Trapa bispinosa Roxb.: A Review on Nutritional and Pharmacological Aspects

Functional Characterization of F3H Gene and Optimization of Dihydrokaempferol Biosynthesis in Saccharomyces cerevisiae

The 1092 bp F3H gene from Trapa bispinosa Roxb., which was named TbF3H, was cloned and it encodes 363 amino acids. Bioinformatic and phylogenetic tree analyses revealed the high homology of TbF3H with flavanone 3-hydroxylase from other plants. A functional analysis showed that TbF3H of Trapa bispinosa Roxb. encoded a functional flavanone 3-hydroxylase; it catalyzed the formation of dihydrokaempferol (DHK) from naringenin in S. cerevisiae. The promoter strengths were compared by fluorescence microscopy and flow cytometry detection of the fluorescence intensity of the reporter genes initiated by each constitutive promoter (FITC), and DHK production reached 216.7 mg/L by the promoter adjustment strategy and the optimization of fermentation conditions. The results presented in this study will contribute to elucidating DHK biosynthesis in Trapa bispinosa Roxb.

In Vivo Behavior of Hydrolyzable Tannins after Oral Administration of the Trapa bispinosa Extract to Rats

The pericarp extract of Trapa bispinosa (TBPE), which is rich in hydrolyzable tannins, has been reported to inhibit α-glucosidase and glycation reactions. We investigated the in vivo behavior of hydrolyzable tannins and related metabolites after administration of TBPE to rats. Using high pressure liquid chromatography-electrospray ionization-tandem mass spectroscopy (HPLC-ESI-MS/MS), 12 ellagitannin metabolites, such as urolithins and 6 gallotannin metabolites, produced in the collected plasma and urine were quantified. Urolithins and gallic acid metabolites reached their maximum blood concentration after 24 and 1 h of administration, respectively. Conversely, the excretion of urolithins in urine required up to 72 h and followed a sigmoidal curve, whereas gallic acid metabolites were rapidly excreted earlier after administration. The results suggest that the metabolites gallotannin and ellagitannin are responsible for the antiglycation effect of TBPE, which proceeds via different mechanisms and times. Our findings provide basic data demonstrating the functionality of hydrolyzable tannins as well as Trapa ingredients.

Trapa Bispinosa Roxb. Inhibits the Insulin-Dependent AKT/WNK1 Pathway to Induce Autophagy in Mice with Type 2 Diabetes

Purpose

To elucidate the antiglycation activity of Trapa bispinosa Roxb. extract (TBE) and the related mechanism using a mouse model with type 2 diabetes.

Materials and Methods

We prepared control mice by giving them a normal diet, leptin-deficient ob/ob mouse (ob/ob mice) with a normal diet (normal ob/ob mice), and ob/ob mice with a diet containing TBE (TBE ob/ob mice). The effect of TBE on diabetic retina was evaluated by immunohistochemical staining and quantitative real-time polymerase chain reaction (qPCR) analysis.

Results

In both groups with ob/ob mice, body weight and hyperglycemia levels increased over time. Immunohistochemical staining analysis revealed that glial fibrillary acidic protein (GFAP) and advanced glycation end products (AGEs) expression levels were higher in normal ob/ob mice than in control mice, and lower in the TBE ob/ob mice than in normal ob/ob mice. Light chain-3 (LC-3) expression levels reduced in normal ob/ob mice compared to the control mice, but increased in TBE ob/ob mice compared to normal ob/ob mice. In the qPCR analysis, LC-3 expression levels were significantly lower in normal ob/ob mice compared to control mice, and significantly higher in TBE ob/ob mice compared to normal ob/ob mice. Conversely, AKT1 and with-no-lysine kinases 1 (WNK1) expression levels were significantly higher in normal ob/ob mice compared to control mice, and significantly lower in TBE ob/ob mice than in normal ob/ob mice.

Conclusion

In type 2 diabetes, it was suggested that TBE inhibits the insulin-dependent AKT/WNK1 pathway to induce autophagy, and thereby might promote anti-glycation and reduce retinal damage.

Water Caltrop (Trapa quadrispinosa Roxb.) Husk Improves Oxidative Stress and Postprandial Blood Glucose in Diabetes: Phenolic Profiles, Antioxidant Activities and α-Glycosidase Inhibition of Different Fractions with In Vitro and In Silico Analyses

The aim of this study was to investigate the phenolic profiles, antioxidant activities and α-glycosidase inhibitory activities of three different phenolic fractions from water caltrop (Trapa quadrispinosa Roxb.) husk and to further explore the predominant compounds and their mechanisms on α-glycosidase inhibition by virtual screening and molecular dynamics. A total of 29 substances were identified and quantified in this study. Tannins were the main constituents of water caltrop husk extract. All of the free phenolic (FP), esterified phenolic (EP) and insoluble-bound phenolic (BP) fractions exhibited good antioxidant activities, and the BP had the highest radical scavenging ability with IC50 values of 0.82 ± 0.12 μg/mL (ABTS) and 1.15 ± 0.02 μg/mL (DPPH), respectively (p < 0.05). However, compared with the EP and BP, the FP showed the strongest inhibition towards the α-glycosidase and the IC50 value of FP was 1.43 ± 0.12 μg/mL. The 1,2,6-trigalloylglucose and α-glycosidase complex had better root mean square deviations (RMSD) stability via molecular dynamics simulation study. Results obtained from this study may provide a good potential natural resource for the improvement of oxidative stress injury and blood glucose control in diabetes mellitus, which could expand the use of water caltrop husk and improve its economic value.

Integrative Analysis of the Transcriptome and Metabolome Reveals Genes Involved in Phenylpropanoid and Flavonoid Biosynthesis in the Trapa bispinosa Roxb

BACKGROUND

Trapa bispinosa Roxb. is grown worldwide as an important aquatic cash crop. Current research on Trapa bispinosa primarily focuses on the separation and identification of active ingredients, as well as the inhibitory effect on tumors; however, research on the molecular mechanism of secondary metabolite accumulation is rather limited. Consequently, an integrative analysis of transcriptome and metabolome is required to identify the key metabolic pathways, and key genes, and to explain the molecular mechanism of Trapa bispinosa.

RESULTS

The biosynthesis pathways of phenolics in Trapa bispinosa were examined through transcriptome and metabolome analyses. Transcriptome analysis yielded 42.76 million clean reads representing 81,417 unigenes with an average length of 1,752 bp. KEGG pathway analysis revealed that 1,623 unigenes, including 88 candidate unigenes related to phenolics biosynthesis, were up-regulated in Trapa bispinosa shell (FR) when compared to leaves (LF), root (RT), and stem (ST). The FR vs. LF group had the highest number of specific genes involved in phenylpropanoid, flavonoid, flavone, and flavonol biosynthesis pathways compared to all other comparison groups. In addition, RNA sequencing revealed 18,709 SSRs spanning 14,820 unigenes and 4,387 unigenes encoding transcription factors. Metabolome analysis identified 793 metabolites, including 136 flavonoids and 31 phenylpropane compounds. In the FR group compared to the LF group, there were 202 differentially accumulated metabolites (DAMs). The combined transcriptome and metabolome analyses indicated a significant correlation between 1,050 differentially expressed genes (DEGs) and 62 DAMs. This view proposes a schematic of flavonoid biosynthesis in the FR vs. LF group, providing evidence for the differences in genes and metabolites between FR and LF.

CONCLUSION

In this study, through de novo transcriptome assembly and metabolome analysis, several DEGs and DAMs were identified, which were subsequently used to build flavonoid biosynthesis pathways and a correlation network. The findings pave the way for future research into the molecular mechanisms and functional characterization of Trapa bispinosa candidate genes for phenolics biosynthesis.

Molecular mechanism of the anti-gastric cancer activity of 1,2,3,6-tetra-O-galloyl-β-D-glucose isolated from Trapa bispinosa Roxb. shell in vitro

Trapa bispinosa Roxb. is a traditional Chinese food which is well known for its medicinal properties. The shell of Trapa bispinosa has anticancer activity, maybe due to its high content of polyphenols. There are few studies on the chemical composition of Trapa bispinosa shells, then we isolated the active components from Trapa bispinosa shell and clarified the mechanism of its anticancer activity. One monomer compound was separated from the ethanol extract of the Trapa bispinosa shell by fractional extraction, silica gel, Sephadex LH-20 gel column chromatography and liquid phase separation. The structure, identified by NMR was 1,2,3,6-tetra-O-galloyl-β-D-glucose. The results of the CCK-8 assay showed that 1,2,3,6-tetra-O-galloyl-β-D-glucose could significantly inhibit the proliferation of gastric cancer SGC7901 cells, and the effect was close to that of 5-fluorouracil. Here, 1,2,3,6-tetra-O-galloyl-β-D-glucose could affect the cell cycle of SGC7901 cells. At the dose of 200 μg/mL and an incubation time of 48 h, SGC7901 cells remained in the G1 phase, apoptosis occurred, the intracellular calcium ion concentration increased and the mitochondrial membrane potential decreased. Transcriptome sequencing analysis showed that the differentially expressed genes were mainly enriched in the P53 signalling pathway associated with apoptosis. The results of qPCR and Western blot showed that 1,2,3,6-tetra-O-galloyl-β-D-glucose could induce apoptosis of SGC7901 cells by up-regulating the expression levels of P21, PUMA, PERP and IGF-BP3 genes, down-regulating the CyclinD gene, increasing the expression levels of cytochrome C, caspase-3, caspase-9 protein and decreasing that of the protein BCL-2.

Beneficial Effect of Long-Term Administration of Supplement With Trapa Bispinosa Roxb. and Lutein on Retinal Neurovascular Coupling in Type 2 Diabetic Mice

Purpose

We investigated the effect of long-term administration of supplement with trapa bispinosa roxb. extract (TBE) and lutein on the susceptibility of retinal blood flow regulation in type 2 diabetic mice.

Methods

Six-week-old db/db mice were randomly divided into the untreated group (n = 6) and the treated group received the supplement with TBE and lutein (n = 6). The longitudinal changes in retinal blood flow responses to systemic hyperoxia and a flicker stimulation were evaluated every 2 weeks in diabetes db/db mice from age 8 to 14 weeks. The retinal blood flow was assessed using laser speckle flowgraphy. We also evaluated the expressions of glial fibrillary acid protein (GFAP) and vascular endothelial growth factor (VEGF) by immunofluorescence.

Results

The resting retinal blood flow was steady and comparable between two groups throughout the study. In db/db mice with supplement, both blood flow responses were restored from 8 to 14 weeks of age compared with diabetic mice treated with the placebo. Supplement prevented the activation of GFAP and decreased the expression of VEGF detected by immunofluorescence compared with the diabetic mice treated with placebo.

Conclusion

We found that the long-term administration of supplement with TBE and lutein improved the impaired regulation of retinal blood flow in response to systemic hyperoxia and flicker stimulation, suggesting that these supplements can prevent diabetic retinopathy by improving abnormal neurovascular coupling in type 2 diabetic mice.

Trapa bispinosa Roxb. extract lowers advanced glycation end-products and increases live births in older patients with assisted reproductive technology: a randomized controlled trial

BACKGROUND

Advanced glycation end-products (AGE), which accumulate with insulin resistance and aging, impair folliculogenesis and may decrease endometrial receptivity. Hishi (Trapa bispinosa Roxb.) extract, a safe herbal medicine, strongly inhibits AGE formation in vitro. We determined whether Hishi lowers AGE and increases live births in older assisted reproductive technology (ART) patients.

METHODS

This prospective randomized open-label controlled trial included 64 patients 38 to 42 years old undergoing ART with or without Hishi extract between June 11, 2015 and July 12, 2019. None had over 2 ART failures, diabetes, uterine anomalies, or exhausted ovarian reserve. After allocation, the Hishi group received Hishi extract (100 mg/day) until late pregnancy or failure. The control group received no extract. Both groups underwent 1 cycle of conventional infertility treatment; 1 long-protocol cycle of ovarian stimulation, oocyte retrieval, in vitro fertilization/intracytoplasmic sperm injection, and fresh embryo transfer (ET); and, if needed, cryopreserved ET until live birth or embryo depletion. Serum AGE were measured before and during ART, as were AGE in follicular fluid (FF).

RESULTS

Cumulative live birth rate among 32 Hishi patients was 47%, significantly higher than 16% among 31 controls (p<0.01; RR, 4.6; 95% CI, 1.4 - 15.0; 1 control dropped out). Live birth rate per ET, including fresh and cryopreserved, was significantly higher with Hishi (28% in 47 ET vs. 10% in 49 ET; p<0.05; RR, 3.4; 95% CI, 1.1-10.4). Among variables including age, day-3 FSH, anti-Müllerian hormone, and Hishi, logistic regression identified only Hishi as significantly associated with increased cumulative live birth (p<0.05; OR, 5.1; 95% CI, 1.4 - 18.3). Hishi significantly enhanced oocyte developmental potential, improved endometrial receptivity in natural cycles, and decreased AGE in serum and FF. Larger serum AGE decreases with Hishi were associated with more oocytes becoming day-2 embryos.

CONCLUSIONS

Hishi decreased AGE in serum and FF and improved oocyte developmental potential and endometrial receptivity, increasing live births in older patients. Treatment of infertility by AGE reduction represents a new addition to infertility treatment. Therapeutic trials of Hishi for other AGE-associated diseases might be considered.

TRIAL REGISTRATION

UMIN registration in Japan ( UMIN000017758 ) on June 1, 2015. https://www.umin.ac.jp/ctr/index.htm.

Characterization and Identification of Bioactive Polyphenols in the Trapabispinosa Roxb. Pericarp Extract

In this study, we present the isolation and characterization of the structure of six gallotannins (1-6), three ellagitannins (7-9), a neolignan glucoside (10), and three related polyphenolic compounds (gallic acid, 11 and 12) from Trapa bispinosa Roxb. pericarp extract (TBE). Among the isolates, the structure of compound 10 possessing a previously unclear absolute configuration was unambiguously determined through nuclear magnetic resonance and circular dichroism analyses. The α-glucosidase activity and glycation inhibitory effects of the isolates were evaluated. Decarboxylated rugosin A (8) showed an α-glucosidase inhibitory activity, while hydrolyzable tannins revealed stronger antiglycation activity than that of the positive control. Furthermore, the identification and quantification of the TBE polyphenols were investigated by high-performance liquid chromatography coupled to ultraviolet detection and electrospray ionization mass spectrometry analysis, indicating the predominance of gallic acid, ellagic acid, and galloyl glucoses showing marked antiglycation properties. These findings suggest that there is a potential food industry application of polyphenols in TBE as a functional food with antidiabetic and antiglycation activities.

Chemical Composition and Biological Activity of Trapa Natans L

Trapa natans L., water chestnut (indian name singada, montenegrin name kasaronja) belonging to Trapaceae family is annual aquatic floating herb native to Asia but widely distributed in the Europe and in North America. The presence of two species, Trapa natans L. and Trapa longicarpa M.Jank. ssp. scutarensis M.Jank has been confirmed on the Skadar lake in Montenegro. Trapa natans is a plant demonstrating promising pharmacological activity mostly due to the presence of its constituens, phenols and flavonoids, showed hepatoprotective potential, antioxidant, anti-inflammatory, antidiabetic, antifungal and in vitro antimicrobial activity.

Lipopolysaccharide-Induced Nitric Oxide and Prostaglandin E2 Production Is Inhibited by Tellimagrandin II in Mouse and Human Macrophages

Sepsis develops from a serious microbial infection that causes the immune system to go into overdrive. The major microorganisms that induce sepsis are Gram-negative bacteria with lipopolysaccharide (LPS) in their cell walls. Nitric oxide (NO) and cyclooxygenase-2 (COX-2) are the key factors involved in the LPS-induced pro-inflammatory process. This study aimed to evaluate the effects of polyphenol Tellimagrandin II (TGII) on anti-inflammatory activity and its underlying basic mechanism in murine macrophage cell line RAW 264.7 and human monocyte-derived macrophages. Macrophages with more than 90% cell viability were found in the cytotoxicity assay under 50 μM TGII. Pre- or post-treatment with TGII significantly reduced LPS-induced inducible nitric oxide synthase (NOS2) protein and mRNA expression, reducing LPS-induced COX-2 protein. Downstream of NOS2 and COX-2, NO and prostaglandin E2 (PGE2) were significantly inhibited by TGII. Upstream of NOS2 and COX-2, phospho-p65, c-fos and phospho-c-jun were also reduced after pre-treatment with TGII. Mitogen-activated protein kinases (MAPKs) are also critical to nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) stimulation, and phospho-p38 expression was found to have been blocked by TGII. TGII efficiently reduces LPS-induced NO production and its upstream regulatory factors, suggesting that TGII may be a potential therapeutic agent for sepsis and other inflammatory diseases.

Commercially and medicinally significant aquatic macrophytes: potential for improving livelihood security of indigenous communities in northern Bihar, India

The dispersed wetlands in the Darbhanga District of northern Bihar, India, provide a diversity of niches supporting substantial floral and faunal richness.  The aquatic macrophytes of a representative range of perennial water bodies were surveyed fortnightly from June to September 2019, supported by a market survey undertaken with local stakeholders. A total of 61 species of vascular macrophytes was recorded, the majority of them Angiosperms (33 species of Dicotyledons from 21 families, and 26 Monocotyledons from 13 families) and two were Pteridophytes.  This paper highlights the distribution pattern and potential commercial and medicinal values of aquatic macrophytes found in different wetland systems in northern Bihar.  It further stresses their importance for subsistence, medicinal and economic purposes supporting the livelihoods of local people.  Current trends and risks contributing to the degradation and loss of this diverse flora and its supporting habitats are considered.  We recommend further assessment of the occurrence and values of this botanical resource, and extension of valuation to encompass the diverse additional ecosystem service benefits provided by the region’s wetland systems, as a basis for wetland conservation strategies founded on sustainable management and wise use, with particular reference to the potential for enhancing livelihood security of indigenous communities. 

Lutein plus Water Chestnut (Trapa bispinosa Roxb.) Extract Inhibits the Development of Cataracts and Induces Antioxidant Gene Expression in Lens Epithelial Cells

Age-related cataract (ARC) is the major cause of blindness worldwide. The most significant factors are the maximal exposure of the eye lens to environmental stressors, including oxidative and glycative load. The administration of antioxidant and antiglycative supplements may reduce the risk of cataract progression. In this study, the effects of lutein (LU) and water chestnut (Trapa bispinosa Roxb.) extract (TBE) on cataracts and the expression of antioxidant-related genes were assessed in Shumiya cataract rats (SCRs). LU+TBE or castor oil (COil) as a control was administered to 6- or 9-week-old cataractous SCRs and noncataractous SCRs via a feeding needle for 3 or 4 weeks. Five-week-old SCRs were provided ad libitum access to solid regular chow containing LU, TBE, LU+TBE, or the same chow without LU and/or TBE for 3 weeks. Lenses from all rats were then extracted and photographed. The right eyes of the rats were processed for histological observation, and the left eyes were used for total RNA extraction from lens epithelial cells (LEC). The mRNA levels of antioxidant proteins, peroxiredoxin 6, and catalase were examined using real-time quantitative polymerase chain reaction. Lens opacity appeared in all cataractous SCRs that began receiving LU+TBE at 9 weeks of age. However, compared to the COil group, lens opacity was decreased in the cataractous LU+TBE SCRs in all experiments. The mRNA expression levels of peroxiredoxin 6 and catalase in LECs of cataractous SCRs and cultured human LECs increased after the administration of LU+TBE. Collectively, our results highlight the anticataract and antioxidative effects of LT+TBE in SCRs. LT+TBE supplementation may, thus, be useful in delaying cataract progression.

Tellimagrandin II, A Type of Plant Polyphenol Extracted from Trapa bispinosa Inhibits Antibiotic Resistance of Drug-Resistant Staphylococcus aureus

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) has become a critical global concern. Identifying new candidates of anti-S. aureus agents is urgently required because the therapeutic strategies for infected patients are limited currently. Therefore, the present study investigated whether Tellimagrandin II (TGII), a pure compound extracted from the shells of Trapa bispinosa, exhibits antibacterial effects against MRSA. We first showed that TGII exerted potent inhibitory activity against MRSA with a minimum inhibitory concentration of 128 μg/mL. The obtained fractional inhibitory concentration suggested that TGII could alone exert antistaphylococcal activity, and TGII combined with low doses of antibiotics displayed synergistic effects against MRSA. Moreover, we found that TGII exerted bactericidal activity by reducing the expression of mecA followed by the negative regulation of the penicillin-binding protein 2a (PBP2a) of MRSA. Transmission electron microscopy (TEM) images further confirmed that TGII destroyed the integrity of the cell wall of MRSA and caused the loss of cytoplasm content. In conclusion, we evidenced the antibacterial effects of TGII against MRSA, which enables the effective dose of current antibiotics to be reduced and the predicament of drug-resistant S. aureus isolates to be overcome.

Hypoglycemic Constituents Isolated from Trapa natans L. Pericarps

Trapa natans L., called water chestnut or water caltrop, is a floating aquarium plant. Its fruits are widely used as food. Two new tannins, 1 and 2, one new neolignan, 14, one new norlignan, 17, and 20 known compounds, 3-13, 15, 16, and 18-24 were isolated from T. natans pericarps in this study. The 1, 2, 14, and 17 structures were elucidated using a chemical method and extensive spectral evidence. A series of hydrolyzable tannins, 1-8, a lignin, 13, a flavonoid, 16, a norlignan, 17, and phenolic compounds, 18, 20, 21, and 24 resulted in the enhanced glucose uptake activity in C2C12 myotubes. Compounds 4 and 5 significantly increased GLUT4 protein expression in C2C12 myotubes. In addition, 4 and 5 improved the phosphorylation of AMPK, AKT(S473), and AKT(T308). The involvement of AMPK and PI3K in the mechanism of action of compounds 4 and 5 was confirmed by use of AMPK and PI3K inhibitors, which completely suppressed the 4- and 5-mediated activities of glucose uptake in C2C12 myotubes. We also demonstrated that 4 and 5 could increase GLUT4 protein levels in plasma membranes.