Abrus precatorius Leaf Extract Stimulates Insulin-mediated Muscle Glucose Uptake: In vitro Studies and Phytochemical Analysis.

Diabetes mellitus, linked with insulin resistance and hyperglycaemia, is a leading cause of mortality. Glucose uptake through glucose transporter type 4, especially in skeletal muscle, is crucial for maintaining euglycaemia and is a key pathway targeted by antidiabetic medication. Abrus precatorius is a medicinal plant with demonstrated antihyperglycaemic activity in animal models, but its mechanisms are unclear.This study evaluated the effect of a 50% ethanolic (v/v) A. precatorius leaf extract on (1) insulin-stimulated glucose uptake and (2) related gene expression in differentiated C2C12 myotubes using rosiglitazone as a positive control, and (3) generated a comprehensive phytochemical profile of A. precatorius leaf extract using liquid chromatography-high resolution mass spectrometry to elucidate its antidiabetic compounds. A. precatorius leaf extract significantly increased insulin-stimulated glucose uptake, and insulin receptor substrate 1 and Akt substrate of 160 kDa gene expression; however, it had no effect on glucose transporter type 4 gene expression. At 250 µg/mL A. precatorius leaf extract, the increase in glucose uptake was significantly higher than 1 µM rosiglitazone. Fifty-five phytochemicals (primarily polyphenols, triterpenoids, saponins, and alkaloids) were putatively identified, including 24 that have not previously been reported from A. precatorius leaves. Abrusin, precatorin I, glycyrrhizin, hemiphloin, isohemiphloin, hispidulin 4'-O-ß-D-glucopyranoside, homoplantaginin, and cirsimaritin were putatively identified as known major compounds previously reported from A. precatorius leaf extract. A. precatorius leaves contain antidiabetic phytochemicals and enhance insulin-stimulated glucose uptake in myotubes via the protein kinase B/phosphoinositide 3-kinase pathway by regulating insulin receptor substrate 1 and Akt substrate of 160 kDa gene expression. Therefore, A. precatorius leaves may improve skeletal muscle insulin sensitivity and hyperglycaemia. Additionally, it is a valuable source of bioactive phytochemicals with potential therapeutic use for diabetes.

Network pharmacology and experimental validation of effects of total saponins extracted from Abrus cantoniensis Hance on acetaminophen-induced liver injury.

ETHNOPHARMACOLOGICAL RELEVANCE: Abrus cantoniensis Hance (AC), an abrus cantoniensis herb, is a Chinese medicinal herb used for the treatment of hepatitis. Total saponins extracted from AC (ACS) are a compound of triterpenoid saponins, which have protective properties against both chemical and immunological liver injuries. Nevertheless, ACS has not been proven to have an influence on drug-induced liver injury (DILI). AIM OF THE STUDY: This study used network pharmacology and experiments to investigate the effects of ACS on acetaminophen (APAP)-induced liver injury. MATERIALS AND METHODS: The targets associated with ACS and DILI were obtained from online databases. Cytoscape software was utilized to construct a "compound-target" network. In addition, Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were used to analyze the related signaling pathways impacted by ACS. AutoDock Vina was utilized to evaluate the binding affinity between bioactive compounds and the key targets. To validate the findings of network pharmacology, in vitro and in vivo experiments were conducted. Cell viability assay, transaminase activity detection, immunofluorescence assay, immunohistochemistry staining, RT-qPCR, and western blotting were utilized to explore the effects of ACS. RESULTS: 25 active compounds and 217 targets of ACS were screened, of which 94 common targets were considered as potential targets for ACS treating APAP-induced liver injury. GO and KEGG analyses showed that the effects of ACS exert their effects on liver injury through suppressing inflammatory response, oxidative stress, and apoptosis. Molecular docking results demonstrated that core active compounds of ACS were successfully docked to core targets such as CASP3, BCL2L1, MAPK8, MAPK14, PTGS2, and NOS2. In vitro experiments showed that ACS effectively attenuated APAP-induced damage through suppressing transaminase activity and attenuating apoptosis. Furthermore, in vivo studies demonstrated that ACS alleviated pathological changes in APAP-treated mice and attenuated inflammatory response. Additionally, ACS downregulated the expression of iNOS, COX2, and Caspase-3, and upregulated the expression of Bcl-2. ACS also suppressed the MAPK signaling pathway. CONCLUSIONS: This study demonstrated that ACS is a hepatoprotective drug through the combination of network pharmacology and in vitro and in vivo experiments. The findings reveal that ACS effectively attenuate APAP-induced oxidative stress, apoptosis, and inflammation through inhibiting the MAPK signaling pathway. Consequently, this research offers novel evidence supporting the potential preventive efficacy of ACS.

Carboxymethylated Abrus cantoniensis polysaccharide prevents CTX-induced immunosuppression and intestinal damage by regulating intestinal flora and butyric acid content.

As a Chinese folk health product, Abrus cantoniensis exhibits good immunomodulatory activity because of its polysaccharide components (ACP), and carboxymethylation of polysaccharides can often further improve the biological activity of polysaccharides. In this study, we explored the impact of prophylactic administration of carboxymethylated Abrus cantoniensis polysaccharide (CM-ACP) on immunosuppression and intestinal damage induced by cyclophosphamide (CTX) in mice. Our findings demonstrated that CM-ACP exhibited a more potent immunomodulatory activity compared to ACP. Additionally, CM-ACP effectively enhanced the abundance of short-chain fatty acid (SCFA)-producing bacteria in immunosuppressed mice and regulated the gene expression of STAT6 and STAT3 mediated pathway signals. In order to further explore the relationship among polysaccharides, intestinal immunity and intestinal flora, we performed a pseudo-sterile mouse validation experiment and fecal microbiota transplantation (FMT) experiment. The findings suggest that CM-FMT and butyrate attenuate CTX-induced immunosuppression and intestinal injury. CM-FMT and butyrate show superior immunomodulatory ability, and may effectively regulate intestinal cell metabolism and repair the damaged intestine by activating STAT6 and STAT3-mediated pathways. These findings offer new insights into the mechanisms by which CM-ACP functions as functional food or drug, facilitating immune response regulation and maintaining intestinal health.

From Tea to Health: Exploring Abrus mollis for Liver Protection and Unraveling Its Potential Mechanisms.

Abrus mollis Hance is a characteristic medicinal herb which is used in Guangdong and Guangxi provinces of China for making soup, medicinal meals, and herbal tea to treat dampheat jaundice and rib discomfort. Current phytochemical study on A. mollis led to the isolation of four new flavones, mollisone A-D (1-4), and thirty two known compounds (5-36). Their structures were characterized by an extensive analysis of spectroscopic data including IR, UV, HR-ESI-MS, and 1D and 2D NMR, as well as electronic circular dichroism calculation. In addition, in order to initially understand their biological activities for traditional applications, in vitro antioxidant and hepatoprotective tests were carried out, whose results illustrated that 25 compounds had significant free radical scavenging ability, and compounds 13 and 16 exhibited protective activities on D-GalN-induced LO2 cell damage than the positive control. Moreover, network pharmacological analysis revealed that the hepatoprotective activity of A. mollis involved multitargets and multipathways such as PI3K/Akt, MAPK, and JAK-STAT pathways and various biological processes such as positive regulation of phosphorylation and regulation of kinase activity. These results suggested that this species could serve as a potential hepatoprotective agent for functional food or medicinal use.

Novel biogenic silver nanoconjugates of Abrus precatorius seed extracts and their antiproliferative and antiangiogenic efficacies.

Biogenic silver nanoconjugates (AgNCs), derived from medicinal plants, have been widely explored in the field of biomedicines. AgNCs for the first-time were synthesized using ethyl acetate seed extracts of Abrus precatorius and their antiproliferative and antiangiogenic efficacies were evaluated against cervical and oral carcinoma. Ultraviolet-Visible spectrophotometry, dynamic light Scattering (DLS), and scanning electron microscopy (SEM) were used for characterization of AgNCs. Antiproliferative activity was investigated using MTT, DNA fragmentation and in-vitro antioxidant enzyme activity assays. In-vivo chick chorioallantoic membrane (CAM) model was used to evaluate antiangiogenic activity. A total of 11 compounds were identified in both the extracts in GCMS analysis. The synthesized AgNCs were spherical shaped with an average size of 97.4 nm for AgAPE (Sox) and 64.3 nm for AgAPE (Mac). AgNCs possessed effective inhibition against Hep2C and KB cells. In Hep2C cells, AgAPE (Mac) revealed the highest SOD, catalase, GST activity and lower MDA content, whereas AgAPE (Sox) showed the highest GSH content. On the other hand, in KB cells, AgAPE (Sox) exhibited the higher SOD, GST activity, GSH content, and least MDA content, while AgAPE (Mac) displayed the highest levels of catalase activity. Docking analysis revealed maximum binding affinity of safrole and linoleic acid with selected targets. AgAPE (Sox), AgAPE (Mac) treatment profoundly reduced the thickness, branching, and sprouting of blood vessels in the chick embryos. This study indicates that A. precatorius-derived AgNCs have enhanced efficacies against cervical and oral carcinoma as well as against angiogenesis, potentially limiting tumour growth.

Metabolomics analysis reveals the differences between Abrus cantoniensis Hance and Abrus mollis Hance.

BACKGROUND: Abrus cantoniensis Hance. (Ac) and Abrus mollis (Am), two edible and medicinal plants with economic value in southern China, belong to the Abrus genus. Due to its growth characteristics, Am often replaces Ac in folk medicine. However, the latest National Pharmacopeia of China only recommends Ac. The differences in the metabolite composition of the plants are directly related to the differences in their clinical efficacy. RESULTS: The difference in metabolites were analyzed using an untargeted metabolomic approach based on ultrahigh-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC‒ESI‒MS/MS). The roots (R), stems (S) and leaves (L) of the two varieties were examined, and 635 metabolites belonging to 8 classes were detected. A comparative study revealed clear variations in the metabolic profiles of the two plants, and the AmR group had more active ingredients (flavonoids and terpenoids) than the AcR group. The metabolites classified as flavonoids and triterpene saponins showed considerable variations among the various samples. Both Ac and Am had unique metabolites. Two metabolites (isovitexin-2''-xyloside and soyasaponin V) specifically belong to Ac, and nine metabolites (vitexin-2"-O-galactoside, ethyl salicylate, 6-acetamidohexanoic acid, rhein-8-O-glucoside, hederagenin-3-O-glucuronide-28-O-glucosyl(1,2)-glucoside, methyl dioxindole-3-acetate, veratric acid, isorhamnetin-3-O-sophoroside-7-O-rhamnoside, and isorhamnetin-3-O-sophoroside) specifically belong to Am. CONCLUSIONS: The metabolite differences between Ac and Am cause the differences in their clinical efficacy. Our findings serve as a foundation for further investigation of biosynthesis pathways and associated bioactivities and provide guidance for the clinical application of traditional Chinese medicine.

Three Undescribed Flavonoids and Amide from Abrus mollis Hance with Hepatoprotective Effects.

Through a phytochemical investigation of Abrus mollis Hance, a folk medicinal plant in China, we isolated and identified three undescribed compounds, including two flavonoids and one amides alkaloid, along with nine known from this plant. Their structures were elucidated by analyses of 1D, 2D NMR, HR-ESI-MS, ECD, and DP4+ analysis. Furthermore, we evaluated the hepatoprotective effects of all twelve compounds on D-GalN-induced Brl-3 A cells. According to the results, at a concentration of 25 µM, the cell survival rates were observed to be 71.92±0.34 %, 70.03±1.29 %, and 69.11±1.90 % for compound 2, 4, and 11, respectively. Further experimental studies showed that compound 2 (EC50 5.76±0.37 µM) showed more significant protective activity than the bicyclol.

A Comparative Study between Abrus cantoniensis and Abrus mollis: Flavonoids Profiles by UPLC-Q-TOF-MS and Anti-Inflammatory Mechanism by Transcriptomics.

Abrus mollis (MJGC) has been used as a substitute herb for Abrus cantoniensis (JGC) in China. However, an in-depth comparison on their key metabolites and the mechanism of anti-inflammation between these two is not available. In this report, high pressure liquid chromatography equipped with mass spectrometry was applied to capture their flavonoid profiles; transcriptomics was adopted to analyze their anti-inflammatory mechanisms. The results showed that the main flavonoids in MJGC were vicenin-2, schaftoside and isoschaftoside, while those in JGC were vicenin-1 isomer and schaftoside isomer. The anti-inflammatory activity of JGC was slightly stronger than that of MJGC. The number of differential expression genes regulated by JGC was significantly higher than MJGC. JGC regulated 151 (42 up and 109 down) of inflammation related genes, while MJGC regulated 58 (8 up and 50 down) of inflammation related genes. The results of this study provided scientific evidence and guidance for the substitution of MJGC and JGC.

LCMS Determination and Cytotoxicity of Abrus precatorius on L6 and SK-N-MC Cell Lines.

OBJECTIVE: The present study aimed to investigate the cytotoxic effect of various extracts derived from Abrus precatorius Linn. leaves on rat L6 and human SK-N-MC neuroblastoma cell lines and determine the secondary metabolites responsible for the cytotoxicity of Abrus precatorius. METHODS: Successive solvent extraction of A. precatorius leaves was carried out using the Soxhlet apparatus with solvents such as petroleum ether, chloroform, ethyl acetate, and ethanol. HPTLC fingerprinting and LC-MS studies were performed to assess the presence of secondary metabolites, such as flavonoids and phenols, in the ethyl acetate extract. Furthermore, the cytotoxic effect of extracts was tested on rat skeletal muscle cell line L6 and human neuroblastoma cell line SK-N-MC using MTT assay. RESULTS: The total phenolic content of ethyl acetate and ethanol extracts of A. precatorius were 72.67 and 60.73 mg, respectively, of GAE/g dry weight of the extract. The total flavonoid content of ethyl acetate and ethanol extract of A. precatorius were 107.33 and 40.66 mg of Quercetin equivalents/g dry weight of the extract. LCMS analysis demonstrated that the flavonoids in specific Naringenin, Diosmetin, Glycitin, and Genistein might play a prominent role in the cytotoxicity of A. precatorius. The cytotoxicity study revealed that the extracts of A. precatorius were non-toxic to rat L6 myotubes, and the IC50 values of the various extracts, such as APPE, APCH, APEA, and APET, were >100 µg/ml. The extracts exhibited cytotoxic activity against human neuroblastoma SK-N-MC cells, and the IC50 values of APPE, APCH, APEA, APET, and the standard drug "Cisplatin" were >100, >100, 64.88, >100, and 3.72 µg/ml, respectively. CONCLUSION: It was concluded from the study that the extracts of Abrus precatorius were cytotoxic to neuroblastoma cell lines but non-toxic to normal cell lines. HPTLC and LC-MS studies confirmed that flavonoids in the ethyl acetate extract could be responsible for the biological activity.

An ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry identification and characterization of the active constituents from Abrus mollis Hance.

Abrus mollis Hance is a traditional Chinese medicine that is widely used to treat acute and chronic hepatitis, steatosis, and fibrosis. Its therapeutic qualities of it have long been acknowledged, although the active ingredients responsible for its efficacy and the mechanisms of its action are unknown. In this study, the chemical constituents absorbed into the blood from Abrus mollis Hance were assessed by using liquid chromatography-quadrupole-time-of-flight mass spectrometry and the data was analyzed with the UNIFI screening platform. The results obtained were compared to existing chromatographic-mass spectrometry information, including retention times and molecular weights as well as known reference compounds. 41 chemical constituents were found in Abrus mollis Hance, and these included 16 flavonoids, 13 triterpenoids, five organic acids, and two alkaloids. Experimentally it was found that Abrus mollis Hance had a therapeutic benefit when treating α-naphthalene isothiocyanate-induced acute liver injury in rats. In addition, 11 blood prototypical constituents, including six flavonoids, three triterpenoids, and two alkaloids, were found in serum samples following intragastric administration of Abrus mollis Hance extracts to rats. This novel study can be used for the quality control and pharmacodynamic assessment of Abrus mollis Hance in order to assess its efficacy in the therapeutic treatment of patients.

Complete genome sequence and phylogenetic analysis of medicinal plant Abrus cantoniensis for evolutionary research and germplasm utilization.

Abrus cantoniensis Hance, a native medicinal plant in southern China, is officially recorded in the Chinese Pharmacopoeia. Here, we presented the first high-quality genome in Abrus genus, A. cantoniensis genome, as well as the detailed genomic information. The assembled genome size was 381.27 Mb with a scaffold N50 of 18.95 Mb, and 98.97% of the assembled sequences were anchored on 11 pseudochromosomes. The A. cantoniensis genome comprised 25,058 protein-coding genes and 45.12% of the assemblies were repetitive sequences. Comparative genome analysis suggested that chromosome translocation and inversion played an important role in the differentiation of Abrus. In addition, 24 toxin-related genes were identified, which formed two tandem gene clusters on chromosomes 2 and 3. The chromosome-level genome of A. cantoniensis obtained in this work provides a valuable resource for understanding the evolution, active ingredient biosynthesis, and genetic improvement for A. cantoniensis and Abrus species.

The traditional uses, phytochemistry and pharmacology of Abrus precatorius L.: A comprehensive review.

ETHNOPHARMACOLOGICAL RELEVANCE: Abrus precatorius L. (AP) is a folk medicine with a long-term medicinal history worldwide, which is extensively applied to various ailments, such as bronchitis, jaundice, hepatitis, contraception, tumor, abortion, malaria, etc. Meanwhile, its leaves are also served as tea in China, and its roots are employed as a substitute for Glycyrrhiza uralensis or as a raw material for the extraction of glycyrrhizin in India. Thus, AP is considered to be a plant with dual values of medicine and economy as well as its chemical composition and biological activity, which are of growing interest to the scientific community. AIM OF REVIEW: In the review, the traditional application, botany, chemical constituents, pharmacological activities, and toxicity are comprehensively and systematically summarized. MATERIALS AND METHODS: An extensive database retrieval was conducted to gather the specific information about AP from 1871 to 2022 using online bibliographic databases Web of Science, PubMed, SciFinder, Google Scholar, CNKI, and Baidu Scholar. The search terms comprise the keywords "Abrus precatorius", "phytochemistry", "pharmacological activity", "toxicity" and "traditional application" as a combination. RESULTS: To date, AP is traditionally used to treat various diseases, including sore throat, cough, bronchitis, jaundice, hepatitis, abdominal pain, contraception, tumor, abortion, malaria, and so on. More than 166 chemical compounds have been identified from AP, which primarily cover flavonoids, phenolics, terpenoids, steroids, alkaloids, organic acids, esters, proteins, polysaccharides, and so on. A wide range of in vitro and in vivo pharmacological functions of AP have been reported, such as antitumor, antimicrobial, insecticidal, antiprotozoal, antiparasitic, anti-inflammatory, antioxidant, immunomodulatory, antifertility, antidiabetic, other pharmacological activities. The crushed seeds in powder or paste form were comparatively toxic to humans and animals by oral administration. Interestingly, the methanolic extracts were non-toxic to adult Wistar albino rats at various doses (200 and 400 mg/kg) daily. CONCLUSIONS: The review focuses on the traditional application, botany, phytochemistry, pharmacological activities, and toxicity of AP, which offers a valuable context for researchers on the current research status and a reference for further research and applications of this medicinal plant.

In-vitro antiproliferative efficacy of Abrus precatorius seed extracts on cervical carcinoma.

Abrus precatorius is a tropical medicinal plant with multiple medicinal benefits whose seeds have not yet been studied against cervical cancer. Herein, we have assessed the antioxidant and antiproliferative properties of seed extracts (ethyl acetate and 70% ethanol) prepared from Soxhlet and Maceration extraction methods against Hep2C and HeLa Cells. We observed that the APE (Sox) extract had a significantly higher total flavonoid content, APA (Mac) extract had a high total phenolic content, and APA (Sox) extract had a high total tannin content. Further, HPLC analysis of extracts revealed the presence of tannic acid and rutin. Moreover, APA (Sox) exhibited the highest free radical scavenging activity. APE (Mac) had the best antiproliferative activity against Hep2C cells, while APA (Sox) had the best antiproliferative activity against HeLa cells. In Hep2C cells, APE (Mac) extract revealed the highest SOD, catalase activity, GSH content, and the lowest MDA content, whereas APA (Mac) extract demonstrated the highest GST activity. In HeLa cells, APA (Sox) extract showed the highest SOD, GST activity, GSH content, and the least MDA content, whereas APA (Mac) extract showed the highest catalase activity. Lastly, docking results suggested maximum binding affinity of tannic acid with HER2 and GCR receptors. This study provides evidence that A. precatorius seed extracts possess promising bioactive compounds with probable anticancer and antioxidant properties against cervical cancer for restricting tumor growth.

Optimization of Ultrasonic-Assisted Extraction of Total Flavonoids from Abrus Cantoniensis (Abriherba) by Response Surface Methodology and Evaluation of Its Anti-Inflammatory Effect.

Abrus cantoniensis is a Chinese herbal medicine with efficacy in clearing heat and detoxification, as well as relieving liver pain. The whole plant, except the seeds, can be used and consumed. Flavonoids have been found in modern pharmacological studies to have important biological activities, such as anti-inflammatory, antibacterial and antioxidant properties. The antibacterial and antioxidant bioactivities of the total flavonoids of Abrus cantoniensis (ATF) have been widely reported in national and international journals, but there are fewer studies on their anti-inflammatory effects. The present study focused on the optimization of the ultrasonic extraction process of ATF by response surface methodology and the study of its anti-inflammatory effects in vitro and in vivo. The results showed that the factors that had a great impact on the ATF extraction were the material-to-liquid ratio, ultrasonic extraction cycles and ethanol concentration. The best extraction process used a material-to-liquid ratio of 1:47, ultrasonic extraction cycles of 4 times, an ethanol concentration of 50%, an ultrasonic extraction time of 40 min and an ultrasonic power of 125 W. Under these conditions, the actual extraction rate of total flavonoids was 3.68%, which was not significantly different from the predicted value of 3.71%. In an in vitro anti-inflammatory assay, ATF was found to be effective in alleviating LPS (lipopolysaccharide)-induced inflammation in mouse peritoneal macrophages. In an in vivo anti-inflammatory assay, ATF was found to have a significant inhibitory effect on xylene-induced ear swelling in mice and cotton ball granuloma in mice, and the inhibitory effect was close to that of the positive control drug dexamethasone. This may provide a theoretical basis for the further development of the medicinal value of Abrus cantoniensis.

The complete chloroplast genome sequence of the medicinal plant Abrus pulchellus subsp. cantoniensis: genome structure, comparative and phylogenetic relationship analysis.

Abrus pulchellus subsp. cantoniensis, an endemic medicinal plant in southern China, is clinically used to treat jaundice hepatitis, cholecystitis, stomachache and breast carbuncle. Here, we assembled and analyzed the first complete chloroplast (cp) genome of A. pulchellus subsp. cantoniensis. The A. pulchellus subsp. cantoniensis cp genome size is 156,497 bp with 36.5% GC content. The cp genome encodes 130 genes, including 77 protein-coding genes, 30 tRNA genes and four rRNA genes, of which 19 genes are duplicated in the inverted repeats (IR) regions. A total of 30 codons exhibited codon usage bias with A/U-ending. Moreover, 53 putative RNA editing sites were predicted in 20 genes, all of which were cytidine to thymine transitions. Repeat sequence analysis identified 45 repeat structures and 125 simple-sequence repeats (SSRs) in A. pulchellus subsp. cantoniensis cp genome. In addition, 19 mononucleotides (located in atpB, trnV-UAC, ycf3, atpF, rps16, rps18, clpP, rpl16, trnG-UCC and ndhA) and three compound SSRs (located in ndhA, atpB and rpl16) showed species specificity between A. pulchellus subsp. cantoniensis and Abrus precatorius, which might be informative sources for developing molecular markers for species identification. Furthermore, phylogenetic analysis inferred that A. pulchellus subsp. cantoniensis was closely related to A. precatorius, and the genus Abrus formed a subclade with Canavalia in the Millettioid/Phaseoloid clade. These data provide a valuable resource to facilitate the evolutionary relationship and species identification of this species.

Abrus precatorius Leaf Extract Reverses Alloxan/Nicotinamide-Induced Diabetes Mellitus in Rats through Hormonal (Insulin, GLP-1, and Glucagon) and Enzymatic (α-Amylase/α-Glucosidase) Modulation.

BACKGROUND: Abrus precatorius is used in folk medicine across Afro-Asian regions of the world. Earlier, glucose lowering and pancreato-protective effects of Abrus precatorius leaf extract (APLE) was confirmed experimentally in STZ/nicotinamide-induced diabetic rats; however, the underlying mechanism of antidiabetic effect and pancreato-protection remained unknown. OBJECTIVE: This study elucidated antidiabetic mechanisms and pancreato-protective effects of APLE in diabetic rats. MATERIALS AND METHODS: APLE was prepared by ethanol/Soxhlet extraction method. Total phenols and flavonoids were quantified calorimetrically after initial phytochemical screening. Diabetes mellitus (DM) was established in adult Sprague-Dawley rats (weighing 120-180 g) of both sexes by daily sequential injection of nicotinamide (48 mg/kg; ip) and Alloxan (120 mg/kg; ip) over a period of 7 days. Except control rats which had fasting blood glucose (FBG) of 4.60 mmol/L, rats having stable FBG (16-21 mmol/L) 7 days post-nicotinamide/Alloxan injection were considered diabetic and were randomly reassigned to one of the following groups (model, APLE (100, 200, and 400 mg/kg, respectively; po) and metformin (300 mg/kg; po)) and treated daily for 18 days. Bodyweight and FBG were measured every 72 hours for 18 days. On day 18, rats were sacrificed under deep anesthesia; organs (kidney, liver, pancreas, and spleen) were isolated and weighed. Blood was collected for estimation of serum insulin, glucagon, and GLP-1 using a rat-specific ELISA kit. The pancreas was processed, sectioned, and H&E-stained for histological examination. Effect of APLE on enzymatic activity of alpha (α)-amylase and α-glucosidase was assessed. Antioxidant and free radical scavenging properties of APLE were assessed using standard methods. RESULTS: APLE dose-dependently decreased the initial FBG by 68.67%, 31.07%, and 4.39% compared to model (4.34%) and metformin (43.63%). APLE (100 mg/kg) treatment restored weight loss relative to model. APLE increased serum insulin and GLP-1 but decreased serum glucagon relative to model. APLE increased both the number and median crosssectional area (×106 µm2) of pancreatic islets compared to that of model. APLE produced concentration-dependent inhibition of α-amylase and α-glucosidase relative to acarbose. APLE concentration dependently scavenged DPPH and nitric oxide (NO) radicals and demonstrated increased ferric reducing antioxidant capacity (FRAC) relative to standards. CONCLUSION: Antidiabetic effect of APLE is mediated through modulation of insulin and GLP-1 inversely with glucagon, noncompetitive inhibition of α-amylase and α-glucosidase, free radical scavenging, and recovery of damaged/necro-apoptosized pancreatic ß-cells.

Bioaccessibility and Absorption of Flavonoid C-glycosides from Abrus mollis Using Simulated Digestion, Caco-2 Cell, and In Situ Single-pass Perfusion Models.

Abrus mollis is commonly used as a traditional Chinese medicine for the treatment of liver diseases due to its hepatoprotection and anti-inflammation, but the absorption properties of its main bioactive ingredients remain unclear. Our previous studies verified that the flavonoid C-glycosides, including vicenin-2 (1: ), isoschaftoside (2: ), and schaftoside (3: ), were the major active components in A. mollis for hepatic protection against nonalcoholic fatty liver disease, hepatitis, and hepatic fibrosis. This study investigated the bioaccessibility and transport mechanisms of total flavonoid C-glycoside, as well as vicenin-2 (1: ), isoschaftoside (2: ), and schaftoside (3: ), in A. mollis by simulated digestion and use of the Caco-2 cell model. Moreover, this study attempted to verify their absorption properties by in situ gastrointestinal perfusion in rats. Total flavonoid C-glycoside and 1, 2: , and 3: exhibited similar bioaccessibility of 84.58%, 85.13%, 83.05%, and 81.65% respectively after simulated digestion. The transport of total flavonoid C-glycoside in the Caco-2 cell model increased with the concentration, and the transport showed saturation characteristics with the time and concentration of total flavonoid C-glycoside to a certain degree. The Papp values of total flavonoid C-glycoside and the 3 flavonoid C-glycosides were significantly improved by verapamil, probenecid, and EDTA-Na2. Their absorption properties in the gastrointestinal tract were consistent with that found in Caco-2 cells, and superior absorption rates were observed in the duodenum and jejunum. The absorption pattern of total flavonoid C-glycoside may involve multiple transport pathways, including active transport, passive diffusion, and the paracellular pathway. TFC was actively pumped out by P-glycoprotein and multidrug resistance-associated protein. These results revealed that the bioaccessibility and intestinal absorption characteristic of total flavonoid C-glycoside were consistent with the 3 major flavonoids.

The isolation, structure and fragmentation characteristics of natural truxillic and truxinic acid derivatives in Abrus mollis leaves.

Five undescribed compounds were separated from Abrus mollis leaves, including two truxillate forms (abrusamide D, H) and three truxinate forms (abrusamide E, F, G). The absolute configuration of abrusamide D was determined by X-ray crystallography. Abrusamide A was reassessed and corrected to be ß-truxinate configuration rather than α-form. LC-MS/MS and CD spectroscopy were applied to determine and analyze ten compounds, including four truxillate forms (abrusamide B ~ D and H), four truxinate forms (abrusamide E ~ G and A), and two precursors [(E)-N-(4-hydroxycinnamoyl) tyrosine, (Z)-N-(4-hydroxycinnamoyl) tyrosine]. It showed that the fragmentation pattern of truxillate was symmetric, while that of truxinate was asymmetric and irregular. The CD Cotton effect was related to cyclobutane configuration. These findings provided strong evidence for the cyclobutane dimers to discriminate their configuration. In addition, the bioactivity assay showed that the compounds had low toxicity and anti-inflammatory effect.

Comparative therapeutic index, lethal time and safety margin of various toxicants and snake antivenoms using newly derived and old formulas.

OBJECTIVE: The assessment of clinical efficacy and toxicity is very important in pharmacology and toxicology. The effects of psychostimulants (e.g. amphetamine), psychotomimetics (e.g. Cannabis sativus) and snake antivenoms are sometimes unpredictable even at lower doses, leading to serious intoxication and fatal consequences. Hence, there is need to re-assess some formulas for calculation of therapeutic index, lethal time and safety margin with a view to identifying therapeutic agents with remarkable toxicity potentials. RESULTS: The therapeutic index formula [Formula: see text] was derived from T1 = LD50/ED50 and ED50 = [Formula: see text]. Findings have shown that, therapeutic index is a function of death reversal (s), safety factor (10-4) and weight of animal (Wa). However, the new safety margin formula [Formula: see text] derived from LT50 = [Formula: see text] and MS = [Formula: see text] shows that safety margin is a function of cube root of ratio between LT50 and LD50 and ED100th. Concentration (k) of toxicant at the receptor [Formula: see text] derived from D1 × Tn = K and LD1 = [Formula: see text] shows that therapeutic index, lethal time and safety margin is a function of drug or toxicant concentration at the receptor, the drug-receptor interaction and dose of toxicant or drug administered at a particular time.

Glucose lowering and pancreato-protective effects of Abrus Precatorius (L.) leaf extract in normoglycemic and STZ/Nicotinamide - Induced diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Abrus precatorius (L.) leaves are used as folk medicine by the local communities in the western region of Ghana to treat diabetes mellitus; however, this health claim remains unverified scientifically. OBJECTIVE: The study investigated glucose lowering and pancreato-protective effects of Abrus precatorius leaf extract (APLE) in normoglycemic and STZ/nicotinamide (NIC)-induced diabetic rats. METHOD: after preparation of APLE, it was subjected to phytochemical screening, proximate composition and elemental assessments by using standard methods. Oral glucose tolerance test (OGTT) and maltose, lactose and sucrose oral challenge were assessed in normoglycemic rats post-APLE. Morphological characteristics of glucose response curve (time of glucose peak and shape of glucose response curve) were determined. Subsequently, diabetes mellitus was experimentally established in normoglycaemic adult Sprague-Dawley rats (weighing 150-250 g) of both sexes by sequential injection of Streptozotocin (STZ, 60 mg/kg ip)-reconstituted in sodium citrate buffer and NIC (110 mg/kg ip)-reconstituted in normal saline (1:1 v/v) for 16 weeks. Except control rats (normal saline 5 ml/kg ip; baseline fasting blood glucose [FBG] of 6.48 mmol/L), rats having FBG (stable at 11.1 mmol/L or ≥ 250 mg/dL) 3 days post-STZ/NIC injection were randomly re-assigned to one of the following groups: model (STZ/NIC-induced diabetic rats), APLE (100, 200 and 400 mg/kg respectively po) and metformin (300 mg/kg po) and treated daily for 28 days. Bodyweight and FBG were measured on weekly basis. FBG was measured by using standard glucometers. On day 28, rats were sacrificed under chloroform anesthesia, blood collected via cardiac puncture; kidney, liver and pancreas surgically harvested. While the pancreas was processed, sectioned and H&E-stained for histological examination, fresh kidney and liver were homogenized for assessment of total anti-oxidant capacity. Median cross-sectional area of pancreatic islets of Langerhans was determined for each group by using Amscope. RESULTS: Cumulatively, APLE (100, 200 and 400 mg/kg respectively) dose-dependently decreased the initial FBG by 55.22, 76.15 and 77.77% respectively compared to model (-1.04%) and metformin (72.29%) groups. APLE treatment recovered damaged pancreatic ß-cells and also increased median cross-sectional area (x106 µm2) of pancreatic islets compared to that of model group. APLE significantly (P < 0.05) increased total anti-oxidant capacity (5.21 ± 0.02 AscAE µg/mL) of plasma, kidney and liver compared to model (4.06 ± 0.04 AscAE µg/mL) and metformin (4.87 ± 0.03 AscAE µg/mL) groups. CONCLUSION: APLE has demonstrated glucose lowering and pancreato-protective effects in rats and arrested the characteristic loss in bodyweight associated with diabetes mellitus. This finding preliminarily confirms folk use of APLE as an anti-diabetic herbal medicine, whiles providing a rationale for further translational studies on APLE.