Metabolomic profiling of the phytomedicinal constituents of Carica papaya L. leaves and seeds by 1H NMR spectroscopy and multivariate statistical analysis

In-silico screening and identification of potential drug-like compounds for dengue-associated thrombocytopenia from Carica papaya leaf extracts

Dengue virus is a mosquito-borne pathogen that causes a variety of illnesses ranging from mild fever to severe and fatal dengue haemorrhagic fever or dengue shock syndrome. One of the major clinical manifestations of severe dengue infection is thrombocytopenia. The dengue non-structural protein 1 (NS1) is the primary protein that stimulates immune cells via toll-like receptor 4 (TLR4), induces platelets, and promotes aggregation, which could result in thrombocytopenia. The leaf extracts of Carica papaya seem to have therapeutic benefits in managing thrombocytopenia associated with dengue. The present study focuses on understanding the underlying mechanism of the use of papaya leaf extracts in treating thrombocytopenia. We have identified 124 phytocompounds that are present in the papaya leaf extract. The pharmacokinetics, molecular docking, binding free energy calculations, and molecular dynamic simulations were performed to investigate the drug-like properties, binding affinities, and interaction of phytocompounds with NS1 protein as well as the interactions of NS1 with TLR4. Three phytocompounds were found to bind with the ASN130, a crucial amino acid residue in the active site of the NS1 protein. Thus, we conclude that Rutin, Myricetin 3-rhamnoside, or Kaempferol 3-(2''-rhamnosylrutinoside) may serve as promising molecules by ameliorating thrombocytopenia in dengue-infected patients by interfering the interaction of NS1 with TLR4. These molecules can serve as drugs in the management of dengue-associated thrombocytopenia after verifying their effectiveness and assessing the drug potency, through additional in-vitro assays.Communicated by Ramaswamy H. Sarma.

Phenolic and Metabolic Profiles, Antioxidant Activities, Glycemic Control, and Anti-Inflammatory Activity of Three Thai Papaya Cultivar Leaves

This study thoroughly examined the proximate composition, bioactive composition, and in vitro biological activities of three different cultivars of papaya leaf extracts (PLEs) as potential functional ingredients and nutraceuticals. The dark green leaves of three papaya cultivars, Khaek Dam (KD), Holland (H), and Thai Local (L), were used in this study. The protein content of the leaves ranged from 25.96 to 32.18%, the fat content ranged from 7.34 to 11.66%, the carbohydrate content ranged from 5.80 to 17.91%, the moisture content ranged from 6.02 to 6.49%, the ash content ranged from 11.23 to 12.40%, and the fiber content ranged from 23.24 to 38.48%. The L cultivar possessed significantly higher protein and carbohydrate contents, whereas the H cultivar had the highest ash content (p < 0.05). The total phenolic content (TPC) ranged from 113.94 to 173.69 mg GAE/g extract, with the KD cultivar having the highest TPC (p < 0.05). Several metabolic compounds such as phenolic compounds (particularly kaempferol, isorhamnetin, quercetin, ferulic acid, isoferulic acid, salicylic acid, sinapic acid, syringic acid, and vanillin), terpenoids (such as eucalyptol), glycosides, and indole were identified. The PLE from the KD cultivar had the highest levels of DPPH• inhibition, metal chelation, reducing power, and antidiabetic activity (p < 0.05), suggesting superior biological activity. All three PLEs reduced the proliferation of RAW 264.7 cells in a dose-dependent manner with low nitric oxide formation. These results indicate that the papaya leaf, particularly from the KD cultivar, could be a promising source of functional food ingredients.

The standardized Jamu pahitan, an Indonesian antidiabetic formulation, stimulating the glucose uptake and insulin secretion in the in-vitro models

Jamu pahitan is a polyherbal formulation commonly used for the traditional management of diabetes in Indonesia and is mainly prepared from Andrographis paniculata (Burm.f.) Nees. It is widely varied in herbal composition for every region has their own plant component addition to the formulation. A version of the formulation used in the greater Surakarta area contained five plant constituents. This study evaluated the in-vitro glucose uptake and insulin secretion stimulatory activities of Jamu pahitan to provide scientific evidence on its efficacy and safety of use. The water and ethanol extracts of three Jamu pahitan formulations were prepared. The total phenolic content (TPC) of the extracts was evaluated by the standard Folin-Ciocalteau method. Their effects on the viability of L6 skeletal muscle and RIN-m5F pancreatic cells were evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The glucose utilized by L6 myotubes treated with Jamu pahitan was assessed indirectly by the glucose oxidase method. The insulin secreted by RIN-m5F treated with the formulation extracts was analyzed by the enzyme-linked immunosorbent assay (ELISA). The correlation between TPC and the profile of safety and efficacy of the formulation was statistically evaluated. The water extracts of Jamu pahitan were safe and exerted significant glucose uptake and insulin secretion stimulatory activity in L6 and RIN-m5F, respectively. The ethanol extracts showed more potent effects than their water counterpart, albeit they exerted cytotoxic effects on the cells at the higher tested concentrations. The formulations at lower concentrations stimulated the proliferation of RIN-m5F. In addition, the TPC was strongly correlated with the glucose uptake and insulin secretion stimulatory activities and also the IC₅₀ of the cells in positive manner. The present study supported the use of Jamu pahitan for the traditional management of diabetes in Indonesia by stimulating glucose uptake in the muscle cells and improving insulin secretion in β-cells.

Characterization of Extracts of Coffee Leaves (Coffea arabica L.) by Spectroscopic and Chromatographic/Spectrometric Techniques

Coffea arabica L. leaves represent a viable alternative to the canonical matrices used for preparation of beverages, such as tea leaves and grounded coffee beans. Coffee leaves infusions are rich in antioxidant phenolic compounds and have a lower concentration of caffeine. Due to increasing interest in this field, a complete study of the bioactive compounds as chlorogenic acids, xanthones and alkaloids is noteworthy. C. arabica leaves were subjected to ultrasound-assisted extraction, and the extracts were studied via nuclear magnetic resonance spectroscopy (NMR) and chromatographic techniques coupled with mass spectrometry (HPLC-MSn) to identify and quantify the secondary metabolites profile through an untargeted data dependent approach. A quantitative analysis was performed for the major components—chlorogenic acids, mangiferin, caffeine and trigonelline—via HPLC-MS in Single Ion Monitoring (SIM) mode. In total, 39 compounds were identified. The presence of these bioactive compounds proved the strong potential of C. arabica leaves as functional food and as an alternative to classic infused beverages.

Degradation kinetics of carpaine and antioxidant properties of dried Carica papaya leaves as affected by drying methods

Carpaine in papaya leaves has the potential to treat dengue fever and it also contains antioxidants which could prevent or inhibit oxidation processes in the human body. Studies were conducted on the effects of storage on carpaine retention and antioxidant properties of dried papaya leaves. Results showed that the Weibull model could predict well the degradation kinetics of carpaine in all samples (freeze drying and hot air drying at 60 °C and 70 °C) except for hot air dried samples at 80 °C and shade dried samples (first order model). Generally, freeze dried samples showed the highest half-life whereas total polyphenols content and antioxidant properties (ABTS and DPPH free radical scavenging activities) of all dried samples decreased with storage period. An increasing trend in total colour difference (ΔE * ) was observed in all samples possibly due to chlorophyll degradation. It is thus recommended to select freeze dried samples for storage purpose due to better stability as indicated by the lowest rate constant (k = 0.0135 1/month) and the highest half-life (t 1/2 = 51.2 months).

Hot Air Treatment Elicits Disease Resistance against Colletotrichum gloeosporioides and Improves the Quality of Papaya by Metabolomic Profiling

Forced air heat treatment could induce defenses to protect fruit from pathogen attacks and has been applied as an alternative to methyl bromide for phytosanitary treatment before exportation. However, few studies were reported on the regulation mechanism of antifungal effect and delayed physiological disorders of papaya by heat treatment. Therefore, we aim to explore the fruit's resistance to pathogens and the inhibition of physiological disorders by metabolomic profiling. In our study, papaya fruits were treated with 47.2°C for 30, 60, and 90 min by forced hot air treatment. The disease resistance against Colletotrichum gloeosporioides, quality parameters, and metabolites of papaya fruits were measured during 10 days of storage after heat treatment by metabolomic profiling. Papaya fruits after 30 and 60 min heat treatment had higher firmness, a delayed degreening and yellowing (lower a value) process, and a higher lightness (L) and hue angle (h) during storage. Heat treatment also delayed ripening, inhibiting the growth of C. gloeosporioides and softening of papaya. Metabolites and enzymes inhibited ROS scavenging, depressed ABA-regulated respiratory, and activated phenylpropanoid metabolism. Our study provides a broad picture of fruit resistance to pathogens and the inhibition of physiological disorders by metabolomic profiling, which is induced by heat treatment.

Enhancement of TRP Gene Expression and UV Absorption by Bioconverted Chestnut Inner Shell Extracts Using Lactiplantibacillus plantarum

In this work, the suppression of tyrosinase-related genes, including an improvement in UV absorption effects of bioconverted CS extracts (BCS), was investigated to improve the skin-whitening effect. Total polyphenols and total flavonoids, which are bioactive components, increased 2.6- and 5.4-times in bioconversion using Lactiplantibacillus plantarum SM4, respectively, as compared to ultrasound-assisted extracts (UCS). The effect of BCS on radical scavenging activity, UV-A absorption, and tyrosinase activity inhibition, contributing to skin-whitening, were 1.3-, 1.2-, and 1.2-times higher than those of UCS, respectively. The main component identified in high-performance liquid chromatography (HPLC) was gallic acid in both UCS and BCS, which increased by 2.9-times following bioconversion. The gene expression of tyrosinase-related proteins, including TRP-1 and TRP-2 genes, was studied to confirm the suppression of melanin synthesis by BCS in order to identify the skin-whitening mechanism, and BCS decreased both genes’ expression by 1.7- and 1.6-times, demonstrating that BCS effectively suppressed melanin synthesis. These findings imply that the chestnut inner shell can be employed as a cosmetic material by simultaneously inhibiting melanogenesis and enhancing UV-A absorption through bioconversion using L. plantarum SM4.

Effect of Different Processing Methods on the Chemical Constituents of Scrophulariae Radix as Revealed by 2D NMR-Based Metabolomics

Scrophulariae Radix (SR) is one of the oldest and most frequently used Chinese herbs for oriental medicine in China. Before clinical use, the SR should be processed using different methods after harvest, such as steaming, “sweating”, and traditional fire-drying. In order to investigate the difference in chemical constituents using different processing methods, the two-dimensional (2D) ¹H-¹³C heteronuclear single quantum correlation (¹H-¹³C HSQC)-based metabolomics approach was applied to extensively characterize the difference in the chemical components in the extracts of SR processed using different processing methods. In total, 20 compounds were identified as potential chemical markers that changed significantly with different steaming durations. Seven compounds can be used as potential chemical markers to differentiate processing by sweating, hot-air drying, and steaming for 4 h. These findings could elucidate the change of chemical constituents of the processed SR and provide a guide for the processing. In addition, our protocol may represent a general approach to characterizing chemical compounds of traditional Chinese medicine (TCM) and therefore might be considered as a promising approach to exploring the scientific basis of traditional processing of TCM.

Carica papaya Leaf Juice for Dengue: A Scoping Review

The potential therapeutic effect of Carica papaya leaf juice has attracted wide interest from the public and scientists in relieving dengue related manifestations. Currently, there is a lack of evaluated evidence on its juice form. Therefore, this scoping review aims to critically appraise the available scientific evidence related to the efficacy of C. papaya leaf juice in dengue. A systematic search was performed using predetermined keywords on two electronic databases (PubMed and Google Scholar). Searched results were identified, screened and appraised to establish the association between C. papaya and alleviating dengue associated conditions. A total of 28 articles (ethnobotanical information: three, in vitro studies: three, ex vivo studies: one, in vivo study: 13, clinical studies: 10) were included for descriptive analysis, which covered study characteristics, juice preparation/formulations, study outcomes, and toxicity findings. Other than larvicidal activity, this review also reveals two medicinal potentials of C. papaya leaf juice on dengue infection, namely anti-thrombocytopenic and immunomodulatory effects. C. papaya leaf juice has the potential to be a new drug candidate against dengue disease safely and effectively.

Compendium of naringenin: potential sources, analytical aspects, chemistry, nutraceutical potentials and pharmacological profile

Naringenin is flavorless, water insoluble active principle belonging to flavanone subclass. It exhibits a diverse pharmacological profile as well as divine nutraceutical values. Although several researchers have explored this phytoconstituent to evaluate its promising properties, still it has not gained recognition at therapeutic levels and more clinical investigations are still required. Also the neutraceutical potential has limited marketed formulations. This compilation includes the description of reported therapeutic potentials of naringenin in variety of pathological conditions alongwith the underlying mechanisms. Details of various analytical investigations carried on this molecule have been provided along with brief description of chemistry and structural activity relationship. In the end, various patents filed and clinical trial data has been provided. Naringenin has revealed promising pharmacological activities including cardiovascular diseases, neuroprotection, anti-diabetic, anticancer, antimicrobial, antiviral, antioxidant, anti-inflammatory and anti-platelet activity. It has been marketed in the form of nanoformulations, co-crystals, solid dispersions, tablets, capsules and inclusion complexes. It is also available in various herbal formulations as nutraceutical supplement. There are some pharmacokinetic issue with naringenin like poor absorption and low dissolution rate. Although these issues have been sorted out upto certain extent still further research to investigate the bioavailability of naringenin from herbal supplements and its clinical efficacy is essential.

Carpaine Promotes Proliferation and Repair of H9c2 Cardiomyocytes after Oxidative Insults

Carpaine has long been identified as the major alkaloid in Carica papaya leaves that possess muscle relaxant properties. Limited study on the molecular signaling properties of carpaine urges us to conduct this study that aims to elucidate the mechanism underlying the cardioprotective effect of carpaine in embryonic cardiomyocytes of the H9c2 cell line. The 50% inhibitory concentration (IC₅₀) of carpaine was first determined using a colorimetric MTT assay to establish the minimum inhibitory concentration for the subsequent test. Using a 1 µM carpaine treatment, a significant increase in the H9c2 proliferation rate was observed following 24 and 48 h of incubation. A Western blot analysis also revealed that carpaine promotes the upregulation of the cell cycle marker proteins cyclin D1 and PCNA. Carpaine-induced H9c2 cell proliferation is mediated by the activation of the FAK-ERK1/2 and FAK-AKT signaling pathways. In the setting of ischemia-reperfusion injury (IRI), carpaine provided a significant protective role to recover the wounded area affected by the hydrogen peroxide (H₂O₂) treatment. Furthermore, the oxidative-stress-induced reduction in mitochondrial membrane potential (MMP) and overproduction of reactive oxygen species (ROS) were attenuated by carpaine treatment. The current study revealed a novel therapeutic potential of carpaine in promoting in vitro cardiomyocyte proliferation and repair following injury.

Carica papaya L. Leaf: A Systematic Scoping Review on Biological Safety and Herb-Drug Interactions

INTRODUCTION

The Carica papaya L. leaf is gaining interest as a potential therapeutic agent for alleviating dengue- and non-dengue-associated thrombocytopaenia. In that regard, safety considerations are as important as efficacy potential. The safety evaluation of botanical products for human use is complicated by variable formulations, complex phytochemical composition, and extrinsic toxicants. This review aimed to systematically collate related safety clinical and preclinical data, as well as reports on herb-drug interactions of C. papaya leaf consumption.

METHODS

A systematic search using predetermined keywords on electronic databases (MEDLINE, Cochrane Library Central, LILACS, and Web of Science) and grey literature was conducted. Relevant clinical and preclinical studies were identified, screened, and analysed to present an overall safety profile of C. papaya leaf consumption.

RESULTS

A total of 41 articles were included (23 clinical, 5 ongoing trials, and 13 preclinical) for descriptive analysis on study characteristics, adverse reactions, toxicity findings, and herb-drug interactions, from which 13 randomised controlled and quasiexperimental trials were further assessed for risk of bias and reporting quality. Overall, C. papaya leaf consumption (in the form of juice and standardised aqueous extract) was well tolerated by adult humans for short durations (

CONCLUSION

C. papaya leaf consumption in adults is generally safe for short-term use though cautioned in pregnancy and people with liver impairment. It has potential herb-drug interactions with oral hypoglycaemic agents, p-glycoprotein substrates, and antibiotics with cation chelating properties.

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Affiliation(s)

X. Y. Lim Herbal Medicine Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Setia Alam 40170, Shah Alam, Malaysia
J. S. W. Chan Herbal Medicine Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Setia Alam 40170, Shah Alam, Malaysia
N. Japri Herbal Medicine Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Setia Alam 40170, Shah Alam, Malaysia
J. C. Lee Herbal Medicine Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Setia Alam 40170, Shah Alam, Malaysia
T. Y. C. Tan Herbal Medicine Research Centre, Institute for Medical Research, National Institutes of Health, Ministry of Health Malaysia, Setia Alam 40170, Shah Alam, Malaysia

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Metabolic analysis of unripe papaya (Carica papaya L.) to promote its utilization as a functional food

Papaya (Carica papaya L.) is widely cultivated in tropical and subtropical countries. While ripe fruit is a popular food item globally, the unripe fruit is only consumed in some Asian countries. To promote the utilization of unripe papaya based on the compositional changes of biological active metabolites, we performed liquid chromatography-Orbitrap-mass spectrometry-based analysis to reveal the comprehensive metabolite profile of the peel and pulp of unripe and ripe papaya fruits. The number of peaks annotated as phenolics and aminocarboxylic acids increased in the pulp and peel of ripe fruit, respectively. Putative carpaine derivatives, known alkaloids with cardiovascular effects, decreased, while carpamic acid derivatives increased in the peel of ripe fruit. Furthermore, the functionality of unripe fruit, the benzyl glucosinolate content, total polyphenol content, and proteolytic activity were detectable after heating and powder processing treatments, suggesting a potential utilization in powdered form as functional material.

Metabolomic and Transcriptomic Profiling Provide Novel Insights into Fruit Ripening and Ripening Disorder Caused by 1-MCP Treatments in Papaya

Treatment with 1-methylcyclopropylene (1-MCP) is an effective technique to preserve fruits, but inappropriate treatment with 1-MCP causes a ripening disorder (rubbery texture) in papaya fruit. In this study, a combined metabolomic and transcriptomic analysis was conducted to reveal the possible mechanism of the ripening disorder caused by unsuitable 1-MCP in papaya. A total of 203 differential accumulated metabolites (DAMs) were identified in the metabolome analysis. Only 24 DAMs were identified in the control (CK) vs. the 1-MCP 2 h group, and they were primarily flavonoids. Ninety and 89 DAMs were identified in the CK vs. 1-MCP 16 h and 1-MCP 2 h vs. 1-MCP 16 h groups, respectively, indicating that long-term 1-MCP treatment severely altered the metabolites during fruit ripening. 1-MCP 16 h treatment severely reduced the number of metabolites, which primarily consisted of flavonoids, lipids, phenolic acids, alkaloids, and organic acids. An integrated analysis of RNA-Seq and metabolomics showed that various energy metabolites for the tricarboxylic acid cycle were reduced by long-term treatment with 1-MCP, and the glycolic acid cycle was the most significantly affected, as well as the phenylpropane pathway. These results provide valuable information for fruit quality control and new insight into the ripening disorder caused by unsuitable treatment with 1-MCP in papaya.

Food forensics on gelatine source via ultra-high-performance liquid chromatography diode-array detector and principal component analysis

This study provided a step-by-step procedure to investigate the distribution of 17 amino acids (AAs) in 50 fish, 50 bovine and 54 porcine gelatines using Ultra-High-Performance Liquid Chromatography Diode-Array Detector (UHPLC–DAD) with the incorporation of principal component analysis (PCA). Dataset pre-processing step, including outlier removal, analysis of variance (ANOVA), dataset adequacy test, dataset transformation and correlation test was performed before the PCA. The method rendered linearity range of 37.5–1000 pmol/µL and accuracy of 85–111% recovery. The bovine and porcine gelatines showed a similar ranking while the l-Alanine (Ala), l-Arginine (Arg) and l-Glutamic acid (Glu) concentrations had differed the fish gelatine from the bovine and porcine gelatines. The PCA, which explained 77.013% cumulative variability at eigenvalue of 5.436, showed AAs with strong FL in PC1 had polar and nonpolar side chains while AAs with strong FL in PC2 had polar side chain. The AAs with moderate and weak FL in PC1 had a nonpolar side chain. The AAs with strong FL of in PC1 were also the same AAs with 7, 6 and 5 strong CMs as determined in the correlation test. The second PCA showed that the l-Serine (Ser), Arg, Glycine (Gly), l-Threonine (Thr), l-Methionine (Met), l-Histidine (His) and L-Hydroxyproline (Hyp) were significant in fish gelatine; Hyp, Met, Thr, Ser, His, Gly, and Arg in bovine gelatine; and l-Proline (Pro), l-Tyrosine (Tyr), l-Valine (Val), l-Leucine (Leu), and l-Phenylalanine (Phe) in porcine gelatine. The 100% fish, bovine and porcine gelatines accommodated grouping 1, 2 and 3, respectively, which proved that AAs with strong FL (Hyp, His, Ser, Arg, Gly, Thr, Pro, Tyr, Met, Val, Leu and Phe) were the significant AAs and becomes the biomarkers to identify the gelatine source. From this study, the PCA was a useful tool to analyse a multivariate dataset that could provide an in-depth understanding of AA distributions as compared to ANOVA and correlation test.

The Authentication of Java Turmeric (Curcuma xanthorrhiza) Using Thin Layer Chromatography and 1H-NMR Based-Metabolite Fingerprinting Coupled with Multivariate Analysis

The identification of adulteration practices of medicinal plants used as herbal medicine is very important to ensure the quality, safety, and efficacy. In this study, thin layer chromatography (TLC) and proton nuclear magnetic resonance (¹H-NMR)-based metabolite fingerprinting coupled with multivariate analysis were used for authentication of Curcuma xanthorrhiza extract from Curcuma aeruginosa. Curcumin contents obtained from C. xanthorrhiza extract from various regions were in the range of 0.74%–1.23%. Meanwhile, curcumin contents obtained from C. xanthorrhiza extract adulterated with 0%, 10%, 25%, 40%, 50%, and 75% of C. aeruginosa were 1.02%, 0.96%, 0.86%, 0.69%, 0.43%, and 0.27%, respectively. The decreasing of curcumin contents in adulterant concentrations of 40% and more in C. xanthorrhiza rhizome could indicate the adulteration with other rhizomes. Multivariate analysis of PCA (principal component analysis) using data set obtained from ¹H-NMR spectra clearly discriminated pure and adulterated C. xanthorrhiza with C. aeruginosa. OPLS-DA (orthogonal projections to latent structures-discriminant analysis) successfully classified pure and adulterated C. xanthorrhiza with higher R2X (0.965), R2Y (0.958), and Q2(cum) (0.93). It can be concluded that ¹H-NMR-based metabolite fingerprinting coupled with PCA and OPLS-DA offers an adequate method to assess adulteration practice and to evaluate the authentication of C. xanthorrhiza extracts.

The gut bacterial community affects immunity but not metabolism in a specialist herbivorous butterfly

Plant tissues often lack essential nutritive elements and may contain a range of secondary toxic compounds. As nutritional imbalance in food intake may affect the performances of herbivores, the latter have evolved a variety of physiological mechanisms to cope with the challenges of digesting their plant-based diet. Some of these strategies involve living in association with symbiotic microbes that promote the digestion and detoxification of plant compounds or supply their host with essential nutrients missing from the plant diet. In Lepidoptera, a growing body of evidence has, however, recently challenged the idea that herbivores are nutritionally dependent on their gut microbial community. It is suggested that many of the herbivorous Lepidopteran species may not host a resident microbial community, but rather a transient one, acquired from their environment and diet. Studies directly testing these hypotheses are however scarce and come from an even more limited number of species.By coupling comparative metabarcoding, immune gene expression, and metabolomics analyses with experimental manipulation of the gut microbial community of prediapause larvae of the Glanville fritillary butterfly (Melitaea cinxia, L.), we tested whether the gut microbial community supports early larval growth and survival, or modulates metabolism or immunity during early stages of development.We successfully altered this microbiota through antibiotic treatments and consecutively restored it through fecal transplants from conspecifics. Our study suggests that although the microbiota is involved in the up-regulation of an antimicrobial peptide, it did not affect the life history traits or the metabolism of early instars larvae.This study confirms the poor impact of the microbiota on diverse life history traits of yet another Lepidoptera species. However, it also suggests that potential eco-evolutionary host-symbiont strategies that take place in the gut of herbivorous butterfly hosts might have been disregarded, particularly how the microbiota may affect the host immune system homeostasis.

Compound Identification and In Vitro Cytotoxicity of the Supercritical Carbon Dioxide Extract of Papaya Freeze-Dried Leaf Juice

Carica papaya leaves are used as a remedy for the management of cancer. Freeze-dried C. papaya leaf juice was extracted using a supercritical fluid extraction system. Compound identification was carried out using analytical techniques including liquid chromatography coupled to high-resolution quadrupole time-of-flight mass spectrometry (LC–QToF-MS) and gas chromatography–mass spectrometry (GC–MS). The cytotoxic activities of the scCO2 extract and its chemical constituents were determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on squamous cell carcinoma (SCC25) and human keratinocyte (HaCaT) cell lines. The chemical constituents were quantified by QToF-MS. The supercritical carbon dioxide (scCO2) extract of papaya freeze-dried leaf juice showed cytotoxic activity against SCC25. Three phytosterols, namely, β-sitosterol, campesterol, and stigmasterol, together with α-tocopherol, were confirmed to be present in the scCO2 extract. Quantitative analysis showed that β-sitosterol was the major phytosterol present followed by α-tocopherol, campesterol, and stigmasterol. β-Sitosterol and campesterol were active against SCC25 (half maximal inhibitory concentration (IC50) ≈ 1 µM), while stigmasterol was less active (~33 µM) but was biologically more selective against SCC25. Interestingly, an equimolar mixture of phytosterols was not more effective (no synergistic effect was observed) but was more selective than the individual compounds. The compounds identified are likely accountable for at least part of the cytotoxicity and selectivity effects of C. papaya.

NMR-based metabolomic profiling of the differential concentration of phytomedicinal compounds in pericarp, skin and seeds of Momordica charantia (bitter melon)

Momordica charantia is a medicinal plant which is widely used in different traditional medicinal systems to treat several diseases. We have identified the differential distribution of phytomedicinally important metabolites in the pericarp, skin and seeds of M. charantia fruit via NMR spectroscopy. Multivariate statistical analysis showed a clustering of the metabolic profiles of seeds and pericarp, and their clear separation from the metabolic profile of the skin. The total phenolic and flavonoid content of the fruit extracts were estimated via bioassays, the radical scavenging activity was estimated via in vitro DPPH and ABTS assays and an inhibitory activity test of α-glucosidase was also performed. The pericarp and seeds contained significant amounts of phenolic compounds and flavonoids, indicating that they are a good source for antioxidants. The skin contained a significantly higher amount of phytosterols such as Charantin and momordicine, which are known to correlate with antidiabetic activity.

Effects of drying on total polyphenols content and antioxidant properties of Carica papaya leaves

BACKGROUND

Papaya is widely grown in Malaysia and normally only the fruits are consumed. Other parts of the plant such as leaves, roots, bark, peel, seeds and pulp are also known to have medicinal properties and have been used to treat various diseases. Papaya leaves also contain flavonoids, alkaloids phenolic compounds and cynogenetic compounds, and are also reported to be able to treat dengue fever.

RESULTS

Studies were carried out on drying of papaya leaves using hot air (60, 70 and 80 °C), shade and freeze drying. Effective diffusivities were estimated ranging from 2.09 × 10^-12 to 2.18 × 10^-12 m² s^-1 from hot air drying, which are within the order of magnitudes reported for most agricultural and food products. The activation energy to initiate drying showed a relatively low value (2.11 kJ mol^-1 ) as a result of the thin leave layer that eased moisture diffusion. In terms of total polyphenols content and antioxidant activities, freeze-dried sample showed a significantly higher (P < 0.05) total polyphenols content [2158 mg gallic acid equivalent 100 g dry weight^-1 ] and antioxidant activities [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) = 571 mg TE 100 g DW^-1 and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) = 215 μg mg^-1 ] compared to hot air and shade dried samples.

CONCLUSION

Freeze dried sample retained the most total polyphenols content and showed the highest antioxidant activities in both ABTS and DPPH antioxidant assays. Hot air and shade drying are not conducive with repect to preserving the antioxidants as a result of possible thermal degradation at elevated temperatures and oxidations under prolonged drying condition. © 2020 Society of Chemical Industry.

Carica papaya: Potential Implications in Human Health

Background:

Carica papaya, a tree-like herb, is cultivated in more than 50 tropical and subtropical countries worldwide. The parts [leaves, fruit (ripe and unripe), seeds and latex] are used as food as well as traditional medicine in several ways for a number of diseases. Papaya, with a variety of phytochemicals like carotenoids, polyphenols, benzyl isothiocynates, benzyl glucosinates, prunasin (cyanogenic substrate), papain and chymopapain, alkaloids, phenolic compounds, flavonoids, vitamins (A, C, E), carotenoids, cyanogenicglucosides, cystatin, and glucosinolates exhibits significant health benefits ranging from digestive to immune modulation. These compounds have antioxidant, chemoprotective, anti-diabetic, anti-bacterial, anti-plasmodial and anti-fungal activities. Papaya aqueous leaf extract was evaluated for immunomodulatory and anti-tumor activities through cytokine modulation with Th1 type shift in human immune system through molecular studies. The platelet augmenting potential of aqueous leaf extract has been reported in numerous clinical studies and deserves special mention.

Objective:

The scientific knowledge of carica papaya in the post-genomic era including molecular studies and clinical trials is discussed in the review.

Methods:

The published literature on botany, chemical composition, ethnopharmacology, and uses of papaya in food and medical industry was searched through databases like Pub- Med, Scopus, and Google scholar to comprehend the benefits of Carica papaya for human use with around more than 600 published peer- reviewed papers.

Results:

Many traditional and novel uses of Carica papaya for the human benefit are detailed in the review that significantly adds to the scientific knowledge of curious readers.

Conclusion:

Each component of the papaya plant is rich in phytochemicals and is economically important. Most of the phytochemicals are linked to biological functions and influence a variety of cellular processes; hence they have implications in refining human health.

Valorization of papaya (Carica papaya L.) agroindustrial waste through the recovery of phenolic antioxidants by supercritical fluid extraction

In this work, supercritical fluid extraction (SFE) for the recovery of phenolic antioxidants from papaya agroindustrial waste (seeds) was explored, making use of neat supercritical CO₂ and CO₂ added with ethanol (CO₂-EtOH). A full factorial design played on in order to evaluate the effect of CO₂ extraction parameters (temperature between 40 and 60 °C, and pressure between 10 and 30 MPa) on yield and total phenols content (TPC), then ethanol was applied as a co-solvent and its effect on the recovery of phenolics was analyzed. The SFE was compared to the conventional extraction using ethanol. The antioxidant activity of all extracts was evaluated, and the phenolic composition in selected extracts was assessed by HPLC-ESI-MS. The highest extraction yields (21.02-26.46%) and TPC (15.34-34.23 mgGAE/g) were found in extracts obtained with CO₂-EtOH and ethanol. Good and selective phenolic recovery was obtained by using CO₂-EtOH, (44.81% of TPC recovered). The CO₂-EtOH extracts showed high radical scavenging activity and higher antioxidant effect against lipid oxidation. Some phenolic acids and flavonoids were observed in the extracts with better antioxidants properties. The results showed that SFE is a suitable green technology for the phenolic recovery from papaya agroindustrial waste, and also an alternative for its valorization.

Antioxidants and α-glucosidase inhibitors from Neptunia oleracea fractions using 1H NMR-based metabolomics approach and UHPLC-MS/MS analysis

Background

Neptunia oleracea is a plant cultivated as vegetable in Southeast Asia. Previous works have revealed the potential of this plant as a source of natural antioxidants and α-glucosidase inhibitors. Continuing our interest on this plant, the present work is focused in identification of the bioactive compounds from different polarity fractions of N. oleracea, namely hexane (HF), chloroform (CF), ethyl acetate (EF) and methanol (MF).

Methods

The N. oleracea fractions were obtained using solid phase extraction (SPE). A metabolomics approach that coupled the use of proton nuclear magnetic resonance (¹H NMR) with multivariate data analysis (MVDA) was applied to distinguish the metabolite variations among the N. oleracea fractions, as well as to assess the correlation between metabolite variation and the studied bioactivities (DPPH free radical scavenging and α-glucosidase inhibitory activities). The bioactive fractions were then subjected to ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS) analysis to profile and identify the potential bioactive constituents.

Results

The principal component analysis (PCA) discriminated EF and MF from the other fractions with the higher distributions of phenolics. Partial least squares (PLS) analysis revealed a strong correlation between the phenolics and the studied bioactivities in the EF and the MF. The UHPLC-MS/MS profiling of EF and MF had tentatively identified the phenolics present. Together with some non-phenolic metabolites, a total of 37 metabolites were tentatively assigned.

Conclusions

The findings of this work supported that N. oleracea is a rich source of phenolics that can be potential antioxidants and α-glucosidase inhibitors for the management of diabetes. To our knowledge, this study is the first report on the metabolite-bioactivity correlation and UHPLC–MS/MS analysis of N. oleracea fractions.

Effect of a Toothpaste/Mouthwash Containing Carica papaya Leaf Extract on Interdental Gingival Bleeding: A Randomized Controlled Trial

Clinical research on herbal-based dentifrice +/− mouth rinse products is very limited compared with the plethora of research on conventional oral care products under normal oral hygiene conditions. The aim of this study was to determine the anti-inflammatory effects of a novel plant Carica papaya leaf extract (CPLE) on interdental bleeding in healthy subjects. In this randomized, single-blind parallel-design study, the eligible subjects were generally healthy non-smokers, aged 18–26, who exhibited healthy periodontal conditions upon study entry. The participants were equally randomized into the following four groups: CPLE dentifrice, CPLE dentifrice and mouthwash, sodium lauryl sulfate (SLS)-free enzyme-containing dentifrice and SLS-free enzyme-containing dentifrice with essential oil (EO) mouthwash. Subjects were instructed to brush their teeth twice a day without changing their other brushing habits. Interdental bleeding (BOIP) was measured from inclusion (T₀) until the fourth week (T₄) of the study. Clinical efficacy was assessed after one, two, three and four weeks of home use. The analyses compared BOIP between groups and were then restricted to participants with ≥70% and then ≥80% bleeding sites at T₀. Pairwise comparisons between groups were performed at T₀ and T₄, and a logistic regression identified correlates of gingival bleeding (T₄). Among 100 subjects (2273 interdental sites), the median percentage of bleeding sites per participant at T₀ was 65%. The bleeding sites dramatically decreased in all groups between T₀ and T₄ (relative variations from −54% to −75%, p < 0.01 for all). Gingival bleeding did not significantly differ between the CPLE dentifrice and the SLS-free dentifrice +/− EO mouthwash groups (from p = 0.05 to p = 0.86), regardless of the baseline risk level. Among the CPLE dentifrice users, fewer bleeding sites were observed when toothpaste and mouthwash were combined compared to bleeding sites in those who used toothpaste alone (21% vs. 32%, p = 0.04). CPLE dentifrice/mouthwash provides an efficacious and natural alternative to SLS-free dentifrice +/−EO-containing mouthwash when used as an adjunct to mechanical oral care to reduce interdental gingival inflammation.

Metabolite profiling of "green" extracts of Corylus avellana leaves by 1H NMR spectroscopy and multivariate statistical analysis

Corylus avellana L. (Betulaceae) leaves, consumed as infusion, are used in traditional medicine, for the treatment of hemorrhoids, varicose veins, phlebitis, and edema due to their astringent, vasoprotective, and antiedema properties. In previous works we reported from the leaves of Corylus avellana cv. "Tonda di Giffoni" diarylheptanoid derivatives, a class of plant secondary metabolites with a wide variety of bioactivities. With the aim to give an interesting and economically feasible opportunity to C. avellana leaves as source of functional ingredients for pharmaceutical and cosmetic formulations, "green" extracts were prepared by employing "eco-friendly" extraction protocols as maceration, infusion and SLDE-Naviglio extraction. Metabolite profiles of the extracts were obtained by ¹H NMR experiments and data were processed by multivariate statistical analysis to highlight differences in the extracts and to evidence the extracts with the highest concentrations of bioactive metabolites. Based on the NMR data, a total of 31 compounds were identified. The metabolite variation among the extracts was evaluated using Principle Component Analysis (PCA) and Partial Least Squares-Discriminant Analysis (PLS-DA). Furthermore, the total phenolic content of the extracts was measured by Folin-Ciocalteu colorimetric assay and the antioxidant activity of extracts was assayed by the spectrophotometric tests DPPH^• and ABTS and by an in vitro test based on the evaluation of cellular reactive oxygen species production stimulated by pyocyanin.

Metabolite profiling, antioxidant, and α-glucosidase inhibitory activities of germinated rice: nuclear-magnetic-resonance-based metabolomics study

In an attempt to profile the metabolites of three different varieties of germinated rice, specifically black (GBR), red, and white rice, a ¹H-nuclear-magnetic-resonance-based metabolomics approach was conducted. Multivariate data analysis was applied to discriminate between the three different varieties using a partial least squares discriminant analysis (PLS-DA) model. The PLS model was used to evaluate the relationship between chemicals and biological activities of germinated rice. The PLS-DA score plot exhibited a noticeable separation between the three rice varieties into three clusters by PC1 and PC2. The PLS model indicated that α-linolenic acid, γ-oryzanol, α-tocopherol, γ-aminobutyric acid, 3-hydroxybutyric acid, fumaric acid, fatty acids, threonine, tryptophan, and vanillic acid were significantly correlated with the higher bioactivities demonstrated by GBR that was extracted in 100% ethanol. Subsequently, the proposed biosynthetic pathway analysis revealed that the increased quantities of secondary metabolites found in GBR may contribute to its nutritional value and health benefits.

Characterization of metabolites in different kiwifruit varieties by NMR and fluorescence spectroscopy

It is known from our previous studies that kiwifruits, which are used in common human diet, have preventive properties of coronary artery disease. This study describes a combination of ¹H NMR spectroscopy, multivariate data analyses and fluorescence measurements in differentiating of some kiwifruit varieties, their quenching and antioxidant properties. A total of 41 metabolites were identified by comparing with literature data Chenomx database and 2D NMR. The binding properties of the extracted polyphenols against HSA showed higher reactivity of studied two cultivars in comparison with the common Hayward. The results showed that the fluorescence of HSA was quenched by Bidan as much as twice than by other fruits. The correlation between the binding properties of polyphenols in the investigated fruits, their relative quantification and suggested metabolic pathway was established. These results can provide possible application of fruit extracts in pharmaceutical industry.

Fast profiling of metabolite mixtures using chemometric analysis of a speeded-up 2D heteronuclear correlation NMR experiment

One-dimensional (1D) NMR spectra of mixtures of metabolites suffer from severe overlap of spectral resonances and hence recent research in NMR-based metabolomics focuses on using two-dimensional (2D) NMR experiments for metabolite fingerprinting.

DNA barcoding and NMR spectroscopy-based assessment of species adulteration in the raw herbal trade of Saraca asoca (Roxb.) Willd, an important medicinal plant

Saraca asoca (Roxb.) Willd, commonly known as "Asoka" or "Ashoka," is one of the most important medicinal plants used in raw herbal trade in India. The bark extracts of the tree are used in the treatment of leucorrhea and other uterine disorders besides also having anti-inflammatory, anti-bacterial, anti-pyretic, anti-helminthic, and analgesic activity. The indiscriminate and rampant extraction of the wood to meet the ever-increasing market demand has led to a sharp decline in naturally occurring populations of the species in the country. Consequently, the species has recently been classified as "vulnerable" by the International Union for Conservation of Nature (IUCN). Increasing deforestation and increasing demand for this medicinal plant have resulted in a limited supply and suspected widespread adulteration of the species in the raw herbal trade market. Adulteration is a serious concern due to: (i) reduction in the efficacy of this traditional medicine, (ii) considerable health risk to consumers, and (iii) fraudulent product substitution that impacts the economy for the Natural Health Product (NHP) Industry and consumers. In this paper, we provide the first attempt to assess the extent of adulteration in the raw herbal trade of S. asoca using DNA barcoding validated by NMR spectroscopic techniques. Analyzing market samples drawn from 25 shops, mostly from peninsular India, we show that more than 80 % of the samples were spurious, representing plant material from at least 7 different families. This is the first comprehensive and large-scale study to demonstrate the widespread adulteration of market samples of S. asoca in India. These results pose grave implications for the use of raw herbal drugs, such as that of S. asoca, on consumer health and safety. Based on these findings, we argue for a strong and robust regulatory framework to be put in place, which would ensure the quality of raw herbal trade products and reassure consumer confidence in indigenous medicinal systems. Graphical Abstract DNA barcoding and NMR spectroscopy-based assessment of adulteration in Saraca asoca.

Protective Action of Carica papaya on β-Cells in Streptozotocin-Induced Diabetic Rats

The aim of the present study was to investigate the effect of C. papaya L. leaf extract (CPLE) on pancreatic islets in streptozotocin (STZ)-induced diabetic rats, as well as on cultured normal pancreatic cells with STZ in the medium. CPLE (3–125 mg/Kg) was administered orally for 20 days, while a group of diabetic rats received 5 IU/Kg/day of insulin. At the end of the treatment the rats were sacrificed. Blood was obtained to assess glucose and insulin levels. The pancreas was dissected to evaluate β cells by immunohistochemistry. In addition, normal pancreatic cells were cultured in a medium that included CPLE (3–12 mg). One half of the cultured cells received simultaneously CPLE and STZ (6 mg), while the other half received CPLE and five days later the STZ. After three days of incubation, insulin was assayed in the incubation medium. The CPLE administered to diabetic rats improved the fasting glycemia and preserved the number and structure of pancreatic islets. However, when CPLE was added to pancreatic cells in culture along with STZ, the insulin concentration was higher in comparison with the cells that only received STZ. In conclusion, the CPLE preserves the integrity of pancreatic islets, improves the basal insulin secretion and protects cultured cells from the adverse effects of STZ.