Phytochemical and biological assessment of secondary metabolites isolated from a rhizosphere strain, Sphingomonas sanguinis DM of Datura metel.

BACKGROUND: The plant roots excrete a large number of organic compounds into the soil. The rhizosphere, a thin soil zone around the roots, is a hotspot for microbial activity, making it a crucial component of the soil ecosystem. Secondary metabolites produced by rhizospheric Sphingomonas sanguinis DM have sparked significant curiosity in investigating their possible biological impacts. METHODS: A bacterial strain has been isolated from the rhizosphere of Datura metel. The bacterium's identification, fermentation, and working up have been outlined. The ethyl acetate fraction of the propagated culture media of Sphingomonas sanguinis DM was fractioned and purified using various chromatographic techniques. The characterization of the isolated compounds was accomplished through the utilization of various spectroscopic techniques, such as UV, MS, 1D, and 2D-NMR. Furthermore, the evaluation of their antimicrobial activity was conducted using the agar well diffusion method, while cytotoxicity was assessed using the MTT test. RESULTS: The extract from Sphingomonas sanguinis DM provided two distinct compounds: n-dibutyl phthalic acid (1) and Bis (2-methyl heptyl) phthalate (2) within its ethyl acetate fraction. Furthermore, the 16S rRNA gene sequence of Sphingomonas sanguinis DM has been registered under the NCBI GenBank database with the accession number PP422198. The bacterial extract exhibited its effect against gram-positive bacteria, inhibiting Streptococcus mutans (12.6 ± 0.6 mm) and Staphylococcus aureus (10.6 ± 0.6 mm) compared to standard antibiotics. Conversely, compound 1 showed a considerable effect against phytopathogenic fungi such as Alternaria alternate (56.3 ± 10.6 mm) and Fusarium oxysporum (21.3 ± 1.5 mm) with a MIC value of 17.5 µg/mL. However, it was slightly active against Klebsiella pneumonia (11.0 ± 1.0 mm). Furthermore, compound 2 was the most active metabolite, having a significant antimicrobial efficacy against Rhizoctonia solani (63.6 ± 1.1 mm), Pseudomonas aeruginosa (16.7 ± 0.6 mm), and Alternaria alternate (20.3 ± 0.6 mm) with MIC value at 15 µg/mL. In addition, compound 2 exhibited the most potency against hepatocellular (HepG-2) and skin (A-431) carcinoma cell lines with IC50 values of 107.16 µg/mL and 111.36 µg/mL, respectively. CONCLUSION: Sphingomonas sanguinis DM, a rhizosphere bacterium of Datura metel, was studied for its phytochemical and biological characteristics, resulting in the identification of two compounds with moderate antimicrobial and cytotoxic activities.

Combined untargeted metabolomics and network pharmacology approaches to reveal the therapeutic role of withanolide B in psoriasis.

Psoriasis is a refractory inflammatory skin disorder in which keratinocyte hyperproliferation is a crucial pathogenic factor. Up to now, it is commonly acknowledged that psoriasis has a tight connection with metabolic disorders. Withanolides from Datura metel L. (DML) have been proved to possess anti-inflammatory and anti-proliferative properties in multiple diseases including psoriasis. Withanolide B (WB) is one of the abundant molecular components in DML. However, existing experimental studies regarding the potential effects and mechanisms of WB on psoriasis still remain lacking. Present study aimed to integrate network pharmacology and untargeted metabolomics strategies to investigate the therapeutic effects and mechanisms of WB on metabolic disorders in psoriasis. In our study, we observed that WB might effectively improve the symptoms of psoriasis and alleviate the epidermal hyperplasia in imiquimod (IMQ)-induced psoriasis-like mice. Both network pharmacology and untargeted metabolomics results suggested that arachidonic acid metabolism and arginine and proline metabolism pathways were linked to the treatment of psoriasis with WB. Meanwhile, we also found that WB may affect the expression of regulated enzymes 5-lipoxygenase (5-LOX), 12-LOX, ornithine decarboxylase 1 (ODC1) and arginase 1 (ARG1) in the arachidonic acid metabolism and arginine and proline metabolism pathways. In summary, this paper showed the potential metabolic mechanisms of WB against psoriasis and suggested that WB would have greater potential in psoriasis treatment.

Four new withanolides with anti-inflammatory activity from Datura inoxia Mill. leaves.

Four previously undescribed withanolides, datinolides A-D (1-4) and eight known withanolides (5-12), were separated from the 70% ethyl alcohol extract of Datura inoxia Mill. leaves. All structures were clarified by comprehensive spectroscopic analysis. Furthermore, all withanolides were assessed for their anti-inflammatory activity and results showed that 1 exhibited a fairly good suppression against nitric oxide generation in lipopolysaccharide-stimulated RAW 264.7 cells (IC50 = 10.33 ± 1.53 µM).

GC-MS analysis & antifungal activity of Datura metel L. against Rhizoctonia solani Kuhn.

The current study was designed to evaluate the antifungal properties of Datura metel L. against Rizoctonia solani Kuhn. To achieve this objective, six concentrations of leaves & stem methanol extract of D. metel viz. 1%, 1.5%, 2%, 2.5%, 3% & 3.5% were tested against R. solani in vitro. Leaf extract of D. metel was found more effective as its 3.5% concentration caused 75% retardation in test fungal growth as compared to the stem extract. D. metel methanolic leaf extract was fractioned between n-butanol, n-hexane, chloroform & ethyl acetate & bioactivities of isolated fractions were tested against R. solani. The chloroform fraction was found highly effective, as its concentrations 0.1% & 0.01% caused 27% & 21% growth inhibition respectively. So, this particular chloroform fraction was further analyzed to identify various chemical constituents through GC-MS (Gas chromatography mass spectroscopic) analysis. Twelve phyto-constituents viz. eugenol, 2-pentadecanone 6,10,14 trimethyl, pentadecanoic acid, pentadecanoic acid, 1 4-methyl- methyl ester, phytol, 9,12,15-octadecatrienoic acid, heptacosane, n-hexadecanoic, 6-octadecanoic acid, 9, 12 octadecanoic acid, dodecanoic & tetradecanoic acids were identified. So, the present study concluded that the presence of these bioactive constituents make D. metel as an effective antifungal agent against R. solani.

Experimental and Theoretical Studies of Green Synthesized Cu2O Nanoparticles Using Datura Metel L.

In biomedical applications, Cu2O nanoparticles are of great interest. The bioengineered route is eco-friendly for the synthesis of nanoparticles. Therefore, in the present study, there is an attempt to synthesis Cu2O nanoparticles using Datura metel L. The synthesized nanoparticles were characterized by UV-Vis, XRD, and FT-IR. UV-Vis results suggest the presence of hyoscyamine, atropine in Datura metel L, and also, nanoparticles formation has been confirmed by the presence of absorption peak at 790 nm. The average crystallite size (19.56 nm) was obtained by XRD. FT-IR was also used to confirm the different functional groups. Fourier Power Spectrum was also employed to examine the synthesized nanomaterials spectrum data to emphasize the peak of the prominent frequencies. Density functional theory (DFT) was also utilized to assess the energy of the substance over time, which appears to indicate a stable molecule. Furthermore, calculated energies, thermodynamic properties (such as enthalpies, entropies, and Gibbs-free energies), modeled structures of complexes, crystals, and clusters, and predicted yields, rates, and regio- and stereospecificity of reactions were all in good agreement with experimental results. Overall, the results show that the successful production of Cu2O nanoparticles with Datura metel L. corresponds to theoretical research.

A new ent-kaurane diterpenoid from the pericarps of Datura metel.

A new ent-kaurane diterpenoid, named kaurane daturoside A (1), was isolated from the 70%-EtOH extract of dried pericarps of Datura metel L., along with six known terpenoids, 16α,17-dihydroxy-ent-kauran-19-diglycoside (2), cyclosieversioside F (3), astragaloside II (4), ginsenoside Rg1 (5), astrojanoside A (6), celerioside E (7). The isolated structures were elucidated by means of spectroscopic analyses, and the compounds 2, 3, 7 were separated from Solanaceae for the first time. Meanwhile, among isolates, compounds 2 and 5 exhibited anti-inflammatory activities against LPS-activated RAW264.7 cells (IC50<11.00 µM).

Evaluation of hepatoprotective effects of crude methanolic extract of Datura metel L. in mice.

Datura metel has been recommended in several human disorders including a remedy for liver toxicity. The current study was designed to evaluate the hepatoprotective effect of methanolic extract of D. metel in animal model. Acute toxicity of methanolic crude extract of Datura metel (MEDM) was studied in animals in various doses 500-2000 mg/kg. Mice of either sex were divided into groups (n=6). One group received normal saline intraperitonially as negative control, while other gentamicin 100mg/kg for 8 days as positive control. 3rd group received 50mg/kg silymarin as standard, 4th group received 100mg/kg of MEDM, 5th group received 200mg/kg MEDM while 6th group received 300mg/kg MEDM and gentamicin 100mg/kg for 8 days. The blood samples were collected on 9th day and the animals were then dissected and the liver of all the animals were isolated. MEDM was found safe in acute toxicity test at various doses up to 2000 mg/kg. The levels of serum glutamic pyruvic transaminase and alkaline phosphatase were elevated significantly with gentamicin treatment which significantly down-regulated by MEDM (100, 200 and 300 mg/kg) in a dose dependent manner.. The histological examination showed that the MEDM has markedly treated the inflammatory infiltrate, fatty changes and congested blood vessels which were induced by gentamicin.  The findings of our study thus proved the absolute of MEDM in acute toxicity test; followed by significant hepatoprotective effect in gentamicin induced hepatotoxic mice.

Discovery of Active Ingredients Targeted TREM2 by SPR Biosensor-UPLC/MS Recognition System, and Investigating the Mechanism of Anti-Neuroinflammatory Activity on the Lignin-Amides from Datura metel Seeds.

As a new target protein for Alzheimer's disease (AD), the triggering receptor expressed on myeloid Cells 2 (TREM2) was expressed on the surface of microglia, which was shown to regulate neuroinflammation, be associated with a variety of neuropathologic, and regarded as a potential indicator for monitoring AD. In this study, a novel recognition system based on surface plasmon resonance (SPR) for the TREM2 target spot was established coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-MS), in order to screen the active ingredients targeting TREM2 from Datura metel seeds. The results showed that four lignan-amides were discovered as candidate compounds by SPR biosensor-UPLC/MS recognition analysis. According to the guidance of the active ingredients discovered by the system, the lignin-amides from Datura metel seeds (LDS) were preliminarily identified as containing 27 lignan-amides, which were enriched compositions by the HP-20 of Datura metel seeds. Meanwhile, the anti-inflammatory activity of LDS was evaluated in BV2 microglia induced by LPS. Our experimental results demonstrated that LDS could reduce NO release in LPS-treated BV2 microglia cells and significantly reduce the expression of the proteins of inducible Nitric Oxide Synthase (iNOS), cyclooxygenase 2 (COX-2), microtubule-associated protein tau (Tau), and ionized calcium-binding adapter molecule 1 (IBA-1). Accordingly, LDS might increase the expression of TREM2/DNAX-activating protein of 12 kDa (DAP12) and suppress the Toll-like receptor SX4 (TLR4) pathway and Recombinant NLR Family, Pyrin Domain Containing Protein 3 (NLRP3)/cysteinyl aspartate specific proteinase-1 (Caspase-1) inflammasome expression by LDS in LPS-induced BV2 microglial cells. Then, the inhibitory release of inflammatory factors Interleukin 1 beta (IL-1ß), Interleukin 6 (IL-6), and Tumor necrosis factor-alpha (TNFα) inflammatory cytokines were detected to inhibit neuroinflammatory responses. The present results propose that LDS has potential as an anti-neuroinflammatory agent against microglia-mediated neuroinflammatory disorders.

In Vitro Antibacterial and Antifungal Potential of Amyrin-Type Triterpenoid Isolated from Datura metel Linnaeus.

The aim of the present investigation was to evaluate the effect of the combined crude extract, fractions, and compound 1 isolated from the fruits of Datura metel against selected microbial (bacteria and fungi) strains. Results of antibacterial screening indicated marked susceptibility of the extract and its fractions against tested bacterial strains. Among the extract and various fractions, the chloroform fraction exhibited a significant effect against different bacterial strains including Escherichia coli, Staphylococcus aureus, and Bacillus subtilis with an inhibitory zone ranging from 18 to 24 mm. Similarly, results of antifungal activity revealed that the chloroform fraction displays a promising effect against various fungal strains. The chloroform fraction was subjected to repeated chromatography analysis, which yielded compound 1 (daturaolone). Daturaolone exhibited potent activity against selected bacterial strains including Klebsiella pneumoniae, B. subtilis, S. epidermidis, and S. aureus with an inhibitory zone ranging from 12 to 30 mm. In addition, the extracts and daturaolone exhibited significant sensitivity against T. longifusus, C. albicans, A. flavus, M. canis, F. solani, and C. glabrata. Taken all together, it is concluded that our findings validated the traditional use of D. metel to treat various infectious diseases, which is supported by daturaolone.

Seven undescribed steroids from the leaves of Datura metel L.

Extraction of Datura metel L. leaves with ethanol as a solvent gave a group of steroids, including two unique 1,10-seco-withanolides (1, 4), an unusual nitrogen-containing withanolides (2), one undescribed saponin (3), two withanolides with a carbohydrate (5, 6), and one C21 steroid (7). These compounds' structures were identified based on HR-ESI-MS and 1H, 13C NMR data analyses, also compared with data from the document. Some compounds showed moderate inhibition on NO production in lipopolysaccharide-stimulated RAW 264.7 cells.

Daturataturin A, a withanolide in Datura metel L., induces HaCaT autophagy through the PI3K-Akt-mTOR signaling pathway.

Daturataturin A (DTA), a withanolide compound in Datura metel L., exhibits excellent anti-inflammatory and anti-proliferative activities. Here, we report the study of DTA-induced proliferation and inflammation in human immortalized keratinocytes (HaCaTs) and the associated molecular mechanisms. HaCaTs are a model of the epidermal proliferative state of cells. The pharmacodynamics and mechanism of DTA were studied by western blot, immunofluorescence, apoptosis and proliferation detection, and real-time quantitative polymerase chain reaction. We confirmed that DTA induced HaCaT autophagy, which, in turn, induced HaCaT senescence and, ultimately, led to cell cycle arrest. DTA also negatively regulated inflammation through the activation of autophagy. This may be one of the mechanisms underlying the action of Datura metel L. preparation used for the treatment of psoriasis.

A new sesquiterpenoid with cytotoxic and anti-inflammatory activity from the leaves of Datura metel L.

A new sesquiterpenoid glycoside, consisting of one vetispirane-type, dmetelisproside A (1), together with two known megastigmane sesquiterpenoids, citroside A (2) and staphylionoside D (3) were isolated from the leaves of Datura metel L. The structures were determined by analysis of their MS and NMR data as well as by comparison with literature values. All isolates were evaluated for cytotoxicity toward SGC-7901, Hepg2, HeLa, MCF-7, and MDA-MB-231 cancer cell lines, and anti-inflammatory activity against nitric oxide (NO) in RAW 264.7 cells in vitro. Compounds 1 and 2 exhibited pronounced cytotoxicity against SGC-7901 and HeLa cells with IC50 values in the range of 21.43 to 29.51 µm. All three compounds displayed potential effects against NO production with IC50 values of 31.10, 34.25, and 44.31 µm, respectively. Thus, these isolated compounds in the leaves of Datura metel L were subjected to bioactivity substances for future studies on medicinal application.

Potent In Vitro α-Glucosidase and ß-Secretase Inhibition of Amyrin-Type Triterpenoid Isolated from Datura metel Linnaeus (Angel's Trumpet) Fruits.

This study deals with α-glucosidase and ß-secretase inhibitory screening of extract/fractions and isolated daturaolone (1), namely, 3-oxo-6-ß-hydroxy-ß-amyrin (daturaolone) from chloroform fraction of Datura metel L. Among entire fractions, the chloroform soluble fraction showed excellent activity against α-glucosidase with % inhibition 90.8 with IC50160.2 ± 1.85 µg and daturaolone (1) with 98.7% inhibition with IC50840.4 ± 1.74 µM, respectively. Similarly, extract and daturaolone (1) also exhibited significant activity against the ß-secretase enzyme (BACE1) with % activities 88.27 and 95.19 and with IC50 values 304.21 ± 2.98 µg and 260.70 ± 1.87 µM, respectively, as compared to the standard inhibitor (Ans670, Sta671, Val672)-amyloid-ß/A4 precursor protein 770 fragments 662-675) with % activity 94.21 and IC50 value 289.24 ± 1.60 µM. This finding encourages and opens a new window for further detail phytochemical investigation on D. metel in order to isolate novel compounds with promising enzyme inhibitory potential.

New indole alkaloids from the seeds of Datura metel L.

Four new indole alkaloids, daturametelindoles A-D (1-4) were isolated from the EtOAc soluble partition of the ethanol extract of the Datura metel seeds. The structures of the new compounds were determined based on spectroscopic evidence, including their 1D- and 2D-NMR spectra and mass spectrometry. In particular, compounds 1-4 were all racemes, confirmed by the optical rotations and CD spectra. Unfortunately, the chiral monomers were not obtained due to the amount, but the developments of their chiral separation and chiral resolution were completed. All isolated compounds were evaluated for cytotoxic effects against human gastric adenocarcinoma cells (SGC-7901), human hepatoma (Hepg2), and human breast cancer (MCF-7).

Nephroprotective effects of Datura metel extract in gentamicin induced mice model: biochemical and histological evidences.

Datura metel is traditionally used as a remedy for renal toxicity. However, the nephroprotection has not been scientifically validated yet. To evaluate the nephroprotective like effect of methanolic extract of D. metel in gentamicin induced mice model, mice of either sex were divided into groups. One group received normal saline as negative control. The 2nd group received gentamicin 100mg/kg for 8 days as positive control, 3rd group received 50mg/kg silymarin as standard, while the reaming groups received 100, 200 and 300 mg/kg of MEDM and gentamicin 100mg/kg, for 8 days. The blood and urine samples were collected on 9th day, animals were then dissected and whole kidneys were removed and preserved in formalin for later histological examinations. The level of serum creatinine, blood urea nitrogen, urine creatinine and urine urea were significantly (P<0.05) elevated and the renal MDA level was also elevated significantly (P<0.05) by gentamicin in mice. After the treatment of test animals with MEDM, the elevated level of serum and urine biomarkers by gentamicin were reversed by MEDM. The nephroprotective effect was found in dose dependent manner. As the MEDM significantly protected the nephrotoxicity via its antioxidant effect. The findings of our study thus proved the scientific background for the nephroprotective effect of MEDM.

Spleen and thymus metabolomics strategy to explore the immunoregulatory mechanism of total withanolides from the leaves of Datura metel L. on imiquimod-induced psoriatic skin dermatitis in mice.

Our previous work demonstrated that total withanolides of Datura metel L. leaves (TWD) exhibited excellent therapeutic effects on psoriasis. However, current knowledge of its mechanisms is incomplete. In this study, integrated spleen and thymus untargeted metabolomics were used to analyze the changes in endogenous metabolites underlying the immunosuppressive activity of TWD on psoriasis animal models induced by imiquimod. The results suggested that TWD treatment markedly attenuated imiquimod-induced psoriasis and showed significant immunosuppressive activity as evidenced by decreased elevation index of spleen and thymus. Meanwhile, TWD significantly reversed the elevation of immunoregulatory factors, including IL-10, IL-17, IL-22 and IL-23. Multivariate trajectory analysis revealed that TWD treatment could restore the psoriasis-disturbed spleen and thymus metabolite profiles towards the normal metabolic status. A total of 25 and 27 metabolites associated with the immunomodulatory effects for which levels changed markedly upon treatment have been identified in spleen and thymus, respectively. These differential metabolites were mainly involved in amino acid metabolism, nucleotide metabolism, fatty acid metabolism and lipid metabolism. Our investigation provided a holistic view of TWD for intervention in psoriasis through immunoregulation and provided further scientific information in vivo about a clinical value of TWD for psoriasis.

Integrated serum metabolomics and network pharmacology approach to reveal the potential mechanisms of withanolides from the leaves of Datura metel L. on psoriasis.

Psoriasis is a chronic, immune-mediated inflammatory skin disease and highly depends on inflammation and angiogenesis as well as other pathways. Our previous study showed that the withanolides from the leaves of Datura metel L. exhibited significant therapeutically effect on psoriasis, but the mechanisms concerning this effect have not been systematically studied. The purpose of this paper was to investigate the possible mechanism of withanolides for treating psoriasis using an integrated metabolomics and network pharmacology strategy. Untargeted metabolomics profiling of serum with UHPLC/Orbitrap MS and a multivariate data method were performed to discover the potential biomarkers and metabolic pathways. Afterward, the compound-target-pathway network of withanolides for psoriasis was constructed by virtue of network pharmacology. Finally, the crucial pathways were selected by integrating the results of metabolomics and network pharmacology, and then validated by ELISA and western blot analysis. The results showed that withanolides could exert excellent effects on psoriasis through regulating two types of pathways, angiogenesis and inflammation, including sphingolipids metabolism and HIF-1α/VEGF pathway, reflected by inhibiting the production of inflammatory cytokines (IL-1ß, IL-6, IL-8, IFN-γ, TNF-α, HIF-1α and VEGF), as well as reducing the protein expressions of HIF-1α and VEGF. Our study successfully explained the polypharmcological mechanisms underlying the efficiency of withanolides from the D. metel L. leaves on treating psoriasis. Meanwhile, it was also valuable for performing a systematical investigation of herb medicines, as well as for efficiently predicting the therapeutic mechanisms of traditional Chinese medicine.

Anti-inflammatory sesquiterpenoids from the leaves of Datura metel L.

Nine new (1-9) and three known (10-12) sesquiterpenoids were isolated from the ethanol-water (7:3, v/v) extract of the Datura metel L. leaves. The structures of 1-9 were elucidated by detailed spectroscopic analyses, including 1D and 2D NMR, HR-ESI-MS. All isolates (1-12) were evaluated for anti-inflammatory activity against the production of nitrogen oxide in lipopolysaccharide-induced RAW264.7 cells and compound 5 possessed the best inhibitory effect among them, with the IC50 value reaching 9.33-11.67 µM, which was lower than positive control, L-NMMA, with IC50 range from 13.64 to 17.02 µM.

UPLC-MS/MS Identification and Quantification of Withanolides from Six Parts of the Medicinal Plant Datura Metel L.

Withanolides from six parts (flower, leaf, stem, root, seed, and peel) of Datura metel L. (D metel L.) obtained from ten production areas in China were identified and quantified by UPLC-MS/MS. A total of 85 withanolides were characterized for the first time using the UPLC-Q-TOF-MS/MS system. Additionally, a simultaneous, rapid and accurate measurement method was developed for the determination of 22 bioactive withanolides from ten production areas with the UPLC-Q-TRAP-MS/MS system. The results show the total withanolide content is highest in the leaves (155640.0 ng/g) and lowest in the roots (14839.8 ng/g). Compared with other production areas, the total content of plants from Dujiangyan was the highest at 82013.9 ng/g (value range of ten areas: 82013.9-42278.5 ng/g). The results also show significant differences in the distribution of withanolides in the different plant parts, as well as across different production areas. This is a breakthrough report providing a simultaneous qualitative and quantitative analysis of 22 withanolides in D. metel L. It could be the basis for the more rational use of various parts of D. metel L., and the expansion of medicinal resources. This work also lays a solid foundation for research on the quality control of D. metel L.

Daturmetesides A-E, five new ergostane-type C28 sterols from the leaves of Datura metel L.

Five undescribed ergostane-type C28 sterols, daturmetesides A-E (1-5), were isolated from the leaves of Datura metel L. The chemical structures of these new compounds were characterized through extensive spectroscopic analysis and comparison with literatures. Among them, the absolute structures of daturmetesides A and C were unambiguously determined by X-ray crystallography. The anti-inflammatory effect of daturmetesides A-E was all tested by measuring nitric oxide production in lipopolysaccharide-activated RAW264.7 cells. Daturmetesides A, C and D moderatelylowered the NO production with IC50 values ranging from 17.05 ± 0.35 to 24.88 ± 0.93 µM.