Evaluation of free radical scavenging and antityrosinase activities of standardized longan fruit extract

Wound healing potential of a formula based on Populus nigra L. flower buds extract with anti-inflammatory activity

ETHNOPHARMACOLOGICAL RELEVANCE

Wound healing is a complex and dysnamic process supported by a myriad of cellular events that are tightly coordinated to repair efficiently damaged tissue. Populus nigra L. (Salicaceae) flower buds are traditionally used in the treatment of dermatitis, upper respiratory tract infections, rheumatism and wounds.

AIM OF THE STUDY

The aim of this study was to assess the wound healing potential of black poplar ointment containing 10 or 20 % of Populus nigra ethanolic flower buds extract using the excision model in rats.

MATERIALS AND METHODS

Two ointments (10 and 20 %) were prepared from Populus nigra flower buds ethanolic extract and topically applied on the area of excised skin of the rats for either 14 or 20 days. Morphological, macroscopic, histological and biochemical parameters were evaluated.

RESULTS

The results showed that the extract contained high amounts of total phenols (89.5 ± 7.7 mg caffeic acid equivalent/g of extract) and hydrolysable tannins (142.05 ± 2.55 mg tannic acid equivalent/g of extract), in correlation with strong DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and beta-carotene bleaching with values of 96.31 ± 3.42 and 85.27 ± 1.79 %, respectively. Anti-inflammatory potential was illustrated by lipoxygenase and cyclooxygenase inhibition (52.80 ± 0.2 and 53.88 ± 2.55 %, respectively). Treatment with Populus nigra ointment (10 and 20 %) promoted wound contraction of 97.37 ± 1.19 and 97.28 ± 0.91 %, respectively. The antioxidant marker enzymes, catalase (0.10 ± 0.001; 0.08 ± 0.003 U/mg protein) and superoxide dismutase (363.34 ± 24.37; 317.82 ± 53.83 U/mg protein) activities in the granulation tissues were upgraded with respective treatments of 10 or 20 % ointment. Concurrently, the myeloperoxidase activity (2.21 ± 1.01; 2.13 ± 0.75 U/mg protein) was repressed, indicating anti-inflammatory potential, when compared to untreated, standard and excipient groups. Moreover, a significant increase in respective levels of hydroxyproline (p < 0.001) (28.05 ± 1.20; 25.29 ± 1.17 μg/mg tissue) and hexosamine (p < 0.05) (20.18 ± 1.21; 18.95 ± 1.98 μg/mg tissue) was triggered, reflecting a high regeneration of collagen in the scarred tissue. Histological examination of treated skin tissue revealed higher rates of re-epithelialization, lower neutrophils infiltration and re-vascularization in comparison to the control group.

CONCLUSION

Given that the 10 % ointment was the optimal concentration, our findings offer an efficient drug formula for wound healing.

Environmental fate and safety analysis of methoxyfenozide application to control litchi and longan pests

Litchi and longan pests significantly affect crop yield and quality. Chemical prevention and control are very effective for production; therefore, it is crucial to study fate assessment and appropriate field efficacy before pesticide application on crops to appropriately assess the health and ecological risks linked with these agents. This study conducted Good Agricultural Practice (GAP) field trials and laboratory experiments to elucidate the dissipation, terminal residues, and efficacy of methoxyfenozide on litchi and longan in six locations throughout China. To detect methoxyfenozide residues on litchi and longan, a QuEChERS/UPLC-MS/MS-based method was designed. The initial methoxyfenozide levels in litchi and longan ranged from 2.21-2.86 to 0.83-0.95 mg kg-1 and indicated half-lives of 5.1-5.3 and 5.3-5.7 days, respectively. After 7 days of foliage treatment, the concentrations of terminal methoxyfenozide residue were 0.78-2.61 and 0.02-1.01 mg kg-1, which were less than the established maximum residue limit for methoxyfenozide in litchi and longan. The chronic (acceptable daily intake = 0.0055-0.0331%) dietary intake risk analysis for methoxyfenozide in longan and litchi indicated acceptable concentrations of terminal residue for the general population. Methoxyfenozide in litchi and longan was readily degraded in first-order kinetics models, the degradation rate on longan was higher than that on litchi, and their dietary risks were negligible to consumers. Two hundred forty grams per liter of methoxyfenozide suspension concentrate (SC) represents a highly efficacious insecticidal dose to control litchi and longan pests and indicates a significant application potential as it is rapidly degraded and linked with reduced post-treatment residue levels.

Anti-Melanogenic Effects of Takifugu flavidus Muscle Hydrolysate in B16F10 Melanoma Cells and Zebrafish

Abnormal melanogenesis can lead to hyperpigmentation. Tyrosinase (TYR), a key rate-limiting enzyme in melanin production, is an important therapeutic target for these disorders. We investigated the TYR inhibitory activity of hydrolysates extracted from the muscle tissue of Takifugu flavidus (TFMH). We used computer-aided virtual screening to identify a novel peptide that potently inhibited melanin synthesis, simulated its binding mode to TYR, and evaluated functional efficacy in vitro and in vivo. TFMH inhibited the diphenolase activities of mTYR, reducing TYR substrate binding activity and effectively inhibiting melanin synthesis. TFMH indirectly reduced cAMP response element-binding protein phosphorylation in vitro by downregulating melanocortin 1 receptor expression, thereby inhibiting expression of the microphthalmia-associated transcription factor, further decreasing TYR, tyrosinase related protein 1, and dopachrome tautomerase expression and ultimately impeding melanin synthesis. In zebrafish, TFMH significantly reduced black spot formation. TFMH (200 μg/mL) decreased zebrafish TYR activity by 43% and melanin content by 52%. Molecular dynamics simulations over 100 ns revealed that the FGFRSP (T-6) peptide stably binds mushroom TYR via hydrogen bonds and ionic interactions. T-6 (400 μmol/L) reduced melanin content in B16F10 melanoma cells by 71% and TYR activity by 79%. In zebrafish, T-6 (200 μmol/L) inhibited melanin production by 64%. TFMH and T-6 exhibit good potential for the development of natural skin-whitening cosmetic products.

A validated bioanalytical method for the simultaneous estimation of telmisartan and gallic acid in rat plasma samples by high-performance thin-layer chromatography-mass spectrometry: Application to an oral pharmacokinetic study

A novel and cost-effective high-performance thin-layer chromatography (HPTLC) method, combined with densitometric quantification, was developed for the biomedical analysis of telmisartan (TEL) and gallic acid (GA). Recent research indicates that when used in combination, these compounds offer improved therapeutic efficacy for the treatment of cardiovascular diseases with reduced side effects. The study focused on the simultaneous quantification and pharmacokinetic analysis of drugs in rat plasma. The separation was conducted using HPTLC silica gel 60 F254 plates with dimensions of 20 × 10 cm and a thickness of 0.2 mm. The mobile phase used for separation consisted of a mixture of ethyl acetate, methanol, chloroform, and acetic acid in the ratio of 4:2:2:0.2 (v/v). GA and TEL were analyzed using ultraviolet detection at specific wavelengths, with GA at 280 nm and TEL at 296 nm. Peak purity was assessed through spectral correlation analysis using Vision CATS software. The method underwent validation following the guidelines of the US Food and Drug Administration (US FDA). Calibration plots demonstrated linearity in the concentration range of 200-1200 ng/spot, with high correlation coefficients (R2 ). The retention factors (Rf ) were 0.67 for TEL and 0.60 for GA. The identity of the separated compounds was further confirmed using MS, with GA having a mass-to-charge ratio (m/z) of 168.9 in negative mode and TEL with m/z 515.2 in positive mode. In the pharmacokinetic study, the maximum peak plasma concentration (Cmax ) for GA was 899.7 ng/mL, and for TEL, it was 1013 ng/mL. The time to reach maximum concentration (Tmax ) was 2 h for GA and 6 h for TEL. This simultaneous qualitative and quantitative determination of the drugs in an oral pharmacokinetic study involving Wistar rats can serve as a valuable tool for future investigations into pharmacokinetic interactions, quality control, and routine analysis of these drugs, both in their pure forms and in novel formulations.

A Review of Medicinal Plants and Phytochemicals for the Management of Gout

Gout, characterized by elevated uric acid levels, is a common inflammatory joint disease associated with pain, joint swelling, and bone erosion. Existing treatments for gout often result in undesirable side effects, highlighting the need for new, safe, and cost-effective anti-gout drugs. Natural products, including medicinal plants and phytochemicals, have gained attention as potential sources of anti-gout compounds. In this review, we examined articles from 2000 to 2020 using PubMed and Google Scholar, focusing on the effectiveness of medicinal plants and phyto-chemicals in managing gout. Our findings identified 14 plants and nine phytochemicals with anti-gout properties. Notably, Teucrium polium, Prunus avium, Smilax riparia, Rhus coriaria, Foenic-ulum vulgare, Allium cepa, Camellia japonica, and Helianthus annuus exhibited the highest xa-thine oxidase inhibitory activity, attributed to their unique natural bioactive compounds such as phenolics, tannins, coumarins, terpenoids, and alkaloids. Herbal plants and their phytochemicals have demonstrated promising effects in reducing serum urate and inhibiting xanthine. This review aims to report recent studies on plants/phytochemicals derived from herbs beneficial in gout and their different mechanisms.

Phukettosides A-E, mono- and bis-iridoid glycosides, from the leaves of Morinda umbellata L

Four undescribed bis-iridoid glycosides, named phukettosides A-D, and one iridoid glycoside, referred to as phukettoside E, were isolated and fully characterized from the leaves of Morinda umbellata L. Phytochemical analysis also revealed the presence of eight known compounds. The structures were determined through extensive analysis of 1D and 2D-NMR spectroscopic and HRMS spectral data, and the absolute configurations of the isolates were deduced through ECD calculations. Biogenetic pathways for the bis-iridoid glycosides, phukettosides A-C, through intermolecular Diels-Alder type reactions, were proposed. The isolated compounds, with the exception of phukettosides B and D, were evaluated against a panel of cancer cell lines (MOLT-3, HuCCA-1, A549, HeLa, HepG2, and MDA-MB-231) and a non-cancerous cell line (MRC-5) for their cytotoxicity. None of the isolates had significant cytotoxic effects on the tested cell lines.

Polyphenol Profile, Antioxidant Activity, and Hypolipidemic Effect of Longan Byproducts

Longan, a popular fruit in Asia, has been used in traditional Chinese medicine to treat several diseases for centuries. Recent studies have indicated that longan byproducts are rich in polyphenols. The aim of this study was to analyze the phenolic composition of longan byproduct polyphenol extracts (LPPE), evaluate their antioxidant activity in vitro, and investigate their regulating effect on lipid metabolism in vivo. The results indicated that the antioxidant activity of LPPE was 231.350 ± 21.640, 252.380 ± 31.150, and 558.220 ± 59.810 (mg Vc/g) as determined by DPPH, ABTS, and FRAP, respectively. UPLC-QqQ-MS/MS analysis indicated that the main compounds in LPPE were gallic acid, proanthocyanidin, epicatechin, and phlorizin. LPPE supplementation prevented the body weight gain and decreased serum and liver lipids in high-fat diet-induced-obese mice. Furthermore, RT-PCR and Western blot analysis indicated that LPPE upregulated the expression of PPARα and LXRα and then regulated their target genes, including FAS, CYP7A1, and CYP27A1, which are involved in lipid homeostasis. Taken together, this study supports the concept that LPPE can be used as a dietary supplement in regulating lipid metabolism.

Evaluation of Ruthenium(II) N-Heterocyclic Carbene Complexes as Enzymatic Inhibitory Agents with Antioxidant, Antimicrobial, Antiparasitical and Antiproliferative Activity

A series of [RuCl₂(p-cymene)(NHC)] complexes were obtained by reacting [RuCl₂(p-cymene)]2 with in situ generated Ag-N-heterocyclic carbene (NHC) complexes. The structure of the obtained complexes was determined by the appropriate spectroscopy and elemental analysis. In addition, we evaluated the biological activities of these compounds as antienzymatic, antioxidant, antibacterial, anticancer, and antiparasitic agents. The results revealed that complexes 3b and 3d were the most potent inhibitors against AchE with IC₅₀ values of 2.52 and 5.06 μM mL^-1. Additionally, 3d proved very good antimicrobial activity against all examined microorganisms with IZ (inhibition zone) over 25 mm and MIC (minimum inhibitory concentration) < 4 µM. Additionally, the ligand 2a and its corresponding ruthenium (II) complex 3a had good cytotoxic activity against both cancer cells HCT-116 and HepG-2, with IC₅₀ values of (7.76 and 11.76) and (4.12 and 9.21) μM mL^-1, respectively. Evaluation of the antiparasitic activity of these complexes against Leishmania major promastigotes and Toxoplasma gondii showed that ruthenium complexes were more potent than the free ligand, with an IC₅₀ values less than 1.5 μM mL^-1. However, 3d was found the best one with SI (selectivity index) values greater than 5 so it seems to be the best candidate for antileishmanial drug discovery program, and much future research are recommended for mode of action and in vivo evaluation. In general, Ru-NHC complexes are the most effective against L. major promastigotes.

Ent-abietane diterpenoid lactone glycosides and a phenolic glycoside from Phlogacanthus pulcherrimus T. Anderson with cytotoxic and cancer chemopreventive activities

Nine undescribed ent-abietane diterpenoid lactone glycosides, pulcherrimosides A-I, and a phenolic glycoside, phlogoside A, together with ten known compounds were isolated from the aerial parts of Phlogacanthus pulcherrimus T. Anderson. Their structures were established through spectral methods, especially 2D NMR and HRESIMS analyses, and by acid hydrolysis. The absolute configurations of pulcherrimosides A-I were determined through the interpretation of electronic circular dichroism (ECD) data. Some of the isolates were evaluated for their in vitro cytotoxic and cancer chemopreventive properties. Helioscopinolide A and 17-hydroxyhelioscopinolide A showed good cytotoxic activity against HeLa cells with IC₅₀ values of 18.16 ± 0.58 and 16.60 ± 0.23 μM, respectively. Pulcherrimoside D inhibited superoxide anion radical formation in the xanthine/xanthine oxidase (XXO) assay with an IC₅₀ value of 59.5 μM. Helioscopinolide A and pulcherrimoside D were strong aromatase inhibitors with IC₅₀ values of 9.0 and 11.9 μM, respectively. Among the tested compounds, pulcherrimoside D was considered an interesting cancer chemopreventive agent for further study as it provided good activity in several in vitro cancer preventive assays and was not toxic to normal cells.

The effects of the ethanol extract of Cordia myxa leaves on the cognitive function in mice

Background

Cordia myxa L. (Boraginaceae) is widely distributed in tropical regions and it’s fruits, leaves and stem bark have been utilized in folk medicine for treating trypanosomiasis caused by Trypanosoma cruzi. A population-based study showed that T. cruzi infection is associated with cognitive impairments. Therefore, if C. myxa has ameliorating activities on cognitive function, it would be useful for both T. cruzi infection and cognitive impairments.

Methods

In this study, we evaluated the effects of an ethanol extract of leaves of C. myxa (ELCM) on memory impairments and sensorimotor gating deficits in mice. The phosphorylation level of protein was observed by the Western blot analysis.

Results

The administration of ELCM significantly attenuated scopolamine-induced cognitive dysfunction in mice, as measured by passive avoidance test and novel object recognition test. Additionally, in the acoustic startle response test, we observed that the administration of ELCM ameliorated MK-801-induced prepulse inhibition deficits. We found that these behavioral outcomes were related with increased levels of phosphorylation phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt) and glycogen synthase kinase 3 beta (GSK-3β) in the cortex and extracellular signal-regulated kinase (ERK) and cAMP response element-binding protein (CREB) in the hippocampus by western blot analysis.

Conclusions

These results suggest that ELCM would be a potential candidate for treating cognitive dysfunction and sensorimotor gating deficits observed in individuals with neurodegenerative diseases.

Anti-Oxidant and Anti-Aging Activities of Callus Culture from Three Rice Varieties

The aims of this study were to induce calli from the seeds of three rice varieties (Hommali 105, Munpu, and Niawdum) and investigate their anti-aging potential. First, rice seeds were cultured on a Murashige and Skoog medium (MS medium) supplemented with 2 mg/L of 2,4-Dichlorophenoxyacetic acid (2,4-D), 1 mg/L of 1-Naphthalene acetic acid (NAA), and 1 mg/L of 6-Benzylaminopurine (BAP). After three weeks, the calli were extracted with ethanol. Then, their phenolic contents were determined by spectrophotometer and the amino acids were identified by ultra-performance liquid chromatography (UPLC). Their cytotoxicity, anti-oxidant (potassium ferricyanide reducing power assay (PFRAP), DPPH radical scavenging assay (DPPH), lipid peroxidation inhibition (LPO), and superoxide dismutase activity (SOD)), and anti-aging (keratinocyte proliferation, anti-collagenase, anti-inflammation, and anti-tyrosinase) activities were also investigated. Munpu callus (385%) was obtained with a higher yield than Hommali (322%) and Niawdum (297%) calli. The results revealed that the phenolic and amino acid contents were enhanced in the calli. Moreover, the calli were rich in glutamic acid, alanine, and gamma aminobutyric acid (GABA). The callus extracts showed no cytotoxic effects at a concentration of equal to or lower than 0.25 mg/mL. The highest anti-oxidant activities (PFRAP (0.81 mg AAE/mL), DPPH (68.22%), LPO (52.21%), and SOD (67.16%)) was found in Munpu callus extract. This extract also had the highest keratinocyte proliferation (43.32%), anti-collagenase (53.83%), anti-inflammation (85.40%), and anti-tyrosinase (64.77%) activities. The experimental results suggest that the amounts of bioactive compounds and anti-aging activities of rice seeds can be enhanced by the induction of callus formation.

Browning inhibition of seabuckthorn leaf extract on fresh-cut potato sticks during cold storage

Seabuckthorn extract is rich in bioactive compounds and well known for its health benefits. The study investigated the effect of seabuckthorn leaf extract on browning of fresh-cut potatoes. The results showed that seabuckthorn leaf extract significantly inhibited the browning of fresh-cut potatoes compared with seabuckthorn fruit extract. Catechin, hypericin, gallic acid, casuarinin and isorhamnetin were main components in seabuckthorn leaf extract. Further research revealed that seabuckthorn leaf extract competitively inhibited polyphenol oxidase (PPO) with IC₅₀ value of 0.7 mg/mL. Molecular docking indicated that gallic acid stably bound to the active site of PPO, while isorhamnetin had low affinity on PPO. These results also demonstrated that seabuckthorn leaf extract inhibited browning of fresh-cut potatoes by reducing activities of peroxidase and phenylalanine ammonia-lyase, decreasing contents of phenolics and elevating antioxidant capacity. In addition, synergistic anti-browning effect was found with casuarinin, isorhamnetin, gallic acid and pedunculagin.

Metabolomic Profiling of Antioxidant Compounds in Five Vachellia Species

The genus Vachellia, previously known as Acacia, belongs to the family Fabaceae, subfamily Leguminosae, which are flowering plants, commonly known as thorn trees. They are traditionally used medicinally in various countries including South Africa for the treatment of ailments such as fever, sore throat, Tuberculosis, convulsions and as sedatives. The aim of this study was to determine biochemical variations in five Vachellia species and correlate their metabolite profiles to antioxidant activity using a chemometric approach. The antioxidant activity of five Vachellia aqueous-methanolic extracts were analyzed using three methods: 2,2-di-phenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS⁺) analysis and the ferric reducing antioxidant power (FRAP) assay by means of serial dilution and bioautography with the thin-layer chromatography (TLC) method. Amongst the Vachellia extracts tested, V. karroo, V. kosiensis and V. xanthophloea demonstrated the highest DPPH, ABTS⁺ and FRAP inhibitory activity. The antioxidant activities of DPPH were higher than those obtained by ABTS⁺, although these values varied among the Vachellia species. Proton nuclear magnetic resonance (¹H NMR), coupled with multivariate statistical modeling tools such as principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA), were performed to profile metabolites responsible for the observed activity. The OPLS-DA categorized the five Vachellia species, separating them into two groups, with V. karroo, V. kosiensis and V. xanthophloea demonstrating significantly higher radical scavenging activity than V. tortilis and V. sieberiana, which clustered together to form another group with lower radical scavenging activity. Annotation of metabolites was carried out using the ultra-high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UHPLC-qTOF-MS), and it tentatively identified 23 metabolites of significance, including epigallocatechin (m/z = 305.0659), methyl gallate (m/z = 183.0294) and quercetin (m/z = 301.0358), amongst others. These results elucidated the metabolites that separated the Vachellia species from each other and demonstrated their possible free radical scavenging activities.

Exhaustive Plant Profile of “Dimocarpus longan Lour” with Significant Phytomedicinal Properties: A Literature Based-Review

Background: “Dimocarpus longan Lour” is a tropical and subtropical evergreen tree species mainly found in China, India, and Thailand; this plant, found naturally in Bangladesh, even locally, is used as “kaviraj” medication for treating different diseases, such as gastrointestinal disorders, wounds, fever, snake bites, menstrual problem, chickenpox, bone fractures, neurological disorders, and reproductive health. Different parts of this plant, especially juice pulp, pericarp, seeds, leaves, and flowers, contain a diverse group of botanical phytocompounds, and nutrient components which are directly related to alleviating numerous diseases. This literature-based review provides the most up-to-date data on the ethnomedicinal usages, phytochemical profiling, and bio-pharmacological effects of D. longan Lour based on published scientific articles. Methodology: A literature-based review was conducted by collecting information from various published papers in reputable journals and cited organizations. ChemDraw, a commercial software package, used to draw the chemical structure of the phytochemicals. Results: Various phytochemicals such as flavonoids, tannins, and polyphenols were collected from the various sections of the plant, and other compounds like vitamins and minerals were also obtained from this plant. As a treating agent, this plant displayed many biologicals activities, such as anti-proliferative, antioxidant, anti-cancer, anti-tyrosinase, radical scavenging activity, anti-inflammatory activity, anti-microbial, activation of osteoblast differentiation, anti-fungal, immunomodulatory, probiotic, anti-aging, anti-diabetic, obesity, neurological issues, and suppressive effect on macrophages cells. Different plant parts have displayed better activity in different disease conditions. Still, the compounds, such as gallic acid, ellagic acid, corilagin acid, quercetin, 4-O-methyl gallic acid, and (-)-epicatechin showed better activity in the biological system. Gallic acid, corilagin, and ellagic acid strongly exhibited anti-cancer activity in the HepG2, A549, and SGC 7901 cancer cell lines. Additionally, 4-O-methyl gallic acid and (-)-epicatechin have displayed outstanding antioxidant activity as well as anti-cancer activity. Conclusion: This plant species can be considered an alternative source of medication for some diseases as it contains a potential group of chemical constituents.

Phytochemical Composition, Antibacterial Activity, and Antioxidant Properties of the Artocarpus altilis Fruits to Promote Their Consumption in the Comoros Islands as Potential Health-Promoting Food or a Source of Bioactive Molecules for the Food Industry

The present study aimed to evaluate the health-promoting potential of breadfruit (Artocarpus altilis (Parkinson) Fosberg, Moraceae family), a traditional Comorian food, considering the sample variability according to geographic localisation. Moreover, the main aims of this research were also to promote its consumption in the Comoros Islands as potential health-promoting food and evaluate it as a source of bioactive molecules for the food industry thanks to its antioxidant and antibacterial properties. Investigations on biologically active substances were carried out on the extracts obtained from breadfruit flours from five regions of Grande Comore (Ngazidja), the main island in Comoros. Phytochemical screening revealed the presence of tannins and polyphenols, flavonoids, leucoanthocyanins, steroids, and triterpenes. The considered secondary metabolites were phenolic compounds, vitamin C, monoterpenes, and organic acids. The contents of total phenolic compounds (mgGAE/100 g of dry weight—DW) in the extracts ranged from 29.69 ± 1.40 (breadfruit from Mbadjini—ExMBA) to 96.14 ± 2.07 (breadfruit from Itsandra—ExITS). These compounds included flavanols, flavonols, cinnamic acid and benzoic acid derivatives, and tannins which were detected at different levels in the different extracts. Chlorogenic acid presented the highest levels between 26.57 ± 0.31 mg/100 g DW (ExMIT) and 43.80 ± 5.43 mg/100 g DW (ExMBA). Quercetin was by far the most quantitatively important flavonol with levels ranging from 14.68 ± 0.19 mg/100 g DW (ExMIT) to 29.60 ± 0.28 mg/100 g DW (ExITS). The extracts were also rich in organic acids and monoterpenes. Quinic acid with contents ranging from 77.25 ± 6.04 mg/100 g DW (ExMBA) to 658.56 ± 0.25 mg/100 g DW of ExHAM was the most important organic acid in all the breadfruit extracts, while limonene was quantitatively the main monoterpene with contents between 85.86 ± 0.23 mg/100 g DW (ExMIT) and 565.45 ± 0.24 mg/100 g DW (ExITS). The antibacterial activity of the extracts was evaluated on twelve pathogens including six Gram (+) bacteria and six Gram (−) bacteria. By the solid medium disc method, except for Escherichia coli and Pseudomonas aeruginosa, all the bacteria were sensitive to one or more extracts. Inhibitory Halo Diameters (IHDs) ranged from 8 mm to 16 mm. Salmonella enterica, Clostridium perfringens, and Vibrio fischeri were the most sensitive with IHD > 14 mm for ExITS. By the liquid microdilution method, MICs ranged from 3.12 mg/mL to 50 mg/mL and varied depending on the extract. Bacillus megaterium was the most sensitive with MICs ≤ 12.5 mg/mL. Pseudomonas aeruginosa, Shigella flexneri, and Vibrio fischeri were the least sensitive with all MICs ≥ 12.5 mg/mL. ExHAM was most effective with a MIC of 3.12 mg/mL on Staphylococcus aureus and 6.25 mg/mL on Salmonella enterica. The antioxidant power of the extracts was evaluated by the FRAP method. The activity ranged from 5.44 ± 0.35 (ExMBA) to 14.83 ± 0.11 mmol Fe²⁺/kg DW (ExHAM). Breadfruit from different regions of Comoros contained different classes of secondary metabolites well known for their important pharmacological properties. The results of this study on phenolics, monoterpenes, and organic acids have provided new data on these fruits. The obtained results showed that breadfruit from the biggest island of the Union of Comoros also presented antimicrobial and antioxidant properties, even if some differences in effectiveness existed between fruits from different regions.

Floral Induction of Longan (Dimocarpus longan) by Potassium Chlorate: Application, Mechanism, and Future Perspectives

Longan (Dimocarpus longan L.) is one of the most important tropical and subtropical fruits in the world. Longan fruit has high nutritional and medical value, and is regarded as a treasure among fruits. Since it was first reported that potassium chlorate (KClO₃) could be successfully applied to promote flowering in longan, this compound has been widely used in the production of on-season and off-season longan fruits. KClO₃ has thus played a great role in promoting the development of the longan industry. In this review, we summarize the application methods, influencing factors, and physiological and molecular mechanisms associated with KClO₃-mediated induction of longan flowering. It can be deduced that leaves may play a crucial role in the transport of and response to KClO₃. Leaves supply carbon and nitrogen nutrition, and hormone and signaling molecules needed for the differentiation of apical buds. Moreover, cytokinins may be crucial for KClO₃-mediated induction of longan flowering. More effort should be focused on studying the molecular mechanisms underlying this process. This will not only help us to better understand floral induction by KClO₃ in longan but also enrich our understanding of flowering regulation mechanisms in woody plants.

Integrative Analysis of the Coloring Mechanism of Red Longan Pericarp through Metabolome and Transcriptome Analyses

The pericarp of longan (Dimocarpus longan Lour.) is rich in secondary metabolites and typically yellow-brown or gray-yellow in appearance. Here, we obtained a specific longan type, called red pericarp (RP) longan, which has a strong red pericarp. To understand the coloring mechanism of RP longan, metabolome and transcriptome data were used to analyze its secondary metabolites and molecular mechanism. From the results of liquid chromatography tandem mass spectrometry, 597 substances were identified in RP longan and 'Shixia' (SX) longan. Among these substances, 33 (mostly including flavonoids) were found in RP longan and 23 (mostly containing phenolic acids) were identified in SX longan. We identified five types of anthocyanins in longan pericarp, including three cyanidin derivatives, one delphinidin derivative, and one pelargonidin derivative. Three cyanidin derivatives, which contained cyanidin 3-O-glucoside, cyanidin 3-O-6″-malonyl-glucoside, and cyanidin O-syringic acid, were the primary components of anthocyanidins, and they only existed in RP longan. Delphinin 3-O-glucoside existed only in SX longan, and pelargonin O-rutinoside existed in RP and SX longan. However, their contents were extremely low. The structural genes F3H, F3'H, UFGT, and GST and the controlling genes containing MYB, bHLH, NAC, and MADS in the biosynthetic pathway of anthocyanin were significantly upregulated in RP longan. In summary, the strong red hue of RP longan is due to the accumulation of cyanidin derivatives in its pericarp, and the genes F3'H and F3'5'H may play an important role in selecting which component of anthocyanins will be synthesized. These results can provide scientific guidance for understanding and developing bioactive compounds from longan fruits.

A Review: Underutilized plant of Sabah and Its Potential Value

Underutilized plants are referred to a plant species which their potential is not fully utilized yet and they are usually found abundantly in certain local area but globally rare. Sabah is known for a high biodiversity and contains many underutilized plants. To our knowledge, this is the first review is to provide an overview information of medicinal value and pharmacological properties of underutilized plant in Sabah. Extract and metabolites in different part of several underutilized plant contains multiple beneficial bioactive compounds and exploitation of these compounds was supported by additional data which plays various biological activities including anti-atherosclerotic, anti-cancer, antihypercholesterolemic and anti-ulcerogenic. A handful of pharmacological studies on the natural product these underutilized plants have conclusively outlined the mode of action in treatment of several diseases and in other health aspects. This paper limits its scope to reviewe and highlight the potential of using underutilized plants in Sabah only which could serve as reliable resource for health product development in pharmaceutical and nutraceutical through continuous discovering of more active and sustainable resources as well as ingredients for food and medicine.

Innovative Technologies for Extraction and Microencapsulation of Bioactives from Plant-Based Food Waste and their Applications in Functional Food Development

The by-products generated from the processing of fruits and vegetables (F&V) largely are underutilized and discarded as organic waste. These organic wastes that include seeds, pulp, skin, rinds, etc., are potential sources of bioactive compounds that have health imparting benefits. The recovery of bioactive compounds from agro-waste by recycling them to generate functional food products is of increasing interest. However, the sensitivity of these compounds to external factors restricts their utility and bioavailability. In this regard, the current review analyses various emerging technologies for the extraction of bioactives from organic wastes. The review mainly aims to discuss the basic principle of extraction for extraction techniques viz. supercritical fluid extraction, subcritical water extraction, ultrasonic-assisted extraction, microwave-assisted extraction, and pulsed electric field extraction. It provides insights into the strengths of microencapsulation techniques adopted for protecting sensitive compounds. Additionally, it outlines the possible functional food products that could be developed by utilizing components of agricultural by-products. The valorization of wastes can be an effective driver for accomplishing food security goals.

Investigation of the Synergistic Effect of Brown Sugar, Longan, Ginger, and Jujube (Brown Sugar Longan Ginger Tea) on Antioxidation and Anti-Inflammation in In Vitro Models

This research unveils the synergistic effect of brown sugar, longan, ginger, and jujube on the beneficial effects of antioxidation and anti-inflammation. Longan, ginger, and jujube are ubiquitous herbs in traditional Chinese medicine (TCM) and are frequently used in folk remedies. Longan and ginger have been reported to be beneficial for antioxidation, anti-inflammation, ant-obesity, and nonalcoholic fatty liver disease (NAFLD) improvements. However, the potential scientific and medical benefits of their combination Brown Sugar Longan Ginger Tea (BSLGT), a popular drink in Chinese cultures, are elusive. Through the in vitro methodologies, we discovered that BSLGT could significantly improve the mitochondrial activity, antioxidant capacity, lipid content, and inflammatory response in human hepatocytes. In addition, BSLGT also exerted positive effects on the downregulation of atherosclerosis-associated, vasoconstrictor, and thrombosis-related gene expression in human umbilical vein endothelial cells. In short, our experimental results successfully revealed that the antioxidative and anti-inflammatory effects of BSLGT may have the potential to improve liver metabolism and cardiovascular inflammation although solid evidence requires further investigation.

Acute and chronic oral toxicity assessment of longan sugar extracts derived from whole fruit and from fruit pulp in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Longan (Dimocarpus longan Lour.) is one of the most popular subtropical fruits. Various parts of longan, including seeds, pericarp and pulp, have long been used in traditional medicine in China, Thailand and other Asian countries. The pulp has high sugar, vitamin and mineral content as well as bioactive components. The seeds and pericarp have also been reported to contain beneficial polyphenolic compounds. Longan sugar extract from pulp (LGSP) is prepared as a conventional sugar product. Longan sugar extract from whole longan fruit (LGSW) is also offered as a health food and as a medicinal product.

AIM OF THE STUDY

The objective of this study was to identify and compare potential health hazards of both LGSW and LGSP by testing for acute and chronic oral toxicity in rats.

MATERIALS AND METHODS

In acute toxicity testing, an oral dose (20 g/kg) of either LGSW or LGSP was administered to groups of rats. Mortality and clinical signs of toxicity were observed for 24 h, and then daily for a total of 14 days. In the chronic toxicity test, either LGSW (1, 2.5 and 5 g/kg/day) or LGSP (5 g/kg/day) was administered orally for a period of 180 days. After that treatment period, the rats in the satellite groups which received the highest doses of either LGSW or LGSP were observed for an additional 28 days. The rats then underwent clinical observation, body and organ weight measurement, hematological and biochemical analyses, and histopathological examination.

RESULTS

In the acute toxicity study, the oral administration of LGSP or LGSW in either pellet or syrup formulations did not cause mortality or any pathological abnormalities. In the chronic toxicity study, neither LGSW nor LGSP resulted in death or in any changes in behavior of the rats. All hematological and serum biochemical values of both the LGSW- and LGSP-treated groups were within the normal ranges. No histopathological abnormalities of any internal organs were observed.

CONCLUSION

The safety of longan sugar extract made from whole fruit (pulp, seeds and pericarb) is comparable to that of longan sugar extract made from pulp alone.

Bioactive Flavonoid Glycosides and HPLC and UPLC Quantification of Commercial Astragali Complanati Semen

Eleven compounds, including nine known flavonoid glycosides (1-4, 6-8, and 10-11), one isoflavone glycoside (5), and a glansreginic acid (9), were isolated from the 80% ethanol extract of commercial Astragali Complanati Semen (ACS). All chemical structures were determined by spectroscopic analyses, including 1D and 2D NMR. Compounds 2, 4, 5, 6, 9, and 10 were isolated and identified from the title plant for the first time. Biological evaluation revealed that all the isolates showed promising anti-NO production, and 1, 2, 3, and 8 were more potent in antioxidant activity than vitamin E. The major peaks in the UPLC and HPLC profiles identified their chemical structures by comparing their retention time and UV spectra with those of the reference substances. Furthermore, nine of the eleven samples collected from North, Middle, and South regions of Taiwan possessed similar HPLC fingerprints and were identified as Astragali Complanati Semen, whereas the other two samples from southern Taiwan would be the adulterants due to the different fingerprinting patterns. In addition, an HPLC-UV method was employed to determine the content of target compound complanatuside (11) with good linear regression (R2 = 0.9998) for ACS in the Taiwanese market. Of the isolates, flavonol glycosides 1 and 3 were the major peaks in HPLC/UPLC, and showed more potent antioxidant and anti-NO production activities than that of 11, revealing that these compounds can be the available agents for the quality control of ACS.

Identification of a Proanthocyanidin from Litchi Chinensis Sonn. Root with Anti-Tyrosinase and Antioxidant Activity

This work follows an ethnobotanical study that took place in the island of Mayotte (France), which pointed out the potential properties of Litchi chinensis Sonn. roots when used to enhance skin health and appearance. Through in vitro testing of a crude methanolic extract, high anti-tyrosinase (skin whitening effect) and antioxidant activities (skin soothing effect) could be measured. HPLC successive bio-guided fractionation steps allowed the purification of one of the compounds responsible for the biological activities. The isolated compound was characterized by UV, IR, MS and 2D-NMR, revealing, for the first time in Litchi chinensis Sonn. roots, an A-type proanthocyanidin and thus revealing a consensus among the traditional use shown by the ethnobotanical study, in vitro biological activities and chemical characterization.

Recent Trends in Controlling the Enzymatic Browning of Fruit and Vegetable Products

Enzymatic browning because of polyphenol oxidases (PPOs) contributes to the color quality of fruit and vegetable (FV) products. Physical and chemical methods have been developed to inhibit the activity of PPOs, and several synthetic chemical compounds are commonly being used as PPO inhibitors in FV products. Recently, there has been an emphasis on consumer-oriented innovations in the food industry. Consumers tend to urge the use of natural and environment-friendly PPO inhibitors. The purpose of this review is to summarize the mechanisms underlying the anti-browning action of chemical PPO inhibitors and current trends in the research on these inhibitors. Based on their mechanisms of action, chemical inhibitors can be categorized as antioxidants, reducing agents, chelating agents, acidulants, and/or mixed-type PPO inhibitors. Here, we focused on the food ingredients, dietary components, food by-products, and waste associated with anti-browning activity.

A biological clean processing approach for the valorization of speckled shrimp Metapenaeus monoceros by-product as a source of bioactive compounds

The efficiency of the proteolytic strain Anoxybacillus kamchatkensis M1V in the fermentation of speckled shrimp by-product was investigated for the recovery of a deproteinized bioactive hydrolysate. The biological activities of the resulting hydrolysate were also examined by applying several antioxidant and enzyme inhibitory assays. The strain M1V was found to produce high level of protease activity (2000 U/mL) when grown in media containing only shrimp powder at 25 g/L. The crude protease displayed a significant deproteinization capabiliy, with the best efficiency (48%) being recorded for an enzyme to substrate (E/S) ratio of 30 U/mg. Following the deproteinization, chitin was recovered and the authenticity was confirmed by Fourier-transform infrared spectroscopy (FTIR) analysis. On the other hand, the obtained hydrolysate showed a significant enzymatic inhibitory potential against acetylcholinesterase, tyrosinase, amylase, and angiotensin I convertase, and a strong antioxidant activity. Graphical Abstract.

Antioxidant potential of theaflavin ameliorates the activities of key enzymes of glucose metabolism in high fat diet and streptozotocin - induced diabetic rats

Objectives: The present study was to evaluate the effect of theaflavin on the activities of key enzymes of carbohydrate metabolism in high fat diet and streptozotocin – induced diabetic rats.

Methods: Diabetes was induced in male albino Wistar rats by feeding them with high fat diet comprising of standard laboratory rat chow 84.3%, lard 5%, egg yolk powder 10%, cholesterol 0.2% and bile salt 0.5% for 2 weeks. After 2 weeks, the animals were kept in an overnight fast and injected with low dose of streptozotocin (40 mg/kg b.w).

Results: Theaflavin (100 mg/kg b.w /day) was administered orally to diabetic rats for 30 days. At the end of the experimental period, diabetic control rats showed significant increase in plasma glucose, homeostatic model assessment of insulin resistance (HOMA-IR), glycosylated hemoglobin (HbA1c) with concomitant decrease in plasma insulin, total hemoglobin and body weight. The activities of key enzymes of carbohydrate metabolism, lipid peroxidation markers, antioxidant enzymes, glycogen content and glycogen synthase and glycogen phosphorylase were also altered in diabetic rats.

Discussion: Oral administration of theaflavin to diabetic rats significantly ameliorated all the biochemical alterations to near normal levels. The results of the present study suggest that theaflavin exhibits antidiabetic effect through its antioxidant activity.

Investigation of the Most Suitable Conditions for Dehydration of Tuckeroo (Cupaniopsis anacardioides) Fruits

Tuckeroo (Cupaniopsis anacardioides) is an Australian native tree, possessing high level bioactivity and antioxidant activity. To prevent deterioration of active constituents, appropriate drying practices must be determined. This study comparatively evaluates the impact of a range of drying methods including freeze-, microwave-, vacuum-, hot air- and sun-drying on the physical, phytochemical and antioxidant characteristics of Tuckeroo fruit. Experimental results showed that the five drying methods had significant impact on the physicochemical properties and antioxidant activity of the fruits. Of the drying methods assessed, freeze drying best preserved Tuckeroo activity, recording higher total phenolic content (TPC) (81.88 mg gallic acid equivalent (GAE)/g), total flavonoids (TFC) (107.71 mg catechin equivalent (CAE)/g), proanthocyanidins (TPro) (83.86 mg CAE/g) and exhibited the strongest antioxidant capacity. However, vacuum drying at 65 kPa, 100 °C for 5 h is recommended for drying Tuckeroo fruits for further processing in a large scale as it also retained high levels of TPC, TFC and TPro (58 mg GAE/g, 91 mg CAE/g and 74 mg CAE/g, respectively).

Ellagic acid, a plant phenolic compound, activates cyclooxygenase-mediated prostaglandin production

In recent years, ellagic acid (EA), a naturally-occurring phenolic compound richly contained in some of the human food sources such as Longan and Litchi, was reported to have a number of biological effects. Based on our earlier 3D-QSAR/CoMFA models for cyclooxygenase (COX) I and II, we hypothesize that EA may have the potential to modulate the catalytic activity of COX enzymes, and this hypothesis is examined in the present study. The results from both in vitro and in vivo experiments show that EA is an activator of COX enzyme-catalyzed production of prostaglandin E2, a representative prostaglandin tested. Mechanistically, EA can activate the peroxidase active site of COX enzymes by serving as a co-substrate, presumably for the reduction of protoporphorin IX with FeIV inside. The effect of EA is abrogated by the co-presence of galangin, which is known to bind to COX's peroxidase active site and thereby blocks the effect of the reducing co-substrates. In view of the known physiological functions of COX enzymes in the body, it is suggested that some of the pharmacological and/or toxicological effects of EA may result from an increased production of certain prostaglandins and their related derivatives in the body.

Antityrosinase, Antioxidant, and Cytotoxic Activities of Phytochemical Constituents from Manilkara zapota L. Bark

Hyperpigmentation is considered by many to be a beauty problem and is responsible for photoaging. To treat this skin condition, medicinal cosmetics containing tyrosinase inhibitors are used, resulting in skin whitening. In this study, taraxerol methyl ether (1), spinasterol (2), 6-hydroxyflavanone (3), (+)-dihydrokaempferol (4), 3,4-dihydroxybenzoic acid (5), taraxerol (6), taraxerone (7), and lupeol acetate (8) were isolated from Manilkara zapota bark. Their chemical structures were elucidated by analysis of their nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) data, and by comparing them with data found in the literature. The in vitro antityrosinase, antioxidant, and cytotoxic activities of the isolated compounds (1-8) were evaluated. (+)-Dihydrokaempferol (4) exhibited higher monophenolase inhibitory activity than both kojic acid and α-arbutin. However, it showed diphenolase inhibitory activity similar to kojic acid. (+)-Dihydrokaempferol (4) was a competitive inhibitor of both monophenolase and diphenolase activities. It exhibited the strongest 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and ferric reducing antioxidant power (FRAP) activities of the isolated compounds. Furthermore, (+)-dihydrokaempferol (4) also demonstrated potent cytotoxicity in breast carcinoma cell line (BT474), lung bronchus carcinoma cell line (Chago-K1), liver carcinoma cell line (HepG2), gastric carcinoma cell line (KATO-III), and colon carcinoma cell line (SW620). These results suggest that M. zapota bark might be a good potential source of antioxidants and tyrosinase inhibitors for applications in cosmeceutical products.

Protective effect of theaflavin on glycoprotein components and TCA cycle enzymes in high-fat diet and streptozotocin-induced diabetic rats

BACKGROUND

Theaflavins are major polyphenols in black tea which is the most widely consumed tea in the world. They possess a broad spectrum of biological activities, such as antioxidant, anti-tumor, anti-inflammatory, and cardio-protective effects. The present study was aimed to evaluate the protective effect of theaflavin on glycoprotein content and tricorboxylic acid cycle enzymes in high-fat diet and streptozotocin-induced diabetic rats as there was no study on this aspect. Diabetes was induced in male albino Wistar rats by feeding them with high-fat diet and injecting them intraperitoneally with streptozotocin (40 mg/kg b.wt).

RESULTS

Different doses of theaflavin (25, 50, and 100 mg/kg b.wt /day) were administered orally to high-fat diet and streptozotocin-induced diabetic rats for 30 days for fixing the glucose lowering dose. However, the dose at 100 mg/kg b.wt showed a significant reduction in the levels of plasma glucose and Homeostatic Model Assessment of Insulin Resistance with concomitant elevation of insulin when compared to the other two doses (25 and 50 mg/kg b.wt). Hence, 100 mg/kg b.wt was fixed as an effective dose and used for further analysis. Theaflavin administration restored the altered glycosylated hemoglobin, hemoglobin and glycoproteins (Hexose, hexosamine, fucose, and sialic acid) and TCA cycle enzymes (isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, succinate dehydrogenase, and malate dehydrogenase) near the normal levels by correcting hyperglycemia. Improved histological changes were observed in the pancreas of diabetic rats upon treatment with theaflavin which supported the biochemicals investigated.

CONCLUSION

The effect produced by the theaflavin on various parameters was comparable to that of metformin-a reference antidiabetic drug. These findings suggest that theaflavin can replace the commercial drugs which could lead to reduction in toxicity and side effect caused by the later as well as reduce the secondary completions.

Pericarp and seed of litchi and longan fruits: constituent, extraction, bioactive activity, and potential utilization

Litchi (Litchi chinensis Sonn.) and longan (Dimocarpus longan Lour.) fruits have a succulent and white aril with a brown seed and are becoming popular worldwide. The two fruits have been used in traditional Chinese medicine as popular herbs in the treatment of neural pain, swelling, and cardiovascular disease. The pericarp and seed portions as the by-products of litchi and longan fruits are estimated to be approximately 30% of the dry weight of the whole fruit and are rich in bioactive constituents. In the recent years, many biological activities, such as tyrosinase inhibitory, antioxidant, anti-inflammatory, immunomodulatory, anti-glycated, and anti-cancer activities, as well as memory-increasing effects, have been reported for the litchi and longan pericarp and seed extracts, indicating a potentially significant contribution to human health. With the increasing production of litchi and longan fruits, enhanced utilization of the two fruit by-products for their inherent bioactive constituents in relation to pharmacological effects is urgently needed. This paper reviews the current advances in the extraction, processing, identification, and biological and pharmacological activities of constituents from litchi and longan by-products. Potential utilization of litchi and longan pericarps and seeds in relation to further research is also discussed.

Microwave synthesis of ZnO nanoparticles using longan seeds biowaste and their efficiencies in photocatalytic decolorization of organic dyes

Crude water extract of the ground longan seeds which have been disposed in a large amount annually in Northern Thailand has been used in a simple and rapid microwave synthesis of ZnO nanoparticles. The particles were characterized by the UV-vis spectroscopy, Fourier-transformed infrared spectroscopy, X-ray diffraction, electron diffraction, energy dispersive X-ray spectroscopy, and transmission electron microscopy and revealed to be pure hexagonal phase. Influences of zinc precursor in the extract, microwave power, and irradiation time on particle sizes were studied. The use of 800 W and 30 cycles of the microwave irradiation provided the ZnO particles of 10-100 nm in size with an active surface area, a band gap energy, and a zero-point charge of 35 m²·g^-1, 3.42 eV, and pH 7.7, respectively, after the calcination. Photocatalytic efficiencies of the synthesized particles were evaluated through the decolorization of methylene blue, malachite green, methyl orange, and orange II, and proved to be on par with commercially available titanium dioxide (Arroxide®P-25) under the same conditions. The use of the longan seeds biowaste as a sustainable supply of natural reagents for the green synthesis of ZnO nanoparticles which can be employed further for waste water treatment of the local textile dyeing industry is therefore presented. Graphical Abstract.

Polyphenols and Alkaloids in Byproducts of Longan Fruits (Dimocarpus Longan Lour.) and Their Bioactivities

The longan industry produces a large amount of byproducts such as pericarp and seed, resulting in environmental pollution and resource wastage. The present study was performed to systematically evaluate functional components, i.e., polyphenols (phenolics and flavonoids) and alkaloids, in longan byproducts and their bioactivities, including antioxidant activities, nitrite scavenging activities in simulated gastric fluid and anti-hyperglycemic activities in vitro. Total phenolic and total flavonoid contents in pericarp were slightly higher than those in seeds, but seeds possessed higher alkaloid content than pericarp. Four polyphenolic substances, i.e., gallic acid, ethyl gallate, corilagin and ellagic acid, were identified and quantified using high-performance liquid chromatography. Among these polyphenolic components, corilagin was the major one in both pericarp and seed. Alkaloid extract in seed showed the highest DPPH radical scavenging activity and oxygen radical absorbance capacity. Nitrite scavenging activities were improved with extract concentration and reaction time increasing. Flavonoids in seed and alkaloids in pericarp had potential to be developed as anti-hyperglycemic agents. The research result was a good reference for exploring longan byproducts into various valuable health-care products.

HPLC Profile of Longan (cv. Shixia) Pericarp-Sourced Phenolics and Their Antioxidant and Cytotoxic Effects

Longan (Dimocarpus longan Lour.) pericarp, the main by-product of aril and pulp processing, is abundant in phenolic compounds and worthy of further utilization. The present work firstly reported HPLC analysis and in vitro antioxidant evaluation of longan (cv. Shixia) pericarp-derived phenolics (LPPs), the purified longan pericarp extract (LPE), as well as their cytotoxic effect on lung cancer cell line, A549. The results indicated that the purified LPE had significant amounts of phenolics, with content of 57.8 ± 0.6 mg of gallic acid equivalents per gram of dry longan pericarp (mg GAE·g^-1 DLP), which consisted of six phenolic compounds (A⁻F), including protocatechuic acid (A), isoscopoletin (B), quercetin (C), ellagic acid (D), corilagin (E), and proanthocyanidins C1 (F). Antioxidant assays showed that LPPs (10 μM) and LPE (1.0 mg·mL^-1) had certain antioxidant activities, in which corilagin (E) possessed the best DPPH radical scavenging rate 71.8 ± 0.5% and •OH inhibition rate 75.9 ± 0.3%, and protocatechuic acid (A) exhibited the strongest Fe²⁺ chelating ability 36.4 ± 0.7%. In vitro cytotoxic tests suggested that LPPs had different effect on A549 cell line, in which corilagin (E) exhibited potent cytotoxicity with an IC₅₀ value of 28.8 ± 1.2 μM. These findings were further confirmed by cell staining experiments.

Bioactive Multilayer Polylactide Films with Controlled Release Capacity of Gallic Acid Accomplished by Incorporating Electrospun Nanostructured Coatings and Interlayers

The present research reports on the development of bi- and multilayer polylactide (PLA) films by the incorporation of electrospun nanostructured PLA coatings and interlayers containing the antioxidant gallic acid (GA) at 40 wt% onto cast-extruded PLA films. To achieve the bilayer structures, submicron GA-loaded PLA fibers were applied on 200-µm cast PLA films in the form of coatings by electrospinning for 1, 2, and 3 h. For the multilayers, the cast PLA films were first coated on one side by electrospinning, then sandwiched with 10-µm PLA film on the other side, and the resultant whole structure was finally thermally post-treated at 150 °C without pressure. Whereas the bilayer PLA films easily delaminated and lacked transparency, the multilayers showed sufficient adhesion between layers and high transparency for deposition times during electrospinning of up to 2 h. The incorporation of GA positively contributed to delaying the thermal degradation of PLA for approximately 10 °C, as all films were thermally stable up to 345 °C. The in vitro release studies performed in saline medium indicated that the GA released from the bilayer PLA films rapidly increased during the first 5 h of immersion while it stabilized after 45–250 h. Interestingly, the PLA multilayers offered a high sustained release of GA, having the capacity to deliver the bioactive for over 1000 h. In addition, in the whole tested period, the GA released from the PLA films retained most of its antioxidant functionality. Thus, during the first days, the bilayer PLA films can perform as potent vehicles to deliver GA while the multilayer PLA films are able to show a sustained release of the natural antioxidant for extended periods.

Ultrasound-Assisted Extraction of Phenolic Compounds from Mango (Mangifera indica cv. Chok Anan) Peel and Its Inhibitory Effect on Enzymatic Browning of Potato Puree

Enzymatic browning is a serious quality deterioration of fresh-cut fruits and vegetables. Recently, consumers and fruit and vegetable industrial processors have demanded the use of natural antibrowning agents to replace the use of chemicals. Mango (Mangifera indica cv. Chok Anan) peel was prepared in the form of mango peel liquid nitrogen powder. This included extraction by ultrasound or ultrasound combined with stirring. The total phenolic content of mango peel liquid nitrogen powder extract (further in the text: mango peel extract) was the highest after the extraction for 15 min using ultrasound followed by stirring for 15 min. The browning value of potato puree treated with mango peel extract was lower, while its L* value and the hue angle were larger than of samples treated with ascorbic or citric acids during storage for 6 h. Mango peel extract had a competitive inhibitory effect on potato polyphenol oxidase (PPO), which was larger than either ascorbic or citric acid. Its IC₅₀ value was 0.3 mg/mL. Mangiferin, protocatechuic and gallic acid found in mango peel extract had high inhibitory effect on potato PPO, making mango peel a potential natural source of enzymatic browning inhibitor.

Evaluation of byproducts from the wine-making industry by identification of bioactive compounds

Byproducts obtained after wine production constitute an important source for the extraction of antioxidant compounds. Phenolic compounds showed a wide spectrum of biological actions for the human health, often associated with neuroprotective, cardioprotective, antimicrobial and other health-related effects. The aim of the present study was to determine the phenolic compounds content and antioxidant activity of grape marc from selected grapes from Iaşi vineyard. The total phenolic content of the extracts was measured using the Folin-Ciocâlteu method, with some modifications. The DPPH (2,2-diphenyl-1-picrylhydrazyl) assay was used to evaluate radical scavenging activity, by bleaching of purple methanolic solution of the stable radical. All extracts were able to reduce DPPH radical with different degrees of scavenging activity. The highest radical scavenging activity was determined for the extract obtained from Merlot and Fetească Neagră (98.142 μg/mL, and 115.78 μg/mL respectively), with positive correlation between scavenging activity on DPPH and total phenolic content. The total phenolic content varied among the analysed extracts, with a higher concentration in extracts obtained from Merlot, Fetească Neagră and Traminer rosé (2.42 GAE/mL, 1.45 GAE/mL and 1.24 GAE/mL respectively), followed by Sauvignon Blanc and Muscat Ottonel extracts with comparable amounts. The FRAP (ferric reducing antioxidant power) method relies on the color change of a complex with Fe+3 ion of the 2,4,6-tri(2-pyridyl) – 1,3,5-triazine (TPTZ) radical due to the reduction of the ferric ion to the ferrous iron (Fe+2) in this complex. The highest radical scavenging activity was determined in the extract obtained from Merlot and Fetească Neagră (1164.22 μM Trolox/100 mL and 782.09 μM Trolox/100 mL respectively), a positive correlation between scavenging activity determined by FRAP method and total phenolic content being observed.Statistical analysis showed a close relationship between content of phenolic compounds and antioxidant capacity, the marc of Merlot and Fetească Neagră had the highest contents of anthocyanins. The results suggested that grape pomace may be exploited as antioxindant source.