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Malaria remains a critical global health issue, particularly in tropical and subtropical regions. The disease, caused by Plasmodium parasites, is transmitted by Anopheles mosquitoes and can lead to severe complications and death if untreated. The emergence of drug‐resistant strains highlights the urgent need for new antimalarial agents. Gnetum gnemon, a plant native to Southeast Asia, has shown promise due to its rich bioactive compounds. This study aims to evaluate the suppressive, curative, and prophylactic antimalarial potential of Gnetum gnemon leaf extract (GGE) against Plasmodium berghei in mice. GGE was prepared using a combination of hot water extraction and microwave‐assisted heating. Acute toxicity tests revealed no significant adverse effects at a dose of 3000 mg/kg. The doses of 100, 200, and 400 mg/kg were selected based on preliminary toxicity assessments to systematically investigate the dose‐dependent antimalarial efficacy of the extract. Suppressive tests showed that GGE at doses of 100, 200, and 400 mg/kg significantly reduced parasitemia levels, with the highest dose achieving a 63.97% inhibition. In these tests, GGE also increased the mean survival time (MST) of treated mice compared to untreated controls. However, GGE did not exhibit significant curative effects, as parasitemia levels in the treated groups were similar to the untreated control group. Prophylactic tests indicated that GGE pretreatment did not significantly reduce parasitemia levels or improve MST compared to controls, unlike chloroquine (CQ), which demonstrated potent prophylactic efficacy with a significant increase in MST. These findings suggest that while GGE has notable suppressive antimalarial activity, it does not exhibit strong curative or prophylactic effects at the tested doses. This study contributes to the understanding of plant‐based antimalarial agents and underscores the importance of continued exploration of natural products for malaria treatment. [ABSTRACT FROM AUTHOR]

Seed storage proteins are a major protein source due to their readily available bioactive peptides. Melinjo (Gnetum gnemon L) seeds have a promising potential for massive production in Indonesia because of their high protein content. The composition and protein content of these seeds depends on their stage of maturity. This study investigated the effect of melinjo seed proteins at green (GG), yellow (YG), and red (RG) stages of maturity on their antioxidant and antidiabetic activities. Also, this study aimed to determine seed maturity's impact and identify the seeds most active stage on free radical scavenging (antioxidant) and antidiabetic activity. This study analyzed the amino acid composition, protein profiles, free radical scavenging, and in vitro antidiabetic activities of GG, YG, and RG seed proteins. The concentration of amino acids in melinjo seed samples was 0.36-9.69 g/100 g protein, with the total amino acid content in GG seeds (59.92 g/100 g protein) being significantly higher than in YG (53.91 g/100 g protein) or RG (52.79 g/100 g protein) seeds. The protein from GG seeds also exhibited significantly (p<0.05) higher free radical scavenging and in vitro antidiabetic activities than YG or RG seeds. The free radical scavenging activities were measured using ABTS, hydroxyl radical, and superoxide radical assays. The antidiabetic activity was assessed based on α-amylase and α-glucosidase inhibitory activities. The results indicated that the maturity stage of the seed proteins significantly affected (p<0.05) free radical scavenging and in vitro antidiabetic activities. GG seed protein showed high potential as an antioxidant and antidiabetic agent, suggesting its possible use in future nutraceuticals and human health applications. [ABSTRACT FROM AUTHOR]

The fermentation effects of melinjo (Gnetum gnemon) seed flour on the physicochemical and retrogradation properties were investigated. Fermented melinjo seed flour (FMF) was prepared using a Lactobacillus fermentum. The DSC and RVA were used to evaluate the properties of the samples. The results indicated that FMF had a higher significant (P<0.05) value for gelatinization temperature and enthalpy but lower values in the starch-lipid temperature, enthalpy, and viscosity peak than the unfermented sample (UMF). X-ray diffraction demonstrated that fermentation resulted had little effect and the crystalline pattern cannot be changed (type A), but it was shown that a crystalline region ratio to region amorphous increased from 30.9 to 36.66%. The FTIR spectra showed that FMF and UMF were identical. Furthermore, the observation of the FMF using a SEM showed that starch granules had slight superficial corrosion, but UMF has a smooth outer surface. The retrogradation rate (k) of UMF was slowed (0.63 day- 1) when compared with the FMF (0.68 day-1). Thus, fermentation may alter starch amorphous region and chemical components, eventually transforming the physicochemical and retrogradation characteristics of melinjo seed flour. [ABSTRACT FROM AUTHOR]

Liang (Gnetum gnemon var. tenerum) leaves are widely consumed as a green vegetable in Southern Thailand, and the plant is valued for its nutritional benefits. However, like other leafy greens, liang is vulnerable to microbial contamination, generating foodborne illnesses. This study examined the nutritional content and microbial load of liang leaves at different maturity stages and the effects of washing with chlorinated water. Various growth stages were analysed for proximate composition, amino acids, vitamins, and minerals. Results revealed distinct nutritional profiles, with tip leaves rich in protein and fat and intermediate leaves high in dietary fibre. Liang leaves are abundant in essential amino acids and proteins. Washing with chlorinated water increased leaf weight due to water retention but also caused physical damage, fostering microbial growth and spoilage. Microbiological analysis showed marginal reductions in total viable counts after washing with chlorinated water and significant decreases in coliform and Escherichia coli counts. However, stem detachment during washing increased the coliform and E. coli counts. Liang leaves exhibited favourable nutritional content, especially in the intermediate stage. Proper handling and storage of liang leaves are crucial to preventing physical damage and microbial contamination. Improved food safety measures, including appropriate post-harvest washing and handling of leafy vegetables, will ensure that consumers can safely enjoy the nutritional benefits of liang leaves. [ABSTRACT FROM AUTHOR]

Functional foods are ingredients which provide health benefits. Gnetum gnemon Linn (melinjo) seeds contain bioactive compounds with extremely high antioxidant activity and are considered to have the potential to be used as raw materials for functional food. The utilization of melinjo seeds as functional food ingredients must consider the general and specific quality standards to ensure the generated products deliver the intended health benefits. The purpose of this study was to determine the specific and nonspecific quality parameters of commercial melinjo products in the form of extracts and flour as well as evaluate its antioxidant capacity as functional food raw materials. The nonspecific parameters evaluated include drying loss, microbial contamination, moisture, total ash, insoluble acid ash, extract yield, fat, and crude fiber. The specific parameters tested were phenolic and flavonoid content, water- and ethanol-soluble compounds, and marker compounds. The results showed that the nonspecific parameter values extract and flour of melinjo seed met the standard's provisions. Analysis of specific parameters showed that the extract was dark brown in the form of a thick paste, while flour was light brown powdery. Both have a distinctive odor with a slightly bitter taste. The phenolic and flavonoid content of the extract was higher than that of the flour. To the contrary, the water- and ethanol-soluble compounds of the extract were lower than that of the flour. Resveratrol, one of the marker compounds in melinjo seeds, was identified by TLC and HPLC. The melinjo seed extract was found to have strong antioxidant activity with IC50 value of 1.45 mg/ml. On the basis of the nonspecific and specific parameter values together with the antioxidant activity it was concluded that the melinjo seed extract has high potential to be used as a raw material for functional food. [ABSTRACT FROM AUTHOR]

The aim of this study is to assess how gamma irradiation affects the chemical profiles of medicinal plants. Two different forms; methanol leaf extracts and dried leaves, of the three medicinal plants were investigated. Utilising FTIR, HPLC, and LCMS techniques, the qualitative measurement of gallic acid (GA) in three different medicinal plants for both plant extract and dried plant before and after the gamma radiation treatment was carried out. In the meantime, HPLC has been used to do a quantitative analysis of GA in these plants in order to show the percentage concentration of phenolic acid. For these medicinal herbs, the FTIR study revealed that both plant extract and dried plant had comparable functional groups both before and after gamma radiation therapy. The chromatogram of the HPLC profile for these medicinal plants was similar in chemical constituents before and after gamma irradiation, but the samples that were treated with gamma irradiation had a slight increase in intensity (between 0.0002-0.0009 Au). Additionally, gamma irradiation at levels of 6-12 kGy and 9-13 kGy caused the mass peak of GA to deteriorate in mass spectrometry analysis. Furthermore, the percentage concentration of GA increased significantly as the gamma radiation dose increased for both forms. [ABSTRACT FROM AUTHOR]

Liang or Gnetum gnemon var. tenerum, an indigenous southern vegetable has recently attracted increasing interest due to its high nutritional value, creamy taste and lack of smell. The leaves with or without stem are washed with chlorinated water at 100 ppm for 15 min, stored at 4°C and investigated for physiochemical, chemical and sensory evaluations over time. Total phenolic and flavonoid contents were higher in treatments with stems (P < 0.05). Washing significantly increased moisture content and water activity (aw) in all treatments (P < 0.05). In addition, washing resulted in significantly higher DPPH and ABTS activity (P < 0.05). However, washing and stem detachment had no effect on sensory and physicochemical qualities. The sensory score of the 8-days stored sample was comparable to the fresh one (Day 0). [ABSTRACT FROM AUTHOR]

To enhance the tenderness of meat, it can be accomplished physically or chemically. In chemical way, the process can be accomplished using protease enzymes that can be obtained from fruit, the higher the protease enzyme activity, the softer the meat. In this experiment, the extract and juice of melinjo skin (Gnetum gnemon L) was used to examine the protease enzyme activity. Papaya (Carica papaya) and pineapple (Ananas comosus) were used as a comparison. The research was conducted to understand the influence of incubation time (t) and incubation temperature (To) towards the optimum activity characteristic of protease enzyme on the juice and the extract of melinjo skin, papaya and pineapple. The incubation time of juice and extract was from 0 to 90 minutes with incubation temperature of 37°C and incubation time at 20 minutes with incubation temperature range from 20 to 80°C. The protease enzyme activity of juice and extract expand significantly (p<0.05) in conjunction with the increase of incubation time and temperature. The research results revealed that the maximum activity of protease enzyme detected at incubation time of 90 minutes for melinjo juice and pineapple skin, and 10 minutes for papaya. The optimum incubation temperature of melinjo skin at 70°C, papaya at 60°C and pineapple juice at 60°C. Meanwhile, the maximum activity of protease enzyme from melinjo extract identified in the incubation time at 80 minutes, papaya at 90 minutes and pineapple 60 minutes, whereas the incubation temperature of melinjo skin juice at 60°C, papaya at 80°C and pineapple at 30°C. [ABSTRACT FROM AUTHOR]

Liang (Gnetum gnemon var. tenerum) leaves are widely consumed as a green vegetable in Southern Thailand, and the plant is valued for its nutritional benefits. However, like other leafy greens, liang is vulnerable to microbial contamination, generating foodborne illnesses. This study examined the nutritional content and microbial load of liang leaves at different maturity stages and the effects of washing with chlorinated water. Various growth stages were analysed for proximate composition, amino acids, vitamins, and minerals. Results revealed distinct nutritional profiles, with tip leaves rich in protein and fat and intermediate leaves high in dietary fibre. Liang leaves are abundant in essential amino acids and proteins. Washing with chlorinated water increased leaf weight due to water retention but also caused physical damage, fostering microbial growth and spoilage. Microbiological analysis showed marginal reductions in total viable counts after washing with chlorinated water and significant decreases in coliform and Escherichia coli counts. However, stem detachment during washing increased the coliform and E. coli counts. Liang leaves exhibited favourable nutritional content, especially in the intermediate stage. Proper handling and storage of liang leaves are crucial to preventing physical damage and microbial contamination. Improved food safety measures, including appropriate post-harvest washing and handling of leafy vegetables, will ensure that consumers can safely enjoy the nutritional benefits of liang leaves.

Wild edible plants are often found to be rich sources of nutrients and medicinally beneficial compounds with pharmacological activities. Gnetum gnemon is a nutritionally important plant and a popular food source in parts of Assam and North-East India. Various microRNAs (miRNAs) have been recently identified in many plants; how ever, there are no records of identification of miRNAs in any species of Gnetum. The prediction of miRNA-target associations in G. gnemon is an important step to facilitate functional genomics studies in this species. In the present study, all known miRNAs from plants available in public domain were used to search for the conserved G. gnemon miRNA homologues in publicly accessible expressed sequence tags (ESTs) in NCBI database. An aggregate of 20 new potential miRNAs belonging to two diverse miRNA families (miR399 and miR5021) were identified through a homology-based search by following stringent filtering criteria. To investigate the potential cross-king dom effects of the identified miRNAs, we further identified the putative target genes of G. gnemon miRNAs in hu man transcriptome and analyzed them against the NCBI non-redundant protein database. The KEGG analysis of the target genes indicated that these genes were involved in different metabolic pathways such as caffeine meta bolism, drug metabolism, and nitrotoluene degradation. The target genes of G. gnemon miRNAs in humans were found to be associated with various disorders of both hereditary and non-hereditary origin. These results could help to shed new light on understanding of miRNA-mRNAs functional networks in this species and its po tential use as a small RNA-based therapy against some human diseases.

Wild edible plants are often found to be rich sources of nutrients and medicinally beneficial compounds with pharmacological activities. Gnetum gnemon is a nutritionally important plant and a popular food source in parts of Assam and North-East India. Various microRNAs (miRNAs) have been recently identified in many plants; however, there are no records of identification of miRNAs in any species of Gnetum. The prediction of miRNA-target associations in G. gnemon is an important step to facilitate functional genomics studies in this species. In the present study, all known miRNAs from plants available in public domain were used to search for the conserved G. gnemon miRNA homologues in publicly accessible expressed sequence tags (ESTs) in NCBI database. An aggregate of 20 new potential miRNAs belonging to two diverse miRNA families (miR399 and miR5021) were identified through a homology-based search by following stringent filtering criteria. To investigate the potential cross-kingdom effects of the identified miRNAs, we further identified the putative target genes of G. gnemon miRNAs in human transcriptome and analyzed them against the NCBI non-redundant protein database. The KEGG analysis of the target genes indicated that these genes were involved in different metabolic pathways such as caffeine metabolism, drug metabolism, and nitrotoluene degradation. The target genes of G. gnemon miRNAs in humans were found to be associated with various disorders of both hereditary and non-hereditary origin. These results could help to shed new light on understanding of miRNA-mRNAs functional networks in this species and its potential use as a small RNA-based therapy against some human diseases. [ABSTRACT FROM AUTHOR]

The purpose of the research is to study the effect of the use of videos and e-module to understand the production of briquettes from melinjo (Gnetum gnemon) shell with various particle sizes and binder concentrations for vocational school students. The production of melinjo skin briquettes is conducted using two factors of the completely randomized design (particle size and concentration of tapioca). The study of the briquettes characteristics conducted is compressed density, relaxed density, relaxation ratio, percentage of moisture content, burning rate, specific fuel consumption, percentage of resistance index, and percentage of durability index. The learning process used a quasi-experimental method (One-group pretest-posttest). The learning is performed in two sessions by using video and emodule. Evaluation of student learning outcomes conducted through pretest, after video posttest, and after e-module posttest. Based on the analysis of variation, the concentration of tapioca, and the size of the particle have a significant effect on the briquettes' characteristics. The t-test results of the pretest, after video posttest, and after e-module posttest indicated that the average students' knowledge value increases and varies significantly on each test. This e-module can also be used to improve vocational high school students' knowledge of melinjo skin briquettes. [ABSTRACT FROM AUTHOR]

The effect of germination on free radical scavenging activities and Angiotensin I-Converting Enzyme (ACE-I) inhibitory of melinjo (Gnetum gnemon) seed proteins was studied to determine its potential use as a nutraceutical ingredient. Investigations into the protein profiles, amino acid composition, free radical scavenging activities and ACE-I-inhibitory of proteins extracted from melinjo seed during germination (0 to 21 days) were carried out. The concentration of amino acids detected in the melinjo seed samples ranged from 0.30 to 12.75 g/100 g protein and the degree of hydrolysis during germination at 21st days was significantly highest than that of either (0-14 days). Furthermore, with all samples a large small-sized peptides degree (<10 kDa) was observed with an increasing degree of hydrolysis value. The free radical scavenging activities were measured using different standard methods, and ACE-I inhibitory activity was determined using in vitro ACE-I inhibitory assay. The time of germination showed a significant effect (p<0.05) on free radical scavenging (ABTS2+, DPPH, O2-, and OH+) activities and ACE-I inhibitory. The above results indicated that germination time has positively affected ACE-I inhibitory activity and free radical scavenging activities. [ABSTRACT FROM AUTHOR]

This study aimed to measure the ability of melinjo peel to reduce uric acid levels of hyperuricemic rats. Twenty five (25) male rats divided into 5 groups: negative control that given by CMC-Na 1%, positive control (allopurinol 100 mg/kgBW), and group III-V given with methanol extract of melinjo peel (MEMP) with dose 50, 100, 200 mg/kgBW. Hyperuricemia rat of 25 male rats was induced with high purine diet twice daily for 4 days. Compstition of high purine diet used chicken liver juice with dose 2ml/200gBB. Uric acid level after dose 50,100 and 200 mg/kg BW intake in 7 day becoming normal with highest effect of reduce uric acid level in dose 200 mg/kg BW with ± 6.32 mg/dl compared than positive control allopurinol (p<0.05). The results showed that MEMP containing resveratrol and Gnetin C have the ability to reduce uric acid levels of hyperuricemia rat. [ABSTRACT FROM AUTHOR]

Gnetum gnemon L. (Melinjo) seed extract (MSE) is potential as skin-whitening agent because it contains trans-resveratrol and its derivatives, to inhibit tyrosinase in melanogenesis process. Using MSE in cosmetic products will be challenging due to resveratrol chemical instability and bioavailability in the skin. Many cosmetic products have been developed using lipid particle technology to improve their limitation. The objective of this research was to examine the skin safety and whitening efficacy of MSE-loaded lipid particle gel in healthy human subjects. Materials and Methods: Single occlusive closed patch test for 24 h was used as the skin irritation analysis. Irritation responses were graded after patch removal and compared to the control for evaluation. Results: The result showed the test product did not induce skin irritation effect. The skin melanin index was statistically significant decreased (P < 0.05) after 28 days of application the test product, with the averaged by 3.50%, and skin melanin index changed by increase 0.75% in the control group. Conclusion: Application MSE-loaded lipid particle gel can brighten the skin, without cause irritation under normal conditions of use. [ABSTRACT FROM AUTHOR]

Root pruning technique may improve new lateral growth. The purposes of this research are to analyse the combined effect of root pruning and inoculum ectomycorrizal types on the growth of gnetum seedling (Gnetum gnemon). This research using split plot design. The source of ectomycorrizhal inoculum as main plot consist of 3 types: control, infected seedling of ectomycorrhizal, and soil inoculum. The root pruning level as sub plot also consist of 3 types: 0, 30, and 50%. Observation is conducted on month 5th and 6th after treatment. The result of this research indicates that root pruning technique on 7 month seedling able to enhance melinjo seedling’s growth and increase ectomycorrhizal colonization (Scleroderma spp.) after 6 months observation. The source of inoculum was able to enhance ectomyrorrhizal colonization but had no significant to gnetum seedling’s growth on month 6th after treatment. Interaction between root pruning 30% and fungal inoculation with soil inoculum source can improve gnetum seedling growth.

Gnetum gnemon var. tenerum (Gnetaceae) is a shrub plant native to South-East Asia. In Thailand, Liang leaves are commonly consumed in South of Thailand as vegetable. According to literature, they have an antihyperglycemic capacity because of their rich chlorophyll, fiber, and protein. However, there is need to assess the safety since natural food products are not completely devoid of toxicity. This study aimed to assess the biological activities as well as the acute and sub-chronic oral toxicity of Liang leaves powder (LLP). The evaluation of LLP for acute oral toxicity was performed at dose level 2000 mg/kg body weight in Wistar rats while the sub-chronic oral toxicity of LLP was performed at the effective dose (1.47 g/kg) for antihyperglycemic property according to Organisation for Economic Co-operation and Development (OECD)-425. The results showed that LLP demonstrated anti-inflammatory activities. It also showed no clinical signs of toxic effects and mortality in rats throughout 90 d. Thus, LLP could be classified in GHS category 5 which are of relatively low acute toxicity and then the lethal dose, 50% (LD 50 ) cut off at 5000 mg/kg body weight to infinity (∞). Administration of LLP to the experimental rats significantly increased (p < 0.05) the concentration of triglyceride and increased concentration of creatinine as a result of kidney malfunction was also noticed in the experimental rats. Hematological alteration was not noticed in the treated female rats, but red blood cell, hemoglobin and hematocrit concentrations significantly increased in the treated male rats. The study concludes that sub-chronic administration of 1.47 g/kg LLP is relatively safe.

Background: Ionizing radiation, such as gamma irradiation, serves as a useful approach to inhibit spore germination and to control pathogens in postharvest seeds. Recently, its application on phytochemical sources and its influence on antioxidant activity of various phytochemical compounds has become an interesting topic to be explored. Objective: The objectives of this study were to determine the effect of gamma irradiation as sterilization method on the resveratrol content and its antioxidant, HMG-CoA reductase inhibitory and dipeptidyl peptidase-4 (DPP-4) inhibitory activities of Melinjo (Gnetum gnemon) seeds. Methods: In this research, melinjo seeds were irradiated by 0.0; 2.5; 5.0; 7.5; and 10.0 kGy with gamma irradiation and then extracted with ethanol. The extracts were tested for resveratrol content with HPLC, antioxidant activities by DPPH assay, HMG-CoA inhibitory activity using HMGCoA reductase assay kit and DPP-4 inhibitory activity using DPP-4 Inhibitor Screening Assay Kit. Gamma irradiation has effect on resveratrol content, antioxidant activity, HMG-CoA reductase inhibition and DPP-4 inhibitory activity. Results: From the research, the highest value of resveratrol content is 0.18±0.004 mg/g seeds powder found in 5.0 kGy gamma irradiation treatment with IC50 94.64±0.236 μg/mL, while the highest HMG-CoA reductase inhibition is shown in 2.5 kGy irradiation dose. Melinjo seeds irradiated by 2.5 kGy gamma irradiation also shown a significant increase of DPP-4 inhibition activity. Conclusion: This study suggests that 2.5-5 kGy radiation is the effective gamma irradiation dose to improve the quality of melinjo seeds. [ABSTRACT FROM AUTHOR]

Objective: Trans-resveratrol is a phenolic compound in the stilbene group present in Melinjo (Gnetum gnemon L.) seeds. In Indonesia, these seeds are consumed by roasting, frying (i.e., emping), and boiling. This study aimed to evaluate the effects of food processing on trans-resveratrol and total phenolic compound levels in melinjo seeds. Methods: Melinjo seed was roasted at 145 °C for 10 and 20 min, boiled at 100 °C for 5, 15, and 30 min, and fried at 160-170 °C for 2 and 4 min. Samples were refluxed with 96% ethanol. The determination of trans-resveratrol levels was performed using high-performance liquid chromatography (HPLC), and total phenolic content was determined using Folin-Ciocalteu method. Results: Based on the results, it was found that trans-resveratrol and total phenolic content levels in Melinjo powder decreased from 36% to 10% (trans-resveratrol) and 15% to 4% (total phenolic) after 20 min of roasting, and in fried empings, it decreased 60%, 68%, and 92% (trans-resveratrol) and 41%, 45%, 97% (total phenolic) after 5, 15, and 30 min of boiling, respectively. Conclusion: There were significant changes in trans-resveratrol levels and total phenolic content in Melinjo seeds before and after various cooking processes (i.e., roasting, boiling, and frying). [ABSTRACT FROM AUTHOR]

Background: Melinjo (Gnetum gnemon L.) seed extract (MSE) is potential as skin-whitening agent because it contains trans-resveratrol and its derivatives, to inhibit tyrosinase in melanogenesis process. Using MSE in cosmetic products will be challenging due to resveratrol chemical instability and bioavailability in the skin. Many cosmetic products have been developed using lipid particle technology to improve their limitation. The objective of this research was to examine the skin safety and whitening efficacy of MSE-loaded lipid particle gel in healthy human subjects. Materials and Methods: Single occlusive closed patch test for 24 h was used as the skin irritation analysis. Irritation responses were graded after patch removal and compared to the control for evaluation. The efficacy study was performed using Mexameter to measure skin melanin index on 25 female volunteers. Results: The result showed the test product did not induce skin irritation effect. The skin melanin index was statistically significant decreased (P < 0.05) after 28 days of application the test product, with the averaged by 3.50%, and skin melanin index changed by increase 0.75% in the control group. Conclusion: Application MSE-loaded lipid particle gel can brighten the skin, without cause irritation under normal conditions of use. Abbreviations Used: α-MSH: α-melanocyte stimulating hormone; MITF: Microphthalmia-associated transcription factor; MSE: Melinjo seed extract. [ABSTRACT FROM AUTHOR]

Main conclusion: Sucrose concentration in phloem sap was several times higher than in the cytosol of mesophyll cells. The results suggest that phloem loading involves active steps in the analyzed tree species.Phloem loading in source leaves is a key step for carbon partitioning and passive symplastic loading has been proposed for several tree species. However, experimental evidence to prove the potential for sucrose diffusion from mesophyll to phloem is rare. Here, we analyzed three tree species (two angiosperms, Fagus sylvatica, Magnolia kobus, and one gymnosperm, Gnetum gnemon) to investigate the proposed phloem loading mechanism. For this purpose, the minor vein structure and the sugar concentrations in phloem sap as well as in the subcellular compartments of mesophyll cells were investigated. The analyzed tree species belong to the open type minor vein subcategory. The sucrose concentration in the cytosol of mesophyll cells ranged between 75 and 165 mM and was almost equal to the vacuolar concentration. Phloem sap could be collected from F. sylvatica and M. kobus and the concentration of sucrose in phloem sap was about five- and 11-fold higher, respectively, than in the cytosol of mesophyll cells. Sugar exudation of cut leaves was decreased by p-chloromercuribenzenesulfonic acid, an inhibitor of sucrose-proton transporter. The results suggest that phloem loading of sucrose in the analyzed tree species involves active steps, and apoplastic phloem loading seems more likely. [ABSTRACT FROM AUTHOR]

This study is to investigate the in vitro propagation and ex vitro root formation of Gnetum gnemon var. griffithii Markgr (G. gnemon), one of the nutrient-rich forest vegetables. The results showed that MS medium supplemented with 1.5 mg l-1 BAP was the most suitable combination for shoot formation after 90 days of culture. The combination between 1 mg l-1 BAP and 0.5 mg l-1 NAA gave the best in vitro rooting rate (40%) after 60 days culture. After 60 days tranfered to the greenhouse, plantlets which planted on the substrate of coconut fiber powder had a better growth (plant height of 6.14 cm, root length of 6.90 cm) than those on a combination substrate of coconut fiber powder and sand (1:1). In additional, plantlets treated with 3.0 mg l-1 IBA for 1 minute had the highest root formation rate (80%), the greatest root number per plantlet (2.80 roots), and the longest root (1.76 cm) when compared with those in different of treatment. [ABSTRACT FROM AUTHOR]

Objective: Gnetum gnemon L. (melinjo) seed extracts have been known to have some biological activities. One of them is ACE (angiotensinconverting enzyme) inhibitor. The present study was conducted to predict potential ACE inhibitory activity of several compounds isolated from Gnetum gnemon L. seeds by using in silico method. Methods: In this study, several compounds isolated from melinjo seeds were determined for their ACE inhibitory activity through molecular docking study and molecular dynamics simulations. Molecular docking experiment was performed by using AutoDock4Zn. Subsequently, molecular dynamics simulations using AMBER within 20 ns was conducted to analyze the interactions stability between zinc-ligand and ligand-amino acids in the active site of ACE since both of these mechanisms were known to play essential roles to inhibit ACE. Results: The results showed that resveratrol, gnetol, isorhapontigenin, gnetin C, trans-e-viniferin, gnemonol K, gnemonol M and aglycone of gnemonoside B exhibited G values which were lower than or close to lisinopril, captopril, and enalaprilat. Some of these ligands were able to bind zinc ion via cation-pi interactions. According to the free-energy binding calculations using MM-GBSA and MM-PBSA methods, gnetin C showed the highest affinity for ACE among other ligands at a temperature of 300 K, while at a temperature of 310 K the highest affinity was exhibited by gnemonol K. Conclusion: According to the molecular docking and molecular dynamics simulations, several compounds isolated from melinjo seed showed potential ACE inhibitory activities, in which gnemonol K promised as the most potential compound to have ACE inhibitory activity. [ABSTRACT FROM AUTHOR]

Abstract: Gnemon chip is a very promising material to be developed as functional food and pharmacological agents. However, it has been stigmatized for its tendency to trigger serum uric acid production. Meanwhile, frying has been assumed to deteriorate important metabolites. This study was aimed to determine uric acid concentration in post feeding and to examine the constituents fitness due to frying based on HPLC, HPTLC methods and antioxidant activity. Uric acid concentrations were found to be normal ranging from 1.07 to 1.35 mg/dl. All chromatograms possessed a similar profile with the raw. A major compound identified with gnemonoside D was isolated and used as a marker. DPPH assay demonstrated that all samples lasted potent antioxidant with IC50 values ranging from 16.12 ± 0.65 to 19.34 ± 0.62 µg/ml, which is stronger than α‐tocopherol. The developed analytical system can be used for future analytical standard in the manufacturing of Gnemon seed‐based derivative products. Practical applications: This is the first article clarifying that Gnetum gnemon chip does not trigger serum uric acid in vivo. The stability and fitness post‐frying processes based on chemical compositions and antioxidant activities were revealed. HPLC and HPTLC systems were successfully developed for quality control methods for future manufacturing or post‐harvesting steps. Gnemonoside D was isolated and exhibited as a reliable marker. [ABSTRACT FROM AUTHOR]

Objectives: Melinjo (Gnetum gnemon) seeds have been known to have some biological properties. One of them is ant hypercholesterolemia. The present study investigated in vitro and in silico methods to predict potential antihypercholesterolemic of the Melinjo seed extracts of through HMG-CoA reductase inhibitory activity. Methods: Melinjo seed powders were successively extracted by reflux method using five solvents with gradient polarity including: n-hexane, dichloromethane, ethyl acetate and methanol. All extracts were evaluated in vitro using HMG-CoA Reductase assay kit, to analyze the inhibitory activity. Molecular docking of the phytochemical content of the seeds were carried out using Auto Dock Vina, and also Ligand Scout to analyses interaction between ligand and receptor. Results: Dichloromethane extract demonstrated the highest inhibitory activity against HMG-CoA reductase with IC50 value is 0.40 µg/mL, followed by that of ethyl acetate extract. UPLC-MS analyses showed that dichloromethane extract contained trans-resveratrol, piceid, gnetin C, gnetol, isorhapontigenin, ε-viniferin, gnemonol L, and gnemonol M. Molecular docking studies demonstrated that dimer of resveratrol such as gnemonol L, gnemosida, and ε-viniferin have better free binding energy than that of monomer. piceid, gnetin C, gnemonol L, and gnemonol M could be considered as HMG-CoA reductase inhibitor. Conclusion: Gnetum gnemon seed extract showed strong HMG-CoA reductase activity. Resveratrol dimer promises as a potential lead compound to design/synthesize anti-cholesterol. [ABSTRACT FROM AUTHOR]

Introduction: Gnetum gnemon L. (Melinjo) is popular in Indonesia as a source of nutrition. Its seeds contain trans-resveratrol, which has been shown to have multiple pharmacological activities. The application of ionic liquid [Bmim]Br as a selected solvent in the microwave assisted extraction (MAE) method was developed for extraction of trans-resveratrol from Melinjo seeds. MAE method with ionic liquid has also been applied to extract trans-resveratrol from the different plant with a high extraction yield value. Methods: The Box-Behnken design on four factors with response surface methodology were used to optimize extraction conditions for transresveratrol content from Melinjo seeds. For further, the various salt was applied to separate of the trans-resveratrol form ionic liquid and facilitate for extraction back using an organic solvent. Results: The optimum process for the ionic liquid-based microwave assisted extraction was below: [Bmim]Br concentration 2.5 mol/L; liquid-melinjo seeds powder ratio 15 mL/g; microwave power 10%; and extraction time 10 min. Under optimized conditions, the trans-resveratrol value was 1.34 mg/g. Moreover, the salt Na2CO3 0.01 mol/L with ethyl acetate were useful to the extraction back of trans-resveratrol from [Bmim]Br solution. Conclusion: This IL-MAE method was suitable to apply as an alternative technique to extract the active compound from the plant. [ABSTRACT FROM AUTHOR]

In this study, antioxidant activities and identification of the bioactive substances in Gnetum gnemon L. (Gg) seed hard shell were evaluated. The seed of Gnetum gnemon L., an Indonesian native plant, is commonly consumed as a vegetable or further processed as cracker. Isolated substances from Gnetum gnemon seed are mainly stilbenoid derivatives which show potent antioxidant, tyrosinase inhibitor, and antimicrobial activities. Nevertheless, the antioxidant activity of its crude extract is still considered weak. In this study, an effort was made to improve antioxidant potency by fractionation using macroporous adsorptive resin (MAR). This fractionation successfully enhanced antioxidant activity of red Gg seed hard shell extract with efficient adsorption contact time within 30 min. Antioxidant activity of fractions 25-75% v/v ethanol increased three- to sevenfold as compared to crude extract and more importantly resulted in dry product which was easier for further processes. Identification of bioactive compounds in Gg seed hard shell extract with different degrees of ripeness was also performed by HPLC and confirmed the presence of Gnetin C, resveratrol, and other stilbenoid derivatives. These other stilbenoid derivatives could be the main substances contributing in antioxidant action with lower IC as compared to both Gnetin C and resveratrol. In summary, fractionation process using MAR HPD-600 reduced unnecessary sugar molecules from red Gg seed hard shell extract hence resulting to fraction with strong antioxidant activity. [ABSTRACT FROM AUTHOR]

The radical scavenging capacities and DNA damage protection of fermented melinjo ( Gnetum gnemon) flour were investigated to determine its potential use as a nutraceutical ingredient. Fermented melinjo flour was prepared using a Lactobacillus fermentum starter culture. The fermented and unfermented melinjo flours were examined for antioxidant activities using different standard methods. The results indicated that fermented flour had significantly ( p < .05) higher phenolic content (10.61 mg Galic acid equivalent (GAE)/g) than the unfermented flour (8.61 mg GAE/g). High-performance liquid chromatography-Diode Array Detector detection demonstrated that fermentation resulted in a loss of phenolic compounds, such as gnetifolin E, gnemonoside E, and resveratrol but not gnetin C. Subsequently, fermentation led to marked increases (significant, p < .05) in the radical scavenging abilities of DPPH, ABTS, hydroxyl, and hydrogen peroxide. In addition, fermented flour extract possessed superior resistance to oxidative damage of DNA by Fenton's reagent. Overall, the antioxidant enhanced melinjo flour was successfully produced and could be used as a functional food to promote the health and nutrition of consumer. Practical applications The Gnetum gnemon tree is popularly known in Indonesia as melinjo. Melinjo seeds are regularly consumed as crackers or cookies made from ground flour. These seeds are a suitable nutritional supplement with high bioavailability. In this study, the antioxidant activity of fermented melinjo flour was increased after Lactobacillus fermentum fermentation. In addition, some bioactive compounds were produced during fermentation. The fermented products can be used as nutritional supplements for the prevention and control of degenerative diseases. Therefore, this study provides a simple and effective strategy to improve the nutritional value of melinjo flour. [ABSTRACT FROM AUTHOR]

Mycorrhizal symbiosis is the result of mutualistic interactions between plants and fungi. Melinjo (Gnetum gnemon) naturally associate with ectomycorrhizal Scleroderma sinnamariense and Scleroderma sp. fungi. Artificial inoculation can be applied to young seedlings (1-2 months old), before the roots contain woody material. The purpose of this study was to apply the root pruning techniques to improve gnetum mycorrhizal seedlings production. The study was conducted in a greenhouse using 7 months old seedlings. The treatments consisted of 3 root pruning levels (0, 30, and 50%) and ectomycorrhizal fungi inoculum (control, mycorrhizal seedlings, and soil inoculum). Observations were carried out for 4 months to the seedling growth and root colonization by ectomycorrhizal fungi. Height, diameter, and biomass of melinjo seedlings in all treatments were not significantly different. Thus, root pruning activities do not affect the growth of seedlings. Artificial inoculation produce mycorrhizal seedlings, whereas controls were uninfected. Root pruning increased number of root branching. Root pruning at level 50% increased mycorrhizal seedlings production, but the percentage of root colonization was not significantly difefernt at all pruning levels.

The economically important gymnosperm Gnetum L. is distributed in humid tropical forests of Africa. Its leaves are used as commercialized vegetables and greatly alleviate poverty for local people. Previously, the number of species recognized in Africa was uncertain, and Gnetum africanum Welw. and G. buchholzianum Engl. had been variously, and erroneously, applied to specimens. Based on recent morphological studies, species limits were clarified and two new African species, Gnetum interruptum E.H.Biye and G. latispicum E.H.Biye, were described. The purpose of this study was to determine species limits, to investigate potential infraspecific variation in wild African Gnetum species and to determine which features distinguish them in order to assess the validity of four species recognized by Biye et al. (Pl Syst Evol 300(2):263-272, 2014). Sixty-seven morphological characters were scored for a total of 175 (56 male and 119 female) specimens and analysed using cluster, principal components and principal coordinates analyses. Four distinct clusters of Gnetum specimens were recognized that correspond to the species now described as G. africanum, G. buchholzianum, G. interuptum and G. latispicum. A lack of geographical correlation with subclusters as well as their structure suggests there is no justification for recognizing infraspecific taxa. Characters that describe features of the spikes should be used to differentiate between and identify the species in Africa. In view of the high levels of utilization of two species and rarity of a third, it is urgent to assess the threat status of Gnetum species in Africa and to design appropriate conservation strategies to conserve these economically valuable plants. [ABSTRACT FROM AUTHOR]

The effect of different lipid extraction on gelatinization and retrogradation of bitter nuts (Gnetum gnemon) starch was studied by the measurement of starch-lipids complex formation using differential scanning calorimetry. The bitter nuts samples were extracted sequentially with hexane for surface lipid starch (SL) and hot water-saturated butanol for internal lipid starch (IL). The gelatinization enthalpies of starch increased significantly with extracting step, but the starch-lipid complex enthalpies of SL and IL were statistically lower, when compared with the native starch. According to the Avrami equation, the retrogradation rate of native bitter nuts starch was slower than that of the SL or IL, whereas the retrogradation rate of IL was slower than SL. High number of starch-lipids complex could retard the retrogradation of bitter nuts starch during storage