The lipid droplet in cancer: From being a tumor-supporting hallmark to clinical therapy.

INTRODUCTION: Abnormal lipid metabolism, one of the hallmarks in cancer, has gradually emerged as a novel target for cancer treatment. As organelles that store and release excess lipids, lipid droplets (LDs) resemble "gears" and facilitate cancer development in the body. AIM: This review discusses the life cycle of LDs, the relationship between abnormal LDs and cancer hallmarks, and the application of LDs in theragnostic and clinical contexts to provide a contemporary understanding of the role of LDs in cancer. METHODS: A systematic literature search was conducted in PubMed and SPORTDiscus. Retrieve and summarize clinical trials of drugs that target proteins associated with LD formation using the Clinical Trials website. Create a schematic diagram of lipid droplets in the tumor microenvironment using Adobe Illustrator. CONCLUSION: As one of the top ten hallmarks of cancer, abnormal lipid metabolism caused by excessive generation of LDs interrelates with other hallmarks. The crosstalk between excessive LDs and intracellular free fatty acids (FFAs) promotes an inflammatory environment that supports tumor growth. Moreover, LDs contribute to cancer metastasis and cell death resistance in vivo. Statins, as HMGCR inhibitors, are promising to be the pioneering commercially available anti-cancer drugs that target LD formation.

Erratum: Author correction to 'Discovery of the radio-protecting effect of ecliptae herba, its constituents and targeting p53-mediated apoptosis in vitro and in vivo' [Acta Pharm Sin B 13 (2023) 1216-1230].

[This corrects the article DOI: 10.1016/j.apsb.2022.09.003.].

Dual targeting of wild-type p53 and gut microbiota by Magnolol represses key metabolic process and kills CRC cells.

Cancer cells consume considerable glucose quantities and majorly employ glycolysis for ATP generation. This metabolic signature (the Warburg effect) allows cancer cells to channel glucose to biosynthesis to support and maintain their dramatic growth along with proliferation. Currently, our understanding of the metabolic and mechanistic implications of the Warburg effect along with its relationship with biosynthesis remains unclear. Herein, we illustrate that the tumor repressor p53 mediate Magnolol (MAG) triggers colon cancer cell apoptosis. And MAG regulates the glycolytic and oxidative phosphorylation steps through transcriptional modulation of its downstream genes TP53-induced glycolysis modulator and biosynthesis of cytochrome c oxidase, attenuating cell proliferation and tumor growth in vivo and in vitro. Meanwhile, we show that MAG cooperates with its own intestinal microflora characteristic metabolites to repress tumors, especially remarkably declined kynurenine (Kyn)/tryptophan (Trp) ratio. Besides, strong relationships of MAG influenced genes, microbiota, as well as metabolites, were explored. Therefore, we established that p53-microbiota-metabolites function as a mechanism, which enable therapy approaches against metabolism-implicated colorectal cancer, in particular MAG as a prospective candidate for treating colorectal cancer.

Discovery of the radio-protecting effect of Ecliptae Herba, its constituents and targeting p53-mediated apoptosis in vitro and in vivo.

Radiation protection drugs are often accompanied by toxicity, even amifostine, which has been the dominant radio-protecting drug for nearly 30 years. Furthermore, there is no therapeutic drug for radiation-induced intestinal injury (RIII). This paper intends to find a safe and effective radio-protecting ingredient from natural sources. The radio-protecting effect of Ecliptae Herba (EHE) was discovered preliminarily by antioxidant experiments and the mouse survival rate after 137Cs irradiation. EHE components and blood substances in vivo were identified through UPLC‒Q-TOF. The correlation network of "natural components in EHE-constituents migrating to blood-targets-pathways" was established to predict the active components and pathways. The binding force between potential active components and targets was studied by molecular docking, and the mechanism was further analyzed by Western blotting, cellular thermal shift assay (CETSA), and ChIP. Additionally, the expression levels of Lgr5, Axin2, Ki67, lysozyme, caspase-3, caspase-8,8-OHdG, and p53 in the small intestine of mice were detected. It was found for the first time that EHE is active in radiation protection and that luteolin is the material basis of this protection. Luteolin is a promising candidate for RⅢ. Luteolin can inhibit the p53 signaling pathway and regulate the BAX/BCL2 ratio in the process of apoptosis. Luteolin could also regulate the expression of multitarget proteins related to the same cell cycle.

Cold stress regulates accumulation of flavonoids and terpenoids in plants by phytohormone, transcription process, functional enzyme, and epigenetics.

Plants make different defense mechanisms in response to different environmental stresses. One common way is to produce secondary metabolites. Temperature is the main environmental factor that regulates plant secondary metabolites, especially flavonoids and terpenoids. Stress caused by temperature decreasing to 4-10 °C is conducive to the accumulation of flavonoids and terpenoids. However, the accumulation mechanism under cold stress still lacks a systematic explanation. In this review, we summarize three aspects of cold stress promoting the accumulation of flavonoids and terpenoids in plants, that is, by affecting (1) the content of endogenous plant hormones, especially jasmonic acid and abscisic acid; (2) the expression level and activity of important transcription factors, such as bHLH and MYB families. This aspect also includes post-translational modification of transcription factors caused by cold stress; (3) key enzyme genes expression and activity in the biosynthesis pathway, in addition, the rate-limiting enzyme and glycosyltransferases genes are responsive to cold stress. The systematic understanding of cold stress regulates flavonoids, and terpenoids will contribute to the future research of genetic engineering breeding, metabolism regulation, glycosyltransferases mining, and plant synthetic biology.

Diosgenin relieves oxaliplatin-induced pain by affecting TLR4/NF-κB inflammatory signaling and the gut microbiota.

Diosgenin extracted from fenugreek, yam and other foods exhibits a wide range of pharmacological activities, especially for the treatment of pain and other nervous system diseases. However, its role in oxaliplatin-induced peripheral neuropathy (OIPN) is unclear. To explore its detailed mechanism on the pain caused by chemotherapy, we carried out this experiment. In this study, the effects of diosgenin on injured PC12 cells and OIPN mice were examined. The results showed that diosgenin not only protected PC12 from injury, but also reduced the mechanical withdrawal threshold and cold hyperalgesia in OIPN mice. Diosgenin inhibited oxidative stress, the cell glial fibrillary acidic protein, and the pro-inflammatory cytokines such as tumor necrosis factor-α, toll-like receptor 4 and nuclear factor-κB in the brain. Furthermore, the fecal microbiota transplantation experiment indicated that diosgenin improved OIPN through regulation of the gut microbiota. All in all, diosgenin ameliorates peripheral neuropathy and is worthy of further study in the treatment of neuropathic pain.

Magnesium Isoglycyrrhizinate Reduces the Target-Binding Amount of Cisplatin to Mitochondrial DNA and Renal Injury through SIRT3.

Nephrotoxicity is the dose-limiting factor of cisplatin treatment. Magnesium isoglycyrrhizinate (MgIG) has been reported to ameliorate renal ischemia-reperfusion injury. This study aimed to investigate the protective effect and possible mechanisms of MgIG against cisplatin-induced nephrotoxicity from the perspective of cellular pharmacokinetics. We found that cisplatin predominantly accumulated in mitochondria of renal tubular epithelial cells, and the amount of binding with mitochondrial DNA (mtDNA) was more than twice that with nuclear DNA (nDNA). MgIG significantly lowered the accumulation of cisplatin in mitochondria and, in particular, the degree of target-binding to mtDNA. MgIG notably ameliorated cisplatin-induced changes in mitochondrial membrane potential, morphology, function, and cell viability, while the magnesium donor drugs failed to work. In a mouse model, MgIG significantly alleviated cisplatin-caused renal dysfunction, pathological changes of renal tubules, mitochondrial ultrastructure variations, and disturbed energy metabolism. Both in vitro and in vivo data showed that MgIG recovered the reduction of NAD+-related substances and NAD+-dependent deacetylase sirtuin-3 (SIRT3) level caused by cisplatin. Furthermore, SIRT3 knockdown weakened the protective effect of MgIG on mitochondria, while SIRT3 agonist protected HK-2 cells from cisplatin and specifically reduced platinum-binding activity with mtDNA. In conclusion, MgIG reduces the target-binding amount of platinum to mtDNA and exerts a protective effect on cisplatin-induced renal injury through SIRT3, which may provide a new strategy for the treatment of cisplatin-induced nephrotoxicity.

Taxifolin attenuates inflammation via suppressing MAPK signal pathway in vitro and in silico analysis.

Objective: Taxifolin is a natural flavonoid compound that can be isolated from onions, grapes, oranges and grapefruit. It also acts as a medicine food homology with extraordinary antioxidant and anti-inflammatory activity. This study aims to explain the protective effects and potential mechanisms of taxifolin against inflammatory reaction. Methods: Levels of interleukin (IL)-6, IL-1ß and intracellular reactive oxygen species (ROS) were assessed in different time after the treatment of taxifolin in RAW264.7 cells induced by lipopolysaccharide (LPS). Subsequently, the mRNA and protein levels of inducible nitric oxide synthase (iNOS), vascular endothelial growth factor (VEGF), cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-α and the phosphorylation expression levels of the MAPK signal pathway were also evaluated. A silico analysis was used to explain the binding situation for the investigation of taxifolin and MAPK signal pathway. And then MAPK inhibitors were used to reveal the expression level of iNOS, VEGF, COX-2 and TNF-α in RAW264.7 cells. Results: It was demonstrated that cell inflammatory damage induced by LPS was significantly alleviated after the treatment of taxifolin. Then, the mRNA and protein levels of iNOS, VEGF, COX-2 and TNF-α were reduced and the phosphorylation expression levels of the MAPK signal pathway were down-regulated remarkably as well. In silico analysis, taxifolin could form a relatively stable combination with MAPK signal pathway. MAPK inhibitors showed increasing or decreasing effect in the mRNA levels of iNOS, VEGF, COX-2 and TNF-α, which suggesting that taxifolin down-regulated iNOS, VEGF, COX-2 and TNF-α expressions were not entirely through the MAPK pathway. Conclusion: This finding demonstrated that taxifolin improved the inflammatory responses that partly involved in the phosphorylation expression level of MAPK signal pathway in RAW264.7 cells exposed to acute stress.

Novel assays for quality evaluation of XueBiJing: Quality variability of a Chinese herbal injection for sepsis management.

XueBiJing is an intravenous five-herb injection used to treat sepsis in China. The study aimed to develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS)- or liquid chromatography-ultraviolet (LC-UV)-based assay for quality evaluation of XueBiJing. Assay development involved identifying marker constituents to make the assay therapeutically relevant and building a reliable one-point calibrator for monitoring the various analytes in parallel. Nine marker constituents from the five herbs were selected based on XueBiJing's chemical composition, pharmacokinetics, and pharmacodynamics. A selectivity test (for "similarity of response") was developed to identify and minimize interference by non-target constituents. Then, an intercept test was developed to fulfill "linearity through zero" for each analyte (absolute ratio of intercept to C response, <2%). Using the newly developed assays, we analyzed samples from 33 batches of XueBiJing, manufactured over three years, and found small batch-to-batch variability in contents of the marker constituents (4.1%-14.8%), except for senkyunolide I (26.5%).

[Anti-photoaging effects and mechanisms of active ingredients of Chinese medicine: a review].

Skin photoaging is exogenous aging caused by long-term ultraviolet radiation, which not only affects skin appearance, but also has a close relationship with the development of skin cancer. Saponins, flavonoids, polyphenols, polysaccharides, and extracts of Chinese medicine have been found to have anti-skin photoaging effects in recent studies. Various mechanisms such as anti-oxidative stress damage, inhibition of matrix metalloproteinase expression, promotion of collagen synthesis, inhibition of inflammatory response, DNA damage repair, enhancement of cell autophagy, and inhibition of melanin synthesis can improve the symptoms of skin photoaging and delay the photoaging process. With the active ingredients of Chinese medicine for anti-skin photoaging as the entry point, the study systematically discussed the research progress of the mechanisms underlying the anti-photoaging effects of active ingredients of Chinese medicine in recent years, in order to provide theoretical reference for the development of new anti-photoaging drugs and methods.

Absolute bioavailability, dose proportionality, and tissue distribution of rotundic acid in rats based on validated LC-QqQ-MS/MS method.

Rotundic acid (RA), an ursane-type pentacyclic triterpene acid isolated from the dried barks of Ilex rotunda Thunb. (Aquifoliaceae), possesses diverse bioactivities. To further study its pharmacokinetics, a simple and sensitive liquid chromatography with triple quadrupole mass spectrometry (LC-QqQ-MS/MS) method was developed and validated to quantify RA concentration in rat plasma and tissue using etofesalamide as an internal standard (IS). Plasma and tissue samples were subjected to one-step protein precipitation. Chromatographic separation was achieved on a ZORBAX Eclipse XDB-C18 column (4.6 mm × 50 mm, 5 µm) under gradient conditions with eluents of methanol:acetonitrile (1:1, V/V) and 5 mM ammonium formate:methanol (9:1, V/V) at 0.5 mL/min. Multiple reaction monitoring transitions were performed at m/z 487.30 → 437.30 for RA and m/z 256.10 → 227.10 for IS in the negative mode. The developed LC-QqQ-MS/MS method exhibited good linearity (2-500 ng/mL) and was fully validated in accordance with U.S. Food and Drug Administration bioanalytical guidelines. Dose proportionality and bioavailability in rats were determined by comparing pharmacokinetic data after single oral (10, 20, and 40 mg/kg) and intravenous (10 mg/kg) administration of RA. Tissue distribution was studied following oral administration at 20 mg/kg. The results showed that the absolute bioavailability of RA after administration at different doses ranged from 16.1% to 19.4%. RA showed good dose proportionality over a dose range of 10-40 mg/kg. RA was rapidly absorbed in a dose-dependent manner and highly distributed in the liver. In conclusion, this study is the first to systematically elucidate the absorption and distribution characteristics of RA in rats, which can provide additional information for further development and evaluation of RA in drug metabolism and pharmacokinetic studies.

Chiral probe for mass spectrometric identification and quantitation of levodropropizine and its enantiomer, dextrodropropizine.

Acyl chlorides react rapidly with hydroxyl and amino groups in the absence of catalysts and therefore hold great promise for chiral mass spectrometry. Herein, a tandem mass spectrometry method based on derivatization with (-)-camphanic acid chloride as a simple chiral probe was developed for the highly sensitive detection and quantitation of levodropropizine and its enantiomer, namely, dextrodropropizine. The diastereomeric derivatization products were quantified based on the relative abundances of their fragment ions produced upon collision-induced dissociation in positive-ion mode. The reactive site was elucidated using nuclear magnetic resonance spectroscopy and two-dimensional total correlation spectroscopy, and the reaction mechanism was proved by stoichiometry studies. The degree of isomer recognition was investigated at different collision energies and determined as Rchiral  ≈ 1.5. Thus, this study gives the way to the mass spectrometric identification and quantitation of levodropropizine and its enantiomer, and the developed method represents a new and practical technique for rapid and sensitive determination and quality control of enantiomers of chiral drugs.

Targeting adipokines: A new strategy for the treatment of myocardial fibrosis.

Cardiac fibrosis is a pathogenic factor of many cardiovascular diseases (CVD), which seriously affects people's life and health, causing huge economic losses.Therefore, it is very significant to find an effective treatment for myocardial fibrosis. Adipokines are mainly derived from adipose tissue and have an prominent regulatory effect on glucose and lipid metabolism, inflammation, immune response and cardiovascular function. Adipose tissue is composed of a variety of cell types, including adipocytes, endothelial cells, macrophages and smooth muscle cells. Adipokines mainly include adiponectin, leptin, resistin, visfatin and omentin, which are synthesized and secreted by adipocytes. More and more evidence shows that adipokines can regulate the progress of cardiac fibrosis. This scientific review provides new ideas for targeting adipokines in the treatment of myocardial fibrosis and provides strategies for the development of new, safe, and effective pharmacological antagonists against myocardial fibrosis based on adipokines activity.

Esterases From Bifidobacteria Exhibit the Conversion of Albiflorin in Gut Microbiota.

Bifidobacteria is an important microbe that inhabits the human gut. It is capable of metabolizing complex compounds in the human diet. Albiflorin, an antidepressant natural product from Radix Paeoniae Alba in China, is difficult to absorb after oral administration, and its metabolism has been proven to be closely related to the gut microbiota. In this study, we demonstrated in vitro that several Bifidobacteria species were able to convert albiflorin to benzoic acid, and four esterases (B2, B3, B4, and BL) from Bifidobacterium breve and Bifidobacterium longum were found through genome mining and modeled by SWISS-MODEL. B2 and B3 presented the strongest albiflorin metabolism ability. The optimal conditions, including temperature, buffer, and pH, for the conversion of albiflorin by the four esterases were investigated. Furthermore, the effect of esterase on the metabolism of albiflorin in vivo was confirmed by transplanting bacteria containing esterase B2. This study demonstrated the vital role of esterases from Bifidobacteria in the metabolism of natural compounds containing ester bonds, which could contribute to the development of new enzymes, microbial evolution, and probiotic adjuvant compounds for treatment.

Reevaluate In Vitro CYP3A Index Reactions of Benzodiazepines and Steroids between Humans and Dogs.

Cytochrome P450 3A (CYP3A), the most important class of drug-metabolizing enzymes, participates in the metabolism of half of clinically used drugs. The CYP3A index reactions of dogs, one of the most widely used preclinical nonrodent species, are still poorly understood. This work evaluated the activity and selectivity of 10 CYP3A index reactions, including midazolam (MDZ) 1'- and 4-hydroxylation, alprazolam (APZ) and triazolam (TRZ) α- and 4-hydroxylation, testosterone (T) 6ß-hydroxylation, lithocholate (LCA) 6α-hydroxylation, deoxycholate (DCA) 1ß- and 5ß-hydroxylation, with quantitative reaction phenotyping and kinetic analysis in human and canine recombinant CYP enzymes (rCYPs). In human studies, all reactions are reconfirmed as mixed index reactions of CYP3A with minor contributions from non-CYP3A isoforms. In canine studies, all reactions are also primarily catalyzed by CYP3A12 with lower contributions from CYP3A26. However, the canine CYP2B11 appreciably contributes to the hydroxylation of benzodiazepines except for APZ 4-hydroxylation. The canine CYP3A isoforms have lower activity than human isoforms toward T 6ß-hydroxylation and LCA 6α-hydroxylation and both substrates undergo non-CYP3A catalyzed side reactions. DCA 1ß- and 5ß-hydroxylation are validated as the CYP3A index reactions in both humans and dogs with limited non-CYP3A contributions and side reactions. In conclusion, this work provides a comprehensive overview for the selectivity and activity of in vitro CYP3A index reactions in humans and dogs. The validated CYP3A index reactions between humans and dogs may benefit future practices in drug metabolism and drug interaction studies. SIGNIFICANCE STATEMENT: Dogs are one of the most important nonrodent animals with limited studies of cytochrome P450 enzymes than humans. This work provides the most comprehensive quantitative data to date for the selectivity and activity of CYP3A index reactions in humans and dogs. The canine CYP2B11 was found to appreciably contribute to hydroxylation of midazolam, alprazolam and triazolam, the well-known probes for human CYP3A. Deoxycholate 1ß- and 5ß-hydroxylation are validated as the CYP3A index reactions in both humans and dogs.

Natural Small Molecules Enabled Efficient Immunotherapy through Supramolecular Self-Assembly in P53-Mutated Colorectal Cancer.

Nanomedicine, constructed from therapeutics, presents an advantage in drug delivery for cancer therapies. However, nanocarrier-based treatment systems have problems such as interbatch variability, multicomponent complexity, poor drug delivery, and carrier-related toxicity. To solve these issues, the natural molecule honokiol (HK), an anticancer agent in a phase I clinical trial (CTR20170822), was used to form a self-assembly nanoparticle (SA) through hydrogen bonding and hydrophobicity. The preparation of SA needs no molecular precursors or excipients in aqueous solution, and 100% drug-loaded SA exhibited superior tumor-targeting ability due to the enhanced permeability and retention (EPR) effect. Moreover, SA significantly enhanced the antitumor immunity relative to free HK, and the mechanism has notable selectivity to the p53 pathway. Furthermore, SA exhibited excellent physiological stability and inappreciable toxicity. Taken together, this supramolecular self-assembly strategy provides a safe and "molecular economy" model for rational design of clinical therapies and is expected to promote targeted therapy of HK, especially in colorectal cancer patients with obvious p53 status.

Intestinal absorption mechanism of rotundic acid: Involvement of P-gp and OATP2B1.

ETHNOPHARMACOLOGICAL RELEVANCE: Ilicis Rotundae Cortex (IRC), the dried barks of Ilex rotunda Thunb. (Aquifoliaceae), has been used for the prevention or treatment of colds, tonsillitis, dysentery, and gastrointestinal diseases in folk medicine due to its antibacterial and anti-inflammatory effects. However, there is no report about the intestinal absorption of major compounds that support traditional usage. AIM OF STUDY: Considering the potential of rotundic acid (RA) - major biologically active pentacyclic triterpenes found in the IRC, this study was purposed to uncover the oral absorption mechanism of RA using in situ single-pass intestinal perfusion (SPIP) model, in vitro cell models (Caco-2, MDCKII-WT, MDCKII-MDR1, MDCKII-BCRP, and HEK293-OATP2B1 cells) and in vivo pharmacokinetics studies in rats. MATERIALS AND METHODS: The molecular properties (solubility, lipophilicity, and chemical stability) and the effects of principal parameters (time, compound concentrations, pH, paracellular pathway, and the different intestinal segments) were analyzed by liquid chromatography-tandem mass spectrometry. The susceptibility of RA to various inhibitors, such as P-gp inhibitor verapamil, BCRP inhibitor Ko143, OATP 2B1 inhibitor rifampicin, and absorption enhancer EGTA were assessed. RESULTS: RA was a compound with low water solubility (12.89 µg/mL) and strong lipophilicity (LogP = 4.1). RA was considered stable in all media during the SPIP and transport studies. The SPIP and cell experiments showed RA was moderate absorbed in the intestines and exhibited time, concentration, pH, and segment-dependent permeability. In addition, results from the cell model, in situ SPIP model as well as the in vivo pharmacokinetics studies consistently showed that verapamil, rifampicin, and EGTA might have significant effect on the intestinal absorption of RA. CONCLUSION: The mechanisms of intestinal absorption of RA might involve multiple transport pathways, including passive diffusion, the participation of efflux (i.e., P-gp) and influx (i.e., OATP2B1) transporters, and paracellular pathways.