Anti-inflammatory constituents and new pterocarpanoid of Crotalaria pallida

Antibiotic Isoflavonoids, Anthraquinones, and Pterocarpanoids from Pigeon Pea (Cajanus cajan L.) Seeds against Multidrug-Resistant Staphylococcus aureus

Cajanus cajan L. (pigeon pea, locally known in the Philippines as kadios) seed is a functional food with health benefits that extend beyond their nutritional value. C. cajan seeds contain highly diverse secondary metabolites with enriched beneficial properties, such as antibacterial, anticancer, and antioxidant activities. However, the antibacterial activities of secondary metabolites from Philippine-grown C. cajan, against multidrug-resistant Staphylococcus aureus have not been thoroughly described. Here, we investigated the in vitro antibacterial properties of C. cajan seed against multidrug-resistant S. aureus ATCC BAA-44 (MDRSA) and three other S. aureus strains (S. aureus ATCC 25923, S. aureus ATCC 6538, and coagulase-negative S. aureus) and, subsequently, identified the antibiotic markers against S. aureus strains using mass spectrometry. Secondary metabolites from C. cajan seeds were extracted using acetone, methanol, or 95% ethanol. Antibacterial screening revealed antibiotic activity for the C. cajan acetone extract. Bioassay-guided purification of the C. cajan acetone extract afforded three semi-pure high-performance liquid chromatography (HPLC) fractions exhibiting 32–64 µg/mL minimum inhibitory concentration (MIC) against MDRSA. Chemical profiling of these fractions using liquid chromatography mass spectrometry (LCMS) identified six compounds that are antibacterial against MDRSA. High-resolution mass spectrometry (HRMS), MS/MS, and dereplication using Global Natural Products Social Molecular Networking (GNPS)™, and National Institute of Standards and Technology (NIST) Library identified the metabolites as rhein, formononetin, laccaic acid D, crotafuran E, ayamenin A, and biochanin A. These isoflavonoids, anthraquinones, and pterocarpanoids from C. cajan seeds are potential bioactive compounds against S. aureus, including the multidrug-resistant strains.

Flavonoids from the leaves of Apocynum venetum and their anti-inflammatory activity

Chemical investigation of the EtOAc-soluble extract of the leaves of Apocynum venetum allowed the isolation of seven flavonoids including a new compound named 4′-hydroxy-7- O-(4-hydroxybenzyl)-3-methoxy-6-prenylflavone (1) and six known compounds (2–7). The structures of these compounds are elucidated by spectroscopic and physico-chemical analyses. All the isolates are evaluated for in vitro anti-inflammatory activity by measuring their inhibitory activities on nitric oxide and tumor necrosis factor-α production in lipopolysaccharide-induced mouse peritoneal macrophages (RAW 264.7). Among them, 5 exhibits significant inhibitory activity toward nitric oxide and tumor necrosis factor-α production with IC50 values of 9.0 ± 0.7 and 42.1 ± 0.8 μM, respectively. In addition, 1 also shows moderate inhibitory activity toward nitric oxide production with an IC50 value of 17.2 ± 0.9 μM.

Isolation and structure elucidation of anti-tyrosinase compounds from the seeds of Crotalaria pallida

Three new compounds, crotalariapallins A-C (1-3), were isolated from the 95% EtOH extract of the seeds of Crotalaria pallida. Their structures were established based on extensive spectroscopic methods, including HRESIMS, UV, 1D and 2D NMR. All compounds were evaluated for their inhibitory activities to tyrosinase. These compounds showed different degrees of inhibitory activities, among them, compound 3 exhibited the strongest inhibition activity (IC₅₀ = 0.42 mM).

The complete chloroplast genome sequences and phylogenetic analysis of Crotalaria pallida (Leguminosae)

The complete chloroplast genome of Crotalaria pallida was obtained using the high-throughput sequencing technology in this article. The complete chloroplast genomes of this species were 152,658 bp in length, consisting of a large single-copy region (LSC) of 83,652 bp and a small single-copy region (SSC) of 18,028 bp, which were separated by a pair of inverted repeat (IRs) regions of 25,489 bp. The chloroplast genome contained 111 unique genes, including 77 protein-coding genes, 30 tRNA genes, and four rRNA genes. The phylogenomic relationship analysis suggested that C. pallida was closely related to Lupinus in the family of Leguminosae.

Synthesis and antiproliferative activity of 6-naphthylpterocarpans

The Heck-oxyarylation of racemic 2-(1-naphthyl)- and 2-(2-naphthyl)-2H-chromene derivatives were carried out resulting diastereoselectively in (6S*,6aR*,11aR*)-6-(1-naphthyl)- and 6-(2-naphthyl)-pterocarpans as major products and bridged (6R*,12R*)-6,12-methanodibenzo[d,g][1,3]dioxocine derivatives as minor products. Antiproliferative activity of two 6-naphthylpterocarpans was identified by MTT assay against A2780 and WM35 human cancer cell lines with low micromolar IC50 values. The measured 0.80 and 3.51 μM IC50 values of the (6S*,6aR*,11aR*)-6-(1-naphthyl)pterocarpan derivative with 8,9-methylenedioxy substitution represent the best activities in the pterocarpan family. Enantiomers of the pterocarpan and dioxocine derivatives and their chiral 2-naphthylchroman-4-one and 2-naphthyl-2H-chromene precursors were separated by HPLC using chiral stationary phase. HPLC-ECD spectra were recorded and absolute configuration and low-energy solution conformations were determined by TDDFT-ECD calculations. Characteristic ECD transitions of the separated enantiomers were correlated with their absolute configuration.

Anti-inflammatory pterocarpanoids from the roots of Pongamia pinnata

A phytochemical study on the roots of Pongamia pinnata afforded 11 pterocarpanoids, including three new compounds. The structures of the isolated compounds were determined by 1D and 2D NMR and HRESIMS data. The absolute configurations of the new compounds were assigned via analysis of the specific rotations and electronic circular dichroism (ECD) spectra. The isolates were evaluated for their inhibitory effects on nitric oxide (NO) production in LPS-stimulated BV-2 microglial cells. Six compounds exhibited inhibitory effects against NO production, and compound 5 showed the best activity with an IC₅₀ value at 12.0 μM.

Metabolites of Medicarpin and Their Distributions in Rats

Medicarpin is a bioactive pterocarpan that has been attracting increasing attention in recent years. However, its metabolic fate in vivo is still unknown. To clarify its metabolism and the distribution of its metabolites in rats after oral administration, the HPLC-ESI-IT-TOF-MSⁿ technique was used. A total of 165 new metabolites (13 phase I and 152 phase II metabolites) were tentatively identified, and 104, 29, 38, 41, 74, 28, 24, 15, 42, 8, 10, 3, and 17 metabolites were identified in urine, feces, plasma, the colon, intestine, stomach, liver, spleen, kidney, lung, heart, brain, and thymus, respectively. Metabolic reactions included demethylation, hydrogenation, hydroxylation, glucuronidation, sulfation, methylation, glycosylation, and vitamin C conjugation. M1 (medicarpin glucuronide), M5 (vestitol-1'-O-glucuronide) were distributed to 10 organs, and M1 was the most abundant metabolite in seven organs. Moreover, we found that isomerization of medicarpin must occur in vivo. At least 93 metabolites were regarded as potential new compounds by retrieving information from the Scifinder database. This is the first detailed report on the metabolism of ptercarpans in animals, which will help to deepen the understanding of the metabolism characteristics of medicarpin in vivo and provide a solid basis for further studies on the metabolism of other pterocarpans in animals.

Flavonoids, alkaloids from the seeds of Crotalaria pallida and their cytotoxicity and anti-inflammatory activities

Three flavonoids, cropalliflavones A-C, including two homoisoflavonoids with rare skeletons; three previously undescribed alkaloids, usaramine-N-oxide and cropallins A-B; and sixteen known compounds, were isolated from the seeds of Crotalaria pallida Ait. The absolute configurations of cropalliflavone A and usaramine-N-oxide were established by an ECD calculation and X-ray crystallography, respectively. Additionally, cropalliflavone B showed anti-proliferative activity against the MCF-7 cell line with an IC₅₀ value of 6.77 μM, and cropalliflavone C showed anti-inflammatory activity, with an IC₅₀ value of 16.07 μM.

In-vivo study of tissue reaction to Crotalaria pallida and Sansevieria roxburghiana fibers

BACKGROUND

A suture material producing least tissue reaction is considered as ideal. Other characteristics like tensile strength, capacity to sustain sterilization process enhance its acceptability. In the present situation there is a need to reascertain the relevance and utility of these materials. Among the suture materials mentioned by Sushrutacharya, Moorva (Sansevieria roxburghiana) and Shana (Crotalaria pallida) have been showed insignificant tissue reaction in operated cases of inguinal hernia. An experimental study to confirm the extent of tissue reaction in deeper planes is needed before extending the use of materials in the deep tissues.

OBJECTIVE

The objective of the study was to analyze deep tissue reaction and tensile strengths of plant fibres extracted from Crotalaria pallida and Sansevieria roxburghiana.

MATERIALS AND METHODS

The study was conducted on 18 albino rats, 3 groups of 6 rats each for a period of 21 days inserting the suture materials in deeper tissue, studying histopathology changes of the deeper connective tissues, hydroxyproline content and blood parameters on 7th, 14th, 21st days of the study. The tensile strength of the two materials was also assessed on 7th day in three different conditions. Statistical analysis was carried out using paired and unpaired t tests.

RESULTS

S. roxburghiana had least tissue reaction. C. pallida showed greater tensile strength in comparison to Moorva.

CONCLUSION

C. pallida can be used for deep tissue approximation because of its moderate tissue reaction and tensile strength, successive increase in hydroxyproline content and its capacity to sustain sterilization.

Leguminous Plants in the Indonesian Archipelago: Traditional Uses and Secondary Metabolites

Indonesia is one of the richest countries with respect to plants resources. People from various ethnic, language, and religious groups have used the plants as alternative medicines, health foods and beverages for hundreds of years. To establish modern application for these understudied plant resources, ethnopharmacological data from more than 40 leguminous plants in Indonesia, spanning the western to the eastern parts of the Indonesian archipelago, were reviewed. In particular, bioactive secondary metabolites, including flavonoids, were described in detail to promote research into these plants as functional foods, nutraceuticals, and medicines.

Pterocarpan scaffold: A natural lead molecule with diverse pharmacological properties

Phytoalexins are substances produced by plants that act as potent inhibitors of pathogens. Pterocarpans are biologically active isoflavonoids most commonly found in the family Fabaceae that have the ability to act as phytoalexins. It is made up of a tetracyclic ring system possessing benzofuran-benzopyran. A very great number of pterocarpans have been isolated from natural sources and they are proved to have significant biological activities such as anti-microbial, anti-cancerous, anti-inflammatory and anti-malarial activities. Recently, pterocarpans gained lot of attention because of the broad range of anti-cancer activities in various cancer cell lines such as breast, leukemia, cervical, lung, colon and melanoma. Interestingly, pterocarpans exhibited inhibitory potency against many enzymes such as PTP1B, Neuraminidase, and α-glycosidase. In addition, they were shown to have anti-estrogenic and anti-diabetic activities. This review is a comprehensive inventory of the structures and sources of pterocarpans and it emphasizes on the biological evaluations of pterocarpans from various plant sources and their scope as a lead molecule.

Estrogenic and mutagenic activities of Crotalaria pallida measured by recombinant yeast assay and Ames test

Background

Crotalaria pallida Ailton is a plant belonging to the Fabaceae family, popularly known as “rattle or rattlesnake” and used in traditional medicine to treat swelling of the joints and as a vermifuge. Previous pharmacological studies have also reported anti-inflammatory, antimicrobial and antifungal activities. Nevertheless, scientific information regarding this species is scarce, and there are no reports related to its possible estrogenic and mutagenic effects. Thus, the purpose of the present study was to investigate the estrogenic potential of C. pallida leaves by means of the Recombinant Yeast Assay (RYA), seeking an alternative for estrogen replacement therapy during menopause; and to reflect on the safe use of natural products to assess the mutagenic activity of the crude extract from C. pallida leaves, the dichloromethane fraction and stigmasterol by means of the Ames test.

Methods

The recombinant yeast assay with the strain BY4741 of Saccharomyces cerevisiae, was performed with the ethanolic extract, dichloromethane fraction and stigmasterol isolated from the leaves of C. pallida. Mutagenic activity was evaluated by the Salmonella/microsome assay (Ames test), using the Salmonella typhimurium tester strains TA100, TA98, TA97 and TA102, with (+S9) and without (-S9) metabolization, by the preincubation method.

Results

All samples showed estrogenic activity, mainly stigmasterol. The ethanolic extract from C. pallida leaves showed mutagenic activity in the TA98 strain (-S9), whereas dichloromethane fraction and stigmasterol were found devoid of activity.

Conclusion

Considering the excellent estrogenic activity performed by stigmasterol in the RYA associated with the absence of mutagenic activity when evaluated by the Ames test, stigmasterol becomes a strong candidate to be used in hormone replacement therapy during menopause.

Isoflavonoids of the leguminosae

Isoflavonoids are found predominantly in subfamily Papilionoideae of the Leguminosae. This review describes more than 420 new examples of Leguminosae isoflavonoids, giving details of their source, identification, biological activity, synthesis, and ecological or chemosystematic significance. Other topics addressed include the application of hyphenated analytical techniques to the characterisation of legume-derived isoflavonoids, and advances made in biosynthetic studies. A checklist of new compounds by species is given, and 404 references are cited.

Inhibition of lipopolysaccharide-stimulated NO production by crotafuran B in RAW 264.7 macrophages involves the blockade of NF-κB activation through the increase in IκBα synthesis

Crotafuran B, a natural pterocarpanoid isolated from Crotalaria pallida, inhibited the lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production (IC50 16.4+/-0.7 microM) and inducible nitric oxide synthase (iNOS) protein and mRNA expression (IC50 11.5+/-0.6 microM and 11.8+/-2.2 microM, respectively), but not via its cytotoxicity or the inhibition of iNOS enzyme activity, in RAW 264.7 macrophages. Crotafuran B also reduced the iNOS promoter activity (IC50 13.4+/-0.1 microM) in piNOS-LUC-transfected cells. Crotafuran B treatment inhibited the p65 nuclear translocation and the nuclear factor-kappaB (NF-kappaB) DNA binding activity in LPS-activated macrophages. Crotafuran B also reduced the NF-kappaB transcriptional activity in pNF-kappaB-LUC-transfected cells. Crotafuran B had no effect on the LPS-induced phosphorylation of inhibitory kappaBalpha (IkappaBalpha), but enhanced the cellular level of IkappaBalpha that rebounded to the basal levels and increased the IkappaBalpha mRNA expression. These results indicate that the crotafuran B inhibition of NO production involves a decrease in the iNOS gene expression via the inhibition of NF-kappaB activation through the increase in IkappaBalpha synthesis.

Anti-inflammatory flavonoids and pterocarpanoid from Crotalaria pallida and C. assamica

One new isoflavone, 5,7,4'-trihydroxy-2'-methoxyisoflavone (3) and seven, and four known compounds were isolated from the barks of Crotalaria pallida and the seeds of C. assamica, respectively. The known compounds, apigenin (1) and 2'-hydroxygenistein (2), isolated from C. pallida, showed significant concentration-dependent inhibitory effects on the release of beta-glucuronidase and lysozyme from rat neutrophils in response to formyl-Met-Leu-Phe/cytochalasin B (fMLP/CB) with IC(50) values of 2.8+/-0.1 and 17.7+/-1.9, and 5.9+/-1.4 and 9.7+/-3.5 microM, respectively. The known compounds, daidzein (4) and 2'-hydroxydaidzein (6), isolated from C. pallida, inhibited of the release of lysozyme and beta-glucuronidase from rat neutrophils in response to fMLP/CB with IC(50) values of 26.3+/-5.5 and 13.7+/-2.6 microM, respectively. Compounds 1 and 4 also showed significant concentration-dependent inhibitory effects on superoxide anion generation in rat neutrophils stimulated with fMLP/CB with IC(50) values of 3.4+/-0.3 and 25.1+/-5.0 microM, respectively. Compounds 1 and 5, previously isolated from C. pallida, showed the inhibition of NO production in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and LPS/interferon-gamma (IFN-gamma)-stimulated N9 microglial cells with IC(50) values of 10.7+/-0.1 and 13.9+/-1.1 microM, respectively. Flavonoids, suppressed chemical mediators in inflammatory cells, may have value in treatment and prevention of central and peripheral inflammatory diseases associated with excess production of chemical mediators.