Comparison of the chemical constituents of raw Fructus Aurantii and Fructus Aurantii stir-baked with bran, and the biological effects of auraptene.

ETHNOPHARMACOLOGICAL RELEVANCE: Fructus Aurantii (FA) is a Chinese herbal medicine commonly used in clinical practice to improve gastrointestinal motility, treat dyspepsia, and relieve constipation. More than 20 processing methods of FA have been recorded, among which FA stir-baked with bran is the earliest, most time consuming, and the most popular one. Raw FA has a strong ability to promote qi-moving and has middle-energizer-soothing effects; therefore, it is often used to relieve hypochondrium distension and pain, and to relax the stagnation of the liver Qi. FA stir-baked with bran is more effective in nourishing the stomach and curing indigestion. AIM OF THE STUDY: In this study, the chemical composition and differences between raw FA and FA stir-baked with bran were systematically compared. The chemical components that increased after stir-baking FA and bran were separated and their pharmacodynamic characteristics were determined. Lastly, the processing mechanism of FA was further explained. MATERIALS AND METHODS: Twelve main chemicals in raw FA and FA stir-baked with bran were compared using high-performance liquid chromatography (HPLC). The main differential components were identified, separated, purified, and then analyzed using pharmacodynamic tests. The intestine-pushing test, in vitro smooth muscle test, and in vitro acetylcholinesterase (AchE) activity test in mice were performed to explain the mechanism of auraptene in improving gastrointestinal motility. RESULTS: Using HPLC, the primary chemical that differed between raw FA and FA stir-baked with bran was identified as auraptene. The processed FA was extracted, separated, and purified to obtain pure auraptene. The intestine-pushing test in mice showed that low (0.6 mg·kg-1) and medium doses (1.2 mg·kg-1) of auraptene could promote peristalsis of the small intestine, whereas a high dose (2.4 mg·kg-1) inhibited peristalsis. In vitro studies on the smooth muscle of mice showed that a low dose of auraptene (0.2 mmol·L-1, 10-800 µL) could promote contraction, whereas a high dose (0.2 mmol·L-1, >1000 µL) had the opposite effect. Auraptene has a mechanism of action similar to that of the acetylcholinesterase inhibitor, neostigmine. Additionally, auraptene could inhibit AchE activity in vitro. CONCLUSIONS: Auraptene is the main chemical constituent that differs between raw FA and FA stir-baked with bran. Pharmacodynamic tests showed that auraptene has a cholinergic effect, by virtue of its role as an acetylcholinesterase inhibitor. Moreover, auraptene could dually regulate the gastrointestinal smooth muscle. Auraptene was present in low levels and its content varied in FA stir-baked with bran, depending on the origin and source of FA, and the treatment procedures it was subjected to. In the Chinese Pharmacopoeia, the recommended dose of FA stir-baked with bran is a low dose of 3-10 g, which effectively promotes small-intestinal peristalsis. The mechanism of action is attributed to an increase in the relative content of acetylcholine by the inhibition of AchE activity to promote gastrointestinal motility. The increased levels of auraptene in FA stir-baked with bran are the main reason and the primary purpose for the change in its medicinal properties. This technique, therefore, has potential to be used as one of the main processing mechanisms of raw FA.

Study on anti-hyperuricemia effects and active ingredients of traditional Tibetan medicine TongFengTangSan (TFTS) by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

TongFengTangSan (TFTS), a traditional Tibetan medicine comprising of Tinospora sinensis (TS), Terminalia chebula Retz (TC) and Trogopterori faeces (TF), is used to treat joint diseases like gout, gout arthritis, swelling, pain etc. Despite the significant therapeutic effects of TFTS, its pharmacological components have not been analyzed so far. Therefore, the chemical composition of the effective part of TFTS was analyzed by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS). The results show that the ethanol extract (EE) of TFTS was more effective in reducing the serum uric acid (SUA) and XOD (Serum and Liver) levels in a hyperuricemic rats model compared to the TFTS raw powder (RP). UHPLC-Q-TOF-MS/MS identified a total of 106 compounds in the positive and negative ion mode, of which 87 were from TC, 13 from TS and 6 from TF. In addition, 106 compounds contained 57 tannins, 6 triterpenoids, 10 alkaloids, 7 flavonoids, 22 organic acids and 4 phenylpropanoids. The preliminary results indicate that the EE of TFTS includes the active anti hyperuricemic substances. The present study first investigated the efficacy and the active components of TFTS in hyperuricemic treatment, and further summarized the diagnostic ion and neutral loss patterns of MS/MS cracking of tannic compounds. These findings lay the foundation for the further study and clinical application of TFTS.

Acute and subacute toxicity of the extract of Aristolochiae fructus and honey-fried Aristolochiae fructus in rodents.

Aristolochiae Fructus (AF) and honey-fried Aristolochiae Fructus (HAF) have been used in China for thousands of years as an anti-tussive and expectorant drug. Few clinical cases were reported associated with the toxicity of AF and HAF, although relatively high contents of aristolochic acids (AAs) were found in them. This work was designed to compare the acute and subacute toxicity of AF and HAF in order to provide references for safe clinical use and to evaluate the possibility of reducing toxicity of AF by honey-processing. The extracts of the herb were fed to mice or rats via gastric tube. Various toxic signs and symptoms, body weights, serum biochemical assay, organ weights and histopathology were used to evaluate the toxic effects. The median lethal dose (LD50) of AF and HAF are 34.1±7.2 g/kg/d and 62.6±8.0 g/kg/d with a 95% average trustable probability (p=0.95), respectively. The subacute results showed a dose-dependant relationship of the toxicity of AF and HAF. Even in the high dose groups, only moderate toxicity was observed. Honey-frying and decoction with water can decrease the contents of AAs, and attenuate the toxic effects of AF. But sufficient attention should be still paid to the safety of AF and HAF due to the existence of AAs.

[Effect of honey-toasting on the constituents and contents of aristolochic acid analogues in aristolochiae fructus].

OBJECTIVE: To evaluate the degree of de-toxification of Aristolochiae Fructus by honey-toasting technology from chemical viewpoint. METHODS: The contents of aristolochic acid analogues (AAs) in Aristolochiae Fructus and its honey-toasted product were determined by HPLC, and the degree of de-toxification was evaluated comprehensively. RESULTS: After honey-toasted, the contents of AAs decreased to varying degrees, and some new compounds were found. CONCLUSION: The constituents and contents of Aristolochiae Fructus change after honey-toasted, which indicate honey-toasting can reduce the toxicity of Aristolochiae Fructus.

Simultaneous quantification of polymethoxylated flavones and coumarins in Fructus aurantii and Fructus aurantii immaturus using HPLC-ESI-MS/MS.

The major lipid-soluble constituents in Fructus aurantii (zhiqiao) and Fructus aurantii immaturus (zhishi) are polymethoxylated flavones (PMFs) and coumarins. In the present study, a high-performance liquid chromatography with electrospray ionization tandem mass spectrometry method was developed to quantify PMFs (nobiletin, tangeretin, 5-hydroxy-6,7,8,4'-tetramethoxyflavone, and natsudaidai) and coumarins (marmin, meranzin hydrate, and auraptene) simultaneously. PMFs and coumarins were detected by electrospray ionization tandem mass spectrometry in positive ion mode and quantified with multiple reaction monitor. Samples were separated on a Diamonsil C18 (150 mm × 4.6 mm, 5 µm) column using acetonitrile and formic acid-water solution as a mobile phase in gradient mode with a flow rate at 0.5 mL/min. All calibration curves showed good linearity (r² > 0.9977) within the test ranges. Variations of the intraday and interday precisions were less than 4.07%. The recoveries of the components were within the range of 95.79%-105.04% and the relative standard deviations were less than 3.82%. The method developed was validated with acceptable accuracy, precision, and extraction recoveries and can be applied for the identification and quantification of four PMFs and three coumarins in citrus herbs.