Antioxidants from a Chinese medicinal herb – Psoralea corylifolia L

Isobavachin, a main bioavailable compound in Psoralea corylifolia, alleviates lipopolysaccharide-induced inflammatory responses in macrophages and zebrafish by suppressing the MAPK and NF-κB signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Psoralea corylifolia L. (PC) is widely used in traditional medicines to treat inflammatory and infectious diseases. Isobavachin (IBC) is a bioavailable prenylated flavonoid derived from PC that has various biological properties. However, little information is available on its anti-inflammatory effects and mechanisms of action.

AIM OF THE STUDY

In this study, we aimed to determine the anti-inflammatory effects of IBC in vitro and in vivo by conducting a mechanistic study using murine macrophages.

MATERIALS AND METHODS

We evaluated the modulatory effects of IBC on the production of pro-inflammatory cytokines and mediators in murine macrophages. In addition, we examined whether IBC inhibits lipopolysaccharide (LPS)-induced inflammatory responses in a zebrafish model. Alterations in inflammatory response-associated genes and proteins were determined using quantitative reverse transcriptional polymerase chain reaction (RT-qPCR) and Western blotting analysis.

RESULTS

IBC markedly reduced the overproduction of inflammatory mediators, pro-inflammatory cytokines, inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), phosphorylation of mitogen-activated protein kinase (MAPK) and nuclear translocation of nuclear factor-kappa B (NF-κB) in macrophages induced by lipopolysaccharides (LPS). In addition, excessive NO, ROS, and neutrophil level induced by LPS, were suppressed by IBC treatment in a zebrafish inflammation model.

CONCLUSIONS

Collectively, bioavailable IBC inhibited on the inflammatory responses by LPS via MAPK and NF-κB signaling pathways in vitro and in vivo, suggesting that it may be a potential modulatory agent against inflammatory disorders.

Theoretical study on the free radical scavenging potency and mechanism of natural coumestans: Roles of substituent, noncovalent interaction and solvent

The free radical scavenging potency and mechanisms of seven representative natural coumestans were systematically evaluated using density functional theory (DFT) approach. Thermodynamic feasibility of different mechanisms was assessed by various physio-chemical descriptors involved in the double (2H⁺/2e^‒) radical-trapping processes. Energy diagram and related transition state structures of the reaction between wedelolactone (WEL) and hydroperoxyl radical were constructed to further uncover the radical-trapping details. Results showed that the studied coumestans prefer to scavenge radicals via formal hydrogen atom transfer (fHAT) mechanism in the gas phase and non-polar environment, whereas sequential proton loss electron transfer (SPLET) is favored in polar media. Moreover, the feasibility of second fHAT and SPLET processes was also revealed. Sequential double proton loss double electron transfer (SdPLdET) mechanism represents the preferred pathway in aqueous solution at physiological pH. Our findings highlight the essential role of ortho-dihydroxyl group, noncovalent interaction and solvents on radical-trapping potency. 4'-OH in D-ring was found to be the most favorable site to trap radical for most of the studied coumestans, whereas 3-OH in A-ring for lucernol (LUN).

Antiobesity Potential of Bioactive Constituents from Dichloromethane Extract of Psoralea corylifolia L. Seeds

Purpose

Effectively controlling the accumulation of adipose tissue can be a therapeutic strategy for treating obesity, which is a global problem. The present study was designed for comparative assessment of in vitro antiobesity activities of the Psoralea corylifolia-dichloromethane seed extract (DCME) and the isolated phytochemicals, bakuchiol, isopsoralen, and psoralen, through antiadipogenesis and pancreatic lipase (PL) inhibition assays. Material and Methods. In vitro pancreatic lipase activity was determined spectrophotometrically by measuring the hydrolysis of p-nitrophenyl butyrate (p-NPB) to p-nitrophenol at 405 nm, and adipogenesis was assayed in 3 T3-L1 adipocytes (by using Oil Red O staining) using P. corylifolia-dichloromethane seed extract (DCME) and individual compounds, isolated from the extract.

Result

Antilipase as well as antiadipogenesis activity was displayed by both the DCME and the compounds. Maximum antilipase property was recorded in DCME (26.02 ± .041%) at 100 μg/ml, while, among the isolated compounds, bakuchiol exhibited a higher activity (24.2 ± 0.037%) at 100 μg/ml concentration, compared to other isolates. DCME was found to exhibit antiadipogenesis property, 75 ± 0.003% lipid accumulation, compared to the control at 100 μg/ml dose. Bakuchiol, isopsoralen, and psoralen inhibited the lipid accumulation in 3T3-L1 preadipocytes, 78.06 ± 0.002%, 80.91 ± 0.004%, and 80.91 ± 0.001%, respectively, lipid accumulation in comparison to control at 25 μM dose.

Conclusion

The present study highlights the antiobesity potential of P. corylifolia and its active constituents. Thus, it can be concluded that P. corylifolia has the potential to treat obesity and related diseases; however, further research on dose standardization and clinical trials are required.

Bioactive Components from Ampelopsis japonica with Antioxidant, Anti-α-Glucosidase, and Antiacetylcholinesterase Activities

The dried root of Ampelopsis japonica (Thunb.) Makino (A. japonica.) is a traditional medicine used to treat fever, pain, and wound healing. It exhibits anti-inflammatory, antitumor, antityrosinase, and antimelanogenic activities. In this paper, we used different solvent extracts from the root of A. japonica to determine their antioxidant activity. Acetone extract showed relatively strong antioxidant properties by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl (DPPH), superoxide radical scavenging activity, and ferric reducing antioxidant power (FRAP) assays. In addition, these extracts also showed significant α-glucosidase and acetylcholinesterase (AChE) inhibitory activities. Acetone extract significantly inhibited α-glucosidase with an IC₅₀ value of 8.30 ± 0.78 μg/mL, and ethanol extract remarkably inhibited AChE with an IC₅₀ value of 37.08 ± 7.67 μg/mL. Using HPLC analysis and comparison with the chemical composition of various solvent extracts, we isolated seven active compounds and assessed their antioxidant, anti-α-glucosidase, and anti-AChE activities. Catechin (1), gallic acid (2), kaempferol (3), quercetin (4), resveratrol (6), and epicatechin (7) were the main antioxidant components in the root of A. japonica. According to the results of DPPH, ABTS, and superoxide radical scavenging assays, these isolates showed stronger antioxidant capacity than butylated hydroxytoluene (BHT). Moreover, 1, 3, 4, euscaphic acid (5), 6, and 7 also expressed stronger anti-α-glucosidase activity than the positive control acarbose, and all the isolated compounds had a good inhibitory effect on AChE. Molecular docking models and hydrophilic interactive modes for AChE assays suggest that 1 and 5 exhibit unique anti-AChE potency. This study indicates that A. japonica and its active extracts and components may be a promising source of natural antioxidants, α-glucosidase, and AChE inhibitors.

Medicinal plants with anti-SARS-CoV activity repurposing for treatment of COVID-19 infection: A systematic review and meta-analysis

The novel SARS-CoV-2 (severe acute respiratory syndrome coronavirus) has emerged as a significant threat to public health with startling drawbacks in all sectors globally. This study investigates the practicality of some medicinal plants for SARS-CoV-2 therapy using a systematic review and meta-analysis of their reported SARS-CoV-1 inhibitory potencies. Relevant data were systematically gathered from three databases, viz., Web of Science, PubMed and Scopus. The information obtained included botanical information, extraction method and extracts concentrations, as well as the proposed mechanisms. Fourteen articles describing 30 different plants met our eligibility criteria. Random effects model and subgroup analysis were applied to investigate heterogeneity. According to subgroup analysis, the substantial heterogeneity of the estimated mean based on the IC ₅₀ values reporting the most potent anti-SARS-CoV 3C--like protease (3CLpro) inhibitors (10.07 %, p < 0.0001), was significantly higher compared to the most active anti-SARS-CoV papain-like protease (PLpro) inhibitors (6.12 %, p < 0.0001). More importantly, the literature analysis revealed that fruit extracts of Rheum palmatum L. and the compound cryptotanshinone isolated from the root of Salvia miltiorrhiza (IC ₅₀ = 0.8 ± 0.2 μmol L^-1) were excellent candidates for anti--SARS-CoV targeting PLpro. Meanwhile, iguesterin (IC ₅₀ = 2.6 ± 0.6 μmol L^-1) isolated from the bark of Tripterygium regelii emerged as the most excellent candidate for anti-SARS--CoV targeting 3CLpro. The present systematic review and meta-analysis provide valuable and comprehensive information about potential medicinal plants for SARS-CoV-2 inhibition. The chemotypes identified herein can be adopted as a starting point for developing new drugs to contain the novel virus.

Constituents promoting osteogenesis from the fruits of Psoralea corylifolia and their structure-activity relationship study

The mature fruit of Psoralea corylifolia L. is a common traditional Chinese medicine used to tonify the kidney and yang, and as well as to treat osteoporosis. Systematic phytochemical investigations have established the most comprehensive constituent library to date, covering over 180 compounds. In this study, 109 chemical constituents containing 37 undescribed compounds were reported and incorrect structures of four known coumarins were corrected. The structures of these undescribed compounds were elucidated using spectroscopic methods, single-crystal X-ray diffraction, Rh₂(OCOCF₃)₄ and Mo₂(OAc)₄-induced circular dichroism spectra. To identify potentially active compounds and investigate their structure-activity relationship (SAR), 89 constituents in the library were evaluated for their osteogenic differentiation and mineralisation activities in MC3T3-E1 cells. We found that coumarins, isoflavones, flavonones, and meroterpenoids were the material basis for Psoralea corylifolia-based treatment of osteoporosis, with some compounds exhibiting excellent activities. These compounds function via the estrogen receptor (ER) pathway and were natural phytoestrogen. Further SAR analysis showed that compounds with an intact isopentenyl replacement possessed superior activities, which was explained by their improved affinity with the ER.

The benzofuran glycosides from the fruits of Psoralea corylifolia L

Six new glucosides of benzofuran (1-6), together with three known glucosides of benzofuran (8, 9, 14), nine flavonoids (12, 13, 15, 18, 19, 20, 21, 22 and 24), three coumarins (16, 17, 23) and four other-typic compounds (7, 10, 11 and 25) were isolated from the fruits of Psoralia corylifolia L. Their structures were elucidated by extensive spectroscopic methods. The biosynthesis pathway of benzofuran system was discussed. Besides, all isolated compounds and additional ring-opening derivatives of psoralen/isopsoralen (P-1, P-2, IP-1 and IP-2) were assayed for inhibition of nitric oxide (NO) production on lipopolysaccharides-induced RAW 264.7 macrophage cells. The results of the assay showed that the glycosides showed weaker or no effects, while most isolated non-glycoside compounds showed moderate or high activities. And the structure-activity relationships of non-glycoside compounds were discussed.

Chemical constituents from the bioactive fraction of the seeds of Psoralea corylifolia and proliferation activities on osteoblastic-like UMR106 cells

A new flavonol named 5,4'-dihydroxy-6,7-[(1''S,2''R)-1''-hydroxy-2''-(1-hydroxy-1-methylethyl)-furano]flavonol (1), together with eight known compounds (2-9), were isolated from the seeds of Psoralea corylifolia. Their chemical structures were elucidated on the basis of spectroscopic analyses. In addition, all compounds were firstly studied for their proliferation effects on osteoblastic-like UMR 106 cells. Results showed that compounds 1, 2, 5 and 8 possessed significant promoting effects on cell proliferation and increased osteoblastic cell numbers by 26.3%, 34.6%, 20.5% and 21.1% at concentrations of 10^-8 M, 10^-8 M, 10^-10 M and 10^-10 M, respectively. These data indicated that flavonoids may be the main constituents accounting for the bone protective effects of the seeds of P. corylifolia.

Impact of Traditional Plants and their Secondary Metabolites in the Discovery of COVID-19 Treatment

BACKGROUND

Coronavirus Disease-2019 belongs to the family of viruses which cause serious pneumonia along with fever, breathing issues and infection of lungs, and was first reported in China and later spread worldwide.

OBJECTIVE

Several studies and clinical trials have been conducted to identify potential drugs and vaccines for Coronavirus Disease-2019. The present study listed natural secondary metabolites identified from plant sources with antiviral properties and could be a safer and tolerable treatment for Coronavirus Disease-2019.

METHODS

A comprehensive search on the reported studies was conducted using different search engines such as Google Scholar, SciFinder, Sciencedirect, Medline PubMed, and Scopus for the collection of research articles based on plant-derived secondary metabolites, herbal extracts, and traditional medicine for coronavirus infections.

RESULTS

Status of COVID-19 worldwide and information of important molecular targets involved in COVID- 19 are described, and through literature search, it is highlighted that numerous plant species and their extracts possess antiviral properties and are studied with respect to coronavirus treatments. Chemical information, plant source, test system type with a mechanism of action for each secondary metabolite are also mentioned in this review paper.

CONCLUSION

The present review has listed plants that have presented antiviral potential in the previous coronavirus pandemics and their secondary metabolites, which could be significant for the development of novel and a safer drug which could prevent and cure coronavirus infection worldwide.

Design, Synthesis, and Biological Evaluation of Membrane-Active Bakuchiol Derivatives as Effective Broad-Spectrum Antibacterial Agents

Infections caused by drug-resistant bacteria seriously endanger human health and global public health. Therefore, it is urgent to discover and develop novel antimicrobial agents to combat multidrug-resistant bacteria. In this study, we designed and synthesized a series of new membrane-active bakuchiol derivatives by biomimicking the structure and function of cationic antibacterial peptides. The most promising compound 28 displayed potent antibacterial activity against both Gram-positive bacteria (minimum inhibitory concentration, MIC = 1.56-3.125 μg/mL) and Gram-negative bacteria (MIC = 3.125 μg/mL), very weak hemolytic activity, and low cytotoxicity. Compound 28 had rapid bactericidal properties and avoided bacterial resistance. More importantly, compound 28 showed strong in vivo antibacterial efficacy against Staphylococcus aureus and Pseudomonas aeruginosa in murine corneal infection models. This design strategy is expected to provide an effective solution to the antibiotic crisis.

Naturally occurring coumestans from plants, their biological activities and therapeutic effects on human diseases

Naturally occurring coumestans are known as a collection of plant-derived polycyclic aromatic secondary metabolites which are characterized by the presence of an oxygen heterocyclic four-ring system comprising a coumarin moiety and a benzofuran moiety sharing a C˭C bond. Recently, there is an increasing attention in excavating the medicinal potential of coumestans, particularly coumestrol, wedelolactone, psoralidin and glycyrol, in a variety of diseases. This review is a comprehensive inventory of the chemical structures of coumestans isolated from various plant sources during the period of 1956-2020, together with their reported biological activities. 120 molecules were collected and further classified as coumestans containing core skeleton, dimethylpyranocoumestans, furanocoumestans, O-glycosylated coumestans and others, which showed a wide range of pharmacological activities including estrogenic, anti-cancer, anti-inflammatory, anti-osteoporotic, organ protective, neuroprotective, anti-diabetic and anti-obesity, antimicrobial, immunosuppressive, antioxidant and skin-protective activities. Furthermore, this review focuses on the counteraction of coumestans against bone diseases and organ damages, and the involved molecular mechanisms, which could provide important information to better understand the medicinal values of these compounds. This review is intended to be instructive for the rational design and development of less toxic and more effective drugs with a coumestan scaffold.

Evaluation of Antioxidant and Anti-α-glucosidase Activities of Various Solvent Extracts and Major Bioactive Components from the Seeds of Myristica fragrans

Myristica fragrans is a well-known species for flavoring many food products and for formulation of perfume and medicated balm. It is also used to treat indigestion, stomach ulcers, liver disorders, and, as emmenagogue, diaphoretic, diuretic, nervine, and aphrodisiac. We examined antioxidant properties and bioactive compounds in various solvent extracts from the seeds of M. fragrans. Methanol, ethanol, and acetone extracts exhibited relatively strong antioxidant activities by 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), superoxide radical, and hydroxyl radical scavenging tests. Furthermore, methanol extracts also displayed significant anti-α-glucosidase activity. Examined and compared to the various solvent extracts for their chemical compositions using HPLC analysis, we isolated the ten higher content compounds and analyzed antioxidant and anti-α-glucosidase activities. Among the isolates, dehydrodiisoeugenol, malabaricone B and malabaricone C were main antioxidant components in seeds of M. fragrans. Malabaricone C exhibited stronger antioxidant capacities than others based on lower half inhibitory concentration (IC₅₀) values in DPPH and ABTS radical scavenging assays, and it also showed significant inhibition of α-glucosidase. These results shown that methanol was found to be the most efficient solvent for extracting the active components from the seeds of M. fragrans, and this material is a potential good source of natural antioxidant and α-glucosidase inhibitor.

Psoralea corylifolia L. extract ameliorates nonalcoholic fatty liver disease in free-fatty-acid-incubated HEPG2 cells and in high-fat diet-fed mice

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease that is closely related to metabolic syndrome. We investigated the effect of a Psoralea corylifolia L. (PC) seeds extract (PCE) on NAFLD. PC seeds were extracted using different ethanol concentrations to produce five extracts, and the 70% ethanol PCE, which had the highest phenolic content, was used in subsequent in vitro and in vivo experiments. The inhibitory effect of PCE on hepatic steatosis was estimated using HepG2 cells treated with oleic acid (OA). In addition, an in vivo NAFLD model was established using high-fat diet (HFD)-induced obese C57BL/6 mice. Obesity was induced in mice over 14 weeks. PCE (100 or 200 mg/kg/day) was administered orally to mice after 8 weeks of the 14-week treatment period for 6 weeks. PCE suppressed lipid accumulation in OA-treated HepG2 cells. PCE ameliorated the antioxidant activity suppressions induced by the HFD. In addition, both PCE100 and PCE200 groups reduced lipid accumulation and the expression levels of inflammatory proteins as compared with HFD group. PCE administration significantly attenuated hepatic steatosis in liver tissues by decreasing the expression of lipogenic protein sterol regulatory element binding protein 1-c (SREBP-1c) and its downstream protein fatty acid synthase (FAS) in HFD-fed mice and in OA-treated HepG2 cells. Furthermore, PCE administration increased the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase. These results suggest that PCE could be used as a functional material to prevent or ameliorate NAFLD by inhibiting lipid accumulation in liver. PRACTICAL APPLICATION: Psoralea corylifolia L. is rich in polyphenol and other phytochemicals. In this study, we identified the beneficial effects of Psoralea corylifolia L. extract on hepatic steatosis in oleic-acid-induced HepG2 cells and high-fat diet-fed mice. The result of this study will provide the evidence that a Psoralea corylifolia L. extract has potential use as a functional material for the prevention and amelioration of nonalcoholic fatty liver disease.

Surface area expansion by flower-like nanoscale layered double hydroxides for high efficient stir bar sorptive extraction

Enhancing the surface area of stationary phase is essential in chromatographic science. In this work, nanoscale NiAl-layered double hydroxides (NiAl-LDHs) with flower-like structure was used as a platform for supporting the stationary phase. Then strong hydrophobic p-naphtholbenzein molecule was immobilized onto the LDHs layer as sorbent for stir bar sorptive extraction (SBSE). The flower-like LDHs layer significantly increased the extraction efficiency through increasing the specific surface area and immobilized amounts of stationary phase. In addition, the LDHs can also provide anion exchange ability, which expanded the application of this stir bar for analysis of not only hydrophobic but also anionic analytes. For improving the workability, a poly(ether ether ketone) (PEEK) jacket stir bar with detachable dumbbell-shaped structure was employed. The PEEK jacket with high mechanical strength and dumbbell-shaped structure improved the durability of stir bar and the detectable design allowed elution to be realized with less solvent that enhanced the enrichment factor. The proposed stir bar showed good performance for the extraction of multiple analytes including flavonoids, non-steroid anti-inflammatory drugs and chlorophenoxy acids. By coupling with high performance liquid chromatography-ultraviolet detection (HPLC-UV), the SBSE-HPLC-UV method was applied for the extraction of three active components including bavachin, isobavachalcone and bavachinin in Psoralea corylifolia L. herb with low limit detection of 0.01-0.02 ng/mL.

A new bioactive coumestan from the seeds of Psoralea corylifolia

A new coumestan named bavacoumestan D (1), together with five known compounds (2-6), was isolated from EtOAc-soluble extract of seeds of Psoralea corylifolia. Their structures were elucidated on the basis of spectroscopic and physico-chemical analyses. All compounds were evaluated for in vitro inhibitory activity against DGAT1, DGAT2 and α-glucosidase. Among them, compounds 1-2, 5-6 showed potential inhibitory activity on DGAT1 with IC₅₀ values ranging from 52.3 ± 1.3 to 81.0 ± 1.0 μM. Compounds 1-3, 6 displayed the significant inhibitory activity on α-glucosidase with IC₅₀ values ranging from 31.2 to 89.1 μM.[Formula: see text].

Corylin, a flavonoid derived from Psoralea Fructus, induces osteoblastic differentiation via estrogen and Wnt/β-catenin signaling pathways

Corylin is a naturally occurring flavonoid isolated from the fruit of Psoralea corylifolia L. (Fabaceae), which is a Chinese medicinal herb in treating osteoporosis. Although a variety of pharmacological activities of corylin have been reported, its osteogenic action and the underlying mechanism in bone development remain unclear. In the present study, the involvement of bone-specific genes in corylininduced differentiated osteoblasts was analyzed by RT-PCR, promoter-reporter assay, and Western blotting. In cultured osteoblasts, corylin-induced cell differentiation and mineralization, as well as increased the expressions of vital biological markers for osteogenesis, such as Runx2, Osterix, Col1, and ALP. Corylin was proposed to have dual pathways in triggering the osteoblastic differentiation. First, the osteogenic function of corylin acted through the activation of Wnt/β-catenin signaling. The nuclear translocation of β-catenin of cultured osteoblasts, as determined by flow cytometry and confocal microscopy, was triggered by applied corylin, and which was blocked by DKK-1, an inhibitor of Wnt/β-catenin signaling. Second, the application of corylin-induced estrogenic response in a dose-dependent manner, and which was blocked by ICI 182 780, an antagonist of estrogen receptor. Furthermore, the activation of Runx2 promoter by corylin was abolished by both DKK-1 and ICI 182,780, indicating that the corylin exhibited its osteogenic effect via estrogen and Wnt/β-catenin signaling pathways. In addition, corylin regulated the metabolic profiles, as well as the membrane potential of mitochondria, in cultured osteoblasts. Corylin also stimulated the osteogenesis in bone micromass derived from mesenchymal progenitor cells. This study demonstrated the osteogenic activities of corylin in osteoblasts and micromass, suggesting that corylin has the potential to be developed as a novel pro-osteogenic agent in targeting for the treatment of osteoblast-mediated osteoporosis.

Quality Control of Psoralea corylifolia L. Based on High-Speed Countercurrent Chromatographic Fingerprinting

Traditional Chinese medicine (TCM)has played an important role in promoting the health of Chinese people. The TCM Psoralea corylifolia L. has been used in the treatment of various kinds of diseases including enuresis, vitiligo, and calvities. However, therapeutic effects of P. corylifolia L. have often influenced by the quality of plants. So, it is very important to control the quality of P. corylifolia L. In this study, analytical high-speed countercurrent chromatography (HSCCC) was successfully used to fingerprint P. corylifolia L. Samples of P. corylifolia L. were extracted by ultrasonic extraction. n-hexane-ethyl acetate–methanol–water at a ratio of 5:5.5:6.5:5 (v/v) was selected as a two-phase solvent system and the condition of HSCCC were optimized in order to good separation. And the method of HSCCC was verified (reproducibility, precision, and stability). HSCCC chromatograms exhibited six common peaks, which were selected as indicator compounds for the quality control of P. corylifolia L. Within 20 types of medicinal materials, chemical components are similar, but the levels of components are quite different in HSCCC fingerprint. The present results demonstrate that the HSCCC method provides a reliable basis for the quality control of P. corylifolia L. and can also be applied to confirm the authenticity of plant materials.

Psoralen Derivatives: Recent Advances of Synthetic Strategy and Pharmacological Properties

Psoralen or furocoumarin is a linear three ring heterocyclic compound. Psoralens are planar, tricyclic compounds, consisting of a furan ring fused to a coumarin moiety. Psoralen has been known for a wide spectrum of biological activities, spanning from cytotoxic, photosensitizing, insecticidal, antibacterial to antifungal effect. Thus, several structural changes were introduced to explore the role of specific positions with respect to the biological activity. Convenient approaches utilized for the synthesis of psoralen skeleton can be categorized into two parts: (i) the preparation of the tricyclic ring system from resorcinol, (ii) the exocyclic modification of the intact ring system. Furthermore, although psoralens have been used in diverse ways, we mainly focus in this work on their clinical utility for the treatment of psioraisis, vitiligo and skin-related disorder.

Transformation of Psoralen and Isopsoralen by Human Intestinal Microbial In Vitro, and the Biological Activities of Its Metabolites

Psoralen (P) and isopsoralen (IP) are the main active ingredients in the dried fruit of Psoralen corylifolia L. (PC), with a wide range of pharmacology activities. The intestinal bacteria biotransformation plays a central role in the metabolism of the complex ingredients in traditional Chinese medicine (TCM). Our study aimed to investigated the metabolic profile of P and IP in the intestinal condition, co-cultured with human fecal bacteria anaerobically. Four bio-transforming products were obtained, including 6,7-furano-hydrocoumaric acid (P-1) and 6,7-furano-hydro- coumaric acid methyl ester (P-2), which transformed from P, and 5,6-furano-hydrocoumaric acid (IP-1) and 5,6-furano-hydrocoumaric acid methyl ester (IP-2), which were transformed from IP. It is worth mentioning that IP-2 is a new compound that has not been published. Their structures were analyzed based on their spectroscopic data. Moreover, a highly sensitive ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was used to characterize the metabolic pathways of P, IP, and their bio-transforming products in the reaction samples. In addition, the dampening effects against the oxidative stress of P, IP, and their bio-transforming products by human intestinal flora were estimated in vitro via the human colorectal cells (HCT116) and heterogeneous human epithelial colorectal adenocarcinoma cells (Caco-2) cell lines. The results showed that the metabolites have stronger activity than P and IP, which possibly provides a basis for elucidating the treating mechanisms of PC extract against inflammatory bowel disease.

Anti-diabetic compounds from the seeds of Psoralea corylifolia

A new aurone named (2Z)-2-[(4'-hydroxyphenyl) methylene]-6-hydroxy-7-prenyl-3(2H)-benzofurane (1), two new flavonoids named (2S)-7-methoxy-6-(2-hydroxy-3-methylbut-3-en-1-yl)-2-(4-hydroxyphenyl)chroman-4-one (2), (2S)-4'-hydroxyl-7-hydroxymethylene-6-(2″,3″-epoxy-3″-methylbutyl)flavanone (3), and a new coumestan named bavacoumestan E (4), together with eleven known compounds (5-15), were isolated from the seeds of Psoralea corylifolia. The chemical structures were elucidated by spectroscopic and physico-chemical analyses. All isolates were evaluated for in vitro inhibitory activity against DGAT, PTP1B and α-glucosidase. Compounds 1, 2 and 3 showed potential inhibitory activities on DGAT1 with IC₅₀ values of 35.2 ± 1.3, 51.3 ± 1.1 and 43.4 ± 0.7 μM, respectively. Compounds 6 and 8 displayed the significant inhibitory activities on α-glucosidase with IC₅₀ value of 28.0 and 23.0 μM, respectively.

Chemical constituents from the fruits of Cullen corylifolium (L.) Medik. by the targeted separation mode

Two new compounds, corylifol H (1) and epi-bavacoumestan C (2), together with a new natural product named 8-geranyl daidzein (3), were isolated from the fruits of Cullen corylifolium (L.) Medik. (syn. of Psoralea corylifolia L.) by the targeted separation mode. The structures of these compounds were elucidated on the basis of spectroscopic methods and by comparison with literature properties. The anti-inflammatory effects of the two new compounds were also evaluated by activity assay in vitro. The results showed that compounds 1 and 2 inhibited nitric oxide production in LPS-activated RAW 264.7 macrophages in a dose dependent manner.

A New Aurone and Other Constituents From the Seeds of Psoralea corylifolia With Their Diacylglycerol Acyltransferase Inhibitory Activity

A new aurone (1), together with 5 known compounds (2-6), were isolated from EtOAc-soluble extract of the seeds of Psoralea corylifolia. Their structures were elucidated on the basis of spectroscopic methods. All compounds were evaluated for in vitro inhibitory activity against diacylglycerol acyltransferase (DGAT). Among them, compound 1 showed selective inhibitory activity on DGAT1 with IC50 value of 54.9 ± 1.4 µM.

Ionic Liquid-Based Ultrasonic-Assisted Extraction to Analyze Seven Compounds in Psoralea Fructus Coupled with HPLC

Psoralea Fructus is widely used in traditional Chinese medicine (TCM), and the content of psoralen, isopsoralen, neobavaisoflavone, bavachin, psoralidin, isobavachalcone, and bavachinin A is the main quality control index of Psoralea Fructus because of its clinical effects. Thus, a fast and environmentally-benign extraction method of seven compounds in Psoralea Fructus is necessary. In this work, an ionic liquid-based ultrasonic-assisted method (ILUAE) for the extraction of seven compounds from Psoralea Fructus was proposed. Several ILs of different types and parameters, including the concentration of ILs, concentration of ethanol (EtOH), solid–liquid ratio, particle size, ultrasonic time, centrifugal speed, and ultrasonic power, were optimized by the Placket–Burman (PB) design and Box–Behnken response surface analysis. Under this optimal condition, the total extraction yield of the seven compounds in Psoralea Fructus was 18.90 mg/g, and significantly greater than the conventional 75% EtOH solvent extraction.

Genus Psoralea: A review of the traditional and modern uses, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Psoralea (Fabaceae) harbours 105 accepted species that are extensively used by local peoples and medicinal practitioners of China, India, and other countries for treatment of tooth decay, psoriasis, leucoderma, leprosy, kidney problems, tuberculosis, indigestion, constipation and impotence. Presently, pharmacological research reports are available on only few species namely Bituminaria bituminosa (Syn: P. bituminosa), P. canescens, P. corylifolia, P. esculenta, P. plicata and P. glandulosa which are valued for their chemical constituents and traditional uses.

AIM OF THE REVIEW

This review article provides explicit information on traditional uses, phytochemistry, and pharmacological activities of selected Psoralea species. The possible trends and perspectives for future research on these plants are also discussed.

MATERIALS AND METHODS

An extensive and systematic review of the extant literature was carried out, and the data under various sections were identified using a computerized bibliographic search via the PubMed, Web of Science and Google Scholar, CAB Abstracts, MEDLINE, EMBASE, INMEDPLAN, NATTS as well as several websites.

KEY FINDINGS

A total of 291 bioactive compounds from 06 species of genus Psoralea have been isolated and characterized. However, P. bituminosa alone possess nearly 150 compounds. These bioactive compounds belong to different chemical classes, including flavonoids, coumarins, furanocoumarins, chalcones, quinines, terpenoids and some others due to which these species exhibit significant anti-oxidant, anti-bacterial, anti-fungal, anti-viral, anti-helmintic, anti-diabetic, diuretic, hepatoprotective, anti-cancer and anti-tumor activities. P. corylifolia L. (Babchi), a Chinese traditional medicinal plant has been used in traditional medicine for many decades for its healing properties against numerous skin diseases such as leprosy, psoriasis and leucoderma.

CONCLUSIONS

The in vitro studies and in vivo models have provided a simple bio-scientific justification for various ethnopharmacological uses of Psoralea species. From the toxicological perspective, the root, leaf, and seed extracts and their preparations have been proven to be safe when consumed in the recommended doses. But, meticulous studies on the pharmaceutical standardization, mode of action of the active constituents, and sustainable conservation of Psoralea species are needed, to meet the growing demands of the pharmaceutical industries, and to fully exploit their preventive and therapeutic potentials.

Effect of Solvents on Phytochemicals Content and Antioxidant Activity of Ganoderma lucidum

Introduction:

The aim of this study was to assess the induction of solvents on the total phenol and flavonoid content and also the antioxidant activity of Ganoderma lucidum extracts.

Materials & Methods:

In this study, two concentrations (100% and 75%) of diethyl ether, ethanol, butanol, chloroform, and acetone were used as extractants of Ganoderma lucidum. Total phenol and flavonoid contents were measured by spectrophotometric methods and 1, 1-diphenyl-2-picrylhydrazyl (DPPH). Free radical scavenging assay was used for the investigation of antioxidant activity.

Results & Discussion:

Extractants significantly affected the % yield of extract, the quantity of phenol and flavonoids and antioxidant activity of Ganoderma lucidum mushroom. The highest extraction yield, around 38%, was achieved by 75% acetone, followed by 100% acetone (about 36%) and 75% chloroform (approximate 21%). Hydro-acetone extract exhibited the most significant antioxidative properties (EC50 value; 645.55 µg/mL) comprised of a higher total of phenol content. In conclusion, the total phenol content encouraged the antioxidative potential of Ganoderma lucidum mushroom.

Conclusion:

These findings indicate that the selective extraction of Ganoderma lucidum shows significant biological activities.

The active compounds derived from Psoralea corylifolia for photochemotherapy against psoriasis-like lesions: The relationship between structure and percutaneous absorption

8‑Methoxypsoralen (8-MOP) in combination with ultraviolet A (PUVA) is a photochemotherapy for management of psoriasis. 8-MOP is a natural compound from Psoralea corylifolia. The present work was undertaken to evaluate the percutaneous absorption of five compounds derived from P. corylifolia, and to further explore the inhibitory effect on psoriasis-like lesions generated by imiquimod stimulation in a mouse model. 8-MOP, psoralen, isopsoralen, psoralidin, and bakuchiol were comparatively tested for in vitro skin permeation, keratinocyte apoptosis, and in vivo antipsoriatic potency. The pig ear skin deposition of 8-MOP, isopsoralen, and bakuchiol at an equimolar dose was 0.47, 0.58, and 0.50 nmol/mg, respectively, which was comparable and higher than that of psoralen (0.25 nmol/mg) and psoralidin (0.14 nmol/mg). Psoralidin and bakuchiol were absorbed into the skin without further penetration across the skin. Besides experimental data of physicochemical properties, the hydrogen bond number, total polarity surface, and stratum corneum lipid docking calculated could explain the correlation of the penetrant structure with the skin permeability. The antiproliferative activity against keratinocytes was stronger for 8-MOP and isopsoralen than the others. Topical application of PUVA by using 8-MOP and isopsoralen on imiquimod-induced plaque significantly reduced transepidermal water loss from 55 to 33 and 38 g/m²/h, respectively. The epidermal thickening elicited by imiquimod (117 μm) was decreased to 62 and 26 μm by 8-MOP and isopsoralen application. IL-6 expression in psoriasiform skin was downregulated by isopsoralen but not 8-MOP. Isopsoralen may be a potential candidate for PUVA therapy.

A New Flavanone from Seeds of Psoralea corylifolia with α-Glucosidase Inhibitory Activity

A new flavanone (2 S)-7,4'-hydroxyl-6-(2″,3″-epoxy-3″-methylbutyl)flavanone (1), together with five known compounds (2–6) were isolated from EtOAc-soluble extract of seeds of Psoralea corylifolia. Their structures were elucidated on the basis of spectroscopic and physico-chemical analyses. All compounds were evaluated for in vitro inhibitory activity against α-glucosidase. Among them, new compound 1 was found to exhibit inhibitory activity on α-glucosidase with IC50 value of 29.2 μM.

Metabolic profiling of corylin in vivo and in vitro

Corylin, an phenolic compound from Psoralea corylifolia, has been reported with various pharmacological properties but has poor bioavailability due to massive metabolism. In this study, twelve metabolites of corylin mainly involving in oxidation, hydration, glucuronidation and sulfation were detected in mice. Furthermore, the oxidation and hydration of corylin (M4) in human liver microsomes (HLM) and human intestine microsomes (HIM) were both efficient with high CL_int (intrinsic clearance) values of 24.29 and 42.85 μL/min/mg, respectively. CYP1A1, 1B1 and 2C19 contributed most for M4 with the CL_int values of 26.63, 33.09 and 132.41 μL/min/mg, respectively. Besides, M4 was strongly correlated with phenacetin-N-deacetylation (r = 0.885, p = 0.0001) and tolbutamide-4-oxidation (r = 0.727, p = 0.001) in twelve individual HLMs, respectively. In addition, corylin was efficiently glucuronidated (M7) in HLM (125.33 μL/min/mg) and in HIM (108.74 μL/min/mg). UGT1A1 contributed the most for M7 with the CL_int value of 122.32 μL/min/mg. Meanwhile, M7 was significantly correlated with β-estradiol-3-O-glucuronidation (r = 0.742, p = 0.006) in twelve individual HLMs. Moreover, the metabolism of corylin showed marked species differences. Taken together, corylin was subjected to massive first-pass metabolism in liver and intestine, while CYP1A1, 1B1, 2C19 and UGT1A1 were the main contributors. Finally, the proposed metabolic pathway of corylin involed CYP and UGT isoforms were summarized, which could help to understand the metabolic fate of corylin in vivo.

Bavachalcone from Cullen corylifolium induces apoptosis and autophagy in HepG2 cells

BACKGROUND

Cullen corylifolium is a plant widely used in traditional Chinese medicine for its stomachic, anthelmintic, and diuretic properties. Bavachalcone, which is known as a component of C. corylifolium has been reported to inhibit osteoclast differentiation. However, the anticancer efficacy and mechanism of C. corylifolium and bavachalcone have not been studied.

HYPOTHESIS/PURPOSE

Our aim is to determine whether C. corylifolium has an anticancer effect and to identify the apoptosis and autophagy mechanism of bavachalcone.

STUDY DESIGN/METHOD

The anti-proliferative activity of C. corylifolium and bavachalcone was measured with MTT assay. Apoptosis was analyzed using Annexin V and propidium iodide staining. The expression of apoptosis, cell cycle and autophagy related gene was evaluated by western blot. Cell cycle stage was investigated with Tali^Ⓡ image-based cytometer. Autophagic activity was assessed using monodansylcadaverine (MDC) staining.

RESULT

C. corylifolium exhibited potent effect on apoptosis in HepG2 cells. To identify which compound in C. corylifolium is responsible for this effect, we determined the effects of psoralen, psoralidin, bavachalcone, and isobavachalcone on the activity of bid, caspase 3, and PARP. Of all the studied compounds, bavachalcone was the most potent inducer of apoptosis and acted via crosstalk between the intrinsic and extrinsic pathways. In addition, bavachalcone caused cell cycle arrest and decreased the levels of early cell cycle regulatory proteins such as CDK 4 and CDK 2, whereas p21 and p27 levels were increased. We also investigated the extent to which bavachalcone-induced autophagy and apoptosis were related. Phosphorylation and expression of Akt and mTOR were decreased, while the LC3 Ⅱ to LC3Ⅰ ratio was increased in bavachalcone-treated cells. These results suggest that bavachalcone has anticancer activity by promoting both autophagy and apoptosis in HepG2 cells.

CONCLUSION

C. corylifolium has an anticancer effect. Especially, bavachalcone has excellent anticancer ability among other components of C. corylifolium by inducing apoptosis and autophagy.

The Evaluation of Toxicity Induced by Psoraleae Fructus in Rats Using Untargeted Metabonomic Method Based on UPLC-Q-TOF/MS

Psoraleae Fructus is the dry and mature fruit of leguminous plant Psoralea corylifolia L., with the activity of warming kidney and enhancing yang, warming spleen, and other effects. However, large doses can cause liver and kidney toxicity. Therefore, it is necessary to evaluate the toxicity of Psoraleae Fructus systematically. Although traditional biochemical indicators and pathological tests have been used to evaluate the safety of drug, these methods lack sensitivity and specificity, so a fast and sensitive analytical method is urgently needed. In this study, an ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) method was used to analyze the metabolic profiles of rat plasma. The changes of metabolites in plasma samples were detected by partial least squares-discriminant analysis (PLS-DA). Compared with the control group, after 7 days of administration, the pathological sections showed liver and kidney toxicity, and the metabolic trend was changed. Finally, 13 potential biomarkers related to the toxicity of Psoraleae Fructus were screened. The metabolic pathways involved were glycerol phospholipids metabolism, amino acid metabolism, energy metabolism, and so forth. The discovery of these biomarkers laid a foundation for better explaining the hepatotoxicity and nephrotoxicity of Psoraleae Fructus and provided a guarantee for its safety evaluation.

Psoralea corylifolia L. Seed Extract Attenuates Diabetic Nephropathy by Inhibiting Renal Fibrosis and Apoptosis in Streptozotocin-Induced Diabetic Mice

The Psoralea corylifolia L. seed (PCS) is a widely used herbal medicine, but its possible effect against diabetic nephropathy has not been studied. To investigate the anti-nephropathic effect of PCS extracts, we performed experiments using a diabetic mouse model and high glucose-treated mesangial cells. Streptozotocin (STZ)-induced diabetic mice were orally administered PCS extract for 8 weeks (500 mg/kg/day). Increased creatinine clearance, urine volume, urine microalbumin, and mesangial expansion were observed in STZ-induced diabetic mice; these were significantly reduced by PCS extract administration. PCS extract significantly reduced fibrosis in the kidney tissue of diabetic mice as evidenced by decreased mRNA expression of collagen type IV-α2, fibronectin, PAI-1, and TGF-β1. In addition, cleaved PARP, an apoptotic gene, was upregulated in the diabetic nephropathy mice, and this was ameliorated after PCS extract treatment. Treatment of high glucose-treated MES-13 cells with isopsoralen and psoralen, major components of PCS extract, also decreased the expression of fibrosis and apoptosis marker genes and increased cell viability. PCS extract exerts protective effects against STZ-induced diabetic nephropathy via anti-fibrotic and anti-apoptotic effects. PCS extract might be a potential pharmacological agent to protect against high glucose-induced renal damage under diabetic conditions.

Corylin protects LPS-induced sepsis and attenuates LPS-induced inflammatory response

Corylin is a main compound isolated from Psoralea corylifolia L. (Fabaceae). A variety of pharmacological effects such as antioxidant, anti-proliferation, and anti-inflammatory properties of corylin have been reported. Nevertheless, the effect of corylin in microbial infection and sepsis remains unclear. In the present study, we investigated the anti-inflammatory effects of corylin. Our experimental results demonstrated that corylin inhibited the production of TNF-α, IL-6 and NO by both LPS-activated RAW 264.7 cells and LPS-activated murine peritoneal macrophages. Moreover, corylin suppressed the expression levels of iNOS and COX-2, reduced the production of PGE₂ and HMGB1, blocked the translocation of HMGB1 from the nucleus to cytosol, and decreased the phosphorylation of MAPKs in LPS-activated RAW 264.7 cells as well as suppressed the activity of NF-κB in LPS-activated J-Blue cells. In addition, the administration of corylin reduced the production of NO and TNF-α, decreased LPS-induced liver damage markers (AST and ALT) and kidney damage markers (BUN and CRE), attenuated infiltration of inflammatory cells and tissue damage of lung, liver and kidney, and enhanced the survival rate of LPS-challenged mice. Taken together, these results show the anti-inflammatory properties of corylin on LPS-induced inflammation and sepsis. Corylin could potentially be a novel anti-inflammatory and immunosuppressive drug candidate in the treatment of sepsis and septic shock.

Phytochemical and Pharmacological Studies on the Genus Psoralea: A Mini Review

The genus Psoralea, which belongs to the family Fabaceae, comprises ca. 130 species distributed all over the world, and some of the plants are used as folk medicine to treat various diseases. Psoralea corylifolia is a typical example, whose seeds have been widely used in many traditional Chinese medicine formulas for the treatment of various diseases such as leucoderma and other skin diseases, cardiovascular diseases, nephritis, osteoporosis, and cancer. So, the chemical and pharmacological studies on this genus were performed in the past decades. Here, we give a mini review on this genus about its phytochemical and pharmacological studies from 1910 to 2015.

Biological importance of structurally diversified chromenes

Compounds incorporating the chromene scaffold are largely present in natural products and display a wide variety of biological activities. Their low toxicity combined to the broad pharmacological properties have inspired medicinal chemists in the search for new therapeutic agents. This review covers the literature between 1993 and on the biological activity of 2H- and 4H-chromenes, both from natural and synthetic origin. Includes a section that identifies a selection of chromene-based natural products, followed by recent literature on bioactive natural chromenes and the corresponding source, covering plants and fruits. Synthetic chromenes are equally important and a separate section addresses the use of these derivatives as new leads for drug discovery. Different biological targets were identified, namely those associated with anticancer, antimicrobial, anti-inflammatory, antithrombotic and antipsychotic activities.

Synthesis of Psoralidin derivatives and their anticancer activity: First synthesis of Lespeflorin I1

Synthetic scheme for the preparation of a number of different derivatives of anticancer natural product Psoralidin is described. A convergent synthetic approach is followed using simple starting materials like substituted phenyl acetic esters and benzoic acids. The developed synthetic route leads us to complete the first synthesis of an analogous natural product Lespeflorin I₁, a mild melanin synthesis inhibitor. Preliminary bioactivity studies of the synthesized compounds are carried out against two commonly used prostate cancer cell lines. Results show that the bioactivity of the compounds can be manipulated by the simple modification of the functional groups.

Psoralea corylifolia L. Seed Extract Attenuates Nonalcoholic Fatty Liver Disease in High-Fat Diet-Induced Obese Mice

Nonalcoholic fatty liver disease (NAFLD), along with obesity, is increasing world-wide and is one of the major causes of chronic hepatic disease. The present study evaluated the ameliorative effect of extract of Psoralea corylifolia L. seed (PCS) on high fat diet-induced NAFLD in C57BL/6 mice after daily administration at 300 or 500 mg/kg for 12 weeks. Treatment with PCS extract significantly reduced body weight and blood glucose levels and improved glucose tolerance and insulin sensitivity. In addition, PCS extract treatment significantly attenuated lipid accumulation in liver and adipose tissue and reduced serum lipid and hepatic triglyceride levels. Furthermore, the expression of lipogenic genes and inflammatory genes were reduced, and the expression of fat oxidation-related genes was increased in the liver of PCS extract-treated mice compared with control mice. Our study suggests the therapeutic potential of PCS extract for NAFLD by inhibiting lipid accumulation and inflammation in liver.

Synthesis and anti-proliferative evaluation of novel 3,4-dihydro-2H-1,3-oxazine derivatives of bakuchiol

Anti-proliferation study of new bakuchiol analogs revealed the anti-pancreatic potential of aliphatic oxazine derivatives of bakuchiol that activate caspase-9 and -3 and cleave PARP-1.

Assessment of Antifungal Activity of Bakuchiol on Oral-Associated Candida spp

Bakuchiol is an active component of Psoralea glandulosa and Psoralea corylifolia, used in traditional Chinese medicine. The study aimed at investigating the antifungal activity of bakuchiol on planktonic and biofilm forms of orally associated Candida species. The antifungal susceptibility testing was determined by the broth micro dilution technique. Growth kinetics and cell surface hydrophobicity (CSH) of Candida were measured to assess the inhibitory effect of bakuchiol on Candida planktonic cells. Biofilm biomass and cellular metabolic activity were quantitatively estimated by the crystal violet (CV) and the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) assays. All Candida strains have been shown to be susceptible to bakuchiol with the MIC ranges from 12.5 to 100 μg/mL. Significant decrease in specific growth rates and viable counts demonstrates the inhibitory effect of bakuchiol on Candida planktonic cells. A brief exposure to bakuchiol also reduced CSH of Candida (P < 0.05), indicating altered surface properties of yeast cells towards hydrophobic interfaces. Biofilm biomass and cell metabolic activity were mostly decreased, except for C. glabrata (P = 0.29). The antifungal properties of bakuchiol on Candida species in this in vitro study may give insights into the application in therapeutic strategy against Candida infections.