Antimicrobial and antioxidant activity and chemical characterisation of Erythrina stricta Roxb. (Fabaceae)

Coumarins and flavones from Ficus erecta and their anti-inflammatory activity

ETHNOPHARMACOLOGICAL RELEVANCE

Ficus erecta, a traditional Chinese She Ethnomedicine, has been historically utilized to treat various inflammatory conditions such as arthritis, nephritis, and osteoporosis. However, the underlying mechanisms accounting for its anti-inflammatory activity, as well as its active components, largely remain elusive.

AIM OF THE STUDY

The purpose of this research was to investigate the chemical constituents of F. erecta that contribute to its anti-inflammatory effects.

MATERIALS AND METHODS

Coumarins and flavones were obtained from the 95% EtOH extract of F. erecta using virous column chromatography and reversed-phase semipreparative HPLC. The structures of the new compounds were elucidated by extensive analysis of spectroscopic methods, including HRESIMS, 1D and 2D NMR spectra, and CD experiments. Cultured macrophage RAW264.7 cells were utilized for the anti-inflammatory experiments. MTT cell viability assay, Griess reagent method, ELISA, and Western blot experiments were employed to evaluate the anti-inflammatory activity and investigate the related mechanism.

RESULTS

Four new (1-4) and eleven previously identified (5-16) coumarins, together with one new (17) and six known flavones (18-23) were isolated from the whole plant of F. erecta. Compounds 7 and 17 significantly reduced nitric oxide (NO) and prostaglandin E2 (PGE2) production without cytotoxic effects. Furthermore, compounds 7 and 17 reduced the production of proinflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in a concentration-dependent manner. Western blot analysis indicated that compounds 7 and 17 suppressed the expression of iNOS, COX-2, and p-IκBα in LPS-stimulated RAW264.7 macrophage cells.

CONCLUSION

The current phytochemical investigations revealed that coumarins and flavones represent the primary chemical constituents of F. erecta. Compounds 7 and 17 exhibit potent anti-inflammatory properties, linked with the inhibition of NF-κB activation by preventing the degradation of IκBα phosphorylation. These compounds may serve as promising candidates for treating or preventing certain inflammatory diseases.

Chemical composition, antimicrobial activity, and antioxidant capacity of Micromeria flagellaris Baker and M. madagascariensis Baker: Two endemic species from Madagascar as sources of essential oils

Background

The aerial parts of Micromeria madagascariensis Baker and M. flagellaris Baker are used by the population of the Vakinankaratra and Itasy regions (Madagascar) to treat breathing difficulty, fever and/or headache, wounds, and sores.

Purpose

This work aimed to characterise plant materials from M. madagascariensis and M. flagellaris to report i) chemical composition, ii) antimicrobial properties, and iii) antioxidant capacity of the essential oils extracted from the aerial parts of these species.

Materials and methods

The essential oils from M. madagascariensis (MMO) and M. flagellaris (MFO) were obtained by hydrodistillation. Their chemical composition was quantified using gas chromatography coupled with mass spectrometry (GC-MS). MMO and MFO were also tested against 7 microbial strains using the disk diffusion method and their antioxidant capacity was assessed using the DPPH scavenging assay.

Results

Hydrodistillation yielded 0.26% MMO and 0.29% MFO (w/w) in relation to the fresh weight. Twenty-seven compounds were identified by GC-MS in MMO extract against 36 in MFO one. The main compounds in MMO were pulegone (24.67%), trans-menthone (24.67%), eucalyptol (8.12%), β-caryophyllene (4.98%), α-guanene (4.47), iso-menthone (3.85%), iso-pulegone (3.34%), azulene (3.28%) and 2-isopropyl-5-methylcyclohexenone (2.82%). The main compounds in the MFO were eudesma-4,11-dien-2-ol (13.88%), δ-guanene (6.62%), pulegone (6.40%), cyperone (5.56%), 4-epi-dehydrobietinol acetate (5.39%), eucalyptol (5.12%), trans-menthone (4.67%), limonene (3.77%) and sabinene (2.29%). Regarding the chemotaxonomy, M. flagellaris was very different from M. madagascariensis and both species also differed from the other Micromeria species, as confirmed by multivariate statistical analysis. Both MMO and MFO exerted activities against a large microbial spectrum; the antimicrobial activity of MMO was higher than MFO one against S. pneumoniae and C. albicans due to the presence of pulegone as the main component. MFO showed an excellent scavenging capacity with an SC50 value of 2.17 ± 0.03 μg/mL.

Conclusion

The biological properties of the essential oils extracted from the selected species may explain their therapeutic value showing that Malagasy Micromeria species may be very important as new natural sources of bioactive compounds. This study may promote the effectiveness and quality of Malagasy Micromeria species, contributing to sustainable development and commercial valorisation of traditional preparations based on natural local resources.

Evaluation of the potential of endophytic Trichoderma sp. isolated from medicinal plant Ampelopsis japonica against MRSA and bioassay-guided separation of the anti-MRSA compound

Endophytic fungi have been recognized as a valuable source for the production of biologically active compounds with potential applications in various domains. This study aimed to isolate endophytic fungi from Ampelopsis japonica (Thunb.) Makino and assess their anti-MRSA activity. Meanwhile, chromatographic separation techniques were applied to analyze the constituents of endophytic fungal secondary metabolites. The isolate BLR24, which exhibited strong inhibition activity against MRSA, was identified as Trichoderma virens based on morphological characteristics and ITS sequence analyses. The ethyl acetate extract of BLR24 (EA-BLR24) showed good anti-MRSA activity with the MIC and MBC values of 25 μg/mL and 50 μg/mL, separately. The inhibition of biofilm formation was up to 34.67% under MIC concentration treatment. Meanwhile, EA-BLR24 could significantly reduce the expression of biofilm-related genes (icaA, sarA, and agrA) of MRSA. Based on LC-MS/MS analysis, twenty compounds in EA-BLR24 could be annotated using the GNPS platform, mainly diketopiperazines. The anti-MRSA compound (Fr.1.1) was obtained from EA-BLR24 by bioassay-guided fractionation and determined as gliotoxin. The results indicated that endophytic Trichoderma virens BLR24 isolated from the medical plant A. japonica roots could be a promising source of natural anti-MRSA agents. Endophytic fungal secondary metabolites are abundant in biologically active compounds. Endophytic fungi from medicinal plants could be a source yielding bioactive metabolites of pharmaceutical importance.

Potential of medicinal plants as antimalarial agents: a review of work done at Kenya Medical Research Institute

Background: Medicinal plants have traditionally been used as remedies against malaria. The present review attempted to compile data on scientific research evidence on antimalarial medicinal plants screened at Kenya Medical Research Institute (KEMRI), Center for Traditional Medicine and Drug (CTMDR) Research from January 2003 to December 2021. Methods: A systematic review was conducted using a predefined protocol based on PRISMA. Search was performed in Google Scholar and PubMed. One hundred and eight journal articles were identified 37 of which published on antimalarial/antiplasmodial work. Thirty journal articles with at least one author from KEMRI-CTMDR and accessible in full were selected for analysis. Relevant data was captured in MS Excel format and descriptive statistics, percentages and tables used to summarize the findings. Results: Assessment of individual plant species was considered as an independent study resulting in 1170 antiplasmodial/antimalarial tests done from 197 plant species. One hundred and fifty plant species were screened in vitro, one in vivo and 46 were both in vivo and in vitro. Three hundred and forty-four of tests reported good activity (IC50 < 10 μg/mL or parasite suppression rate of ≥50%), 414 moderate activity (IC50 values of 10-49 μg/mL or parasite suppression rate of 30%-49%) and 412 were reports of inactivity (IC50 ˃ 50 μg/mL or parasite suppression rate of <30%). Fuerstia africana and Ludwigia erecta were reported to have the highest activities, with IC50 < 1 μg/mL against Plasmodium falciparum D6 strain and chemosuppression in mice at an oral dose of 100 mg/kg, was reported as 61.9% and 65.3% respectively. Fifty five antimalarial/antiplasmodial active compounds isolated from eight plant species were reported with resinone (39) having the best activity (IC50 < 1 μg/mL). Conclusion: Though 344 of tests reported promising antimalarial activity, it was noted that there was limited evaluation of these plants in animal models, with only 9.0% (105/1170) studies and no clinical trials. This highlights an important research gap emphasizing the need for drug development studies that aim to progress study findings from preclinical to clinical studies. There is still need for extensive research on promising plant species aimed at developing new plant based antimalarial drugs.

An overview of techniques and strategies for isolation of flavonoids from the genus Erythrina

Plants in the genus Erythrina is a potential source of chemical constituents, one of which is flavonoids, which have diverse bioactivities. To date, literature on the flavonoids from the genus Erythrina has only highlighted the phytochemical aspects, so this review article will discuss isolation techniques and strategies for the first time. More than 420 flavonoids have been reported in the Erythrina genus, which are grouped into 17 categories. These flavonoid compounds were obtained through isolation techniques and strategies using polar, semi-polar, and non-polar solvents. Various chromatographic techniques have been developed to isolate flavonoids using column flash chromatography, quick column chromatography, centrifugally accelerated thin-layer chromatography, radial chromatography, medium-pressure column chromatography, semi-preparative high-performance liquid chromatography, and preparative high-performance liquid chromatography. Chromatographic processes for isolating flavonoids can be optimized using multivariate statistical applications such as response surface methodology with central composite design, Box-Behnken design, Doehlert design, and mixture design.

The ameliorative efficacy of Thymus vulgaris essential oil against Escherichia coli O157:H7-induced hematological alterations, hepatorenal dysfunction and immune-inflammatory disturbances in experimentally infected rats

The purpose of the present study was to evaluate the possible ameliorative role of Thymus vulgaris (T. vulgaris) essential oil against Escherichia coli O157:H7 (E. coli O157:H7) deleterious effects in both blood and different tissues of rats by assessing the hematological, biochemical and immune-inflammatory parameters besides the histopathological alterations in the different organs. Forty male rats were randomly divided into four equal groups as follows: group I served as control, group II orally inoculated with E. coli O157:H7 at a dose of 1.0 × 10⁹ cfu/ml, group III orally received 250 mg/kg BW T. vulgaris oil daily for 7 days and group IV orally inoculated with E. coli O157:H7 as the same dose of group II and orally received T. vulgaris oil as the same dose and duration of group III. Bacterial challenge in groups II and IV was once at the beginning of experiment and administration of oil began after 72 h from bacterial inoculation. At the end of the study, blood was sampled and complete blood picture, liver and kidney function alongside immunoglobulins and cytokines concentrations were estimated and tissues of large intestine (colon), liver and kidneys were collected for histopathological examinations. The results revealed that there was an increase of red blood cells count, hematocrit value and hemoglobin concentration besides white blood cells and thrombocytes counts and substantial increment of serum markers of hepatorenal damage such as the activities of transaminases and concentrations of bilirubin (total, direct and indirect), total proteins, albumin, creatinine and urea in E. coli O157:H7-challenged group. Also, there was a considerable increase in serum immunoglobulins M and G, interleukin 6 and 8 and tumor necrosis factor alpha as well as decreased serum alkaline phosphatase activity. Moreover, T. vulgaris oil could partially improve the hematological, biochemical and histopathological alterations induced by E. coli O157:H7 without any significant alterations in all measured parameters when used alone. The study concluded that the T. vulgaris oil relatively diminished the alterations in hematological parameters, hepatic and renal function markers and immune-inflammatory variables alongside the histopathological changes in different organs induced by E. coli O157:H7. The ameliorative effects of T. vulgaris oil are mediated through its anti-inflammatory, antioxidant and immunomodulatory activities.

Five new Erythrina alkaloids from the stems of Erythrina corallodendron

Five new Erythrina alkaloids and five known E. alkaloids were isolated from a 95% ethanol extract of the stems of Erythrina corallodendron L. Their chemical structures were elucidated by UV, IR, HRESIMS, NMR and X-ray. Furthermore, the analgesic activities of E. alkaloids 1, 2 and 6 were evaluated by using an acetic acid-induced writhing test in mice, and their writhing inhibition rates were 67.9%, 64.6% and 70.3% at doses of 20 mg/kg, respectively.

In Vitro Antioxidant and Anticancer Properties of Various E. senegalensis Extracts

Although Erythrina senegalensis is a plant widely used in traditional medicine in sub-Saharan Africa, its biological properties have been poorly investigated to date. We first characterized by conventional reactions the composition of several stem bark extracts and evaluated in acellular and cellular assays their pro- or antioxidant properties supported by their high phenolic and flavonoid content, particularly with the methanolic extract. The pro- or antioxidant effects observed did not correlate with their IC₅₀ concentrations against five cancer cell lines determined by MTT assay. Indeed, the CH₂Cl₂ extract and its ethyl acetate (EtOAc) subfraction appeared more potent although they harbored lower pro- or antioxidant effects. Nevertheless, at equipotent concentration, both extracts induced ER- and mitochondria-derived vacuoles observed by fluorescent microscopy that further led to non-apoptotic cell death. LC coupled to high resolution MS investigations have been performed to identify chemical compounds of the extracts. These investigations highlighted the presence of compounds formerly isolated from E. senegalensis including senegalensein that could be retrieved only in the EtOAc subfraction but also thirteen other compounds, such as 16:3-Glc-stigmasterol and hexadecanoic acid, whose anticancer properties have been previously reported. Nineteen other compounds remain to be identified. In conclusion, E. senegalensis appeared rich in compounds with antioxidant and anticancer properties, supporting its use in traditional practice and its status as a species of interest for further investigations in anticancer drug research.

Ethnomedicinal study of medicinal plants used by Mizo tribes in Champhai district of Mizoram, India

BACKGROUND

Medicinal plants have been used countless times for curing diseases mainly in developing countries. They are easily available with little to no side effects when compared to modern medicine. This manuscript encompasses information on ethnomedicinal plants in Champhai district, located in the North East Region (NER) of India. The region lies within Indo-Burma biodiversity hotspot. This study will be the first quantitative report on the ethnomedicinal plants used by the local tribes of this region. Knowledge of medicinal plants is mostly acquired by word of mouth, and the knowledge is dying among the local youths with the prevalence of modern medicine. Hence, there is urgency in deciphering and recording such information.

METHODS

Information was gathered through interviews with 200 informants across 15 villages of the Champhai district. From the data obtained, we evaluate indices such as used report (UR), frequency of citation (FC), informant consensus factor (Fic), cultural values (CVs) and relative importance (RI) for all the plant species. Secondary data were obtained from scientific databases such as Pubmed, Sci Finder and Science Direct. The scientific name of the plants was matched and arranged in consultation with the working list of all plant species ( http://www.theplantlist.org ).

RESULTS

Totally, 93 plant species from 53 families and 85 genera were recorded. The most common families are Euphorbiaceae and Asteraceae with six and five species representatives, respectively. Leaves were the most frequently used part of a plant and were usually used in the form of decoction. Curcuma longa has the most cultural value (27.28 CVs) with the highest used report (136 FC), and the highest RI value was Phyllanthus emblica. The main illness categories as per Frequency of citation were muscle/bone problem (0.962 Fic), gastro-intestinal disease (0.956 Fic) and skin care (0.953 Fic).

CONCLUSION

The people of Mizoram living in the Champhai district have an immense knowledge of ethnomedicinal plants. There were no side effects recorded for consuming ethnomedicinal plants. We observed that there is a scope of scientific validation of 10 plant species for their pharmacological activity and 13 species for the phytochemical characterisation or isolation of the phytochemicals. This might pave the path for developing a scientifically validated botanical or lead to semisyntheic derivatives intended for modern medicine.

Short Overview of Some Assays for the Measurement of Antioxidant Activity of Natural Products and Their Relevance in Dermatology

Impaired systemic redox homeostasis is implicated in the onset and development of various diseases, including skin diseases. Therefore, continuous search for natural products with antioxidant bioactivities applicable in biomedicine is attractive topic of general interest. Research efforts aiming to validate antioxidant potentials of natural products has led to the development of several assays based on various test principles. Hence, understanding the advantages and limitations of various assays is important for selection of assays useful to study antioxidant and related bioactivities of natural products of biomedical interest. This review paper gives a short overview on some chemical and cellular bioassays used to estimate the antioxidant activity of chosen natural products together with a brief overview on the use of natural products with antioxidant activities as adjuvant medicinal remedies in dermatology.

Herbal Extracts with Antifungal Activity against Candida albicans: A Systematic Review

In the era of antimicrobial resistance, fungal pathogens are not an exception. Several strategies, including antimicrobial stewardship programs and high throughput screening of new drugs, are being implemented. Several recent studies have demonstrated the effectiveness of plant compounds with antifungal activity. In this systematic review, we examine the use of natural compounds as a possible avenue to fight fungal infections produced by Candida albicans, the most common human fungal pathogen. Electronic literature searches were conducted through PubMed/MEDLINE, Cochrane, and Science Direct limited to the 5 years. A total of 131 articles were included, with 186 plants extracts evaluated. Although the majority of the natural extracts exhibited antifungal activities against C. albicans (both in vivo and in vitro), the strongest antifungal activity was obtained from Lawsonia inermis, Pelargonium graveolens, Camellia sinensis, Mentha piperita, and Citrus latifolia. The main components with proven antifungal activities were phenolic compounds such as gallic acid, thymol, and flavonoids (especially catechin), polyphenols such as tannins, terpenoids and saponins. The incorporation of nanotechnology greatly enhances the antifungal properties of these natural compounds. Further research is needed to fully characterize the composition of all herbal extracts with antifungal activity as well as the mechanisms of action of the active compounds.

1H NMR-based metabolomics and UHPLC-ESI-MS/MS for the investigation of bioactive compounds from Lupinus albus fractions

Lupinus albus or white lupine has recently received increase attention for its medicinal values. Several studies have described the hypoglycemic effect of the white lupine, which is known as a food plant with potential value for treatment of diabetes. This study provides useful information for the identification and quantification of compounds in L. albus fractions by proton nuclear magnetic resonance (¹H NMR) spectroscopy. In total, 35 metabolites were identified from L. albus fractions.Principal component analysis (PCA) was used as a multivariate projection method for visualizing the different composition of four different fractions. The bioactivities of fractions with different polarity obtained from the extract of L. albus seeds are reported. Among the fractions studied, the chloroform fraction (CF) exhibits a high free radical scavenging (DPPH) and α-glucosidase inhibitory activities with IC₅₀ values of 24.08 and 20.08 μg/mL, respectively. A partial least-squares analyses (PLS) model had been successfully performed to correlate the potential active metabolites with the corresponding biological activities. Metabolites containing proline, caprate, asparagine, lupinoisolone C, hydroxyiso lupalbigenin and some unknown compounds show high correlation with the bioactivities studied. Moreover, the structural identification in the active fraction was supported by ultrahigh-performance-liquid chromatography-electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) analysis. A total of 21 metabolites were tentatively identified from MS/MS data by comparison with previously reported data. Most of these compounds are isoflavonoids without known biological activity. This information may be useful for developing functional food from L. albus with potential application in the management of diabetes.

UPLC-ESI-Q-TOF-MS-Based Metabolite Profiling, Antioxidant and Anti-Inflammatory Properties of Different Organ Extracts of Abeliophyllum distichum

Plant extracts have gained more attention as natural therapeutic agents against inflammation characterized by an overproduction of several inflammatory mediators such as reactive oxygen species and pro-inflammatory cytokines. Although Abeliophyllum distichum Nakai is generally known for its ornamental value, recent pharmacological research has demonstrated its potential therapeutic properties. Thus, to further evaluate the applicability of A. distichum in the food, cosmetic, and medical industries, we identified the phytochemicals in three organ extracts (fruits: AF, branches: AB, leaves: AL) of A. distichum and determined their antioxidant and anti-inflammatory activities. Using UPLC-ESI-Q-TOF-MS, a total of 19 compounds, including dendromoniliside D, forsythoside B, isoacteoside, isomucronulatol 7-O-Glucoside, plantamajoside, and wighteone were identified in the A. distichum organ extracts. AB exhibited a strong reducing power, an oxygen radical antioxidant capacity, and radical scavenging values compared with other samples, whereas AL exhibited the best anti-inflammatory properties. Gene expression, western blot, and molecular docking analyses suggested that the anti-inflammatory effect of AL was mediated by its ability to suppress lipopolysaccharide (LPS)-induced production of reactive oxygen species and/or inhibit LPS-stimulated activation of extracellular signal-regulated protein kinases (ERK1/2) in RAW264.7 cells. Collectively, these results indicate that AL is a potential source of phytochemicals that could be used to treat inflammation-associated diseases.

Promising Antioxidant Activity of Erythrina Genus: An Alternative Treatment for Inflammatory Pain?

The negative impact that oxidative stress has on health is currently known. The complex mechanism of free radicals initiates a series of chain reactions that contribute to the evolution or development of different degenerative disorders. Likewise, these disorders are usually accompanied by inflammatory processes and, therefore, pain. In this sense, reactive oxygen species (ROS) have been shown to promote the nociceptive process, but effective treatment of pain and inflammation still represents a challenge. Over time, it has been learned that there is no single way to relieve pain, and as long as there are no other alternatives, the trend will continue to apply multidisciplinary management, such as promote the traditional use of the Erythrina genus to manage pain and inflammation. In this sense, the Erythrina genus produces a wide range of secondary metabolites, including flavanones, isoflavones, isoflavones, and pterocarpans; these compounds are characterized by their antioxidant activity. Phenolic compounds have demonstrated their ability to suppress pro-oxidants and inhibit inflammatory signaling pathways such as MAPK, AP1, and NFκB. Although there is preclinical evidence supporting its use, the pharmacological effect mechanisms are not entirely clear. Nowadays, there is a fast advancement in knowledge of the disciplines related to drug discovery, but most of nature's medicinal potential has not yet been harnessed. This review analyzes the decisive role that the Erythrina genus could play in managing inflammatory pain mediated by its compounds and its uses as an antioxidant.

Bio- and chemo- transformations of glabranin and 7-O-methylglabranin and cytotoxic evaluations of the transformed products

The biotransformation of glabranin (1) with Aspergillus niger and Cunninghamella blakesleeana favoured the formation of benzofuran derivatives (3 and 4), while in contrast, its acid-catalysed chemical transformation favoured the formation of benzopyran derivatives (6 and 7). Compound 6 was further biooxidised at C-4'. Biotransformation of 7-O-methylglabranin (2) proceeded via oxidation of the prenyl group and C-4' by the same fungi, and the obtention of 11 mimics the biosynthesis of this last compound. Some compounds displayed moderate antiproliferative activity against selected human cancer cell lines, with glabranin being the most active, suggesting that the prenyl group and the phenol at C-7 are important structural determinants for cytotoxicity.

The Chemical Compositions of Essential Oils Derived from Cryptocarya alba and Laurelia sempervirens Possess Antioxidant, Antibacterial and Antitumoral Activity Potential

Cryptocarya alba (Peumo; CA) and Laurelia sempervirens (Laurel; LS) are herbs native to the Chilean highlands and have historically been used for medicinal purposes by the Huilliches people. In this work, the essential oils were extracted using hydrodistillation in Clevenger apparatus and analyzed by GC-MS to determine their composition. The antioxidant capacity (AC) was evaluated in vitro. The cytotoxicity was determined using cell line cultures both non tumoral and tumoral. The toxicity was determined using the nematode Caenorhabditis elegans. The antimicrobial activity was evaluated against 52 bacteria using the agar disc diffusion method and the minimum inhibitory concentrations (MICs) were determined. The principal compounds found in C. alba essential oil (CA_EO) were α-terpineol (24.96%) and eucalyptol (21.63%) and were isazafrol (91.9%) in L. sempervirens essential oil (LS_EO). Both EOs showed antioxidant capacity in vitro. Both EO showed antibacterial activity against bacteria using. LS_EO showed more inhibitory effect on these cell lines respect to CA_EO. Both EOs showed toxicity against the nematode C.elegans at 3.12–50 mg/mL. The essential oils of CA and LS have an important bioactive potential in their antioxidant, antibacterial and cytotoxicity activity. Both essential oils could possibly be used in the field of natural medicine, natural food preservation, cosmetics, sanitation and plaguicides among others.

Antibacterial Activity of Endostemon tereticaulis (Poir.) M. Ashby Essential Oil and Ethanolic Extract Against Resistant Pathogenic Bacteria

Endostemon tereticaulis (poir.) M.Ashby is a species of the Lamiaceae family present in Niger. This plant is used in traditional medicine due to its various biological potentialities. The present study investigated the chemical composition of the essential oil and the antibacterial activity of the essential oil and ethanolic extract of Endostemon tereticaulis against resistant pathogenic bacteria. Gas chromatography-mass spectrometry analysis of the essential oil led to the identification of 43 compounds representing 99.55% of the total essential oil. The major components were caryophyllene oxide (15.17%) followed by α-humulene (13.96%), α-copaene (11.75%), ( E)-β-caryophyllene (8.44%), and δ-cadinene (6.78%). The antibacterial activity was tested against multiresistant Acinetobacter baumannii P1483, Salmonella spp. H1548, extended-spectrum β-lactamase- Escherichia coli Bu8566, Enterobacter cloacae Bu147, Proteus mirabilis Bu190 , Pseudomonas aeruginosa (ATCC 27853), Klebsiella pneumoniae (ATCC 700603), Escherichia coli (ATCC 25922), Enterococcus faecium H3434, methicillin-resistant Staphylococcus aureus P1123, and Staphylococcus aureus (ATCC 25923). The antibacterial assays revealed that the essential oil was more active than the ethanolic extract against the studied bacteria with minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values ranging from 0.06 to 2 mg/mL. Also, the ethanolic extract was effective against the bacteria tested with MIC and MBC values ranging from 0.12 to 3 mg/mL. This study showed that Endostemon tereticaulis essential oil is rich in bioactive compounds. Ethanolic extract and essential oil exhibited potential antibacterial activity. These results provide a scientific basis for the use of this plant in traditional medicine. The current study described for the first time the antibacterial activity of Endostemon tereticaulis.

Development of a Cell-Based Assay for Identifying KCa3.1 Inhibitors Using Intestinal Epithelial Cell Lines

Inhibition of the K_Ca3.1 potassium channel has therapeutic potential in a variety of human diseases, including inflammation-associated disorders and cancers. However, K_Ca3.1 inhibitors with high therapeutic promise are currently not available. This study aimed to establish a screening assay for identifying inhibitors of K_Ca3.1 in native cells and from library compounds derived from natural products in Thailand. The screening platform was successfully developed based on a thallium flux assay in intestinal epithelial (T84) cells with a Z' factor of 0.52. The screening of 1352 compounds and functional validation using electrophysiological analyses identified 8 compounds as novel K_Ca3.1 inhibitors with IC₅₀ values ranging from 0.14 to 6.57 µM. These results indicate that the assay developed is of excellent quality for high-throughput screening and capable of identifying K_Ca3.1 inhibitors. This assay may be useful in identifying novel K_Ca3.1 inhibitors that may have therapeutic potential for inflammation-associated disorders and cancers.

Flavonoids and other Non-alkaloidal Constituents of Genus Erythrina: Phytochemical Review

BACKGROUND

Genus Erythrina belongs to family Fabaceae, which is widely distributed in tropical and subtropical areas. It has been used in both traditional herbal medicines and pharmacological applications. Original research articles and publications on the overview of alkaloids related to this genus are available, but a supportive systematic review account which highlighted phytochemical aspects of other types of secondary metabolites is currently insufficient.

OBJECTIVE

With the utilization of data and information from SCI-Finder, Google Scholar, the Web of Science, Scopus, Science Direct, PubMed, Chemical Abstracts, ACS journals, Springer, Taylor Francis, Bentham Science and IOP Science, the reliable material sources of this systematic review paper were obtained from the literature published from the 1980s to now.

CONCLUSION

A vast amount of data showed that the non-alkaloidal secondary metabolites were obtained from genus Erythrina with various classes of chemical structures. Herein, approximately five hundred constituents were isolated, comprising flavonoids, terpenoids, saponins, phytosterols, phenols, arylbenzofurans, coumarins, alcohols, ceramides, mono-sugars and fatty acid derivatives. In agreement with the previous phytochemical reports on the plants of the family Fabaceae, flavonoids reached a high amount in the plants of genus Erythrina. Numerous biological activity investigations such as anti-bacteria, anti-cancer, anti-virus using isolated compounds from Erythrina species suggested that secondary metabolites of Erythrina plants are now becoming the promising agents for drug developments.

Antimicrobial Isoflavones and Derivatives from Erythrina (Fabaceae): Structure Activity Perspective (Sar & Qsar) on Experimental and Mined Values Against Staphylococcus Aureus

Prenylated (iso)flavonoids, -flavans and pterocarpans from taxa in Erythrina are repeatedly flagged as potent antimicrobial compounds. In the current study, bark from E. lysistemon was extracted and seven isoflavone derivatives were purified: erybraedin A (1), phaseollidin (2), abyssinone V-4′ methyl ether (3), eryzerin C (4), alpumisoflavone (5), cristacarpin (6) and lysisteisoflavone (7). Minimum inhibition concentration (MIC) values were determined against a range of species of bacteria (skin pathogens), then values for another 67 derivatives from Erythrina, only against Staphylococcus aureus, were mined from the literature. Of the seven isolates, MIC values widely ranged from 1–600 μg/mL, with no obvious pattern of selectivity for Gram-types. Nevertheless, using the mined and experimentally determined values against S. aureus, Klekota-Roth fragments (Structure Activity Relationship: SAR) were determined then used as molecular descriptors to make a ‘decision tree’ based on structural characters inspired by the classes of antimicrobial potency (classes A-D). Furthermore, to make quantitative predictions of MIC values (Quantitative SAR: QSAR) ‘pace regression’ was utilized and validated (R² = 0.778, Q² = 0.727 and P² = 0.555). Evidently, the position and degree of prenylation is important; however, the presence of hydroxyl groups at positions 5 and 7 in ring A and 4′ in ring B is associated with lower MIC values. While antimicrobial results continue to validate the traditional use of E. lysistemon extracts (or Erythrina generally) in therapeutic applications consistent with anti-infection, it is surprising that this class of compound is not being utilized more often in general industry applications, such as food or cosmetic preservation, or in topical antimicrobial creams. Prenylated (iso)flavonoids are derived from several other Genera, such as Dorstenia (Moraceae), Ficus (Moraceae), Glycyrrhiza (Fabaceae), Paulownia (Lamiales) or Pomifera (Moraceae).

The Antioxidant Activity of Prenylflavonoids

Prenylated flavonoids combine the flavonoid moiety and the lipophilic prenyl side-chain. A great number of derivatives belonging to the class of chalcones, flavones, flavanones, isoflavones and other complex structures possessing different prenylation patterns have been studied in the past two decades for their potential as antioxidant agents. In this review, current knowledge on the natural occurrence and structural characteristics of both natural and synthetic derivatives was compiled. An exhaustive survey on the methods used to evaluate the antioxidant potential of these prenylflavonoids and the main results obtained were also presented and discussed. Whenever possible, structure-activity relationships were explored.

Alkaloids from the stem barks of Erythrina stricta

Four previously undescribed erythrinan alkaloids, 8α-acetonylerythristemine, 8α-acetonylerysotrine, 10β-hydroxy-11β-methoxyerysotramidine and 3-epierysotrine, one undescribed pyrrolidine derivative, S-1-(4-hydroxy-3-methoxyphenethyl)-5-hydroxy pyrrolidin-2-one, and one undescribed amide, N-(3-hydroxy-4-methoxyphenethyl)-4-hydroxylbutanamide, along with thirteen known alkaloids were isolated from the stem barks of Erythrina strica Roxb. (Leguminosae). Their structures were identified by extensive analysis of physical, spectroscopic and spectrometric data. It's very interesting that the coexistence of 3-methoxytyramine, erythrinarbine, S-1-(4-hydroxy-3-methoxyphenethyl)-5-hydroxy pyrrolidin-2-one and N-(3-hydroxy-4-methoxyphenethyl)-4-hydroxylbutanamide that may be closely related in biosynthesis, supports the hypothetical biogenetic pathway of pyrrolo [2,1-a]isoquinoline alkaloids.

Determining the Potential of Haematococcus pluvialis Oleoresin as a Rich Source of Antioxidants

Haematococcus pluvialis is known to be a natural source of antioxidants for numerous applications. In this study, an oleoresin rich in carotenoids extracted by supercritical CO₂ treatment of H. pluvialis was extensively characterized for its antioxidant capacity. Carotenoid content, fatty acid profile, total phenol content, antioxidant capacity, and viscosity of the oleoresin were determined with the aim of ascertaining the potential of the oleoresin in terms of its antioxidant content for food applications. The oleoresin contained 96.22 mg/g of total astaxanthin (which includes free astaxanthin and astaxanthin esters) and mostly included unsaturated fatty acids (~78% of total fatty acids). High total phenol content and ferric reducing antioxidant potential indicated high antioxidant capacity, but oxygen radical absorbance capacity was lower compared to the oleoresin samples obtained from other species. The oleoresin was a non-Newtonian fluid since it had shear-thinning (pseudoplastic) and shear-thickening (dilatant) flow. Therefore, the H. pluvialis oleoresin is a potential alternative in developing functional ingredients for designing healthy food products. To the best of our knowledge, this is the first study that has reported an extensive characterization of the antioxidant properties of a microalgal oleoresin obtained by means of supercritical CO₂ fluid extraction.

Erythrina suberosa: Ethnopharmacology, Phytochemistry and Biological Activities

Plants are a great and irreplaceable source of medicines, fuel, food, energy and even cosmetics. Since prehistory, humans have learned to use plants for survival, growth and proliferation and still today it relies on natural and cultivated vegetables for food and the source of novel compounds with pharmacological activity. Not only herbs and flowers, but also trees are used. Indeed, Erythrina suberosa Roxb. is a deciduous tree of the family Fabaceae, common in Southeast Asia. In India, E. suberosa is called the “corky coral tree” or simply the “Indian coral tree”, given its peculiar red-orange flowers that can flower throughout the year and its corky irregular bark covered by prickles. It is a plant commonly used as an ornamental tree, but it also holds ethnopharmacological and socioeconomic uses. This article explored phytobiological features of E. suberosa, analysing its taxonomy, examining its traditional and common uses and investigating its bioactive components and pharmacological properties.

A Pharmacological Overview of Alpinumisoflavone, a Natural Prenylated Isoflavonoid

Over the last decade, several studies demonstrated that prenylation of flavonoids enhances various biological activities as compared to the respective nonprenylated compounds. In line with this, the natural prenylated isoflavonoid alpinumisoflavone (AIF) has been explored for a number of biological and pharmacological effects (therapeutic potential). In this review, we summarize the current information on health-promoting properties of AIF. Reported data evidenced that AIF has a multitherapeutic potential with antiosteoporotic, antioxidant and anti-inflammatory, antimicrobial, anticancer, estrogenic and antiestrogenic, antidiabetic, and neuroprotective properties. However, research on these aspects of AIF is not sufficient and needs to be reevaluated using more appropriate methods and methodology. Further series of studies are needed to confirm these pharmacological effects, and this review should lay the basis for the design of respective investigations. Overall, despite the drawbacks of studies recorded, AIF exhibits a potential as drug candidate.

TLC-bioautography identification and GC-MS analysis of antimicrobial and antioxidant active compounds in Musa × paradisiaca L. fruit pulp essential oil

INTRODUCTION

The absence of microbial growth and resistance to oxidative deterioration in fruits of Musa × paradisiaca L. (bananas) is an indication of the presence of antimicrobial and antioxidant metabolites.

OBJECTIVE

In order to investigate the secondary metabolomic spectrum as well as the active antimicrobial and antioxidants present in essential oils (EOs) from fruits of different geographical areas of M. × paradisiaca, gas chromatography-mass spectroscopy (GC-MS) principal component data correlation analysis is complemented with antimicrobial assays and phytochemical and bioautographic antioxidant fingerprints with thin layer chromatography (TLC).

METHODOLOGY

An EO was obtained by steam distillation and subjected to GC-MS and TLC for metabolomic profiling from fruit pulp. The antimicrobial potential was tested in both Escherichia coli as a gram negative and Bacillus subtilis as a gram positive microbe. Potential antioxidant metabolites were identified through TLC-bioautography and GC-MS analysis of active zones.

RESULTS

A maximum of 0.56% v/w EO was isolated from fruit pulps of M. × paradisiaca. Minimum inhibitory concentrations (MICs) against B. subtillis and E. coli were 0.25 and 0.35 μg/mL, respectively. Thus, 56 metabolites were identified through GC-MS. The major abundant antimicrobial metabolites found in EOs are α-thujene, γ-terpinene, α- and β-pinene, sabinene, β-myrcene, limonene, α-capaene, caryophyllene and (Z,E)-α farnesene. Aceteugenol, palmitic acid, stearic acid, palmitin, and stearin were identified as antioxidant metabolites. Principal component analysis of metabolite data reveals correlations and a clear separation based on metabolites obtained from various areas.

CONCLUSION

The data generated using metabolic profiling and cluster analysis helped to identify antimicrobial and antioxidant compounds in M. × paradisiaca.

Standardized extract of Erythrina velutina Willd. attenuates schizophrenia-Like behaviours and oxidative parameters in experimental animal models

OBJECTIVES

To study the effects of the standardized extract from the leaves of Erythrina velutina in behavioural and oxidative parameters in the ketamine-induced schizophrenia model.

METHODS

Mice received ketamine (KET) or saline for 7 days. From 8th to 14th day, the animals received Erythrine (Eryt) (100, 200 or 400 mg/kg) or olanzapine (Olanz), 1 h after KET administration. At 14th day, 30 min after the last administration of KET, the open-field and pre-pulse inhibition (PPI) tests were performed. Then, the animals were sacrificed and the prefrontal cortex (PFC), hippocampus (HC) and striatum (ST) were dissected for the oxidative tests.

KEY FINDINGS

Ketamine increased spontaneous locomotor activity and grooming. KET decreased the PPI, which was reversed by combining it with Eryt or olanzapine. KET decreased GSH concentration in PFC and ST this was reversed by Eryt. KET increased MDA concentration in PFC and HC this was reversed by Eryt. Eryt and Olanzapine reduced MDA concentration in ST when compared to KET group. Nitrite concentration was reduced by administration of KET in the PFC.

CONCLUSIONS

These results demonstrate that the standardized extract of E. velutina can prevent behavioural symptoms and oxidative stress induced by repeated doses of KET.

Ethnomedicinal plant diversity in Thailand

ETHNOPHARMACOLOGICAL RELEVANCE

Plants have provided medicine to humans for thousands of years, and in most parts of the world people still use traditional plant-derived medicine. Knowledge related to traditional use provides an important alternative to unavailable or expensive western medicine in many rural communities. At the same time, ethnomedicinal discoveries are valuable for the development of modern medicine. Unfortunately, globalization and urbanization causes the disappearance of much traditional medicinal plant knowledge.

AIM OF THE STUDY

To review available ethnobotanical knowledge about medicinal plants in Thailand and to estimate its diversity.

METHODS

Information about ethnomedicinal uses of plants in Thailand was extracted from 64 scientific reports, books, and theses produced between 1990 and 2014. Plant identifications in the primary sources were updated to currently accepted names following The Plant List website and the species were assigned to family following the Angiosperm Phylogeny Website. Use Values (UV) were calculated to estimate the importance of medicinal plant species (UV_s) and families (UV_f). Medicinal use categories, plant parts used, preparations of the medicine, and their applications were noted for each use report.

RESULTS

We found 16,789 use reports for 2187 plant species in 206 families. These data came from 19 ethnic groups living in 121 villages throughout Thailand. The health conditions most commonly treated with medicinal plants were in the categories digestive system disorders, infections/infestations, nutritional disorders, muscular-skeletal system disorders, and genitourinary system disorders. Plant families with very high use values were Fabaceae, Asteraceae, Acanthaceae, Lamiaceae, and Zingiberaceae and species with very high use values were Chromolaena odorata (L.) R.M.King & H.Rob., Blumea balsamifera (L.) DC., and Cheilocostus speciosus (J.Koenig) C.D.Specht. Stems and leaves were the most used plant parts, but also other parts of the plants were used in medicinal recipes. The most common way of using the medicinal plants was as a decoction in water.

CONCLUSION

We found 2187 plant species that were used in traditional medicine in Thailand. Of these a few hundred had high use values, suggesting that they may produce bioactive compounds with strong physiological effects.