Bakuchiol Research Articles

BAK ameliorated cerebral infarction/ischemia–reperfusion injury by activating AMPK/Nrf2 to inhibit TXNIP/NLRP3/caspase-1 axis

BackgroundCerebral ischemia/reperfusion (I/R) injury is a serious vascular disease with extremely high mortality and disability rate. Bakuchiol (BAK) was found in leaves and seeds of Psoralea corylifolia Linn and has been shown to decrease inflammation and reduce oxidative stress, while the mechanism of BAK in ameliorating cerebral I/R injury remains unclear. MethodsMiddle cerebral artery occlusion reperfusion (MACO/R) was used to establish mouse model. The protective effect of BAK in MCAO/R mices was detected by performing neurological deficit testing, TTC staining, and H&E staining. Oxygen/glucose deprivation and reperfusion (OGD/R) was used to stimulate SH-SY5Y cells in vitro. Protein expression was detected by western blotting, gene expression was detected by quantitative real-time polymerase chain reaction and apoptosis was detected by immunofluorescence. ResultsOur study indicated that BAK protected ischemia–reperfusion injury in MACO/R mice, and upregulated superoxide dismutase (SOD) and the catalase (CAT) enzyme activity. BAK also inhibited the expression of TNF-α, IL-1β, IL-6, and IL-18 and suppressed apoptosis and pyroptosis both in MACO/R mice and in OGD/R SH-SY5Y cells. Further results showed that BAK could suppress TXNIP, ASC, NLRP3, and caspase-1 mRNA levels to reverse assembly of inflammasome. And BAK could also upregulate the expression of phosphorylated AMP-activated protein kinase (AMPK) and nuclear factor erythroid 2-related factor (Nrf2). In addition, Nrf2 inhibitor ML385 reversed the BAK induced reduction of TXNIP, ASC, NLRP3, and the AMPK inhibitor also abolished BAK’ the effect on the regulation of Nrf2 TXNIP, ASC, NLRP3, caspase-1, and pro-inflammatory cytokines. In conclusion, BAK, found in leaves and seeds of Psoralea corylifolia Linn, could ameliorated cerebral I/R injury through activating AMPK/Nrf2 to inhibit NLRP3 inflammasome, which might present new therapeutic strategy for cerebral I/R injury.

De Novo Biosynthesis of a Bioactive Meroterpene Bakuchiol in Yeast.

Bakuchiol (BAK), a specialized meroterpene, is known for its valuable biological properties and has recently gained prominence in cosmetology for its retinol-like functionality. However, low abundance in natural sources leads to environmentally unfriendly and unsustainable practices associated with crop-based manufacturing and chemical synthesis. Here, we identified a prenyltransferase (PT) from Psoralea corylifolia that catalyzes the reverse geranylation of a nonaromatic carbon in para-coumaric acid (p-CA), coupled with a decarboxylation step to form BAK. Given that the biosynthesis pathway of BAK is well elucidated, we engineered Saccharomyces cerevisiae to produce BAK, starting from glucose. To enhance the titer of BAK, we employed a multifaceted approach that included increasing the supply of precursors, balancing the fluxes in the two parallel biosynthetic pathways, engineering of prenyltransferase, and fusing enzymes. Consequently, the engineered yeast strains showed a marked improvement of 117.3-fold in BAK production, reaching a titer of 9.28 mg/L from glucose. Our work provides a viable approach for the sustainable microbial production of complex natural meroterpenes.

Bakuchiol nanoemulsion loaded electrospun nanofibers for the treatment of burn wounds.

The present work aims to develop and evaluate the wound healing potential of bakuchiol nanoemulsion loaded electrospun scaffolds. Since oxidative stress and microbial burden leads the burn wounds to become chronic and fatal to patients, a phytoconstituent, bakuchiol (BAK), was screened on the basis of antioxidant and antimicrobial potential which also defined its dose. Furthermore, BAK was incorporated into a nanoemulsion to enhance its therapeutic efficacy, reduce its dosage frequency, and maximize its stability. The present study is inclined towards the collaborative interaction of natural products and novel drug delivery systems to develop safe and therapeutically efficient systems for burn wound healing. The optimized nanoemulsion showed excellent antioxidant and antimicrobial potential against wound susceptible pathogens, i.e., Candida albicans and Methicillin-resistant Staphylococcus aureus which was further loaded into gelatin based hydrogel and nanofibrous scaffold system. The mesh structure of scaffolds was chosen as a suitable carrier system for wound healing process not only because it offers resemblance to skin's anatomy but is also capable of providing uniform distribution of wound biomarkers across the skin. The prepared nanofibers were assessed for their analgesic, anti-inflammatory, and wound healing potential which was observed to be significantly better than its gel formulation.

Fatty acid profiles of olive oil and moringa oil and their influence on nanoemulsion formation via D-phase emulsification using bakuchiol as a model active compound

Moringa oil (MO) and olive oil (OV) share similar chemical compositions, often considered interchangeable in various applications. However, their behavior in nanoemulsion formation, a widely-used process in the cosmetic industry, remains relatively unexplored. This study aimed to investigate their fatty acid compositions and how they respond to nanoemulsion formation using the D-phase emulsification method. MO comprises approximately 79% oleic acid, 7% palmitic acid, 6% stearic acid, and other minor components. In contrast, OV contains roughly 70% oleic acid, 14% palmitic acid, 10% linoleic acid, and other constituents. In the context of nanoemulsion formation, both oils exhibited similar trends in particle size, polydispersity index (PDI), and zeta potential when varying the formulation compositions. The type of oil significantly influenced particle size at low surfactant concentrations and PDI at higher oil concentrations, consistently affecting zeta potential. The optimal formulation, O1T15G5, yielded droplet sizes of approximately 222 nm (MO) and 50 nm (OV). Both MO and OV nanoemulsions responded similarly to the substitution of oil with bakuchiol (BK), with O0.7B0.3T15G5 achieving the smallest spherical particle size confirmed by TEM and DLS analysis. Encapsulation efficiency and antioxidant activity remained largely unaffected by types of oil. Stability tests at different temperatures showed some distinctions in physical stability but similarities in antioxidant activity stability. The types of oil did not significantly impact BK release or cytotoxicity levels. This research underscores the potential utility of MO as a viable alternative to OV in cosmetic applications, shedding light on their similarities and performance within nanoemulsion formulations.

Natural Retinol Analogs Potentiate the Effects of Retinal on Aged and Photodamaged Skin: Results from In Vitro to Clinical Studies.

Plants are a source of natural ingredients with retinol-like properties that can deliver anti-aging benefits without the side effects typically associated with retinoid use. We hypothesized that by combining two such analogs, bakuchiol (BAK) and Vigna aconitifolia extract (VAE), with the potent retinoid retinal (RAL), the anti-photoaging potential of RAL could be enhanced without compromising its skin irritation profile. The purpose of this study was to demonstrate that BAK and VAE potentiate the anti-photoaging activity of RAL. Gene expression profiling of full-thickness reconstructed skin was first used to examine the impact of BAK or VAE in combination with RAL on skin biology. Next, the irritative potential of this combination, and its capacity to reverse key signs of photoaging in an ex vivo model was assessed. Finally, a proof-of-concept open label clinical study was performed to evaluate the anti-photoaging capacity and skin compatibility of a cosmetic formulation (tri-retinoid complex; 3RC) containing this complex in combination with other well characterized anti-photoaging ingredients. In vitro profiling suggested that combining 0.1% RAL with BAK or VAE potentiates the effect of RAL on keratinocyte differentiation and skin barrier function without affecting its skin irritation profile. When formulated with other anti-photoaging ingredients, such as niacinamide and melatonin, 3RC reversed ultraviolet radiation-induced deficits in structural components of the dermal extracellular matrix, including hyaluronic acid and collagen. In vivo, it led to a reversal of clinical signs of age and photodamage, with statistically significant improvement to skin firmness (+5.6%), skin elasticity (+13.9%), wrinkle count (-43.2%), and skin tone homogeneity (+7.0%), observed within 28days of once nightly use. Notably, the number of crow's feet wrinkles was reduced in 100% of subjects. Furthermore, 3RC was very well tolerated. These data suggest that 3RC is a highly effective and well-tolerated treatment for photoaging.

Bakuchiol inhibits lung cancer by modulating tumor microenvironment and the expression of PD-L1.

Immune checkpoint therapy is an emerging frontier in cancer therapy. With the aim to develop an efficient herb derived compound to facilitate immune checkpoint therapy, here we investigate if a herb-derived compound, Bakuchiol (BAK), can be used to treat lung cancer and elucidate if BAK could serve as a PD-L1 regulator. To this end, a murine lung cancer model was established by subcutaneously inoculating murine Lewis lung carcinoma (LLC) cells. BAK of 5 to 40 mg/kg was used for treatment in vivo for 15 days. On Day 15, the population of CD4+ and CD8+ T cells, Treg cells. BAK could effectively inhibit tumor growth by starting treatment either on Day 0 or 6 after tumor inoculation at doses of 5-40 mg/kg. BAK treatment increased the population of cytotoxic immune cells (i.e., CD8+ T cells, and M1 macrophages), meanwhile decreasing pro-tumor immune cells (i.e., CD3+ T cells, Treg cells, and M2 macrophages). Anti-inflammatory cytokines, including IL1β, IL2, IFNγ, TNF-α, IL4 and IL10 were upregulated by BAK. PD-L1 expression in the tumor was also lowered by BAK. AKT and STAT3 signaling were inhibited by BAK. BAK is an efficient agent in reducing LLC tumor growth. These data support the potential of BAK as a new drug for treating lung cancer by serving as a PD-L1 inhibitor that suppresses the activation of AKT and STAT3.

Preliminary Approaches to Cosmeceuticals Emulsions Based on N-ProlylPalmitoyl Tripeptide-56 Acetat-Bakuchiol Complex Intended to Combat Skin Oxidative Stress.

This study focuses on the development of a performant formulation for O/W dermato-cosmetic emulsions, which can be incorporated into novel dermato-cosmetic products or used as such. The O/W dermato-cosmetic emulsions contain an active complex based on a plant-derived monoterpene phenol, bakuchiol (BAK) and a signaling peptide named n-prolyl palmitoyl tripeptide-56 acetate (TPA). As a dispersed phase, we used a mix of vegetable oils, and as a continuous phase, Rosa damascena hydrosol was employed. Three emulsions containing different concentrations of the active complex were formulated (0.5% BAK + 0.5% TPA = E.1.1., 1% BAK + 1%TPA = E.1.2., 1% BAK + 2% TPA = E.1.3.). Stability testing was performed through sensory analysis, stability after centrifugation, conductivity and optical microscopy. A preliminary in vitro study regarding the diffusion ability of antioxidants through chicken skin was also undertaken. DPPH and ABTS assays were used to highlight the optimal concentration and combination in the formulation in terms of antioxidant properties and safety level of the active complex (BAK/TPA). Our results showed that the active complex used for preparing emulsions with BAK and TPA showed good antioxidant activity and is suitable for obtaining topical products with potential antiaging effects.

Bakuchiol and Ethyl (Linoleate/Oleate) Synergistically Modulate Endocannabinoid Tone in Keratinocytes and Repress Inflammatory Pathway mRNAs

The endocannabinoid (eCB) system plays an active role in epidermal homeostasis. Phytocannabinoids such as cannabidiol modulate this system but also act through eCB-independent mechanisms. This study evaluated the effects of cannabidiol, bakuchiol (BAK), and ethyl (linoleate/oleate) (ELN) in keratinocytes and reconstituted human epidermis. Molecular docking simulations showed that each compound binds the active site of the eCB carrier FABP5. However, BAK and ethyl linoleate bound this site with the highest affinity when combined 1:1 (w/w), and invitro assays showed that BAK+ ELN most effectively inhibited FABP5 and fatty acid amide hydrolase. In TNF-stimulated keratinocytes, BAK+ ELN reversed TNF-induced expression shifts and uniquely downregulated type I IFN genes and PTGS2 (COX2). BAK+ ELN also repressed expression of genes linked to keratinocyte differentiation but upregulated those associated with proliferation. Finally, BAK+ ELN inhibited cortisol secretion in reconstituted human epidermis skin (not observed with cannabidiol). These results support a model in which BAK and ELN synergistically interact to inhibit eCB degradation, favoring eCB mobilization and inhibition of downstream inflammatory mediators (e.g., TNF, COX-2, type I IFN). A topical combination of these ingredients may thus enhance cutaneous eCB tone or potentiate other modulators, suggesting novel ways to modulate the eCB system for innovative skincare product development.

ITRAQ Quantitative Proteomic Analysis of Different Expressed Proteins and Signal Pathways in Bakuchiol-Induced Hepatotoxicity.

Bakuchiol (BAK) is an abundant natural compound. BAK has been reported to have several biological activities such as anticancer, antiaging, anti-inflammatory, and prevention of bone loss. However, it causes hepatotoxicity, the mechanism of which is not known. In this study, we explored the mechanism of BAK hepatotoxicity by treating rats with 52.5 mg/kg and 262.5 mg/kg of BAK, administered continuously for 6 weeks. We examined the liver pathology and biochemical composition of bile to determine toxicity. Mechanisms of BAK hepatotoxicity were analyzed based on relative and absolute quantification (iTRAQ) protein equivalent signatures and validated in vitro using LO2 cells. iTRAQ analysis revealed 281 differentially expressed proteins (DEPs) in liver tissue of the BAK-treated group, of which 215 were upregulated, and 66 were downregulated. GO and KEGG enrichment analysis revealed that bile secretion, lipid metabolism, and cytochrome P450 signaling pathways were enriched in DEPs. Among them, peroxisome proliferator-activated receptor α (PPARα), farnesoid X receptor (FXR), and cholesterol 7α-hydroxylase (CYP7a1) were closely associated with the development and progression of BAK-induced hepatic metabolic dysfunction and abnormal bile metabolism. This study shows that BAK can induce hepatotoxicity through multiple signaling pathways.

Bakuchiol, main component of root bark of Ulmus davidiana var. japonica, inhibits TGF-β-induced in vitro EMT and in vivo metastasis

Cancer is a second leading cause of death worldwide, and metastasis is the major cause of cancer-related mortality. The epithelial–mesenchymal transition (EMT), known as phenotypic change from epithelial cells to mesenchymal cells, is a crucial biological process during development. However, inappropriate activation of EMT contributes to tumor progression and promoting metastasis; therefore, inhibiting EMT is considered a promising strategy for developing drugs that can treat or prevent cancer. In the present study, we investigated the anti-cancer effect of bakuchiol (BC), a main component of Ulmus davidiana var. japonica, in human cancer cells using A549, HT29 and MCF7 cells. In MTT and colony forming assay, BC exerted cytotoxicity activity against cancer cells and inhibited proliferation of these cells. Anti-metastatic effects by BC were further confirmed by observing decreased migration and invasion in TGF-β-induced cancer cells after BC treatment. Furthermore, BC treatment resulted in increase of E-cadherin expression and decrease of Snail level in Western blotting and immunofluorescence analysis, supporting its anti-metastatic activity. In addition, BC inhibited lung metastasis of tail vein injected human cancer cells in animal model. These findings suggest that BC inhibits migration and invasion of cancers by suppressing EMT and in vivo metastasis, thereby may be a potential therapeutic agent for treating cancers.

Bakuchiol ameliorates cerebral ischemia-reperfusion injury by modulating NLRP3 inflammasome and Nrf2 signaling

Cerebral ischemia/reperfusion (I/R) injury is a common cerebrovascular disease with high mortality. Bakuchiol (BAK), extracted from the seeds of psoralea corylifolia, exhibits anti-inflammatory effects on lung, kidney and heart injuries. However, the effect of BAK on brain I/R injury remains elusive. In our study, a cerebral I/R model in mice was established by 1-h middle cerebral artery occlusion and 24-h reperfusion (1-h MCAO/24-h R). Prior to it, mice were gavaged with BAK (2.5 or 5 mg/kg) per day for 5 days. BAK pre-treatment improved neurological deficit, and reduced infarct volume, cerebral edema and neuronal injury in MCAO/R-injured mice. BAK decreased the number of Iba1-immunoreactive cells in the brain, indicating a reduction of microglial activation. BAK also reduced the expressions of NLRP3, ASC, cleaved-caspase-1, IL-1β and IL-18. BAK triggered Nrf2 nuclear accumulation and elevated HO-1 level. Further, the role of BAK was explored in BV-2 microglia with 3-h oxygen-glucose deprivation/24-h reperfusion (3-h OGD/24-h R). It was found that the functions of BAK in vitro were consistent with those in vivo, as manifested by reduced NLRP3 inflammasome and activated Nrf2 signaling. In addition, BV-2 cells were treated with Brusatol, an Nrf2 inhibitor. Results showed that Brusatol partially reversed the protective effect of BAK on OGD/R-injured BV-2 cells, further confirming that BAK might exhibit its anti-inflammatory property via activating Nrf2 signaling. In short, BAK is more meaningful in improving cerebral ischemic injury through suppressing NLRP3-mediated inflammatory response and activating the Nrf2 signaling pathway.

Evaluation of the immunomodulatory and anti-inflammatory activity of Bakuchiol using RAW 264.7 macrophage cell lines and in animal models stimulated by lipopolysaccharide (LPS)

Bakuchiol (BAK) has been reported to have a diverse pharmacological property as an antibiotic, anti-cancer, anti-hypolipidemic, anti-inflammatory and anti-convulsant agent. This study aimed to elucidate the immunomodulation and anti-inflammatory mechanism of bakuchiol using lipopolysaccharide stimulated RAW 264.7 macrophages and various animal models. The present study has shown that BAK significantly suppressed the pro-inflammatory cytokine expression in a dose-dependent manner and its oral administration significantly decreased delayed hypersensitivity responses as compared to control group. The assessment of immunomodulatory activity was carried out by the testing Hemagglutinating antibody (HA) titer, delayed type hypersensitivity (DTH) responses and phagocytic index by carbon clearance test. On the other hand, it showed significant decrease in circulating antibody titer and carbon clearance assay in a concentration-dependent manner. BAK has significantly potentiated the cellular immunity as well as humoral immunity by facilitating the footpad thickness responses in sheep RBCs in sensitized mice by significantly decreasing circulating antibody titer. Molecular studies revealed that BAK inhibited the activation of upstream mediator nuclear factor-κB by suppressing the phosphorylation of IκBα and p65. The responses were statistically significant as compared with the control (*p < 0.05, **p < 0.01).

Bakuchiol from Psoralea corylifolia L. Ameliorates acute kidney injury and improves survival in experimental polymicrobial sepsis

Bakuchiol (BAK) is a prenylated phenolic mono-terpene extracted from the fruit of Psoralea corylifolia L., which exerts a protective effect on organs. However, whether BAK has a protective effect on sepsis-induced acute kidney injury (S-AKI) is not clear. In our study we have demonstrated for the first time that pretreatment with BAK significantly reduced bacterial load, inflammation and renal oxidative stress in caecal ligation and puncture (CLP)-induced sepsis. Moreover, CLP-induced renal histological damage, mortality and clinical signs were markedly attenuated by BAK. Additionally, BAK inhibited sepsis-induced activation of NF-κB and p38 MAPK signaling in the kidneys. The evidence presented here has confirmed that BAK exerts multifunctional activity in protection against S-AKI. This action of BAK is probably due to the blockade of the NF-κB and p38 MAPK signaling pathways. Our findings offer a novel potential for BAK in protection against sepsis and S-AKI.

Bakuchiol Alleviates Hyperglycemia-Induced Diabetic Cardiomyopathy by Reducing Myocardial Oxidative Stress via Activating the SIRT1/Nrf2 Signaling Pathway.

Bakuchiol (BAK), a monoterpene phenol reported to have exerted a variety of pharmacological effects, has been related to multiple diseases, including myocardial ischemia reperfusion injury, pressure overload-induced cardiac hypertrophy, diabetes, liver fibrosis, and cancer. However, the effects of BAK on hyperglycemia-caused diabetic cardiomyopathy and its underlying mechanisms remain unclear. In this study, streptozotocin-induced mouse model and high-glucose-treated cell model were conducted to investigate the protective roles of BAK on diabetic cardiomyopathy, in either the presence or absence of SIRT1-specific inhibitor EX527, SIRT1 siRNA, or Nrf2 siRNA. Our data demonstrated for the first time that BAK could significantly abate diabetic cardiomyopathy by alleviating the cardiac dysfunction, ameliorating the myocardial fibrosis, mitigating the cardiac hypertrophy, and reducing the cardiomyocyte apoptosis. Furthermore, BAK achieved its antifibrotic and antihypertrophic actions by inhibiting the TGF-β1/Smad3 pathway, as well as decreasing the expressions of fibrosis- and hypertrophy-related markers. Intriguingly, these above effects of BAK were largely attributed to the remarkable activation of SIRT1/Nrf2 signaling, which eventually strengthened cardiac antioxidative capacity by elevating the antioxidant production and reducing the reactive oxygen species generation. However, all the beneficial results were markedly abolished with the administration of EX527, SIRT1 siRNA, or Nrf2 siRNA. In summary, these novel findings indicate that BAK exhibits its therapeutic properties against hyperglycemia-caused diabetic cardiomyopathy by attenuating myocardial oxidative damage via activating the SIRT1/Nrf2 signaling.

Extraction, Quantification, and Cytokine Inhibitory Response of Bakuchiol in Psoralea coryfolia Linn.

(1) Background: The present investigation studies the optimization of extraction, quantification, and cytokine inhibitory effects bakuchiol (BKL) in Psoralea coryfolia Linn. (2) Methods: The seeds of Psoralea coryfolia cleaned, dried, and powdered. Different separation methods maceration, reflux, Soxhlet, and ultrasonic assisted extraction (UAE) were employed for the isolation of BKL by five pure solvents. The quantity of BKL was measured by high-performance liquid chromatography (HPLC) method to determine the highest yield percentage. The effect of optimized BKL was then tested in an animal model of sepsis induced by lipopolysaccharides (LPS). (3) Results: The UAE method was found to be the best among tested separation methods and yielded highest percentage of BKL in petroleum ether extract. Septic rats showed a significant elevation in levels of biochemical markers like AST, ALT, ALP, BIL, SCr, and BUN in plasma. Proinflammatory cytokines (TNF-α and IL-1) levels were also increased in LPS-induced animals. BKL has been found to significantly reverse these elevated levels as compared to the LPS-induced animals. (4) Conclusion: The present results suggest that BKL has positive effects when administered in animals with pathogenic shock by decreasing the circulating levels of biomarkers. Further studies are necessary to explore the clinical implications of such findings.

Efficacy of a Dermocosmetic Serum Combining Bakuchiol and Vanilla Tahitensis Extract to Prevent Skin Photoaging in vitro and to Improve Clinical Outcomes for Naturally Aged Skin.

BackgroundSkin aging is characterized by slacking and loss of density, especially under ultraviolet (UV) radiation exposure.ObjectiveTo investigate the beneficial effects of a combination containing bakuchiol (BK) and vanilla tahitensis extract (VTE) to prevent skin photoaging in vitro and to improve clinical outcomes for naturally aged skin.Materials and MethodsHuman dermal fibroblasts were treated with active compounds, exposed to an acute dose of UVA and analyzed by confocal microscopy: actin network for morphology, interleukin-8 (IL-8) for inflammation and p16 for senescence. Human skin was used to evaluate chronic UVA-induced glycosaminoglycan (GAG) loss and to assess the benefit of topical application of a BK+VTE serum (Alcian blue staining). An open-label clinical trial was conducted in women applying the serum twice daily for 56 days (n=43). Skin remodeling was assessed by FaceScan®. Firmness was evaluated through Dynaskin® and clinical scoring. Skin radiance was also rated on standardized full-face photographs.ResultsUVA induced a significant increase in IL-8 and p16 expression and marked morphological changes in fibroblasts. Treatment with BK or VTE alone prevented both actin network alteration and IL-8 upregulation. Interestingly, BK+VTE demonstrated synergistic protection against IL-8 and p16 overexpression. Serum application prevented GAG loss at the dermo-epidermal junction and increased dermal GAG in UVA-exposed skin explants. In the clinical trial, face ptosis was reduced by 11% on average for 26 responsive subjects and up to 23%. Depth of skin deformation was also reduced by 24% on average for 30 responsive subjects and up to 30%. This firming effect was confirmed by clinical scoring. Radiance was significantly improved by 29% on average for 33 responsive subjects. The serum demonstrated good tolerance/safety.ConclusionBK+VTE combination demonstrated anti-aging efficacy and might provide a substantial benefit in the daily care of naturally aged skin in women, through their synergistic effect on inflammaging and senescence.

Effects of Bakuchiol on chondrocyte proliferation via the PI3K-Akt and ERK1/2 pathways mediated by the estrogen receptor for promotion of the regeneration of knee articular cartilage defects.

ObjectivesCartilaginous tissue degradation occurs because of the lack of survival of chondrocytes. Here, we ascertained whether bakuchiol (BAK) has the capability of activating chondrocyte proliferation.Materials and methodsThe effect of BAK on the proliferation of rat chondrocytes at a concentration of 10 and 20 µmol/L was investigated. The molecular mechanisms involving target binding and signalling pathways were elucidated by RNA‐sequencing, qPCR, molecular docking and Western blotting. Matrigel mixed with bakuchiol was implanted locally into rat knee articular cartilage defects to verify the activation of chondrocytes due to bakuchiol in vivo.ResultsBakuchiol implantation resulted in the activation of rat chondrocyte proliferation in a dose‐dependent manner. RNA‐sequencing revealed 107 differentially expressed genes (DEGs) with 75 that were up‐regulated and 32 that were down‐regulated, indicating increased activation of the PI3K‐Akt and cell cycle pathways. Activation of the phosphorylation of Akt, ERK1/2 and their inhibitors blocked the proliferative effect of bakuchiol treatment, confirming its direct involvement in these signal transduction pathways. Molecular docking and siRNA silencing revealed that estrogen receptor‐α (ERα) was the target of bakuchiol in terms of its cell proliferative effect via PI3K activation. Two weeks after implantation of bakuchiol, the appearance and physiological structure of the articular cartilage was more integrated with abundant chondrocytes and cartilage matrix compared to that of the control.ConclusionsBakuchiol demonstrated significant bioactivity towards chondrocyte proliferation via the PI3K‐Akt and ERK1/2 pathways mediated by estrogen receptor activation and exhibited enhanced promotion of the remodelling of injured cartilage.

Qualitative analysis of Psoraleae Fructus by HPLC-DAD/TOF-MS fingerprint and quantitative analysis of multiple components by single marker.

A variety of bioactive substances may account for the recognized efficacy and wide clinical application of Psoraleae Fructus in China. A high-performance liquid chromatography-diode array detector (HPLC-DAD) fingerprint method was developed to present the comprehensive phytochemical profile of the crude drug. Thirteen major compounds were separated and identified by HPLC coupled with time-of-flight mass spectrometry (HPLC/TOF-MS), namely psoralenoside (PO), isopsoralenoside (IPO), psoralen (PS), isopsoralen (IPS), neobavaisoflavone (NBF), bavachin(BC), corylin (CN), bavachromene(BCM), psoralidin(PD), isobavachalcone (IBC), bacachinin (BCN), corylifol A (CA) and bakuchiol (BK). Then quantitative analysis of multiple components by single marker (QAMS) was applied in content determination of PO, IPO, PS, IPS, BC, IBC, BCN, CA and BK, with NBF as the internal standard. The calculation results indicated no significant difference from the traditional external standard method (p > 0.05, RSD < 2.62%), suggesting that QAMS is a reliable and convenient method for content determination of multiple chemical compositions, especially when there is a shortage of reference substances. In conclusion, simultaneous qualitative and quantitative analysis of Psoraleae Fructus may be fulfilled through the newly proposed method of QAMS combined with HPLC-DAD/TOF-MS fingerprint.

Bakuchiol Contributes to the Hepatotoxicity of Psoralea corylifolia in Rats.

Psoralea corylifolia L. (Fructus Psoraleae) is widely used in Asia, but there are concerns about hepatotoxicity caused by constituents such as psoralens and bakukiol. Bakuchiol (BAK) has antiinflammatory, antipyretic, antibacterial antiviral, anticancer, and estrogenic activity but appears to be hepatotoxic in in vitro tests. This study investigated the hepatotoxicity in vivo in rats. Using intragastrically administered bakuchiol at doses of 52.5 and 262.5mg/kg for 6weeks. Bodyweight, relative liver weight, biochemical indicators, histopathology, mRNA expression of CYP7A1, HMG-CoA reductase, BSEP, PPARα, SREBP-2, and MRP3 were measured. Many abnormalities were observed in the bakuchiol-treated groups including suppression of weight gain and food intake, change of some parameters in serum biochemistry, and increased weight of liver. The mRNA expression of CYP7A1, HMG-CoA reductase, PPARα, and SREBP-2 decreased in bakuchiol-treated group, the expression of BSEP increased in bakuchiol-treated low dosage, and the expression of BSEP decreased in bakuchiol-treated high dosage. In conclusion, we provide evidence for the first time that bakuchiol can induce cholestatic hepatotoxicity, suggesting potential hepatotoxicity. The mechanism may be related to effects on liver lipid metabolism, but further investigation is necessary. Copyright © 2017 John Wiley & Sons, Ltd.

Glycyrrhetinic acid might increase the nephrotoxicity of bakuchiol by inhibiting cytochrome P450 isoenzymes.

BackgroundLicorice, a popular traditional Chinese medicine (TCM), is widely used to moderate the effects (detoxification) of other herbs in TCM and often combined with Fructus Psoraleae. However, the classical TCM book states that Fructus Psoraleae is incompatible with licorice; the mechanism underlying this incompatibility has not been identified. Glycyrrhetinic acid (GA), the active metabolite of licorice, may increase the toxicity of bakuchiol (BAK), the main chemical ingredient in Psoralea corylifolia, by inhibiting its detoxification enzymes CYP450s.MethodsThe effect of concomitant GA administration on BAK-induced nephrotoxicity was investigated, and the metabolic interaction between BAK and GA was further studied in vitro and in vivo. The cytotoxicity was assessed using an MTT assay in a co-culture model of HK-2 cell and human liver microsomes (HLMs). The effect of GA on the metabolism of BAK, and on the activities of CYP isoforms were investigated in HLMs. The toxicokinetics and tissue exposure of BAK as well as the renal and hepatic functional markers were measured after the administration of a single oral dose in rats.ResultsIn vitro studies showed that the metabolic detoxification of BAK was significantly reduced by GA, and BAK was toxic to HK-2 cells, as indicated by 25∼40% decreases in viability when combined with GA. Further investigation revealed that GA significantly inhibited the metabolism of BAK in HLMs in a dose-dependent manner. GA strongly inhibits CYP3A4 and weakly inhibits CYP2C9 and CYP1A2; these CYP isoforms are involved in the metabolism of BAK. In vivo experiment found that a single oral dose of BAK combined with GA or in the presence of 1-aminobenzotriazole (ABT), altered the toxicokinetics of BAK in rats, increased the internal exposure, suppressed the elimination of BAK prototype, and therefore may have enhanced the renal toxicity.ConclusionThe present study demonstrated that GA inhibits CYP isoforms and subsequently may increase the nephrotoxicity of BAK, which underlie one of the possible mechanisms responsible for the incompatibility of Licorice with Fructus Psoraleae.