Anti-inflammatory activities of cucurbitacin E isolated from Citrullus lanatus var. citroides: Role of reactive nitrogen species and cyclooxygenase enzyme inhibition

Ethnobotany and phytochemistry of plants used to treat musculoskeletal disorders among Skaw Karen, Thailand

CONTEXT

Musculoskeletal system disorders (MSD) are prevalent around the world affecting the health of people, especially farmers who work hard in the field. Karen farmers use many medicinal plants to treat MSD.

OBJECTIVE

This study collects traditional plant-based remedies used by the Skaw Karen to treat MSD and evaluates their active phytochemical compounds.

MATERIALS AND METHODS

The ethnobotanical study was conducted in six Karen villages in Chiang Mai province using semi-structured interviews were of 120 informants. The data were analyzed using ethnobotanical indices including use values (UV), choice value (CV), and informant consensus factor (ICF). Consequently, the 20 most important species, according to the indices, were selected for phytochemical analysis using LC-MS/MS.

RESULTS

A total of 3731 use reports were obtained for 139 species used in MSD treatment. The most common ailments treated with those plants were muscular pain. A total of 172 high-potential active compounds for MSD treatment were identified. Most of them were flavonoids, terpenoids, alkaloids, and steroids. The prevalent phytochemical compounds related to treat MSD were 9-hydroxycalabaxanthone, dihydrovaltrate, morroniside, isoacteoside, lithocholic acid, pomiferin, cucurbitacin E, leonuriside A, liriodendrin, and physalin E. Sambucus javanica Reinw. ex Blume (Adoxaceae), Betula alnoides Buch.-Ham. ex D.Don (Betulaceae), Blumea balsamifera (L.) DC. (Asteraceae), Plantago major L. (Plantaginaceae) and Flacourtia jangomas (Lour.) Raeusch. (Salicaceae) all had high ethnobotanical index values and many active compounds.

DISCUSSION AND CONCLUSIONS

This study provides valuable information, demonstrating low-cost medicine plants that are locally available. It is a choice of treatment for people living in remote areas.

Quantification of cucurbitacin E in different varieties of melon (Cucumis melo L.) fruit through validated RP-HPLC method

The different varieties of melons (Cucumis melo L.) have been used in various traditional systems of medicine for decades to treat different ailments, including inflammation, cancer, cardiovascular, diabetes, edema, etc. The present study was designed for the quantification of cucurbitacin E in five different varieties of melon fruit through a validated RP-HPLC method. A solvent system is being optimized with a 70:30 (v/v) ratio of acetonitrile: water (1% glacial acetic acid) at a 1 mL/min flow rate and scanning spectrum (λmax) of 230 nm. A calibration curve for standard cucurbitacin E was generated and found to be linear (1-100 µg/mL). The variation of cucurbitacin E content among five different varieties of melon fruits is 0.0129% w/w- 0.231% w/w. This precise and reproducible method may be beneficial in addressing the quality-related aspects of medicinal food plants of Cucurbitaceae and its derived products or formulations.

The Antiproliferative and Proapoptotic Effects of Cucurbitacin B on BPH-1 Cells via the p53/MDM2 Axis

Cucurbitacin B (Cu B), a triterpenoid compound, has anti-inflammatory and antioxidant activities. Most studies only focus on the hepatoprotective activity of Cu B, and little effort has been geared toward exploring the effect of Cu B on the prostate. Our study identified that Cu B inhibited the proliferation of the benign prostatic hyperplasia epithelial cell line (BPH-1). At the molecular level, Cu B upregulated MDM2 and thrombospondin 1 (THBS1) mRNA levels. Immunocytochemistry results revealed that the protein expressions of p53 and MDM2 were upregulated in BPH-1 cells. Furthermore, Cu B upregulated THBS1 expression and downregulated COX-2 expression in the BPH-1 cell supernatant. Altogether, Cu B may inhibit prostate cell proliferation by activating the p53/MDM2 signaling cascade and downregulating the COX-2 expression.

Cucurbitacin E reduces IL-1β-induced inflammation and cartilage degeneration by inhibiting the PI3K/Akt pathway in osteoarthritic chondrocytes

BACKGROUND

Osteoarthritis is a degenerative joint disease. Cartilage degeneration is the earliest and most important pathological change in osteoarthritis, and persistent inflammation is one of the driving factors of cartilage degeneration. Cucurbitacin E, an isolated compound in the Cucurbitacin family, has been shown to have anti-inflammatory effects, but its role and mechanism in osteoarthritic chondrocytes are unclear.

METHODS

For in vitro experiments, human chondrocytes were stimulated with IL-1β, and the expression of inflammatory genes was measured by Western blotting and qPCR. The expression of extracellular matrix proteins was evaluated by immunofluorescence staining, Western blotting and saffron staining. Differences in gene expression between cartilage from osteoarthritis patients and normal cartilage were analysed by bioinformatics methods, and the relationship between Cucurbitacin E and its target was analysed by a cellular thermal shift assay, molecular docking analysis and molecular dynamics simulation. For in vivo experiments, knee osteoarthritis was induced by DMM in C57BL/6 mouse knee joints, and the effect of Cucurbitacin E on knee joint degeneration was evaluated.

RESULTS

The in vitro experiments confirmed that Cucurbitacin E effectively inhibited the production of the inflammatory cytokine interleukin-1β(IL-1β) and cyclooxygenase-2 (COX-2) by IL-1β-stimulated chondrocytes and alleviates extracellular matrix degradation. The in vivo experiments demonstrated that Cucurbitacin E had a protective effect on the knee cartilage of C57BL/6 mice with medial meniscal instability in the osteoarthritis model. Mechanistically, bioinformatic analysis of the GSE114007 and GSE117999 datasets showed that the PI3K/AKT pathway was highly activated in osteoarthritis. Immunohistochemical analysis of PI3K/Akt signalling pathway proteins in pathological slices of human cartilage showed that the level of p-PI3K in patients with osteoarthritis was higher than that in the normal group. PI3K/Akt were upregulated in IL-1β-stimulated chondrocytes, and Cucurbitacin E intervention reversed this phenomenon. The cellular thermal shift assay, molecular docking analysis and molecular dynamics experiment showed that Cucurbitacin E had a strong binding affinity for the inhibitory target PI3K. SC79 activated Akt phosphorylation and reversed the effect of Cucurbitacin E on IL-1β-induced chondrocyte degeneration, demonstrating that Cucurbitacin E inhibits IL-1β-induced chondrocyte inflammation and degeneration by inhibiting the PI3K/AKT pathway.

CONCLUSION

Cucurbitacin E inhibits the activation of the PI3K/AKT pathway, thereby alleviating the progression of OA. In summary, we believe that Cucurbitacin E is a potential drug for the treatment of OA.

Anti-Influenza Virus Activity of Citrullus lanatus var. citroides as a Functional Food: A Review

Influenza is an acute respiratory illness caused by the influenza virus, in response to which vaccines and antiviral drugs are administered. In recent years, the antiviral effects of plants and foods have garnered attention. This review is the first to summarize the therapeutic properties of wild watermelon (Citrullus lanatus var. citroides) against influenza from a phytochemical viewpoint. Wild watermelon is a wild plant with significant potential as a therapeutic candidate in antiviral strategies, when focused on its multiple anti-influenza functionalities. Wild watermelon juice inhibits viral growth, entry, and replication. Hence, we highlight the possibility of utilizing wild watermelon for the prevention and treatment of influenza with stronger antiviral activity. Phytochemicals and phytoestrogen (polyphenol, flavonoids, and prenylated compounds) in wild watermelon juice contribute to this activity and inhibit various stages of viral replication, depending on the molecular structure. Wild plants and foods closely related to the original species contain many natural compounds such as phytochemicals, and exhibit various viral growth inhibitory effects. These natural products provide useful information for future antiviral strategies.

Cucurbitacins B, E and I Concentrations and Relationship with Drought Tolerance in Bottle Gourd [Lagenaria siceraria (Molina) Standl.]

Bottle gourd [Lagenaria siceraria (Molina) Standl.]) is a relatively drought-tolerant cucurbit due to the high composition of unique biochemical compositions, including cucurbitacin. The objective of this study was to determine the concentrations of cucurbitacins in bottle gourd and their relationship to drought tolerance. The study assessed 12 bottle gourd accessions grown under two moisture levels (i.e., non-stressed (NS) and drought-stressed (DS)) and three drought stress intensities (i.e., mild, moderate, and severe) using a 12 × 2 × 3 factorial experiment designed in a randomized complete block design with three replications. Control studies were undertaken under glasshouse conditions. The content of cucurbitacins B, E, and I were quantified in leaves and roots using high-performance liquid Cchromatography-mass spectrometry (HPLC-MS). The free radical scavenging activities of pure cucurbitacins B, E, and I were quantified using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and a ferrulic acid power assay (FRAP). Results revealed that cucurbitacins B and I were present in accessions BG-48, BG-58, BG-70, BG-78, BG-79, BG-81, BG-52, and GC in leaves and roots under DS condition. The contents of cucurbitacins B and I were enhanced under increased drought intensity for accessions BG-48, BG-81, and GC. In all the leaf and root samples, cucurbitacin E was not detectable. Based on the DPPH test, pure cucurbitacins I, B, and E reduced free radicals at maximum values of 78, 60, and 66%, respectively. Based on the FRAP assay, pure cucurbitacins I, B, and E had maximum ferric-reducing powers of 67, 62, and 48%. Additionally, cucurbitacin I recorded the highest antioxidant activity compared to cucurbitacins B and E. Increased cucurbitacin accumulation and antioxidant properties indicate their role in minimising cell damage caused by oxidative stress under drought-stressed environments. The present study revealed that cucurbitacins B and I serve as novel biochemical markers for screening drought tolerance in bottle gourd or related cucurbits.

Lessons learned from metabolic engineering in hairy roots: Transcriptome and metabolic profile changes caused by Rhizobium-mediated plant transformation in Cucurbitaceae species

Cucurbitaceae species are used in traditional medicine around the world. Cucurbitacins are highly oxygenated triterpenoids found in Cucurbitaceae species and exhibit potent anticancer activity alone and in combination with other existing chemotherapeutic drugs. Therefore, increasing production of these specialized metabolites is of great relevance. We recently showed that hairy roots of Cucurbita pepo can be used as a platform for metabolic engineering of cucurbitacins to modify their structure and increase their production. To study the changes in cucurbitacin accumulation upon formation of hairy roots, an empty vector (EV) control and Cucurbitacin inducing bHLH transcription factor 1 (CpCUCbH1)-overexpressing hairy roots of C. pepo were compared to untransformed (WT) roots. Whilst CpCUCbH1-overexpression increased production of cucurbitacins I and B by 5-fold, and cucurbitacin E by 3-fold when compared to EV lines, this increase was not significantly different when compared to WT roots. This indicated that Rhizobium rhizogenes transformation lowered the cucurbitacins levels in hairy roots, but that increasing expression of cucurbitacin biosynthetic genes by CpCUCbH1-overexpression restored cucurbitacin production to WT levels. Subsequent metabolomic and RNA-seq analysis indicated that the metabolic profile and transcriptome of hairy roots was significantly changed when compared to WT roots. Interestingly, it was observed that 11% of the differentially expressed genes were transcription factors. It was noteworthy that the majority of transcripts showing highest Pearson correlation coefficients to the Rhizobium rhizogenes genes rolB, rolC and ORF13a, were predicted to be transcription factors. In summary, hairy roots are an excellent platform for metabolic engineering of plant specialized metabolites, but these extensive transcriptome and metabolic profile changes should be considered in subsequent studies.

Identification and quantification of cucurbitacin in watermelon frost using molecular networking integrated with ultra-high-performance liquid chromatography-tandem mass spectrometry

Watermelon frost, a traditional Chinese medicine produced using watermelon and Glauber's salt, has been widely used for the therapy of oral and throat disorders. Watermelon contains various phytochemical compounds including cucurbitacins and their glycoside derivatives, which have attracted considerable attention because of their medicinal values. However, whether the composition of cucurbitacins existed in watermelon frost was rarely reported. In this study, three cucurbitacins including cucurbitacin B, isocucurbitacin B, and cucurbitacin E were found from watermelon frost extract assisted by ultra-high-performance liquid chromatography-tandem mass spectrometry and molecular networking guided strategy, and the compounds were verified using standard solutions. Furthermore, a quantification method for simultaneously targeted analysis of cucurbitacins was established using ultra-high-performance liquid chromatography-tandem mass spectrometry operating in the multiple reaction monitoring mode. Among them, cucurbitacin B and cucurbitacin E in watermelon frost samples were determined, and the concentrations were 3.78 ± 0.18 and 0.86 ± 0.19 ng/ml, respectively. While isocucurbitacin B was not detected due to the lower content possibly. In conclusion, ultra-high-performance liquid chromatography-tandem mass spectrometry combined with molecular networking is a very useful technique for the rapid identification of unknown cucurbitacin components in watermelon frost.

Female naturalists and the patterns of suppression of women scientists in history: the example of Maria Sibylla Merian and her contributions about useful plants

BACKGROUND

This work reunites many women naturalists who registered knowledge about native flora in scientific expeditions around the globe between the seventeenth and nineteenth centuries. Since male naturalists are more recognized in this period of time, we aimed to list female naturalists that published plant descriptions and observations, focusing on the work of Maria Sibylla Merian and to analyze her trajectory as an example to discuss the patterns of the suppression of women scientists. A second aim was to inventory the useful plants described in Maria Sibylla's Metamorphosis Insectorum Surinamensium and find pharmacological evidence about the traditional uses described for those plants cited as medicinal and toxic.

METHODS

A survey of female naturalists was carried out by searching information in Pubmed, Scielo, Google Scholar and Virtual Health Library. Once Maria Sibylla published her book Metamorphosis Insectorum Surinamensium by her own, without male co-authors, and also this book is one of the only to have text and illustrations altogether and there are reports indicating information on useful plants in this work, she and her book were chosen as subject of this research. All the information was tabulated by dividing the plants into food, medicinal, toxic, aromatic or other uses. Finally, with the combinations of the scientific name of medicinal and toxic plants with information about their popular uses, a search was carried out in databases in order to indicate current pharmacological studies that reported evidences about the traditional uses described.

RESULTS

We found 28 women naturalists who participated in scientific expeditions or trips, or in a curiosity cabinet, or who were collectors of Natural History between the seventeenth and nineteenth centuries. All these women illustrated botanical species and/or recorded their everyday or medicinal use or reported their observations in the form of a published work, letters or diaries. Also, the trajectory of Maria Sibylla Merian revealed that her scientific relevance has been neglected from the eighteenth century by mechanisms of suppression, most of the time by male depreciation, which can be seen as a pattern for suppression of women in science. However, Maria Sibyllas' contributions have been valued again in the twenty-first century. In Maria Sibylla's work, 54 plants were identified, 26 of them used for food, 4 of them aromatic, 8 medicinal, 4 toxic and 9 other uses.

CONCLUSION

This study evidences that there are female naturalists whose work could be an important source for ethnopharmacological studies. Researching about women scientists, talking about them and highlighting the gender bias present in the scientific academy about the way the history of science is told is essential for the construction of a more diverse and richer scientific academy. The traditional use of 7 of 8 medicinal plants and 3 of 4 toxic plants reported was correlated with pharmacological studies, highlighting the importance of this historical record and its potential to direct strategic research in traditional medicine.

Metabolic engineering of cucurbitacins in Cucurbita pepo hairy roots

In this paper we show that metabolic engineering in Cucurbita pepo hairy roots can be used to both effectively increase and modify cucurbitacins. Cucurbitacins are highly-oxygenated triterpenoids originally described in the Cucurbitaceae family, but have since been found in 15 taxonomically distant plant families. Cucurbitacin B, D, E and I are the most widespread amongst the Cucurbitaceae and they have both important biological and pharmacological activities. In this study C. pepo hairy roots were used as a platform to boost production and alter the structures of the afore mentioned cucurbitacins by metabolic engineering to potentially provide new or more desirable bioactivities. We report that the ability to induce cucurbitacin biosynthesis by basic Helix-Loop-Helix transcription factors is partially conserved within the Cucurbitaceae and therefore can potentially be used as a biotechnological tool to increase cucurbitacins in several genera of this family. Additionally, overexpression of a novel acyltransferase from cucurbitacin producing Iberis amara generates a hitherto undescribed acetylation at the C3-hydroxyl group of the cucurbitadienol backbone. While overexpression of the cytochromes P450 CsCYP88L2 and McCYP88L7 from Cucumis sativus and Momordica charantia (respectively), results in accumulation of new spectral feature as revealed by High resolution liquid chromatography mass spectroscopy analysis; the m/z of the new peak supports it might be a cucurbitacin hydroxylated at the C19 position in C. pepo hairy roots. Finally, this paper is a case study of how hairy roots can be used to metabolically engineer and introduce novel modifications in metabolic pathways that have not been fully elucidated.

Pharmacokinetics and Biological Activity of Cucurbitacins

Cucurbitacins are a class of secondary metabolites initially isolated from the Cucurbitaceae family. They are important for their analgesic, anti-inflammatory, antimicrobial, antiviral, and anticancer biological actions. This review addresses pharmacokinetic parameters recently reported, including absorption, metabolism, distribution, and elimination phases of cucurbitacins. It includes recent studies of the molecular mechanisms of the biological activity of the most studied cucurbitacins and some derivatives, especially their anticancer capacity, to propose the integration of the pharmacokinetic profiles of cucurbitacins and the possibilities of their use. The main botanical genera and species of American origin that have been studied, and others whose chemo taxonomy makes them essential sources for the extraction of these metabolites, are summarized.

Four cucurbitane glycosides taimordisins A–D with novel furopyranone skeletons isolated from the fruits of Momordica charantia

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Four new cucurbitane-type triterpenoids glycosides were isolated from the fresh fruit of Momordica charantia and determined by NMR, HRESIMS, and biosynthesis.

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Taimordisins A and B possess rare bicyclic-fused and trifuso-centro-fused ring systems at side chain of the cucurbitane-type triterpenoids at the first time.

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Taimordisins A-D showed the inhibition of NO production by LPS-stimulated in RAW264.7 macrophage cells.

Four novel triterpene glycosides, taimordisins A–D (1–4), were discovered from fresh fruits of Taiwanese Momordica charantia. The chemical framework and relative stereochemistry of these four natural products were isolated, purified, and determined by using various separation and spectroscopy techniques. Each of them features a unique bicyclic-fused or trifuso-centro-fused ring system. Notably, 1 and 2 are cucurbitane-based compounds possessing a new C-24 and C-2″ carbon–carbon linkage with 5-hydroxy-2-(hydroxymethyl)tetrahydro-4H-pyran-4-one and 6-(hydroxymethyl)tetrahydro-4H-pyran-3,4,4-triol units, respectively, and represented an unprecedented molecular skeleton. In terms of biosynthesis, they all originate from a common precursor 3-hydroxycucurbita-5,24-dien-19-al-7,23-di-O-β-glucopyranoside. Of two sugar moieties, the one at 23-O-β-glucopyranoside grants each individual congener uniqueness likely through microbial symbiont-mediated intramolecular transformation into two major types of furo[2,3-b]pyranone and furo[3,2-c]pyranone derivatives. These new products possess desirable anti-inflammatory biological activities in addition to being generally regarded as safe.

In vitro Antimicrobial Activity of Cucumis L. and Momordica L. against Human Pathogens

Plants are the rich source of compounds having antimicrobial properties against human pathogens. The present study has been carried out to evaluate the antimicrobial potential of Cucumis melo var. agrestis (morphotype I), Cucumis melo var. agrestis (morphotype II), Cucumis melo var. momordica L., Cucumis melo L., Momordica balsamina L., Momordica charantia L., Momordica dioica L. against Staphylococcus aureus, Pseudomonas flourescens, Bacillus coagulans, and Klebsiella pneumoniae. Crude extract of Cucumis L. and Momordica L. species were prepared with methanol, acetone and water for the determination of antimicrobial properties. Maximum yield was reported in methanol extract while minimum in acetone for all plant species. The maximum zone of inhibition of about 32.3 ± 0.57 mm was found against Staphylococcus aureus in Cucumis melo L., 21.3 ± 0.57 mm for Pseudomonas flourescens in Cucumis melo var. agrestis (morphotype II), 17 ± 0 mm for Klebsiella pneumoniae in Momordica balsamina L., and 23.3 ± 0.57 mm for Bacillus coagulans in Cucumis melo var. agrestis (morphotype II) extracts, respectively. The most active antimicrobial plants species were reported to be Cucumis melo var. agrestis (morphotype I), Cucumis melo L. and Momordica charantia L. having antimicrobial activities against all tested microorganisms.

Elucidation of the Metabolite Profile of Yucca gigantea and Assessment of Its Cytotoxic, Antimicrobial, and Anti-Inflammatory Activities

The acute inflammation process is explained by numerous hypotheses, including oxidative stress, enzyme stimulation, and the generation of pro-inflammatory cytokines. The anti-inflammatory activity of Yucca gigantea methanol extract (YGME) against carrageenan-induced acute inflammation and possible underlying mechanisms was investigated. The phytochemical profile, cytotoxic, and antimicrobial activities were also explored. LC-MS/MS was utilized to investigate the chemical composition of YGME, and 29 compounds were tentatively identified. In addition, the isolation of luteolin-7-O-β-d-glucoside, apigenin-7-O-β-d-glucoside, and kaempferol-3-O-α-l-rhamnoside was performed for the first time from the studied plant. Inflammation was induced by subcutaneous injection of 100 μL of 1% carrageenan sodium. Rats were treated orally with YGME 100, 200 mg/kg, celecoxib (50 mg/kg), and saline, respectively, one hour before carrageenan injection. The average volume of paws edema and weight were measured at several time intervals. Levels of NO, GSH, TNF-α, PGE-2, serum IL-1β, IL-6 were measured. In additionally, COX-2 immunostaining and histopathological examination of paw tissue were performed. YGME displayed a potent anti-inflammatory influence by reducing paws edema, PGE-2, TNF-α, NO production, serum IL-6, IL-1β, and COX-2 immunostaining. Furthermore, it replenished the diminished paw GSH contents and improved the histopathological findings. The best cytotoxic effect of YGME was against human melanoma cell line (A365) and osteosarcoma cell line (MG-63). Moreover, the antimicrobial potential of the extract was evaluated against bacterial and fungal isolates. It showed potent activity against Gram-negative, Gram-positive, and fungal Candida albicans isolates. The promoting multiple effects of YGME could be beneficial in the treatment of different ailments based on its anti-inflammatory, antimicrobial, and cytotoxic effects.

Cell-modified plasmonic interface for the signal-amplified detection of Cucurbitacin E

Cucurbitacin E (CuE) plays an important role in anticancer, antichemical carcinogenesis, and body immunity, etc., and the detection of its concentration is meaningful to pharmacological studies and clinical applications. However, the small molecular weight of CuE makes direct detection difficult through a surface plasmon resonance (SPR) sensor. In this work, we propose a cells-amplified signal strategy at the plasmonic interface, realizing the detection of CuE with ultra-low concentration. The seeded HeLa cells are modified onto the surface of the SPR sensor, and a small amount of CuE can lead to the remarkable morphology change of cells and the release of cell-related substances onto the plamonic interface, thus significantly amplifying the signal. Experimental results show that by using an unmodified SPR sensor with the bulk refractive index sensitivity of 2367.3 nm/RIU (RIU: refractive index unit), there no effective signal can be detected during the CuE concentration range of 0-100 nM; whereas, employing the proposed strategy, the signal for CuE detection can be significantly enhanced, resulting in a high detection sensitivity of 0.6196 nm/nM, corresponding to a limit of detection of 45.2 pM (25.2 pg/mL). The proposed cells-based signal amplifying strategy shows great potential applications in drug screening or bio-sensing to small molecules with low concentration.

Creation of an Anti-Inflammatory, Leptin-Dependent Anti-Obesity Celastrol Mimic with Better Druggability

Obesity is characterized by an excessive body mass, but is also closely associated with metabolic syndrome. And, so far, only limited pharmacological treatments are available for obesity management. Celastrol, a pentacyclic triterpenoid from a traditional Chinese medicine (Tripterygium wilfordii Hook.f.), has shown remarkable potency against obesity, inflammation and cancer, but its high toxicity, low natural abundance and tedious chemical synthesis hindered its translation into clinics. In the present work, a triterpenoid library was screened for compounds with both high natural abundance and structural similarity to celastrol; from this library, glycyrrhetinic acid (GA), a compound present in extremely high yields in Glycyrrhiza uralensis Fisch. ex DC., was selected as a possible scaffold for a celastrol mimic active against obesity. A simple chemical modification of GA resulted in GA-02, a derivative that suppressed 68% of food intake in diet-induced obesity mice and led to 26.4% weight loss in 2 weeks. GA-02 plays a role in obesity treatment by re-activating leptin signaling and reducing systemic and, more importantly, hypothalamic inflammation. GA-02 was readily bioavailable with unnoticeable in vitro and in vivo toxicities. The strategy of scaffold search and modification on the basis of bio-content and structural similarity has proved to be a green, economic, efficient and practical way of widening the medicinal applications of “imperfect” bioactive natural compounds.

A Catalog of Natural Products Occurring in Watermelon-Citrullus lanatus

Sweet dessert watermelon (Citrullus lanatus) is one of the most important vegetable crops consumed throughout the world. The chemical composition of watermelon provides both high nutritional value and various health benefits. The present manuscript introduces a catalog of 1,679 small molecules occurring in the watermelon and their cheminformatics analysis for diverse features. In this catalog, the phytochemicals are associated with the literature describing their presence in the watermelon plant, and when possible, concentration values in various plant parts (flesh, seeds, leaves, roots, rind). Also cataloged are the chemical classes, molecular weight and formula, chemical structure, and certain physical and chemical properties for each phytochemical. In our view, knowing precisely what is in what we eat, as this catalog does for watermelon, supports both the rationale for certain controlled feeding studies in the field of precision nutrition, and plant breeding efforts for the development of new varieties with enhanced concentrations of specific phytochemicals. Additionally, improved and comprehensive collections of natural products accessible to the public will be especially useful to researchers in nutrition, cheminformatics, bioinformatics, and drug development, among other disciplines.

Phyto-constituents profiling of Luffa echinata and in vitro assessment of antioxidant, anti-diabetic, anticancer and anti-acetylcholine esterase activities

Luffa echinata Roxb. is one of the neglected medicinal plants. It is an important source of bioactive metabolites and used in several Ayurvedic formulations. In the present analysis, mature leaves and fruits were extracted with acetone, ethanol, acetonitrile, methanol and water. Phytochemicals like total phenolic (TPC), flavonoid (TFC), tannin (TTC), alkaloid (TAC) and terpenoid (TTEC) content were analysed. Further, antioxidant (AOX) activities like 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'-azino-bis-(3-ethyl) benzothiazoline-6-sulfonic acid (ABTS) radical scavenging, metal chelating activity (MC), ferric reducing antioxidant power (FRAP) and phosphomolybdenum assay (PMA) were studied. Highest TPC and TFC (189.57 ± 1.9 mg TAE/g extract, 30.48 ± 0.7 mg CE/g extract, respectively) were reported from acetone extract of the leaves. Ethanolic fruit extract showed the highest TTC (13.79 ± 0.2 mg CE/g extract). Acetone and acetonitrile fruit extract revealed maximum TTEC (602.79 ± 3.5 mg UAE/g extract) and moderate TAC (19.96 ± 0.9 mg GE/g extract), respectively. In AOX, highest DPPH (50.52 ± 0.03 mg AAE/g extract) and ABTS (26.78 ± 0.03 mg TE/g extract) radical scavenging reported in methanolic extract of fruit; however, acetone extract of leaf showed highest FRAP (376.89 ± 1.95 mg Fe(II)/g extract) and PMA (326.54 ± 4.73 mg AAE/g extract). In contrast, aqueous extract of leaf and fruit revealed highest metal chelating activity (41.67 ± 0.49 mg EDTA/g extract). In anti-diabetic studies, acetonitrile extract of leaves and fruits exhibited appreciable inhibition of α-amylase (83.33%) and α-glycosidase (77.42%) enzymes. Similarly, acetyl cholinesterase (AChE) inhibition was highest in water (88.91%) and acetone (81.87%) extracts of leaf and fruits. Fruit extracts showed potent anticancer activity against breast (MCF-7) and colon (HT-29) cancer cell lines (LC50 329.36 and 385.17 µg/mL, respectively). RP-HPLC analysis revealed highest cucurbitacin B (CuB) (196.24 ± 1.4 mg/g DW), followed by cucurbitacin I (CuI) and cucurbitacin E (CuE) in the fruits (57.14 ± 4.9 and 2.03 ± 0.03 mg/g DW, respectively). RP-HPLC analysis of extracts revealed presence of gallic acid (GA), catechin (CA), vanillic acid (VA), chlorogenic acid (CHLA) and coumaric acid (COA), in which highest GA found in the fruits (1.26 ± 0.07 mg/g DW). Liquid chromatography and mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) analysis revealed presence of bioactive compounds from various groups. Based on the present findings, it was revealed that the fruit and leaf of L. echinata can be used as potent bioresource for natural antioxidants, anti-diabetic, and anticancer drug.

Genetic and Pre- and Postharvest Factors Influencing the Content of Antioxidants in Cucurbit Crops

Cucurbitaceae is one of the most economically important plant families, and includes some worldwide cultivated species like cucumber, melons, and squashes, and some regionally cultivated and feral species that contribute to the human diet. For centuries, cucurbits have been appreciated because of their nutritional value and, in traditional medicine, because of their ability to alleviate certain ailments. Several studies have demonstrated the remarkable contents of valuable compounds in cucurbits, including antioxidants such as polyphenols, flavonoids, and carotenoids, but also tannins and terpenoids, which are abundant. This antioxidant power is beneficial for human health, but also in facing plant diseases and abiotic stresses. This review brings together data on the antioxidant properties of cucurbit species, addressing the genetic and pre- and postharvest factors that regulate the antioxidant content in different plant organs. Environmental conditions, management, storage, and pre- and postharvest treatments influencing the biosynthesis and activity of antioxidants, together with the biodiversity of this family, are determinant in improving the antioxidant potential of this group of species. Plant breeding, as well as the development of innovative biotechnological approaches, is also leading to new possibilities for exploiting cucurbits as functional products.

New insights into molecular mechanisms of "Cold or Hot" nature of food: When East meets West

Traditional Chinese medicines are largely adopted in China and have a key importance in the world medical system. Cold-hot nature is the important characteristics of food and Chinese Materia Medica in the traditional Chinese medicine, relating to food functions in the organism. As compared to the studies on the cold and hot nature in Chinese medicine, the research studies carried out to establish the association between cold-hot nature and food are insufficient. Intending to investigate the criteria to discriminate the cold-hot nature of food and Chinese medicine scientifically, this review collected the cold-hot nature-related literature in recent 20 years in several popular databases such as PubMed, Google Scholar, and Science Direct. This review explored that the cold and hot natures are not only linked to the chemical components such as water, carbohydrates, lipids, and amino acids, but also correlated to the biological effects, comprising of energy metabolism, inflammation response, oxidation reaction, immune response, and cell growth and proliferation. Besides, this review further put forward the possibility that cold-hot nature of food and Chinese medicine exert different biological effects on the inflammatory response via regulating the signaling pathways viz. NF-κB and MAPK. More extensive studies are needed to consider the overall connections between both the biological effects and chemical components and how food processing affects the cold-hot nature of the food.

Nootropic Effects of C. melo and C. lanatus seed extracts

Dementia and related conditions disturb the ability to perform routine life activities prohibiting a person from making appropriate decisions. Seeds of Cucumis melo and Citrullus lanatus have been investigated extensively for various pharmacological properties; hence, considering the presence of bioactive compounds, it was assumed that these seed extracts may support the functioning of the central nervous system. Thus, the present study was designed to investigate the short-term and long-term memory-enhancing effects of C. melo and C. lanatus seed extracts in mice by the Morris water maze (spatial learning and memory), stationary rod test, and passive avoidance tests (fear-motivated tests). Ethanol extract of both seeds were prepared by standard procedure and given to animals in the doses of 50 mg/kg, 100 mg/kg, and 200 mg/kg. The results were compared to standard drugs diazepam and imipramine given in the doses of 3 mg/kg and 30 mg/kg, respectively. Extracts of both the seeds were found to possess significant memory and cognition-enhancing effects in mice when tested by passive avoidance, stationary rod, and water maze tests. Results demonstrate memory and cognition-enhancing effects of these extracts which may be due to the presence of bioactive compounds in these seeds.

Bioactive fractions of Eucalyptus camaldulensis inhibit important foodborne pathogens, reduce listeriolysin O-induced haemolysis, and ameliorate hydrogen peroxide-induced oxidative stress on human embryonic colon cells

Extract of E. camaldulensis was partitioned into aqueous and ethanol fractions by a precipitation and sedimentation-based technique and profiled for phytochemical components. Antimicrobial evaluation yielded inhibitory concentrations of 16-64 and 158-316 µg/mL, and bactericidal concentrations of 32-64 and 316->2528 µg/mL for ethanol and aqueous fractions, respectively. Antioxidant activities evaluated using 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic) acid assays showed IC₅₀ values of 7.07 and 65.67 µg/mL, and 17.96 and 201.3 µg/mL for aqueous and ethanol fractions. Total phenolic content of 9.04 ± 0.26 and 3.58 ± 0.04 GAE/mg fraction, and flavonoid content of 2.07 ± 0.02 and 3.37 ± 0.05 QE/mg fraction were recorded for aqueous and ethanol fractions. At subinhibitory concentrations fractions significantly reduced listeriolysin O-induced haemolysis (p < 0.05), and ameliorated H₂O₂-induced toxicity by 8-23 and 15-83%. Nitrite production reduced by 4-17 and 3-14 µM following fractions treatment. The fractions showed bioactive properties, with oxidative stress amelioratory effects, and could be a potentials source of preservatives and functional food additives.

The anti-inflammatory, anti-ulcer activities and phytochemical investigation of Cucumis melo L. cv. Ismailawi fruits

This study aims to evaluate the anti-inflammatory and anti-ulcer activities of Cucumis melo L. cv. Ismailawi fruits, as well as the investigation of the phenolic content and lipoidal matter composition via high performance liquid chromatography and gas chromatography coupled to mass spectrometry respectively. Both the petroleum ether and defatted methanol extracts of the fruit pulp showed 63.13% and 54.97% decrease in oedema volume respectively after 4 h in comparison to indomethacin standard drug. Both the petroleum ether extract and ethyl acetate fractions at a dose (200 mg/kg) showed significant anti-ulcer activity decreasing both ulcer number and severity in comparison to ranitidine as standard drug. Histopathological investigation further confirmed these results. Moreover; this is the first report for the investigation of the phenolic content and the lipoidal matter of Cucumis melo L. cv. Ismailawi fruits where methyl palmatate, gallic acid and rutin represented the major detected components.

Metabolite Profiles of Red and Yellow Watermelon (Citrullus lanatus) Cultivars Using a 1H-NMR Metabolomics Approach

Watermelon, a widely commercialized fruit, is famous for its thirst-quenching property. The broad range of cultivars, which give rise to distinct color and taste, can be attributed to the differences in their chemical profile, especially that of the carotenoids and volatile compounds. In order to understand this distribution properly, water extracts of red and yellow watermelon pulps with predominantly polar metabolites were subjected to proton nuclear magnetic resonance (1H-NMR) analysis. Deuterium oxide (D2O) and deuterated chloroform (CDCl3) solvents were used to capture both polar and non-polar metabolites from the same sample. Thirty-six metabolites, of which six are carotenoids, were identified from the extracts. The clustering of the compounds was determined using unsupervised principal component analysis (PCA) and further grouping was achieved using supervised orthogonal partial least squares discriminant analysis (OPLS-DA). The presence of lycopene, β-carotene, lutein, and prolycopene in the red watermelon plays an important role in its differentiation from the yellow cultivar. A marked difference in metabolite distribution was observed between the NMR solvents used as evidenced from the PCA model. OPLS-DA and relative quantification of the metabolites, on the other hand, helped in uncovering the discriminating metabolites of the red and yellow watermelon cultivars from the same solvent system.

Toxicity and developmental effect of cucurbitacin E from Citrullus colocynthis L. (Cucurbitales: Cucurbitaceae) against Spodoptera litura Fab. and a non-target earthworm Eisenia fetida Savigny

Pest management with natural botanical insecticides is a significant implementation for the sustainability of agroecosystem by reducing the unnecessary risk from the inputs of synthetic insecticides. In this research, we isolated the bioactive compound cucurbitacin E from Citrullus colocynthis (L.) Schrad, and their toxicological effects were screened against different larval instars of Spodoptera litura. The bioactive compound cucurbitacin E was chemically characterized through TLC, FT-IR, and NMR analyses. The larval mortality bioassay revealed that the larvae exposed to cucurbitacin E at the discriminating dose of 50 ppm display higher mortality rate against second (93.8%), third (86.4%), and fourth (73.2%) instar respectively. The lethal concentrations (LC₅₀ and LC₉₀) was detected as 15.84 and 67.60 ppm for third instar respectively. The sub-lethal concentration of cucurbitacin E (2, 4, and 6 ppm) intentionally altered the percentage of survival, pupation, fecundity, and egg hatchability of S. litura. Moreover, antifeedant activity of cucurbitacin E was analyzed using choice-based test. In addition, we found the toxic effects of cucurbitacin E (50 and 100 ppm) and chemical pesticides (cypermethrin and monocrotophos) against terrestrial beneficial earthworm Eisenia fetida, and the result revealed that cucurbitacin E has no harmful effect on non-target organism. Hence, the present study reveals that cucurbitacin E might be a part of a new biorational product alternative to synthetic pesticides.

Anti-Inflammatory Properties of Plant Derived Natural Products - A Systematic Review

Traditionally, natural medicines have been administered as plant extracts, which are composed of a mixture of molecules. The individual molecular species in this mixture may or may not contribute to the overall medicinal effects and some may even oppose the beneficial activity of others. To better control therapeutic effects, studies that characterized specific molecules and describe their individual activity that have been performed over the past decades. These studies appear to underline that natural products are particularly effective as antioxidants and anti-inflammatory agents. In this systematic review we aimed to identify potent anti-inflammatory natural products and relate their efficacy to their chemical structure and physicochemical properties. To identify these compounds, we performed a comprehensive literature search to find those studies, in which a dose-response description and a positive control reference compound was used to benchmark the observed activity. Of the analyzed papers, 7% of initially selected studies met these requirements and were subjected to further analysis. This analysis revealed that most selected natural products indeed appeared to possess anti-inflammatory activities, in particular anti-oxidative properties. In addition, 14% of the natural products outperformed the remaining natural products in all tested assays and are attractive candidates as new anti-inflammatory agents.

Cucurbitacin E ameliorates lipopolysaccharide-evoked injury, inflammation and MUC5AC expression in bronchial epithelial cells by restraining the HMGB1-TLR4-NF-κB signaling

Asthma is a chronic inflammatory disorder of airway affecting people from childhood to old age, and is characterized by airway epithelial dysfunction. Cucurbitacin E (CuE), a tetracyclic triterpene isolated from Cucurbitaceae plants, has been recently proved to exert anti-inflammation and immunology regulation activities. Nevertheless, its roles in asthma remains poorly defined. In the current study, CuE had little cytotoxicity on cell viability of human bronchial epithelial cell line BEAS-2B. Moreover, lipopolysaccharide (LPS) exposure inhibited cell viability and induced cell apoptosis, which was reversed following CuE pretreatment. Additionally, CuE administration suppressed LPS-induced inflammatory cytokine production, including TNF-α, IL-6, and IL-8. Simultaneously, supplementation with CuE decreased the transcripts and releases of mucin 5AC (MUC5AC) in LPS-treated BEAS-2B cells. Intriguingly, CuE inhibited LPS-evoked activation of the high-mobility group box1 (HMGB1)-TLR4-NF-κB signaling by reducing the expression of HMGB1, TLR4 and p-p65 NF-κB. Notably, restoring this pathway by elevating HMGB1 expression largely offset the protective function of CuE against LPS-triggered cell injury, inflammatory response and MUC5AC expression. Consequently, these findings highlight that CuE can ameliorate human bronchial epithelial cell insult and inflammation under LPS-simulated asthmatic conditions by blocking the HMGB1-TLR4-NF-κB signaling, thereby supporting its usefulness as a promising therapeutic agent against asthma.

Cytotoxicity of cucurbitacin E from Citrullus colocynthis against multidrug-resistant cancer cells

BACKGROUND

Cucurbitacin E (CuE) is an oxygenated tetracyclic triterpenoid isolated from the fruits of Citrullus colocynthis (L.) Schrad.

PURPOSE

This study outlines CuE's cytotoxic activity against drug-resistant tumor cell lines. Three members of ABC transporters superfamily, P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and ABCB5 were investigated, whose overexpression in tumors is tightly linked to multidrug resistance. Further factors of drug resistance studied were the tumor suppressor TP53 and the epidermal growth factor receptor (EGFR).

METHODS

Cytotoxicity assays (resazurin assays) were used to investigate the activity of Citrullus colocynthis and CuE towards multidrug resistant cancer cells. Molecular docking (In silico) has been carried out to explore the CuE's mode of binding to ABC transporters (P-gp, BCRP and ABCB5). The visualization of doxorubicin uptake was done by a Spinning Disc Confocal Microscope. The assessment of proteins expression was done by western blotting analysis. COMPARE and hierarchical cluster analyses were applied to identify, which genes correlate with sensitivity or resistance to cucurbitacins (CuA, CuB, CuE, CuD, CuI, and CuK).

RESULTS

Multidrug-resistant cells overexpressing P-gp or BCRP were cross-resistant to CuE. By contrast, TP53 knock-out cells were sensitive to CuE. Remarkably, resistant cells transfected with oncogenic ΔEGFR or ABCB5 were hypersensitive (collateral sensitive) to CuE. In silico analyses demonstrated that CuE is a substrate for P-gp and BCRP. Immunoblot analyses highlighted that CuE targeted EGFR and silenced its downstream signaling cascades. The most striking result that emerged from the doxorubicin uptake by ABCB5 overexpressing cells is that CuE is an effective inhibitor for ABCB5 transporter when compared with verapamil. The COMPARE analyses of transcriptome-wide expression profiles of tumor cell lines of the NCI identified common genes involved in cell cycle regulation, cellular adhesion and intracellular communication for different cucurbitacins.

CONCLUSION

CuE represents a potential therapeutic candidate for the treatment of certain types of refractory tumors. To best of our knowledge, this is the first time to identify CuE and verapamil as inhibitors for ABCB5 transporter.

Are plants used in the Eastern Cape province for cosmetics fully commercialized?

Plants have been used for years for various cosmetic purposes. In the Eastern Cape province of South Africa, a large proportion of the population reliant (to some extent) on botanical resources for beauty and health. Despite the use of these botanical resources for various cosmetic purposes, only a few have been fully commercialized or used as ingredients in cosmetic formulation. The present study aimed to review plant species that are fully explored commercially for cosmetic products in the Eastern Cape province. A survey of cosmetic products with plant-based ingredients was done covering the major supermarkets (SPAR, Shoprite, and Pick n Pay), cosmetic shops (Clicks), and pharmacies in the Eastern Cape province, and electronic databases including Embase, Google Scholar, Medline, PubMed, Scopus, SciFinder^®, Springer, Science Direct, and Web of Science were used as data sources for ethnobotanical information. Surprisingly, out of 150 plant species used by both Xhosa men and women for various cosmeceutical purposes, only six plant species have been used commercially with regard to cosmeceutical application. These plants species belong to five major plant families, namely Lamiaceae (two species), Asphodelaceae (one species) Cucurbitaceae (one species), Oleaceae (one species), and Verbenaceae (one species). The findings revealed that the use of Eastern Cape plants for cosmetic purposes has not been fully explored commercially. Thus, there is a need for cosmeceutical industries to explore these species commercially in order to develop new possible cosmetic products for local and international markets.

Determination of cucurbitacin E in some selected herbs of ayurvedic importance through RP-HPLC

Background

The consumption of the fruits of cucurbitaceae plants is widely popular among Indians due to their various nutritional and medicinal purposes. Some of these plants are well reported in Ayurveda due to their potential therapeutic importance. In particular, the plants of this family are well-characterized by the presence of its bitter principle, Cucurbitacin E which differs within the species due to its genetic variations.

Objectives

The objective of the study was to develop a validated RP-HPLC method for standardization in some widely consumed cucurbits with cucurbitacin E as a marker compound.

Materials and methods

The RP-HPLC method was developed with a reverse phase C₁₈ column, using acetonitrile and water (1% glacial acetic acid) as mobile phase (70:30 v/v). The flow rate and λ_max were optimized at 1 mL/min and 230 nm respectively. The HPLC method was validated in terms of accuracy, specificity, sensitivity, and repeatability as per ICH guideline.

Results

The calibration curve was found linear in the concentration range of 1–100 μg/mL. The % RSD of precision and recovery was found to be <2%, which confirms high repeatability of the method. The results indicated that the content of cucurbitacin E was highest (0.0663% w/w) in Cucurbita pepo whereas Lagenaria siceraria contains the lowest (0.0356% w/w).

Conclusion

The study was able to explore the variation of cucurbitacin E content in some selected food plants of Cucurbitaceae family. The applicability of the method can be established in nutraceutical industry for the effective quality control of cucurbits for safe human consumption.

A Review of Malaysian Medicinal Plants with Potential Anti-Inflammatory Activity

This article aims to provide detailed information on Malaysian plants used for treating inflammation. An extensive search on electronic databases including PubMed, Google Scholar, Scopus, and ScienceDirect and conference papers was done to find relevant articles on anti-inflammatory activity of Malaysian medicinal plants. The keyword search terms used were "inflammation," "Malaysia," "medicinal plants," "mechanisms," "in vitro," and "in vivo." As a result, 96 articles on anti-inflammatory activity of Malaysian medicinal plants were found and further reviewed. Forty-six (46) plants (in vitro) and 30 plants (in vivo) have been identified to possess anti-inflammatory activity where two plants, Melicope ptelefolia (Tenggek burung) and Portulaca oleracea (Gelang pasir), were reported to have the strongest anti-inflammatory activity of more than 90% at a concentration of 250 µg/ml. It was showed that the activity was mainly due to the occurrence of diverse naturally occurring phytochemicals from diverse groups such as flavonoids, coumarins, alkaloids, steroids, benzophenone, triterpenoids, curcuminoids, and cinnamic acid. Hence, this current review is a detailed discussion on the potential of Malaysian medicinal plants as an anti-inflammatory agent from the previous studies. However, further investigation on the possible underlying mechanisms and isolation of active compounds still remains to be investigated.

Correlations Between Nutrition Habits, Anxiety and Metabolic Parameters in Greek Healthy Adults

BACKGROUND

Anxiety combined with nervousness and apprehension consist a focal response to different life conditions. Lifestyle habits, anxiety and biochemical markers are in a constant interaction.

AIM

To investigate the prevalence of anxiety in healthy adults and its possible association with biochemical factors-lipid profile, liver markers, thyroid hormones-and lifestyle habits.

METHODS

Quantitative descriptive correlation study. A total of 100 healthy adults participated in the research. A specially designed questionnaire and Hamilton's scale were used. Anthropometric and biochemical analyses were performed.

FINDINGS

Overall, 61% of the participants presented moderate to very serious anxiety. The average score on the Hamilton scale was 13.82 (±9.000), with men exhibiting less stress than women. For p ≤ 0.05: Stress was positively correlated with impaired thyroid and hepatic function. Hepatic function was affected by both sugar products and water melon, which were positively correlated with total bilirubin and AST/SGOT respectively. Tomato, peppers and legumes were negatively correlated with AST/SGOT. Deep fried food was positively correlated with GGT and triglycerides. Legumes and fish were negatively correlated with CPK. Regarding the lipid metabolism, it was found that food cooked with oil was positively associated with uric acid, but non-cooked olive oil was negatively correlated with the risk for CAD. Thyroid function was negatively correlated with non-homemade food and pasta consumption and positively correlated with consumption of whole grains and green tea. Participants with subclinical hypothyroidism seemed to consume less vitamin B12, folic acid and vegetables.

CONCLUSION

No direct correlation between lifestyle habits and anxiety was found. Nevertheless, eating habits influenced biochemical markers-especially the thyroid hormones-which may be indirectly responsible for anxiety and related moods.

Cucurbitacin E Potently Modulates the Activity of Encephalitogenic Cells

Cucurbitacin E (CucE) is a highly oxidized steroid consisting of a tetracyclic triterpene. It is a member of a Cucurbitacin family of biomolecules that are predominantly found in Cucurbitaceae plants. CucE has already been identified as a potent anti-inflammatory compound. Here, its effects on CD4(+) T helper (Th) cells and macrophages, as the major encephalitogenic cells in the autoimmunity of the central nervous system, were investigated. Production of major pathogenic Th cell cytokines: interferon-gamma and interleukin-17 were inhibited under the influence of CucE. The effects of CucE on CD4(+) T cells were mediated through the modulation of aryl hydrocarbon receptor, STAT3, NFκB, p38 MAPK, and miR-146 signaling. Further, production of nitric oxide and reactive oxygen species, as well as phagocytic ability, were inhibited in macrophages treated with CucE. These results imply that CucE possesses powerful antiencephalitogenic activity.

Cucurbitacin E induces caspase-dependent apoptosis and protective autophagy mediated by ROS in lung cancer cells

Cucurbitacin E (CuE) is a triterpenoid with potent anticancer activities while the underlying mechanisms remain elusive. In the present study, the anticancer effects of CuE on 95D lung cancer cells were investigated. CuE decreased cell viability, inhibited colony formation, and increased reactive oxygen species (ROS) in a concentration-dependent manner, which were reversed by N-acetyl-l-cysteine (NAC). CuE induced apoptosis as determined by JC-1 staining, expression of Bcl-2 family proteins, cleavage of caspases, and TUNEL staining. NAC and Ac-DEVD-CHO partially reversed CuE-induced cleavage of caspase-3, caspase-7, and PARP. Furthermore, CuE caused accumulation of autophagic vacuoles and concentration- and time-dependent expression of LC3II protein. Autophagy inhibitors chloroquine and bafilomycin A1 enhanced CuE-induced LC3II expression and cell death. CuE-triggered protein expression of p-AKT, p-mTOR, Beclin-1, and p-ULK1 was partially reversed by NAC pretreatment. In addition, CuE treatment damaged F-actin without affecting β-tubulin as confirmed by immunofluorescence. In conclusion, CuE induced ROS-dependent apoptosis through Bcl-2 family and caspases in 95D lung cancer cells. Furthermore, CuE induced protective autophagy mediated by ROS through AKT/mTOR pathway. This study provides novel roles of ROS in the anticancer effect of CuE.

(±)-Homocrepidine A, a Pair of Anti-inflammatory Enantiomeric Octahydroindolizine Alkaloid Dimers from Dendrobium crepidatum

A pair of racemic indolizidine enantiomers, (±)-homocrepidine A (1), and a piperidine derivative, homocrepidine B (2), were isolated from Dendrobium crepidatum along with the known alkaloid crepidine (3). The racemic mixture of 1 was separated into a pair of enantiomers, (+)-1 and (-)-1, by HPLC using a chiral chromatographic substrate, which represents the first successful example of resolving indolizidine racemic mixtures. The absolute configurations of (+)-1 and (-)-1 were assigned from single-crystal X-ray diffraction data. The evaluation of anti-inflammatory activity with LPS-induced RAW 264.7 macrophages revealed that (+)-1 strongly inhibited the production of nitric oxide (IC50, 3.6 μM) and significantly decreased the expression of inducible nitric oxide synthase, while (-)-1 and (±)-1 only had moderate inhibitory effects (IC50, 22.8 and 14.7 μM). Compound 2 showed moderate anti-inflammatory activity (IC50, 27.6 μM).

Cucurbitacins attenuate microglial activation and protect from neuroinflammatory injury through Nrf2/ARE activation and STAT/NF-κB inhibition

Emerging evidence suggests that neuroinflammatory responses are involved in the neuronal injury. Neuroinflammatory response is mediated by cellular components such as microglia and molecular components, including nitric oxide, prostaglandins and inflammatory cytokines, activation of complement proteins etc. Cucurbitacins is a class of highly oxidized tetracyclic triterpenoids isolated mainly from Cucurbitaceae but also from other plan families and has been reported to have pharmacological activities. The present study aimed to investigate the anti-neuroinflammatory effects of Cucurbitacins on TLR 2/4 agonists (amyloid-β, LTA, and LPS)-induced neuroinflammatory response in microglia and the underlying mechanism for Nrf2/ARE pathways. Results indicates that pretreatment with Cucurbitacins significantly reduced the pro-inflammatory cytokine (TNF-α, IL-1β and IL-6) and attenuated iNOS and COX-2 expression in TLR 2/4 agonists-stimulated microglia. In addition, Cucurbitacins inhibited JNK and p38 MAPKs activation and attenuated JAK-STAT and NF-κB activation in TLR 2/4 agonists-stimulated microglia. Next, we evaluate the potential involvement of Cucurbitacins in the activation of Nrf2/ARE signaling pathways and phase II detoxification enzymes activity. Results indicate that Cucurbitacins markedly promoted the activation of Nrf-2/ARE pathway-related downstream factors including NQO-1 and HO-1. Furthermore, anti-neuroinflammatory effects of Cucurbitacins are attenuated in the knockdown of Nrf2, HO-1 and NQO-1 respectively. Cucurbitacins also has neuroprotective effect against microglia over-activation related neuronal damage. This study demonstrates that Cucurbitacins is potent activator of the Nrf2/ARE pathway and is therapeutically relevant not only to neuroinflammatory responses of microglia but also neuroinflammation mediated neuronal injury.

In vitro and in vivo evaluation of cucurbitacin E on rat hepatic CYP2C11 expression and activity using LC-MS/MS

This study explored the effects of cucurbitacin E (CuE), a bioactive compound from Cucurbitaceae, on the metabolism/pharmacokinetic of tolbutamide, a model CYP2C9/11 probe substrate, and hepatic CYP2C11 expression in rats. Liquid chromatography-(tandem) mass spectrometry (LC-MS/MS) assay was used to detect tolbutamide as well as 4-hydroxytolbutamide, and then successfully applied to the pharmacokinetic study of tolbutamide in rats. The effect of CuE on CYP2C11 expression was determined by western blot. CuE (1.25-100 μmol L^-1) competitively inhibited tolbutamide 4-hydroxylation (CYP2C11) activity only in concentration-dependent manner with a K _i value of 55.5 μmol L^-1 in vitro. In whole animal studies, no significant difference in metabolism/pharmacokinetic of tolbutamide was found for the single pretreatment groups. In contrast, multiple pretreatments of CuE (200 μg kg^-1 d^-1, 3 d, i.p.) significantly decreased tolbutamide clearance (CL) by 25% and prolonged plasma half-time (T _1/2) by 37%. Moreover, CuE treatment (50-200 μg kg^-1 d^-1, i.p.) for 3 d did not affect CYP2C11 expression. These findings demonstrated that CuE competitively inhibited the metabolism of CYP2C11 substrates but had no effect on rat CYP2C11 expression. This study may provide a useful reference for the reasonable and safe use of herbal or natural products containing CuE to avoid unnecessary drug-drug interactions.

Cucurbitacin E suppresses cytokine expression in human Jurkat T cells through down-regulating the NF-κB signaling

Cucurbitacin E (CucE), a triterpenoid isolated from Cucurbitaceae plants, has been shown to possess an anti-inflammatory or immunosuppressive activity in vitro and in vivo, yet the underlying mechanism has been incompletely understood. The aim of the present study was to explore its effect on cytokine expression and the underlying mechanism in human Jurkat T cells as a cellular model. The results showed that CucE significantly inhibited the production of interleukin-2, tumor necrosis factor-α, and interferon-γ in culture medium of cells treated with phorbol 12,13-dibutyrate (PDB) plus ionomycin (Ion). Furthermore, the mRNA levels of these cytokines in activated Jurkat T cells were also decreased upon CucE treatment, suggesting a potential modulatory effect on the critical signaling pathways for cytokine expression, including nuclear factor-κB (NF-κB) or mitogen-activated protein kinases (MAPKs). In support of its effect on the NF-κB signaling pathway, CucE decreased the phosphorylation levels of inhibitor of κB (IκB) and NF-κB/p65 in PDB + Ion-stimulated cells. Further supporting this, the nuclear translocation of NF-κB/p65 was significantly suppressed in response to PDB plus Ion stimulation in the presence of CucE. The phosphorylation of p38MAPK, c-Jun N-terminal kinase (JNK), and Erk1/2, however, was not decreased or slightly increased at some time points by CucE treatment. Collectively, these data suggest that CucE may exhibit immunosuppressive effect by attenuating critical cytokine expression through down-regulating the NF-κB signaling pathway.

Cucurbitacin E has neuroprotective properties and autophagic modulating activities on dopaminergic neurons

Natural molecules are under intensive study for their potential as preventive and/or adjuvant therapies for neurodegenerative disorders such as Parkinson's disease (PD). We evaluated the neuroprotective potential of cucurbitacin E (CuE), a tetracyclic triterpenoid phytosterol extracted from the Ecballium elaterium (Cucurbitaceae), using a known cellular model of PD, NGF-differentiated PC12. In our postmitotic experimental paradigm, neuronal cells were treated with the parkinsonian toxin 1-methyl-4-phenylpyridinium (MPP⁺) to provoke significant cellular damage and apoptosis or with the potent N,N-diethyldithiocarbamate (DDC) to induce superoxide (O₂^•−) production, and CuE was administered prior to and during the neurotoxic treatment. We measured cellular death and reactive oxygen species to evaluate the antioxidant and antiapoptotic properties of CuE. In addition, we analyzed cellular macroautophagy, a bulk degradation process involving the lysosomal pathway. CuE showed neuroprotective effects on MPP⁺-induced cell death. However, CuE failed to rescue neuronal cells from oxidative stress induced by MPP⁺ or DDC. Microscopy and western blot data show an intriguing involvement of CuE in maintaining lysosomal distribution and decreasing autophagy flux. Altogether, these data indicate that CuE decreases neuronal death and autophagic flux in a postmitotic cellular model of PD.

The use of plants in the traditional management of diabetes in Nigeria: pharmacological and toxicological considerations

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence of diabetes is on a steady increase worldwide and it is now identified as one of the main threats to human health in the 21st century. In Nigeria, the use of herbal medicine alone or alongside prescription drugs for its management is quite common. We hereby carry out a review of medicinal plants traditionally used for diabetes management in Nigeria. Based on the available evidence on the species׳ pharmacology and safety, we highlight ways in which their therapeutic potential can be properly harnessed for possible integration into the country׳s healthcare system.

MATERIALS AND METHODS

Ethnobotanical information was obtained from a literature search of electronic databases such as Google Scholar, Pubmed and Scopus up to 2013 for publications on medicinal plants used in diabetes management, in which the place of use and/or sample collection was identified as Nigeria. 'Diabetes' and 'Nigeria' were used as keywords for the primary searches; and then 'Plant name - accepted or synonyms', 'Constituents', 'Drug interaction' and/or 'Toxicity' for the secondary searches.

RESULTS

The hypoglycemic effect of over a hundred out of the 115 plants reviewed in this paper is backed by preclinical experimental evidence, either in vivo or in vitro. One-third of the plants have been studied for their mechanism of action, while isolation of the bioactive constituent(s) has been accomplished for twenty three plants. Some plants showed specific organ toxicity, mostly nephrotoxic or hepatotoxic, with direct effects on the levels of some liver function enzymes. Twenty eight plants have been identified as in vitro modulators of P-glycoprotein and/or one or more of the cytochrome P450 enzymes, while eleven plants altered the levels of phase 2 metabolic enzymes, chiefly glutathione, with the potential to alter the pharmacokinetics of co-administered drugs.

CONCLUSION

This review, therefore, provides a useful resource to enable a thorough assessment of the profile of plants used in diabetes management so as to ensure a more rational use. By anticipating potential toxicities or possible herb-drug interactions, significant risks which would otherwise represent a burden on the country׳s healthcare system can be avoided.

Therapeutic ROS targeting of GADD45γ in the induction of G2/M arrest in primary human colorectal cancer cell lines by cucurbitacin E

Cucurbitacin E (CuE) or α-elaterin is a natural compound previously shown to be an antifeedant as well as a potent chemopreventive agent against several types of cancer. The present study investigated the anticancer effects of CuE on colorectal cancer (CRC) using primary cell lines isolated from five CRC patients in Taiwan, Specifically, we explored the anti-proliferation and cell cycle G2/M arrest induced by CuE in CRC cells. MPM-2 flow cytometry tests show that CuE-treated cells accumulated in metaphase (CuE 2.5-7.5 μM). Results further indicate that CuE produced G2/M arrest as well as the downregulation of CDC2 and cyclin B1 expression and dissociation. Both effects increased proportionally with the dose of CuE; however, the inhibition of proliferation, arrest of mitosis, production of reactive oxygen species (ROS), and loss of mitochondrial membrane potential (ΔΨm) were found to be dependent on the quantity of CuE used to treat the cancer cells. In addition, cell cycle arrest in treated cells coincided with the activation of the gene GADD45(α, β, γ). Incubation with CuE resulted in the binding of GADD45γ to CDC2, which suggests that the delay in CuE-induced mitosis is regulated by the overexpression of GADD45γ. Our findings suggest that, in addition to the known effects on cancer prevention, CuE may have antitumor activities in established CRC.