In vitro pharmacological evaluation of three Barleria species

Acetyl barlerin from Barleria trispinosa induces chemopreventive NQO1 and attenuates LPS-induced inflammation: in vitro and molecular dynamic studies

Extraction and fractionation of Barleria trispinosa growing in Saudi Arabia yielded four iridoid compounds identified by spectroscopic techniques as acetylbarlerin (1), barlerin (2), shanzhiside methyl ester (3) and 6-⍺-L-rhamnopyranosyl-8-O-acetylshanzihiside methyl ester (4). Preliminary experiments confirmed that compound 1 acts as an inducer of chemopreventive NAD(P)H:Quinone oxidoreductase 1 (NQO1) enzymatic activity in a murine hepatoma (Hepa1c1c7) chemoprevention model. It also demonstrated the ability to inhibit the lipopolysaccharides (LPS)-induced nitric oxide (NO) production in the RAW264.7 macrophage model. Western blotting revealed the ability of compound 1 to up-regulate the protein expression of the NQO1 marker. Furthermore, compound 1 elicited NO suppression in RAW264.7 macrophages by inhibiting iNOS protein expression. Molecular docking and molecular simulation studies of 1 supported its experimental results as an inhibitor of the nuclear factor erythroid 2-Kelch-like ECH-associated protein 1 (Nrf2-KEAP1) complex, resulting in Nrf2-mediated induction of chemopreventive NQO1.Communicated by Ramaswamy H. Sarma.

Phytochemical Composition and Antibacterial Activity of Barleria albostellata C.B. Clarke Leaf and Stem Extracts

Barleria albostellata (Acanthaceae) is a shrub located in South Africa and is relatively understudied. However, plants within this genus are well known for their medicinal and ethnopharmacological properties. This study aimed to characterise the phytochemical compounds and antibacterial efficacies of B. albostellata. Phytochemical analysis, fluorescence microscopy and gas chromatography-mass spectrometry (GC-MS) analysis were performed to determine the composition of compounds that may be of medicinal importance. Crude leaf and stem extracts (hexane, chloroform and methanol) were subjected to an antibacterial analysis against several pathogenic microorganisms. The qualitative phytochemical screening of leaf and stem extracts revealed the presence various compounds. Fluorescence microscopy qualitatively assessed the leaf and stem powdered material, which displayed various colours under bright and UV light. GC-MS chromatograms represents 10-108 peaks of various compounds detected in the leaf and stem crude extracts. Major pharmacologically active compounds found in the extracts were alpha-amyrin, flavone, phenol, phytol, phytol acetate, squalene and stigmasterol. Crude extracts positively inhibited Gram-positive and Gram-negative bacteria. Significance was established at p < 0.05 for all concentrations and treatments. These results indicate that the leaves and stems of B. albostellata are rich in bioactive compounds, which could be a potential source of antibacterial agents for treating various diseases linked to the pathogenic bacteria studied. Future discoveries from this plant could advance the use of indigenous traditional medicine and provide novel drug leads.

Distribution profile of iridoid glycosides and phenolic compounds in two Barleria species and their correlation with antioxidant and antibacterial activity

INTRODUCTION

Barleria prionitis is known for its medicinal properties from ancient times. Bioactive iridoid glycosides and phenolic compounds have been isolated from leaves of this plant. However, other parts of a medicinal plants are also important, especially roots. Therefore, it is important to screen all organs for complete chemical characterization.

METHOD

All parts of B. prionitis, including leaf, root, stem and inflorescence in search of bioactive compounds, with a rapid and effective metabolomic method. X500R QTOF system with information dependent acquisition (IDA) method was used to collect high resolution accurate mass data (HRMS) on both the parent (MS signal) and their fragment ions (MS/MS signal). ESI spectra was obtained in positive ion mode from all parts of the plant. A comparative analysis of antioxidant and antibacterial activity was done and their correlation study with the identified compounds was demonstrated. Principal component analysis was performed.

RESULT

Iridoid glycosides and phenolic compounds were identified from all parts of the showing variability in presence and abundance. Many of the compounds are reported first time in B. prionitis. Antioxidant and antibacterial activity was revealed in all organs, root being the most effective one. Some of the iridoid glycoside and phenolic compounds found to be positively correlated with the tested biological activity. Principal component analysis of the chemical profiles showed variability in distribution of the compounds.

CONCLUSION

All parts of B. prionitis are rich source of bioactive iridoid glycosides and phenolic compounds.

Bioactive Potential: A Pharmacognostic Definition through the Screening of Four Hypericum Species from the Canary Islands

In this work, we propose a general methodology to assess the bioactive potential (BP) of extracts in the quest of vegetable-based drugs. To exemplify the method, we studied the anticancer potential (AP) of four endemic species of genus Hypericum (Hypericum canariense L, Hypericum glandulosum Aiton, Hypericum grandifolium Choisy and Hypericum reflexum L.f) from the Canary Islands. Microextracts were obtained from the aerial parts of these species and were tested against six human tumor cell lines, A549 (non-small-cell lung), HBL-100 (breast), HeLa (cervix), SW1573 (non-small-cell lung), T-47D (breast) and WiDr (colon). The methanol–water microextracts were evaluated further for cell migration, autophagy and cell death. The most promising bioactive polar microextracts were analyzed by UHPLC–DAD–MS. The extraction yield, the bioactivity evaluation and the chemical profiling by LC–MS suggested that H. grandifolium was the species with the highest AP. Label-free live-cell imaging studies on HeLa cells exposed to the methanol–water microextract of H. grandifolium enabled observing cell death and several apoptotic hallmarks. Overall, this study allows us to select Hypericum grandifolium Choisy as a source of new chemical entities with a potential interest for cancer treatment.

Phytochemicals and Biological Activities of Barleria (Acanthaceae)

Plant species belonging to the family Acanthaceae are globally known to possess various medicinal properties and have cultural and economic importance in both traditional medicine and horticulture. They are important to both animals and humans and are used as food or for ornamental purposes worldwide. Barleria is the third largest genus in the family Acanthaceae. A few of the highly important and reported species of Barleria include B. prionitis, B. cristata, B. grandiflora, and B. lupulina. The flowers, leaves, stems, roots, and seed extracts of plants belonging to this genus are rich in bioactive compounds and have exhibited significant medicinal potential for the treatment of various ailments and infections. Evidence derived from several studies has demonstrated the antioxidant, antibacterial, antifungal, anti-inflammatory, anticancer, antidiabetic, antiulcer, hepatoprotective, analgesic, antiamoebic, antihelminthic, antiarthritic, antihypertensive, antiviral properties and toxicity of extracts, in addition inhibition of acetylcholinesterase activity and biosynthesis of nanoparticles, of the plant and seed extracts of species belonging to Barleria. Studies have reported that bioactive compounds such as flavonoids, quinones, iridoids, phenylethanoid glycosides, the immunostimulant protein “Sankaranin”, and antibiotics isolated from Barleria species are resposnsible for the above biological activities. Traditionally, the genus Barleria has significant medicinal potential; however, there is a scarcity of information on various species that are yet to be evaluated. This review provides a comprehensive report on existing literature, concerning the phytochemistry and biological activities of the genus Barleria.

Inhibition of the pro-inflammatory mediators in rat neutrophils by shanzhiside methyl ester and its acetyl derivative isolated from Barleria prionitis

ETHNOPHARMACOLOGICAL RELEVANCE

The aerial parts of Barleria prionitis Linn. (BP) (Acanthaceae) plant has long been used to treat inflammatory disorders such as toothache, swellings, arthritis and gout.

AIM OF THE STUDY

The purpose of this study was to evaluate the effects of shanzhiside methyl ester (SME), 8-O-acetyl shanzhiside methyl ester (ASME) and iridoid glycosides rich monoterpenoidal fraction (IFBp), isolated from the aerial part of BP, on the pro-inflammatory mediators in stimulated rat neutrophils.

MATERIALS AND METHODS

Rat neutrophils were incubated with or without test drugs. The influence of laboratory isolated and identified SME, ASME and IFBp on the production and release of pro-inflammatory mediators i.e. myeloperoxidase (MPO), elastase, matrix metalloproteinase-9 (MMP-9), interleukin 8 (IL-8), tumor necrosis factor alpha (TNF-α) and leukotriene B4 (LTB4) was evaluated in the formyl-met-leu-phenylalanine (f-MLP) and lipopolysaccharide (LPS) stimulated rat neutrophils using enzyme-linked immunosorbent assay (ELISA) methods. IFBp was also standardized with the high performance thin layer chromatography by simultaneous determination of SME and ASME marker compounds.

RESULTS

SME, ASME and IFBp displayed concentration-dependent inhibitory effects on the MPO, elastase and MMP-9 enzymes release, and IL-8, TNF-α and LTB4 cytokines production in the f-MLP and LPS stimulated rat neutrophils. The content of SME and ASME was found to be 17.32 ± 1.98 and 11.30 ± 1.06% w/w, respectively, in IFBp by HPTLC method.

CONCLUSION

Altogether, the present results suggest that the iridoidal glycosides of BP may be considered as therapeutic strategy against neutrophil-mediated inflammatory diseases. Developed and validated HPTLC method for the standardization of IFBp of BP can be used as a quality control tool for the routine qualitative and quantitative analysis of Barleria species containing SME and/or ASME.

African Herbal Remedies with Antioxidant Activity: A Potential Resource Base for Wound Treatment

The use of traditional herbal remedies as alternative medicine plays an important role in Africa since it forms part of primary health care for treatment of various medical conditions, including wounds. Although physiological levels of free radicals are essential to the healing process, they are known to partly contribute to wound chronicity when in excess. Consequently, antioxidant therapy has been shown to facilitate healing of such wounds. Also, a growing body of evidence suggests that, at least, part of the therapeutic value of herbals may be explained by their antioxidant activity. This paper reviews African herbal remedies with antioxidant activity with the aim of indicating potential resources for wound treatment. Firstly, herbals with identified antioxidant compounds and, secondly, herbals with proven antioxidant activity, but where the compound(s) responsible for the activity has not yet been identified, are listed. In the latter case it has been attempted to ascribe the activity to a compound known to be present in the plant family and/or species, where related activity has previously been documented for another genus of the species. Also, the tests employed to assess antioxidant activity and the potential caveats thereof during assessment are briefly commented on.

Antimicrobial, antioxidant, mutagenic and antimutagenic activities of Distephanus angulifolius and Ormocarpum trichocarpum

ETHNOPHARMACOLOGICAL RELEVANCE

The leaves of Distephanus angulifolius and Ormocarpum trichocarpum are used for treating stomach-related ailments in traditional medicine.

AIMS OF THE STUDY

The present study evaluated the antibacterial, antioxidant, mutagenic and antimutagenic properties of extracts obtained from the leaves of Distephanus angulifolius and Ormocarpum trichocarpum.

MATERIALS AND METHODS

The microtitre bioassay was used to determine the antibacterial activity against three Gram-positive and three Gram-negative bacteria. Antioxidant activity was determined using the free-radical scavenging and β-carotene-linoleic acid model assays. The safety and possible protective properties of the extracts were investigated using Ames test.

RESULTS

Dichloromethane fractions of both plants displayed a broad-spectrum antibacterial activity with minimum inhibitory concentrations ranging from 0.16 to 0.63 mg/ml. A dose-dependent antioxidant activity was recorded in both plant species. All the evaluated samples showed no mutagenic as well as weak or no antimutagenic properties in the absence of exogenous metabolic activation.

CONCLUSION

The results demonstrated the antibacterial and antioxidant activities of the leaves obtained from the two plant species. Furthermore, the data provides a rationale for the use of the plant species in treating stomach-related ailments in traditional medicine.

Antimycobacterial evaluation of fifteen medicinal plants in South Africa

Fifteen plant species were collected from the Nelspruit Botanical Garden based on a list of plants provided by Phytomedicine Programme at the University of Pretoria and their ethnopharmacological information. Hexane, dichloromethane (DCM), acetone and methanolic extracts were screened for antimycobacterial activity against Mycobacterium smegmatis. The acetone extract of Milletia stulhimannii was the most active, showing activity against Mycobacterium smegmatis with minimum inhibitory concentration (MIC) value of 0.13 mg/ml. Acetone extracts for all plants had lower MIC values ranging between 0.11-1.25 mg/ml against M. smegmatis. Milletia stulhimannii, Albizia gummifera, Xanthocercis zambesiaca and Barringtonia racemosa have shown great potential as anti-tuberculosis agents. They were active against M. smegmatis with average MIC values of acetone extracts of 0.13 mg/ml.