The Effect of Methanol Extracts of Tsao-ko (Amomum tsao-ko Crevost et Lemaire) on Digestive Enzyme and Antioxidant Activity In Vitro, and Plasma Lipids and Glucose and Liver Lipids in Mice

Antidiabetic diarylheptanoids from the leaves of Amomum tsao-ko and their inhibition mechanism against α-glucosidase

Thirteen diarylheptanoids, including four undescribed ones (1-4), were isolated from the leaves of Amomum tsao-ko. Compounds 1 and 2 are two unusual diarylheptanoid-phenylpropanoid hybrids. Several of the isolates were tested for their biological activity in promoting GLP-1 secretion and inhibiting multiple type 2 diabetes-related enzymes. 2-Hydroxymusaitinerin A (1) demonstrated broad inhibitory activity against GPa, PTP1B and α-glucosidase with inhibition rates of 99.0 %, 59.4 % and 55.9 %, respectively at 200 μM. Platyphyllone (12) is a mixed-type inhibitor of α-glucosidase (IC50 = 25.8 μM), inhibiting the enzyme through both non-competitive and anti-competitive modes, as shown by enzyme kinetic study. Fluorescence quenching test confirmed that compound 12 directly interacted with α-glucosidase, forming a basal complex via a single binding site. Molecular docking predicted hydrogen-bonding interactions between OH-4'', OH-5 and 3‑carbonyl groups of 12 and α-glucosidase. This study highlights that the leaves of Amomum tsao-ko are a rich source of diarylheptanoids with multi-enzyme inhibitory effects.

Isospongian Diterpenoids from the Leaves of Amomum tsao-ko Promote GLP-1 Secretion via Ca2+/CaMKII and PKA Pathways and Inhibit DPP-4 Enzyme

Three uncommon isospongian diterpenoids including a new one, 3-epi-kravanhin A (2), were isolated from the leaves of Amomum tsao-ko. Compounds 2 and 3 dose-dependently promoted GLP-1 secretion on STC-1 cells with promotion ratios of 109.7 % and 186.1 % (60 μM). Mechanism study demonstrated that the GLP-1 stimulative effects of 2 and 3 were closely related with Ca2+/CaMKII and PKA pathways, but irrelevant to GPBAR1 and GPR119 receptors. Moreover, compound 1 showed DPP-4 inhibitory activity with an IC50 value of 311.0 μM. Molecular docking verified the binding affinity of 1 with DPP-4 by hydrogen bonds between the γ-lactone carbonyl (C-15) and Arg61 residue. Bioinformatics study indicated that compound 1 exerted antidiabetic effects by improving inflammation, oxidative stress and insulin resistance. This study first disclosed the presence of isospongian diterpenoids in A. tsao-ko, which showed antidiabetic potency by promoting GLP-1 secretion and inhibiting DPP-4 activity.

Characterization, Hypoglycemic Activity, and Antioxidant Activity of Methanol Extracts From Amomum tsao-ko: in vitro and in vivo Studies

The dried fruit of Amomum tsao-ko is well-known as a spice as well as a Chinese traditional herb. This study aimed to identify the bioactive constituents in the powder of methanol extract from Amomum tsao-ko (PMEAT) and to evaluate the hypoglycemic and antioxidant effects of PMEAT, in vitro and in vivo. We identified 36 phytochemicals in PMEAT by employing HPLC-MS/MS. PMEAT solution was found to have potent α-glucosidase-inhibiting activity (IC₅₀, 0.145 mg/mL) in vitro, twice as strong as that of acarbose (IC₅₀, 0.273 mg/mL). To investigate the hypoglycemic activity of PMEAT in vivo, we studied the impact of low-dose PMEAT (the addition of 100 mg/kg PMEAT to the mice diet) and high-dose PMEAT (200 mg/kg PMEAT addition) treatments in STZ-induced diabetic mice. After 6 weeks of intervention, significantly decreased fasting blood glucose (FBG) (p < 0.05), significantly decreased area under the curve (AUC) of the oral glucose tolerance test (p < 0.05), significantly decreased HOMA-IR (p < 0.05), and significantly increased HOMA-β (p < 0.05) were observed in the high-dose PMEAT group. Moreover, we performed an antioxidant activity experiment in vitro. The results showed that PMEAT had a strong ability to scavenge DPPH (IC₅₀, 0.044 mg/mL) as well as ABTS free radicals (IC₅₀, 0.040 mg/mL). In an animal experiment conducted on oxidative damage mice model which was induced by D-glucose and a high-fat diet, we observed significantly increased dismutase (SOD) (p < 0.01), glutathione (GSH) (p < 0.01), and glutathione peroxidase (GSH-Px) (p < 0.01) and significantly reduced malondialdehyde (MDA) and 8-ISO-prostaglandin-PGF2α (8-ISO-PGF2α), after treatment with PMEAT for 90 days. In conclusion, this study reveals the therapeutic potential of Amomum tsao-ko for the treatment of diabetes and helps us discover new antioxidant candidates from natural sources.

Flavonoid constituents of Amomum tsao-ko Crevost et Lemarie and their antioxidant and antidiabetic effects in diabetic rats - in vitro and in vivo studies

Amomum tsao-ko Crevost et Lemarie (A. tsao-ko) is a well-known dietary spice and traditional Chinese medicine. This study aimed to identify the flavonoids in A. tsao-ko and evaluate their antioxidant and antidiabetic activities in in vitro and in vivo studies. A. tsao-ko methanol extracts possessed a high flavonoid content (1.21 mg QE per g DW) and a total of 29 flavonoids were identified by employing UPLC-MS/MS. In vitro, A. tsao-ko demonstrated antioxidant activity (ORAC value of 34276.57 μM TE/100 g DW, IC₅₀ of ABTS of 3.49 mg mL^-1 and FRAP value of 207.42 μM Fe²⁺ per g DW) and α-amylase and α-glucosidase inhibitory ability with IC₅₀ values of 14.23 and 1.76 mg mL^-1, respectively. In vivo, type 2 diabetes mellitus (T2DM) models were induced by a combined high-fat diet (HFD) and streptozotocin (STZ) injection in rats. Treatment with the A. tsao-ko extract (100 mg freeze-dried powder per kg bw) for 6 weeks could significantly improve impaired glucose tolerance, decrease the levels of fasting blood glucose (FBG), insulin, and malondialdehyde (MDA), and increase the superoxide dismutase (SOD) level. Histopathology revealed that the A. tsao-ko extract preserved the architecture and function of the pancreas. In conclusion, the flavonoid composition of A. tsao-ko exhibits excellent antioxidant and antidiabetic activity in vitro and in vivo. A. tsao-ko could be a novel natural material and developed as a related functional food and medicine in T2DM management.

Amomum tsao-ko Crevost & Lemarié: a comprehensive review on traditional uses, botany, phytochemistry, and pharmacology

Tsaoko Fructus, the dried ripe fruit of Amomum tsao-ko Crevost & Lemarié, is used as both medicinal material and food additive. This review summarized the traditional uses, botany, phytochemistry, and pharmacological progress on Tsaoko Fructus. One classical prescription and the other 11 representative prescriptions containing Tsaoko Fructus were reviewed. The indications of these prescriptions are major in treating spleen and stomach disorders and epidemic febrile diseases including malaria. At least 209 compounds have been isolated and identified from Tsaoko Fructus, most of which belong to terpenoids, phenylpropanoids, and organic acids. Essential oil, crude extract, and some compounds were observed to have pharmacological activities such as anti-biotics, anti-inflammation, antioxidant, mostly via in vitro experiments. However, the mechanism of its medicinal uses remains unclear. This review provides a comprehensive understanding of Tsaoko Fructus, which will be beneficial to exploring the mechanism and potential medicinal applications of Tsaoko Fructus, as well as developing a rational quality control system for Tsaoko Fructus as a medicinal material in the future.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11101-021-09793-x.

Chemistry and bioactivity of plants from the genus Amomum

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Amomum belonging to the family Zingiberaceae, is mainly distributed in tropical regions of Asia and Oceania. Their fruits and seeds are valuable traditional medicine and used extensively, particularly in South China, India, Malaysia, and Vietnam. The genus Amomum has long been used for treating gastric diseases, digestive disorder, cancer, hepatopathy, malaria, etc. AIMS OF THE REVIEW: The main purpose of this review is to provide the available information on the traditional medicinal uses, phytochemistry, and pharmacology aspects of the genus Amomum in order to explore the trends and perspectives for further studies on its non-volatile constituents.

MATERIALS AND METHODS

The present review collected the literatures published prior to 2020 on the traditional medicinal uses, phytochemistry, and pharmacology of the genus Amomum. The available literatures were extracted from scientific databases, such as Sci-finder, PubMed, Web of Science, Google Scholar, Baidu Scholar, and CNKI, books, and others.

RESULTS

Herein, we summarize all 166 naturally occurring non-volatile compounds from 16 plants of the genus Amomum reported in 171 references, including flavonoids, terpenoids, diarylheptanoids, coumarins, etc. Triterpenes and flavonoids are the main constituents among these compounds and maybe play an important role in the activities directly or indirectly. As traditional medicine, the plants from the genus Amomum have been usually used in some traditional herbal prescriptions, and pharmacological researches in vitro and in vivo revealed that the extracts possessed significant antioxidant, anti-inflammatory, anti-allergic activities, etc. CONCLUSION: The review systematically summarizes current studies on traditional medicinal uses, phytochemistry, pharmacological activity on the plants from the genus Amomum. To date, the majority of publications still focused on the research of volatile constituents. However, the promising preliminary data of non-volatile constituents indicated the research potential of this genus in phytochemical and pharmacological aspects. Furthermore, the further in-depth investigations on the safety, efficacy, as well as the stereo-chemistry and structure-activity relationships of pure compounds from this genus are essential in the future.

Identification of in vitro-in vivo components of Caoguo using accelerated solvent extraction combined with gas chromatography-mass spectrometry integrated with network pharmacology on indigestion

Background

Caoguo (Tsaoko Fructus), a traditional Chinese medicine, is widely used as medicine and dietary spices. Volatile components are among its important bioactive constituents used to treatment of abdominal distension and pain, but the mechanism is not clear up to now. The purpose of this study was to develop a simple, sensitive, and accurate method to analyze and identify components of Caoguo in vitro and in vivo, and further investigate the therapeutic mechanism of Caoguo on indigestion using network pharmacology.

Methods

Caoguo were extracted by accelerated solvent extraction (ASE) and n-hexane:ethyl acetate (1:1, v/v) was selected as the extraction solvent. Gas chromatography-mass spectrometry (GC-MS) was adopted to analyze and identify the volatile components in vitro and in vivo. Network pharmacology including protein-protein network construction, Gene Ontology (GO) enrichment and pathway enrichment analysis and component-target-pathway network construction was applied.

Results

By comparing the retention times and mass spectrometry data, as well as retrieving the reference literature, a total of 169 components were tentatively identified in Caoguo extract and 43 components were identified in rats plasma samples for the first time. The results of network pharmacology analysis indicated that the potential mechanism was mainly associated with regulation of lipolysis in adipocytes and serotonergic synapse signaling pathway, which might be responsible for the effect of indigestion.

Conclusions

Caoguo was first extracted by ASE and the volatile chemical components in vivo were first identified by GC-MS. Coupled with network pharmacology analysis, a network of component-target-pathway was constructed to reveal the possible mechanism of Caoguo in treatment of indigestion. This study provided a new reference method for the extraction and analysis of Caoguo, laid a chemical basis for in-depth studies on pharmacodynamics and pharmacology, and revealed an updated understanding of the therapeutic effects of Caoguo on indigestion.

Multi-platform integration based on NIR and UV-Vis spectroscopies for the geographical traceability of the fruits of Amomum tsao-ko

Due to the world-wide concern relating to herb quality and safety, there is a momentum to authenticate the geographical origin of herb with multi-platform techniques. This study attempted to assess multi-platform information as a practical strategy for the geographical traceability of the fruits of Amomum tsao-ko. To this aim, one hundred and eighty dried fruits of A. tsao-ko from five geographical regions were analyzed by near infrared (NIR) and ultraviolet visible (UV-Vis) spectroscopy. On this basis, two variable dimension reduction strategies, including principal component analysis (PCA) and sequential and orthogonalized partial-least squares (SO-PLS), and two variables selection strategies, including variable importance in projection (VIP) and sequential and orthogonalized covariance selection (SO-CovSel), were performed to extract the feature information in the two blocks. Partial least squares discriminant analysis (PLS-DA) classification algorithm combined with fused matrices was used to identify the geographical origins. The results of PLS-DA models indicated that SO-PLS and SO-CovSel, taking advantage of the sequential modeling coupled to orthogonalization, could not only identify the common information presented in the two blocks but also provide more concise methods without any loss of classification ability, which could be employed in authenticating the geographical regions of the fruits of A. tsao-ko, effectively.

Nineteen New Flavanol-Fatty Alcohol Hybrids with α-Glucosidase and PTP1B Dual Inhibition: One Unusual Type of Antidiabetic Constituent from Amomum tsao-ko

The dried fruits of Amomum tsao-ko were first revealed to have hypoglycemic effects on db/db mice at a concentration of 200 mg/kg. In order to clarify the antidiabetic constituents, 19 new flavanol-fatty alcohol hybrids, tsaokoflavanols A-S (1-19), were isolated and determined by extensive spectroscopic data and ECD calculations. Most of the compounds showed α-glucosidase and PTP1B dual inhibition, among which 1, 2, 6, 11, and 18 exhibited obvious activity against α-glucosidase with IC₅₀ values of 5.2-9.0 μM, 20-35 times stronger than that of acarbose (IC₅₀, 180.0 μM); meanwhile, 6, 10-12, and 19 were PTP1B/TCPTP-selective inhibitors with IC₅₀ values of 56.4-80.4 μM, 2-4 times stronger than that of suramin sodium (IC₅₀, 200.5 μM). Enzyme kinetics study indicated that compounds 1, 2, 6, and 11 were α-glucosidase and PTP1B mixed-type inhibitors with K_i values of 13.0, 11.7, 2.9, and 5.3 μM and 142.3, 88.9, 39.2, and 40.8 μM, respectively. Docking simulations proved the importance of hemiacetal hydroxy, the orientation of 3,4-dihydroxyphenyl, and the length of alkyl in binding with α-glucosidase and PTP1B.

Amomutsaokols A-K, diarylheptanoids from Amomum tsao-ko and their α-glucosidase inhibitory activity

Eleven undescribed diarylheptanoids, amomutsaokols A‒K (1-11), together with 13 known ones (13-24), were isolated from the active fraction of the fruits of Amomum tsao-ko. The structures of the undescribed compounds were determined by extensive 1D and 2D NMR, HRESIMS and ECD calculations. Compounds 3-5, 7, 8, 12, 14 and 19 showed obviously α-glucosidase inhibitory activity with IC₅₀ values ranging from 12.9 to 48.8 μM. An enzyme kinetic analysis indicated that compounds 8 and 9 were α-glucosidase noncompetitive inhibitors with K_i values of 18.5 and 213.0 μM, respectively. This study supported diarylheptanoids as the active constituents of A. tsao-ko with α-glucosidase inhibitory effects.

Effect of Yikou-Sizi powder hot compress on gastrointestinal functional recovery in patients after abdominal surgery: Study protocol for a randomized controlled trial

BACKGROUND

Postoperative gastrointestinal dysfunction (PGD) is a common complication of patients who have undergone surgery. The clinical manifestations cause great discomfort to postoperative patients and can severely affect postoperative recovery. However, although various pharmacologic agents have been explored for several years, success has been limited. Because some commonly used drugs have caused adverse reactions and because abdominal surgery patients generally cannot consume food or medication during the perioperative period, we were prompted to try an external Chinese medicine treatment method. Yikou-Sizi powder hot compress is an efficient therapy in our hospital, but there is a lack of rigorous studies to certify the safety and effectiveness of its external use to improve gastrointestinal motility. This study aimed to introduce the clinical trial design and test the ability of Yikou-Sizi powder hot compress treatment to accelerate gastrointestinal functional recovery after abdominal surgery.

METHODS

This study is a randomized controlled clinical trial. The participants will undergo laparoscopic colorectal cancer surgery and laparoscopic total hysterectomy. The primary outcome measure will be the gastrointestinal functional evaluation index, including the time to first passage of flatus, first defecation, first normal bowel sounds, and first consumption of liquid/semigeneral diet foods. According to good clinical practice (GCP), we will evaluate the clinical efficacy and safety of Yikou-Sizi powder hot compress and objectively study the acting mechanism of ghrelin. This pilot trial will be a standard, scientific, and clinical study designed to evaluate the effect of Yikou-Sizi powder hot compress for the recovery of gastrointestinal function after surgery and determine its overall safety.

DISCUSSION

This is the first study to describe the use of Yikou-Sizi powder hot compress to accelerate the recovery of gastrointestinal function after abdominal surgery. The study is designed as a randomized, controlled, clinical, large sample size and pilot trial. Evaluation will consist of combining the primary outcome measures with secondary outcome measures to ensure the objectivity and scientific validity of the study. Due to the observational design and the limited follow-up period, it is not possible to evaluate to what extent the connection between the observed improvement and the interventions represents a causal relationship. Efficient comparison between groups will be analyzed by chi-square test.

Rapid extraction of Amomum tsao-ko essential oil and determination of its chemical composition, antioxidant and antimicrobial activities

A simple, green and efficient extraction method named modified-solvent free microwave extraction (M-SFME) was employed for the extraction of essential oils (EOs) from Amomun tsao-ko. The process of M-SFME was optimized with the prominent preponderance of such higher extraction yield (1.13%) than those of solvent free microwave extraction (SFME, 0.91%) and hydrodistillation (HD, 0.84%) under the optimal parameters. Thirty-four volatile substances representing 95.4% were identified. The IC₅₀ values of EOs determined by DPPH radical scavenging activity and β-carotene/linoleic acid bleaching assay were 5.27 and 0.63mg/ml. Furthermore, the EOs exhibited moderate to potent broad-spectrum antimicrobial activity against all tested strains including five gram-positive and two gram-negative bacteria (MIC: 2.94-5.86mg/ml). In general, M-SFME is a potential and desirable alternative for the extraction of EOs from aromatic herbs, and the EOs obtained from A. tsao-ko can be explored as a potent natural antimicrobial and antioxidant preservative ingredient in food industry from the technological and economical points of view.

Anti-Trichomonas vaginalis properties of the oil of Amomum tsao-ko and its major component, geraniol

CONTEXT

Trichomonosis, caused by the flagellate protozoan Trichomonas vaginalis, is the most common non-viral sexually transmitted disease (STD) and 5-nitroimidazole drugs are used for the treatment. However, a growing number of T. vaginalis isolates are resistant to these drugs, which make it becomes an urgent issue.

OBJECTIVE

The current study was designed to evaluate the anti-T. vaginalis activity of the essential oil from A. tsao-ko used in traditional Chinese medicine and as a spice and its main component, geraniol.

MATERIALS AND METHODS

The anti-T. vaginalis activities of A. tsao-ko essential oil and geraniol were evaluated by the minimum lethal concentration (MLC) and 50% inhibitory concentration (IC50) in vitro. The morphological changes of T. vaginalis were observed by transmission electron microscopy (TEM). Additionally, sub-MLC concentration treatment with sub-MLC A. tsao-ko essential oil and geraniol was also performed.

RESULTS

This study shows that MLC/IC50 of A. tsao-ko essential oil was 44.97 µg/ml/22.49 µg/ml for T. vaginalis isolate Tv1, and 89.93 µg/ml/44.97 µg/ml for T. vaginalis isolate Tv2. Those of geraniol were 342.96 µg/ml/171.48 µg/ml, respectively. After A. tsao-ko essential oil or geraniol treatment, obvious similar morphological changes of T. vaginalis were observed by TEM: the nuclear membrane was damaged, nuclei were dissolved, and the chromatin was accumulated; in the cytoplasm, numerous vacuoles appeared, rough endoplasmic reticulum dilated, the number of ribosomes were reduced, organelles disintegrated, the cell membrane was partially damaged, with cytoplasmic leakage, and cell disintegration was observed. The action time did not increase the effect of A. tsao-ko essential oil or geraniol against T. vaginalis, as no significant difference was observed after sub-MLC concentration treatment for 1, 3, and 5 h with A. tsao-ko essential oil and geraniol.

DISCUSSION AND CONCLUSION

The study describes the first report on the activity and morphological changes of A. tsao-ko essential oil and geraniol against T. vaginalis. The results obtained herein presented new opportunities for antitrichomonal drugs.