Phytochemical investigation of Gynura bicolor leaves and cytotoxicity evaluation of the chemical constituents against HCT 116 cells

Novel compounds of Djulis (Chenopodium formosanum Koidz) increases collagen, antioxidants, inhibits adipogenesis

Djulis (Chenopodium formosanum Koidz), is rich in nutrients and contains various bioactive components such as polyphenols and alkaloids. The new compound has a broad application prospect, including food additives, health products, drugs, etc. The purpose of this study was to find out new compounds from Djulis. It was found that 24 compounds including 7 phenols, 11 flavonoids, 4 plant alkaloids, 2 sterols. Among those, TCI-CF-22-S (Methyl 3,6-dihydroxy-2-oxo-1,2,3,4-tetrahydroquinoline-3-carboxylate), TCI-CF-23-S (Methyl 6-hydroxy-2-oxo-1,2,3,4-tetrahydroquinoline-3-carboxylate), TCI-CF-24-S (Kaempferol-3-O-b-D-apifuranosyl-(1→2)-a-L-arabinopyranoside) were isolated from djulis sources for the first time, and the structures of compounds were assigned by 1D, 2D NMR spectroscopy. TCI-CF-01(Caffeic acid), TCI-CF-02 (20-Hydroxyecdysone), TCI-CF-03 (Japonicone), TCI-CF-04 (3,4-Dihydroxyphenylacetiate), TCI-CF-05 (Quercetin-3-O-rutinoside-7-O-rhamnopyranoside), TCI-CF-06 (Guanosine), TCI-CF-07(Adenine), TCI-CF-08 (Coumaric acid) increased collagen production, and TCI-CF-03 (Japonicone), TCI-CF-04 (3,4-Dihydroxyphenylacetiate), TCI-CF-06 (Guanosine), TCI-CF-17 (Rutin), TCI-CF-20 (Protocatechuic acid) decreased advanced glycation end products (AGEs). In addition, TCI-CF-22-S (Methyl 6-hydroxy-2-oxo-1,2,3,4-tetrahydroquinoline-3-carboxylate), TCI-CF-23-S (Methyl 3,6-dihydroxy-2-oxo-1,2,3,4-tetrahydroquinoline-3-carboxylate) inhibited the formation of fatty oil droplets. Djulis has 24 compounds that may have various applications, including increasing collagen production and reducing advanced glycation end products and fatty oil droplets.

Inula viscosa (L.) Aiton Ethanolic Extract Inhibits the Growth of Human AGS and A549 Cancer Cell Lines

The present study shows the chemical profile and cytotoxic properties of the ethanolic extracts of Inula viscosa from Northeast Algeria. The extract was obtained by maceration using ethanol. Its phenolic profile was determined using ultra-high-performance liquid chromatography coupled with a diode array detector and an electrospray mass spectrometer (UHPLC-DAD-ESI/MS), which allowed the identification and quantification of 17 compounds, 1,5-O-caffeoylquinic acid being the most abundant. The cytotoxic activity was assessed against human gastric cancer (AGS) and human non-small-cell lung cancer (A549) cell lines, whereas ethanolic extract elicited nearly 60 % and 40 % viability loss toward AGS and A549 cancer cells, respectively. Results also showed that cell death is caspase-independent and confirmed the involvement of RIPK1 and the necroptosis pathway in the toxicity induced by the I. viscosa extract. In addition, the ethanolic extract would not provoke morphological traits in the cancer cells. These findings suggest that I. viscosa can be a source of new antiproliferative drugs or used in preparation plant-derived pharmaceuticals.

Ethanol extract of Gynura bicolour reduces atherosclerosis risk by enhancing antioxidant capacity and reducing adhesion molecule levels

CONTEXT

Gynura bicolour (Roxb. and Willd.) DC (Asteraceae) leaf is a common vegetable. Ethanol extracts of fresh G. bicolour leaves (GBEE) have several physiological effects, but studies on atherosclerosis are limited.

OBJECTIVE

We investigated the oxidant scavenging ability and vascular adhesion molecule expression of these extracts.

MATERIALS AND METHODS

The antioxidant effects of 0.05-0.4 mg/mL GBEE were analyzed in vitro. Intracellular antioxidant capacity and adhesion molecule levels were detected in EA.hy926 cells pre-treated with 10-100 μg/mL GBEE for 8 h, then TNF-α for 3 h. The antioxidant capacity of red blood cells and the adhesion molecule levels in the thoracic aorta were detected in high-fat diet (HFD)-fed Sprague-Dawley rats treated with GBEE for 12 weeks.

RESULTS

The in vitro EC₅₀ values of GBEE based on its DPPH radical-scavenging ability, reducing power, and ferrous ion-chelating ability were 0.20, 3.21 and 0.49 mg/mL, respectively. In TNF-α-treated EA.hy926 cells, the thiobarbituric acid-reactive substance levels were decreased after 10, 50, or 100 μg/mL GBEE treatments (IC₅₀: 19.1 mg/mL). When HFD-fed rats were co-treated with GBEE, the GBEE-H group exhibited 25% higher glutathione levels than the HFD group (p < 0.05). E-selectin, intercellular adhesion molecule-1, and vascular cell adhesion protein-1 levels were decreased in TNF-α-treated EA.hy926 cells after GBEE treatment (by approximately 11-73%; p < 0.05), and the above three adhesion molecules levels were decreased in HFD-fed rats with combined GBEE treatment (by approximately 30-77%; p < 0.05).

CONCLUSIONS

GBEE can protect the vascular endothelium by reducing adhesion molecule expression and regulating antioxidants. It may have the potential to prevent atherosclerosis.

Review On Documented Medicinal Plants Used For The Treatment Of Cancer

Background:

Cancer is a frightful disease and it is the second leading cause of death worldwide. Naturally derived compounds are gaining interest of research workers as they have less toxic side effects as compared to currently used treatments such as chemotherapy. Plants are the pool of chemical compounds which provides a promising future for research on cancer.

Objective:

This review paper provides updated information gathered on medicinal plants and isolated phytoconstituents used as anticancer agents and summarises the plant extracts and their isolated chemical constituents exhibiting anticancer potential on clinical trials.

Methods:

An extensive bibliographic investigation was carried out by analysing worldwide established scientific databases like SCOPUS, PUBMED, SCIELO, ScienceDirect, Springerlink, Web of Science, Wiley, SciFinder and Google Scholar etc. In next few decades, herbal medicine may become a new epoch of medical system.

Results:

Many researches are going on medicinal plants for the treatment of cancer but it is a time to increase further experimental studies on plant extracts and their chemical constituents to find out their mechanism of action at molecular level.

Conclusion:

The article may help many researchers to start off further experimentation that might lead to the drugs for the cancer treatment.

Caffeoylquinic acids: chemistry, biosynthesis, occurrence, analytical challenges, and bioactivity

Caffeoylquinic acids (CQAs) are specialized plant metabolites we encounter in our daily life. Humans consume CQAs in mg-to-gram quantities through dietary consumption of plant products. CQAs are considered beneficial for human health, mainly due to their anti-inflammatory and antioxidant properties. Recently, new biosynthetic pathways via a peroxidase-type p-coumaric acid 3-hydroxylase enzyme were discovered. More recently, a new GDSL lipase-like enzyme able to transform monoCQAs into diCQA was identified in Ipomoea batatas. CQAs were recently linked to memory improvement; they seem to be strong indirect antioxidants via Nrf2 activation. However, there is a prevalent confusion in the designation and nomenclature of different CQA isomers. Such inconsistencies are critical and complicate bioactivity assessment since different isomers differ in bioactivity and potency. A detailed explanation regarding the origin of such confusion is provided, and a recommendation to unify nomenclature is suggested. Furthermore, for studies on CQA bioactivity, plant-based laboratory animal diets contain CQAs, which makes it difficult to include proper control groups for comparison. Therefore, a synthetic diet free of CQAs is advised to avoid interferences since some CQAs may produce bioactivity even at nanomolar levels. Biotransformation of CQAs by gut microbiota, the discovery of new enzymatic biosynthetic and metabolic pathways, dietary assessment, and assessment of biological properties with potential for drug development are areas of active, ongoing research. This review is focused on the chemistry, biosynthesis, occurrence, analytical challenges, and bioactivity recently reported for mono-, di-, tri-, and tetraCQAs.

Traditional uses, phytochemistry, pharmacology and toxicology of the genus Gynura (Compositae): A comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

Gynura cass., belonging to the tribe Senecoineae of the family Compositae, contains more than 40 accepted species as annual or perennial herbs, mainly distributed in Asia, Africa and Australia. Among them, 11 species are distributed in China. Many of the Gynura species have been used as traditional herbal medicines for the treatment of diabetes mellitus, rheumatism, eruptive fever, gastric ulcer, bleeding, abscesses, bruises, burning pains, rashes and herpes zoster infection in tropical Asia countries such as China, Thailand, Indonesia, Malaysia, and Vietnam. Some of the species have been used as vegetables, tea beverage or ornamental plants by the local people.

AIM OF THE STUDY

A more comprehensive and in-depth review about the geographical distribution, traditional uses, chemical constituents and pharmacological activities as well as safe and toxicity of Gynura species has been summarized, hoping to provide a scientific basis for rational development and utilization as well as to foster further research of these important medicinal plant resources in the future.

MATERIALS AND METHODS

A review of the literature was performed based on the existing peer-reviewed researches by consulting scientific databases including Web of Science, PubMed, Elsevier, Google Scholar, SciFinder and China National Knowledge Infrastructure.

RESULTS

Many of the Gynura species have been phytochemically studied, which led to the isolation of more than 338 compounds including phenolics, flavonoids, alkaloids, terpenoids, steroids, cerebrosides, aliphatics and other compounds. Pharmacological studies in vitro and in vivo have also confirmed the various bioactive potentials of extracts or pure compounds from many Gynura plants, based on their claimed ethnomedicinal and anecdotal uses, including antioxidant, anti-inflammation, anticancer, antidiabetic, antihypertension, antibacterial and other activities. However, pyrrolizidine alkaloids (PAs) pose a threat to the medication safety and edible security of Gynura plants because of toxicity issues, requiring the need to pay great attention to this phenomenon.

CONCLUSION

The traditional uses, phytochemistry and pharmacology of Gynura species described in this review demonstrated that these plants contain a great number of active constituents and display a diversity of pharmacological activities. However, the mechanism of action, structure-activity relationship, potential synergistic effects and pharmacokinetics of these components need to be further elucidated. Moreover, further detailed research is urgently needed to explain the mechanisms of toxicity induced by PAs. In this respect, effective detoxification strategies need to be worked out, so as to support the safe and reasonable utilization of Gynura plant resources in the future.

Ethnomedicinal uses, phytochemistry, and biological activities of plants of the genus Gynura

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Gynura (Compositae) includes around 46 species and is native to the tropical regions of Southeast Asia, Africa and Australia. Many species within this genus are used in ethnomedicine to treat various disorders including skin diseases, injuries, ulcers, wounds, burns, sores, scalds, as well as for the management of diabetes, hypertension, hyperlipidemia, constipation, rheumatism, bronchitis and inflammation.

AIM OF THE REVIEW

This review is an attempt to provide scientific information regarding the ethnopharmacology, phytochemistry, pharmacological and toxicological profiles of Gynura species along with the nomenclature, distribution, taxonomy and botanical features of the genus. A critical analysis has been undertaken to understand the current and future pharmaceutical prospects of the genus.

MATERIALS & METHODS

Several electronic databases, including Google scholar, PubMed, Web of Science, Scopus, ScienceDirect, SpringerLink, Semantic Scholar, MEDLINE and CNKI Scholar, were explored as information sources. The Plant List Index was used for taxonomical authentications. SciFinder and PubChem assisted in the verification of chemical structures.

RESULTS

A large number of phytochemical analyses on Gynura have revealed the presence of around 342 phytoconstituents including pyrrolizidine alkaloids, phenolic compounds, chromanones, phenylpropanoid glycosides, flavonoids, flavonoid glycosides, steroids, steroidal glycosides, cerebrosides, carotenoids, triterpenes, mono- and sesquiterpenes, norisoprenoids, oligosaccharides, polysaccharides and proteins. Several in vitro and in vivo studies have demonstrated the pharmacological potential of Gynura species, including antidiabetic, anti-oxidant, anti-inflammatory, antimicrobial, antihypertensive and anticancer activities. Although the presence of pyrrolizidine alkaloids within a few species has been associated with possible hepatotoxicity, most of the common species have a good safety profile.

CONCLUSIONS

The importance of the genus Gynura both as a prominent contributor in ethnomedicinal systems as well as a source of promising bioactive molecules is evident. Only about one fourth of Gynura species have been studied so far. This review aims to provide some scientific basis for future endeavors, including in-depth biological and chemical investigations into already studied species as well as other lesser known species of Gynura.

Suppressive Effects of the Gynura bicolor Ether Extract on Endothelial Permeability and Leukocyte Transmigration in Human Endothelial Cells Induced by TNF-α

Gynura bicolor (Roxb. and Willd.) DC (G. bicolor) is generally used as a dietary vegetable and traditional herb in Taiwan and the Far East. G. bicolor exerts antioxidant and anti-inflammatory effects and regulates blood lipids and cholesterol. However, the effects of G. bicolor on endothelial transmigration and atherosclerosis are not clear. The present study investigated the effects of G. bicolor on endothelial permeability and transmigration in human endothelial cells. We prepared G. bicolor ether extract (GBEE) for use as the experimental material. Under TNF-α stimulation, HL-60 cell adherence to EA.hy926 cells, the shape of EA.hy926 cells, and the expression of adhesion molecules and transmigration-related regulatory molecules were analysed after pretreatment with GBEE for 24 h. GBEE inhibited leukocyte adhesion to endothelial cells, reduced intercellular adhesion molecule-1 (ICAM-1) and platelet endothelial cell adhesion molecule-1 (PECAM-1) expressions, and decreased endothelial monolayer permeability. GBEE also reduced paracellular transmigration by reducing the levels of reactive oxygen species (ROS), Src phosphorylation, and vascular endothelial-cadherin (VE-cadherin) phosphorylation. GBEE reduced transcellular migration via inhibition of Ras homolog family member A (RhoA) and Rho-associated protein kinase (ROCK) expression and phosphorylation of the ezrin-radixin-moesin (ERM) protein. Incubation of EA.hy926 cells with GBEE for 8 h and stimulation with TNF-α for 3 h reduced the phosphorylation of the inhibitor of kappa B (IĸB) and DNA-binding activity of nuclear factor-ĸB (NF-ĸB). These results suggest that GBEE has a protective effect against endothelial dysfunction via suppression of leukocyte-endothelium adhesion and transmigration.

A new steroidal alkaloid from Fritillaria michailovskyi Fomin

A new steroidal alkaloid, michainine (1), was isolated from Fritillaria michailovskyi Fomin, along with nine known compounds 2-10 of different classes, including ribonucleoside, steroids, and fatty acids, which were isolated for the first time from this plant. Their structures were elucidated through extensive spectroscopic techniques, as well as by comparing the data in the literature. Furthermore, the dichloromethane fraction of F. michailovskyi showed a positive butyrylcholinesterase inhibitory activity, along with non-cytotoxicity against 3T3 cell line.

Potential Effects of Antioxidant and Serum Cholesterol-Lowering Effects ofGynura bicolorWater Extracts in Syrian Hamster

Gynura bicolor(Roxb. and Willd.) DC (G. bicolor) is a dietary vegetable in the Far East. The aims of the present study were to investigate the antioxidant effects of theG. bicolorwater extract (GBWE) and its ability to regulate the blood lipid and lipoprotein profiles. In this study, the pigment composition and antioxidant ability of the GBWE were analyzed. Syrian hamsters were fed a high-fat diet (HFD) and the GBWE for 12 weeks, and the blood lipid levels, lipoprotein profiles, and cholesterol metabolism-related enzyme levels were then examined. The results showed that the GBWE exhibited excellent 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity and ferrous-ion-chelating ability. The hepatic glutathione levels in the hamsters were increased after the administration of low (0.4 g/kg BW, GBWE-L) or high (0.8 g/kg BW, GBWE-H) levels of the GBWE. The GBWE-H-treated hamsters exhibited significantly decreased serum levels of total cholesterols (TC) and low-density lipoprotein-cholesterol (LDL-C) and significantly increased levels of lectin-cholesterol acetyltransferase (LCAT). These results showed that GBWE-H can reduce the total cholesterol and LDL-C levels in HFD-fed hamsters, and this reduction might be involved in the regulation of LCAT expression.

Caffeoylquinic Acids: Separation Method, Antiradical Properties and Cytotoxicity

Twelve chlorogenic acid derivatives and two flavones were isolated from Moquiniastrum floribundum (Asteraceae, other name: Gochnatia floribunda). Compounds were evaluated in relation to their cytotoxicity and antiradical properties. Cytotoxicity was not observed for compounds, however, chlorogenic acid derivatives showed antiradical activity and were more active than the Trolox standard. Quinic acid esterified with caffeoyl group at C-4 position showed higher antiradical activity compared to acylation at C-3 or C-5 positions. Additional caffeoyl groups esterified in quinic acid increase the antiradical activity observed for 4-caffeoylquinic acid. Excepted to 3,4-dicaffeoylquinic acid methyl ester, methyl ester derivatives show higher capacity of trapping radicals than their respective acids. Consequently, the presence of caffeoyl group at C-4 position of quinic acid is suggested as fundamental to obtain the highest antiradical activity.

Chemopreventive Effects of Strawberry and Black Raspberry on Colorectal Cancer in Inflammatory Bowel Disease

Colorectal cancer (CRC) remains the third most common cause of cancer-related death in the United States and the fourth globally with a rising incidence. Inflammatory bowel disease (IBD) is a chronic immunologically mediated disease that imposes a significant associated health burden, including the increased risk for colonic dysplasia and CRC. Carcinogenesis has been attributed to chronic inflammation and associated with oxidative stress, genomic instability, and immune effectors as well as the cytokine dysregulation and activation of the nuclear factor kappa B (NFκB) signaling pathway. Current anti-inflammation therapies used for IBD treatment have shown limited effects on CRC chemoprevention, and their long-term toxicity has limited their clinical application. However, natural food-based prevention approaches may offer significant cancer prevention effects with very low toxicity profiles. In particular, in preclinical and clinical pilot studies, strawberry and black raspberry have been widely selected as food-based interventions because of their potent preventive activities. In this review, we summarize the roles of strawberry, black raspberry, and their polyphenol components on CRC chemoprevention in IBD.

Gynura bicolor aqueous extract attenuated H2O2 induced injury in PC12 cells

BACKGROUND

Protective effects of Gynura bicolor aqueous extract (GAE) at three concentrations upon nerve growth factor (NGF) differentiated-PC12 cells against H₂O₂ induced injury were examined.

METHODS

NGF differentiated-PC12 cells were treated with GAE at 0.25%, 0.5% or 1%. 100 μM H₂O₂ was used to treat cells with GAE pre-treatments. After incubating at 37 °C for 12 hr, experimental analyses were processed.

RESULTS

H₂O₂ exposure decreased cell viability, increased plasma membrane damage, suppressed Bcl-2 mRNA expression and enhanced Bax mRNA expression. GAE pre-treatments reversed these changes. H₂O₂ exposure reduced mitochondrial membrane potential, lowered Na⁺-K⁺-ATPase activity, and increased DNA fragmentation and Ca²⁺ release. GAE pre-treatments attenuated these alterations. H₂O₂ stimulated the production of reactive oxygen species (ROS), interleukin (IL)-1beta, IL-6 and tumor necrosis factor-alpha, lowered glutathione content, and reduced glutathione peroxidase (GPX) and catalase activities. GAE pretreatments maintained GPX and catalase activities; and concentration-dependently diminished the generation of ROS and inflammatory cytokines. H₂O₂ enhanced mRNA expression of nuclear factor kappa (NF-κ) B and p38. GAE pre-treatments decreased mRNA expression of NF-κB and p38.

CONCLUSION

These findings suggested that GAE might be a potent neuronal protective agent.

Anti-Diabetic Effects of Gynura Bicolor Aqueous Extract in Mice

The effects of Gynura bicolor aqueous extract (GAE) upon glycemic control, coagulation disorder, lipid accumulation, and glycative, oxidative, and inflammatory stresses in diabetic mice were investigated. Mice were treated with streptozotocin to induce type 1 diabetes. Diabetic mice were divided into four groups, consumed GAE at 0%, 0.25%, 0.5%, or 1%. Normal group consumed standard mouse basal diet. After 8-week treatments, mice were sacrificed after overnight fasting. Results showed that GAE supplement at 0.5% and 1% decreased plasma glucose level and increased plasma insulin level. Diabetes lowered plasma level of protein C and anti-thrombin III; and raised plasminogen activator inhibitor-1 activity and fibrinogen level in plasma. GAE supplement at 0.5% and 1% reversed these alterations. Histological data, assayed by Oil Red O stain, indicated that GAE supplement decreased lipid accumulation in liver. GAE supplement at 0.5% and 1% reduced aldose reductase activity in heart and kidney; and lowered the levels of carboxymethyllysine and pentosidine in plasma and two organs. Diabetes decreased glutathione content, and increased reactive oxygen species, interleukin (IL)-1β, IL-6, and tumor necrosis factor-α production in heart and kidney. GAE supplement at three test doses reversed these changes. Diabetes upregulated the mRNA expression of p38 and nuclear factor kappa (NF-κ)B in heart and kidney. GAE supplement suppressed the mRNA expression of both p38 and NF-κB. These novel findings suggest that Gynura bicolor is a potent functional food for diabetic prevention or alleviation.

Pyrrolizidine Alkaloids: Biosynthesis, Biological Activities and Occurrence in Crop Plants

Pyrrolizidine alkaloids (PAs) are heterocyclic secondary metabolites with a typical pyrrolizidine motif predominantly produced by plants as defense chemicals against herbivores. They display a wide structural diversity and occur in a vast number of species with novel structures and occurrences continuously being discovered. These alkaloids exhibit strong hepatotoxic, genotoxic, cytotoxic, tumorigenic, and neurotoxic activities, and thereby pose a serious threat to the health of humans since they are known contaminants of foods including grain, milk, honey, and eggs, as well as plant derived pharmaceuticals and food supplements. Livestock and fodder can be affected due to PA-containing plants on pastures and fields. Despite their importance as toxic contaminants of agricultural products, there is limited knowledge about their biosynthesis. While the intermediates were well defined by feeding experiments, only one enzyme involved in PA biosynthesis has been characterized so far, the homospermidine synthase catalyzing the first committed step in PA biosynthesis. This review gives an overview about structural diversity of PAs, biosynthetic pathways of necine base, and necic acid formation and how PA accumulation is regulated. Furthermore, we discuss their role in plant ecology and their modes of toxicity towards humans and animals. Finally, several examples of PA-producing crop plants are discussed.

Aqueous Extract of Gynura Bicolor Attenuated Hepatic Steatosis, Glycative, Oxidative, and Inflammatory Injury Induced by Chronic Ethanol Consumption in Mice

Gynura bicolor leaf aqueous extract (GAE) is rich in phytochemicals including phenolic acids, flavonoids, carotenoids, and anthocyanins. Effects of GAE upon hepatic injury in mice with chronic ethanol intake were examined. Lieber-DeCarli liquid diet with ethanol was used to induce hepatic lipid accumulation, oxidative, glycative, and inflammatory injury. GAE at 0.25% or 0.5% was added in feeds, and supplied to mice consumed Lieber-DeCarli liquid diet with ethanol for 6 wk. Blood and liver were collected for analyses. Results showed that ethanol increased plasma and hepatic triglyceride and cholesterol content, and affected plasma levels of insulin, adiponectin, leptin, and ghrelin. GAE at both doses decreased lipid accumulation, and at high dose improved hormones abnormality. Histological data revealed that GAE supplement mitigated hepatic lipid deposit. Ethanol increased plasma N^ε -(carboxyethymethyl)-lysine and pentosidine levels. GAE at high doses lowered those glycative factors. Ethanol depleted glutathione content, increased CYP2E1 activity and reactive oxygen species production, and reduced the activity of glutathione peroxide, glutathione reductase and catalase in liver. GAE supplement at both doses reversed these alterations and attenuated hepatic oxidative stress. GAE supplement also at both doses decreased hepatic inflammatory cytokines release in ethanol treated mice. These findings support that leaves of G. bicolor is a functional food with liver protective activities against ethanol.

Computational Analysis of Gynura bicolor Bioactive Compounds as Dipeptidyl Peptidase-IV Inhibitor

The inhibition of dipeptidyl peptidase-IV (DPPIV) is a popular route for the treatment of type-2 diabetes. Commercially available gliptin-based drugs such as sitagliptin, anagliptin, linagliptin, saxagliptin, and alogliptin were specifically developed as DPPIV inhibitors for diabetic patients. The use of Gynura bicolor in treating diabetes had been reported in various in vitro experiments. However, an understanding of the inhibitory actions of G. bicolor bioactive compounds on DPPIV is still lacking and this may provide crucial information for the development of more potent and natural sources of DPPIV inhibitors. Evaluation of G. bicolor bioactive compounds for potent DPPIV inhibitors was computationally conducted using Lead IT and iGEMDOCK software, and the best free-binding energy scores for G. bicolor bioactive compounds were evaluated in comparison with the commercial DPPIV inhibitors, sitagliptin, anagliptin, linagliptin, saxagliptin, and alogliptin. Drug-likeness and absorption, distribution, metabolism, and excretion (ADME) analysis were also performed. Based on molecular docking analysis, four of the identified bioactive compounds in G. bicolor, 3-caffeoylquinic acid, 5-O-caffeoylquinic acid, 3,4-dicaffeoylquinic acid, and trans-5-p-coumaroylquinic acid, resulted in lower free-binding energy scores when compared with two of the commercially available gliptin inhibitors. The results revealed that bioactive compounds in G. bicolor are potential natural inhibitors of DPPIV.

Antiproliferation effect of guanosine on HCT 116 cells involves MAPK and AMPK pathways

This study aims to investigate the mechanisms associated with the antiproliferation effect of guanosine on human colon carcinoma HCT 116 cells. In this study, guanosine induced more drastic cell cycle arrest effect than cell death effect on HCT 116 cells. The cell cycle arrest effect of guanosine on HCT 116 cells appeared to be associated with the increased activation of mitogen-activated protein kinases (MAPK) such as ERK1/2, p38 and JNK. The decrease of AMP-activated protein kinase (AMPK) activation and cyclin D1 expression was also involved. Thus, the antiproliferation of colon cancer cells of guanosine could be mediated by the disruption of MAPK and AMPK pathways.