Chemical structures and hepatoprotective effects of constituents from Cassia auriculata leaves

Green synthesis of silver nanoparticles from Cassia Auriculata: Targeting antibacterial, antioxidant activity, and evaluation of their possible effects on saltwater microcrustacean, Artemia Nauplii (non-target organism)

Due to their huge surface area to volume ratio, metallic nanoparticles are becoming increasingly important in numerous spheres of life. Here, initially, we aimed to evaluate the potential use of Cassia auriculata (CA) extract to synthesize silver nanoparticles (AgNPs). Then, we evaluated its antimicrobial potential and antioxidant capacity, as well as performed in silico analysis, and investigated the possible non-toxic effect of AgNPs on Artemia nauplii. Fourier transform infrared (FTIR) spectroscopy, scanning and transmission electron microscopy (SEM/TEM), energy dispersive spectroscopy (EDX), X-ray diffraction (XRD), and dynamic light scattering (DLS) studies were used to characterize the biosynthesized AgNPs. Our data indicate that Bacillus cereus, Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus bacteria were susceptible to the biosynthesized AgNPs, whose effect was concentration-response. With a ZOI of 10 mm, the AgNPs were most efficient against gram-positive B. cereus bacteria at the highest concentration (75 μg/mL). The biosynthesized AgNPs (at 25 to 125 μg/mL) showed good antioxidant activity in the DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) and FRAP (ferric reducing antioxidant power) assays. Oleanolic acid from CA exhibited strong binding affinity and high binding energy to E. coli and B. cereus (-9.66 and - 9.74 kcal/mol) on in silico research. According to the comparative non-toxicity analysis, AgNPs, AgNO₃, and CA bark extract had the least toxic effects on A. nauplii, with respective mortality rates of 28.14, 32.26, and 38.42 %, respectively. In conclusion, the current work showed that AgNPs produced from CA bark could be a promising material for diverse applications.

Structural Elucidation of an Atropisomeric Entcassiflavan-(4β→8)-Epicatechin Isolated from Dalbergia monetaria L.f. Based on NMR and ECD Calculations in Comparison to Experimental Data

A rare dihydoxyflavan-epicatechin proanthocyanidin, entcassiflavan-(4β→8)-epicatechin, was isolated from Dalbergia monetaria, a plant widely used by traditional people from the Amazon to treat urinary tract infections. The constitution and relative configuration of the compound were elucidated by HR-MS and detailed 1D- and 2D-NMR measurements. By comparing the experimental electronic circular dichroism (ECD) spectrum with the calculated ECD spectra of all 16 possible isomers, the absolute configuration, the interflavan linkage, and the atropisomers could be determined.

Green route synthesis of ZnO nanoparticles using Senna auriculata aqueous flower extract as reducing agent and evaluation of its antimicrobial, antidiabetic and cytotoxic activity

The nanoparticles have unique and superior properties which make them applicable in almost every field of human life. Among the various methods that exist for the synthesis of nanoparticles, green synthesis is one of the best economic and eco-friendly methods compared with other conventional chemical methods. The nanoparticles synthesized by this method are also free from toxicity properties. This paper describes one such green synthesis method for zinc oxide nanoparticles (ZnO NPs) using the aqueous flower extract of Senna auriculata. The synthesized nanoparticles (SA-ZnO NPs) have been examined using UV-Vis spectrophotometer, photoluminescence spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. The antibacterial and antifungal activities of the synthesized NPs were evaluated against gram-positive bacteria (S. aureus, B. subtilis), gram-negative bacteria (E. coli, S. typhi) and fungal organisms (C. albicans, A. nigar) using disc diffusion method. Furthermore, the antidiabetic and anticancer activities of the NPs were also been examined by α-amylase inhibition assay and MTT assay, respectively. These studies ensured that the SA-ZnO NPs have significant antimicrobial, antidiabetic and anticancer activities.

Ethnopharmacological, Phytochemical, Pharmacological, and Toxicological Review on Senna auriculata (L.) Roxb.: A Special Insight to Antidiabetic Property

Avartaki (Senna auriculata (L.) Roxb. syn. Cassia auriculata L.; Family- Fabaceae ) is a traditional medicinal plant, widely used for the treatment of various ailments in Ayurveda and Siddha system of medicine in India. Almost all the parts of the plant, such as flowers, leaves, seeds, barks, and roots have been reported for their medicinal uses. Traditionally, it has been used in the treatment of diabetes, asthma, rheumatism, dysentery, skin disease, and metabolic disorders. The principle phytochemicals in Senna auriculata (L.) Roxb. are alkaloids, anthraquinone, flavone glycosides, sugar, saponins, phenols, terpenoids, flavonoids, tannins, steroids, palmitic acid, linoleic acid, benzoic acid 2-hydroxyl methyl ester, 1-methyl butyl ester, resorcinol, α-tocopherol-β-D-mannosidase, epicatechin, ferulic acid, quercetin-3-O-rutinoside, quercetin, proanthocyanidin B1. The extracts from its different parts and their isolated compounds possess a wide range of pharmacological activities such as antidiabetic, antioxidant, anti-inflammatory, antihyperlipidemic, hepatoprotective, nephroprotective, cardioprotective, anti-atherosclerotic, anticancer, antimutagenic, antimicrobial, antiulcer, antipyretic, anthelmintic, immunomodulatory, antifertility, anti-venom, and anti-melanogenesis. The toxicological findings from preclinical studies ensured the safety of the plant, but comprehensive clinical studies are required for the safety and efficacy of the plant in humans. The current review article aimed to provide up-to-date information about Senna auriculata (L.) Roxb. covering its ethnomedicinal, phytochemical, pharmacological, and toxicological aspects with special emphasis on its clinical implications in diabetes.

Characterization of Antibacterial Proanthocyanidins of Dalbergia monetaria, an Amazonian Medicinal Plant, by UHPLC-HRMS/MS

Dalbergia monetaria is an Amazonian plant whose bark is widely used to treat urinary tract infections. This paper describes a bio-guided study of ethanolic extracts from the bark and leaves of D. monetaria, in a search for metabolites active against human pathogenic bacteria. In vitro assays were performed against 10 bacterial strains, highlighting methicillin-sensitive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. Fractioning of the extracts was performed using instrumental and classical techniques, and samples were characterized by UHPLC-HRMS/MS. Ethyl acetate fractions from bark and leaves showed similar antibacterial activities. EAFB is enriched in isoflavone C-glucosides and EAFL enriched in proanthocyanidins. Subfractions from EAFL presented higher activity and showed a complex profile of proanthocyanidins constructed by (epi)-cassiaflavan and (epi)-catechin units, including dimers, trimers and tetramers. The fragmentation pattern emphasized the neutral loss of cassiaflavan units by quinone-methide fission. Fraction SL7-6, constituted by (ent)-cassiaflavan-(ent)-cassiaflavan-(epi)-catechin isomers, showed the lowest MIC against the S. aureus and P. aeruginosa with values corresponding to 64 and 32 µg/mL, respectively. Cassiaflavan-proanthocyanidins have not been found previously in another botanical genus, except in Cassia, and the traditional medicinal use of D. monetaria might be related to the antibacterial activity of proanthocyanidins characterized in the species.

A Review of Biologically Active Natural Products from a Desert Plant Cistanche tubulosa

An Orobanchaceae plant Cistanche tubulosa (SCHENK) WIGHT (Kanka-nikujuyou in Japanese), which is one of the authorized plant resources as Cistanches Herba in both Japanese and Chinese Pharmacopoeias, is a perennial parasitic plant growing on roots of sand-fixing plants. The stems of C. tubulosa have traditionally been used for treatment of impotence, sterility, lumbago, and body weakness as well as a promoting agent of blood circulation. In recent years, Cistanches Herba has also been widely used as a health food supplement in Japan, China, and Southeast Asian countries. Here we review our recent studies on chemical constituents from the stems of C. tubulosa as well as their bioactivities such as vasorelaxtant, hepatoprotective, and glucose tolerance improving effects.

Inhibition of melanin production by anthracenone dimer glycosides isolated from Cassia auriculata seeds

The methanol extract of Cassia auriculata seeds was found to inhibit melanogenesis in B16 melanoma 4A5 cells under conditions of theophylline stimulation. Two new phlegmacin-type anthracenone dimer glycosides, auriculataosides A and B, were isolated from the active methanol fraction, and their inhibitory effects were observed in the concentration range of 0.03 to 0.3 μM. Inhibition of microphthalmia-associated transcription factor, tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 protein expression was observed, suggesting that the inhibition of these factors is part of the mechanism of action underlying melanogenesis inhibition.

A Review on the Phytochemistry, Medicinal Properties and Pharmacological Activities of 15 Selected Myanmar Medicinal Plants

Medicinal plants are a reservoir of biologically active compounds with therapeutic properties that over time have been reported and used by diverse groups of people for treatment of various diseases. This review covers 15 selected medicinal plants distributed in Myanmar, including Dalbergia cultrata, Eriosema chinense, Erythrina suberosa, Millettia pendula, Sesbania grandiflora, Tadehagi triquetrum, Andrographis echioides, Barleria cristata, Justicia gendarussa, Premna integrifolia, Vitex trifolia, Acacia pennata, Cassia auriculata, Croton oblongifolius and Glycomis pentaphylla. Investigation of the phytochemical constituents, biological and pharmacological activities of the selected medicinal plants is reported. This study aims at providing a collection of publications on the species of selected medicinal plants in Myanmar along with a critical review of the literature data. As a country, Myanmar appears to be a source of traditional drugs that have not yet been scientifically investigated. This review will be support for further investigations on the pharmacological activity of medicinal plant species in Myanmar.

Structures of Aromatic Glycosides from the Seeds of Cassia auriculata

A new benzocoumarin glycoside, cassiaglycoside I (1), a new naphthol glycoside, cassiaglycoside II (2), a new chromon glycoside, cassiaglycoside III (3), a new phenylethyl glycoside, cassiaglycoside IV (4), were isolated from the seeds of Cassia auriculata, together with seven known constituents. The chemical structures of four new constituents were characterized on the basis of chemical and physicochemical evidence.

Hepatoprotective Limonoids from Andiroba (Carapa guianensis)

Three gedunin-type limonoids, gedunin (1), 6α-acetoxygedunin (2), and 7-deacetoxy-7-oxogedunin (3), which were isolated from the seed and flower oils of andiroba (Carapa guianensis Aublet, Meliaceae), exhibited hepatoprotective effects at doses of 25 mg/kg, p.o. against d-galactosamine (d-GalN)/lipopolysaccharide (LPS)-induced liver injury in mice. To characterize the mechanisms of action of 1-3 and clarify the structural requirements for their hepatoprotective effects, 17 related limonoids (1-17) isolated from the seed and/or flower oils of C. guianensis were examined in in vitro studies assessing their effects on (i) d-GalN-induced cytotoxicity in primary cultured mouse hepatocytes, (ii) LPS-induced nitric oxide (NO) production in mouse peritoneal macrophages, and (iii) tumor necrosis factor-α (TNF-α)-induced cytotoxicity in L929 cells. The mechanisms of action of 1-3 are likely to involve the inhibition of LPS-induced macrophage activation and reduced sensitivity of hepatocytes to TNF-α; however, these compounds did not decrease the cytotoxicity caused by d-GalN. In addition, the structural requirements of limonoids (1-17) for inhibition of LPS-induced NO production in mouse peritoneal macrophages and TNF-α-induced cytotoxicity in L929 cells were evaluated.