300 mg/kg neohesperidin.

RESULTS

It indicated that the pharmacokinetic process of naringin and neohesperidin in four groups were demonstrated bimodal phenomenon after oral administration. Comparing to pharmacokinetic parameters of the single herbs administration, there were no significant difference after the compatibility of Fructus Aurantii and Radix et Rhizoma Rhei. However, the absorption of two flavonoid glycosides was increased dramatically after the compatibility of Fructus Aurantii or Semen Crotonis Pulveratum. The same results were attained after co-administration of the extract of three herbs.

CONCLUSION

Some components in the extract of Semen Crotonis Pulveratum promoted the absorption of naringin and neohesperidin.