2,3,5,4'- tetrahydroxystilbene-2-O-ß-D- glucopyranoside (TSG)-Driven immune response in the hepatotoxicity of Polygonum multiflorum.

ETHNOPHARMACOLOGICAL RELEVANCE: 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucopyranoside (TSG) as the primary constituent of Polygonum multiflorum Thumb. (PM) possesses anti-oxidative, antihypercholesterolemic, anti-tumor and many more biological activities. The root of PM has been used as a tonic medicine for thousands of years. However, cases of PM-induced liver injury are occasionally reported, and considered to be related to the host immune status. AIM OF THE STUDY: The primary toxic elements and specific mechanisms PM causing liver damage are still not thoroughly clear. Our study aimed to investigate the influences of TSG on the immune response in idiosyncratic hepatotoxicity of PM. MATERIALS AND METHODS: The male C57BL/6 mice were treated with different doses of TSG and the alterations in liver histology, serum liver enzyme levels, proportions of T cells and cytokines secretion were evaluated by hematoxylin and eosin (HE), RNA sequencing, quantitative real time polymerase chain reaction (qRT-PCR), Flow cytometry (FCM), and enzyme-linked immunosorbent assay (ELISA), respectively. Then, primary spleen cells from drug-naive mice were isolated and cultured with TSG in vitro. T cell subsets proliferation and cytokines secretion after treated with TSG were assessed by CCK8, FCM and ELISA. In addition, mice were pre-treated with anti-CD25 for depleting regulatory T cells (Tregs), and then administered with TSG. Liver functions and immunological alterations were analyzed to evaluate liver injury. RESULTS: Data showed that TSG induced liver damage, and immune cells infiltration in the liver tissues. FCM results showed that TSG could activate CD4+T and CD8+T in the liver. Results further confirmed that TSG notably up-regulated the levels of inflammatory cytokines including TNF-α, IFN-γ, IL-18, perforin and granzyme B in the liver tissues. Furthermore, based on transcriptomics profiles, some immune system-related pathways including leukocyte activation involved in inflammatory response, leukocyte cell-cell adhesion, regulation of interleukin-1 beta production, mononuclear cell migration, antigen processing and presentation were altered in TSG treated mice. CD8+T/CD4+T cells were also stimulated by TSG in vitro. Interestingly, increased proportion of Tregs was observed after TSG treatment in vitro and in vivo. Foxp3 and TGF-ß1 mRNA expressions were up-regulated in the liver tissues. Depletion of Tregs moderately enhanced TSG induced the secretion of inflammatory cytokines in serum. CONCLUSIONS: Our findings showed that TSG could trigger CD4+T and CD8+T cells proliferation, promote cytokines secretion, which revealed that adaptive immune response associated with the mild liver injury cause by TSG administration. Regulatory T cells (Tregs) mainly sustain immunological tolerance, and in this study, the progression of TSG induced liver injury was limited by Tregs. The results of our investigations allow us to preliminarily understand the mechanisms of PM related idiosyncratic hepatotoxicity.

Hepatic Effect of 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucoside, the Signature Component of Traditional Chinese Medicine Heshouwu: Advances and Prospects.

Traditional Chinese medicine Heshouwu, named Polygoni Multiflori Radix in Pharmacopoeia of the People's Republic of China (PPRC, 2020), is derived from the root tuber of Polygonum multiflorum Thunb., Heshouwu or processed Heshouwu is well known for its function in reducing lipids and nourishing the liver. However, increasing cases of Heshouwu-induced hepatotoxicity were reported in recent years. Researchers have begun to study the paradoxical effects of Heshouwu on the liver. 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucoside (TSG), an abundant functional component of Heshouwu, shows various biological activities, among which its effect on the liver is worthy of attention. This paper reviews the current studies of TSG on hepatoprotection and hepatotoxicity, and summarizes the doses, experimental models, effects, and mechanisms of action involved in TSG's hepatoprotection and hepatotoxicity, aiming to provide insight for future study of TSG and understanding the effects of Heshouwu on the liver. Emerging evidence suggests that TSG ameliorates both pathological liver injury and chemical-induced liver injury by modulating lipid metabolism, inhibiting the inflammatory response and oxidative stress in the liver. However, with the reports of clinical cases of Heshouwu induced liver injury, it has been found that long-term exposure to a high dose of TSG cause hepatocyte or hepatic tissue damage. Moreover, TSG may cause hepatotoxicity by affecting the transport and metabolism of other possible hepatoxic compounds in Heshouwu. Studies indicate that trans-TSG can be isomerized into cis-TSG under illumination, and cis-TSG had a less detrimental dose to liver function than trans- TSG in LPS-treated rats. In brief, TSG has protective effects on the liver, but liver injury usually occurs under highdose TSG or is idiosyncratic TSG-induced liver injury.

Biochemical and histopathological analysis after sub-chronic administration of oxyresveratrol in Wistar rats.

Oxyresveratrol (OXY) is a naturally occurring phenolic compound; however, there are no toxicity studies reported on its long term use. The aim of our work was to demonstrate the evaluation of acute and sub-chronic toxicity of oxyresveratrol in rats to assess its safety profile. To evaluate the LD50 value, 2000 mg/kg of oxyresveratrol was administered to Wistar rats by oral gavage. For sub-chronic toxicity assessment, 80 Wistar rats were randomly divided into four groups (10 animal/sex/group) and oxyresveratrol administered at a dose of 50, 100, 150 mg/kg/day by oral gavage. Bodyweight, food, and water consumption were monitored every week. At the end of the experiments, biochemical and hematological parameters were analyzed. Gross and microscopic organ analyses were also carried out. LD50 of oxyresveratrol was greater than 2000 mg/kg sub-chronic administration of oxyresveratrol did not influence any mortality. Doses of 50 and 100 mg/kg of oxyresveratrol did not produce any sign of toxicity. However, the 150 mg/kg oxyresveratrol group depicted changes in multiple biochemical and hematological parameters with changes in the pathology of cardiac, hepatic, and renal tissues when compared with control. Therefore, no observed adverse effect level (NOAEL) of oxyresveratrol was observed to be 100 mg/kg per day for both male and female rats.

Toxicological analysis of stilbenes against the fall armyworm, Spodoptera frugiperda.

The fall armyworm (FAW), Spodoptera frugiperda, is a global pest of multiple economically important row crops and the development of resistance to commercially available insecticidal classes has inhibited FAW control. Thus, there is a need to identify chemical scaffolds that can provide inspiration for the development of novel insecticides for FAW management. This study aimed to assess the sensitivity of central neurons and susceptibility of FAW to chloride channel modulators to establish a platform for repurposing existing insecticides or designing new chemicals capable of controlling FAW. Potency of select chloride channel modulators were initially studied against FAW central neuron firing rate and rank order of potency was determined to be fipronil > lindane > Z-stilbene > DIDS > GABA > E-stilbene. Toxicity bioassays identified fipronil and lindane as the two most toxic modulators studied with topical LD50's of 41 and 75 ng/mg of caterpillar, respectively. Interestingly, Z-stilbene was toxic at 300 ng/mg of caterpillar, but no toxicity was observed with DIDS or E-stilbene. The significant shift in potency between stilbene isomers indicates structure-activity relationships between stilbene chemistry and the binding site in FAW may exist. The data presented in this study defines the potency of select chloride channel modulators to FAW neural activity and survivorship to establish a platform for development of novel chemical agents to control FAW populations. Although stilbenes may hold promise for insecticide development, the low toxicity of the scaffolds tested in this study dampen enthusiasm for their development into FAW specific insecticides.

Discovery of Novel Pterostilbene-Based Derivatives as Potent and Orally Active NLRP3 Inflammasome Inhibitors with Inflammatory Activity for Colitis.

Studies have shown that the abnormal activation of the NLRP3 inflammasome is involved in a variety of inflammatory-based diseases. In this study, a high content screening model targeting the activation of inflammasome was first established and pterostilbene was discovered as the active scaffold. Based on this finding, total of 50 pterostilbene derivatives were then designed and synthesized. Among them, compound 47 was found to be the best one for inhibiting cell pyroptosis [inhibitory rate (IR) = 73.09% at 10 µM], showing low toxicity and high efficiency [against interleukin-1ß (IL-1ß): half-maximal inhibitory concentration (IC50) = 0.56 µM]. Further studies showed that compound 47 affected the assembly of the NLRP3 inflammasomes by targeting NLRP3. The in vivo biological activity showed that this compound significantly alleviated dextran sodium sulfate (DSS)-induced colitis in mice. In general, our study provided a novel lead compound directly targeting the NLRP3 protein, which is worthy of further research and structural optimization.

Stilbene glucoside: recent advances in pharmacology, bioinformatics investigation, toxicity and future opportunities.

Background: 2,3,5,4'-Tetrahydroxystilbene-2-O-ß-D-glucoside (TSG) from Polygonum multijiorum Thunb. (PMT), is a major bioactive component. This review is aimed to summarize the present development of TSG regarding pharmaceutics, pharmacology and toxicology, with a focus on the novel mechanism of drug-induced toxicity and provides insight for its potential developments and applications in the future on traditional Chinese medicine. Methods: Studies about TSG's activities and toxicity were searched and summarized. Targets and mechanisms were predicted and analyzed with network pharmacology methods. Affinities and binding modes of key targets with TSG were verified by AutoDock Vina software. Results: TSG plays an essential role among the chemical components of PMT because of multiple pharmacological activities, which suggests a potential application of TSG for a variety of diseases, like atherosclerosis, Alzheimer's disease, Parkinson's disease, cerebral I/R injury, diabetes, osteoporosis, colitis. However, mild liver toxicity of TSG is also pointed out. Conclusions: As a biologically active natural product in PMT, TSG has shown prospective pharmacological activities, particularly as an agent for cardiovascular protection and neuroprotection.

Investigation of toxicity attenuation mechanism of tetrahydroxy stilbene glucoside in Polygonum multiflorum Thunb. by Ganoderma lucidum.

ETHNOPHARMACOLOGICAL RELEVANCE: The idiosyncratic hepatotoxicity of Polygonum multiflorum Thunb. (PM) has attracted great interest, and tetrahydroxy stilbene glucoside (TSG) was the main idiosyncratic hepatotoxicity constituent, but biological detoxification on idiosyncratic hepatotoxicity of PM was not well investigated. AIM OF THE STUDY: This study aimed to illustrate biological detoxification mechanism on PM-induced idiosyncratic hepatotoxicity by Ganoderma lucidum (G. lucidum). MATERIALS AND METHODS: G. lucidum was used for biological detoxification of tetrahydroxy stilbene glucoside (TSG)-induced idiosyncratic hepatotoxicity of PM. The TSG consumption and products formation were dynamically determined during transformation using high-performance liquid chromatography coupled with diode-array detection and electrospray ionization tandem mass spectrometry (HPLC-DAD-MSn). The transformation invertases (ß-D-glucosidase and lignin peroxidase) were evaluated by using intracellular and extracellular distribution and activity assay. The key functions of lignin peroxidase (LiP) were studied by experiments of adding inhibitors and agonists. The entire TSG transformation process was confirmed in vitro simulated test. The cellular toxicity of TSG and the transformation products was detected by MTT. RESULTS: A suitable biotransformation system of TSG was established with G. lucidum, then p-hydroxybenzaldehyde and 2,3,5-trihydroxybenzaldehyde can be found as transformation products of TSG. The transformation mechanism involves two extracellular enzymes, ß-D-glucosidase and LiP. ß-D-glucosidase can remove glycosylation of TSG firstly and then LiP can break the double bond of remaining glycosides. The toxicity of TSG after biotransformation by G. lucidum was attenuated. CONCLUSIONS: This study would reveal a novel biological detoxification method for PM and explain degradation processes of TSG by enzymic methods.

In vitro assessment of the mutagenic and genotoxic potential of a pure stilbene extract.

Stilbenes are secondary metabolites of great interest produced by many plant species due to their important bioactive properties. These phytochemicals have become of increasing interest in the wine industry as a natural alternative to sulphur dioxide, which has been associated with human health risks. However, there is still little toxicological information on stilbenes and the results thus far have been contradictory. Considering the key role of genotoxicity in risk assessment and the need to offer safe products in the market, the aim of this study was to assess the mutagenic and genotoxic potential of a stilbene extract with 99% purity (ST-99 extract). A complete series of different in vitro tests (Ames test, micronucleus (MN) test, and standard and enzyme-modified comet assays) was performed before its use as a preservative in wines. The ST-99 extract induces a significant increase of binucleated cells with micronuclei only in presence of the metabolic fraction S9 at the highest concentration assayed. Neither the Ames test nor the comet assay revealed the extract's genotoxic potential. Further studies are necessary, including in vivo assays, to ensure consumer safety before it can be used.

Cytotoxicity studies of a stilbene extract and its main components intended to be used as preservative in the wine industry.

The use of stilbenes has been proposed as an alternative to sulfur dioxide in wine. Provided the feasibility from a technological approach, the cytotoxicity of an extract from grapevine shoots containing a stilbene richness of 99% (ST-99 extract) was assessed in the human cell lines HepG2 and Caco-2. In addition, the effects of the main stilbenes found in ST-99, trans-resveratrol and trans-ε-viniferin were studied, as well as its mixture. Similar cytotoxic effects were obtained in the exposures to trans-ε-viniferin, ST-99 and the mixture; however, trans-resveratrol alone exerted less toxicity. When HepG2 cells were exposed to trans-ε-viniferin, ST-99 and the mixture, the mean effective concentration (EC50) were 28.28 ± 2.15, 31.91 ± 1.55 and 29.47 ± 3.54 µg/mL, respectively. However, in the exposure to trans-resveratrol, the EC50 was higher 50 µg/mL. The morphological study evidenced damage at ultrastructural level in HepG2 cells, highlighting the inhibition of cell proliferation and the induction of apoptosis. The type of interaction produced by trans-ε-viniferin and trans-resveratrol mixtures was assessed by an isobologram analysis using the CalcuSyn software, evidencing an antagonist effect. These data comprise a starting point in the toxicological assessment; further studies are needed in this field to assure the safety of the extract ST-99.

Preparation and characterization of a pterostilbene-peptide prodrug nanomedicine for the management of dry eye.

In the present study, a pterostilbene-peptide amphiphile (PS-GA-RGD) that can spontaneously self-assemble into prodrug nanomedicine, was rationally designed and developed as a novel ophthalmic formulation for the potential management of dry eye. The formed PS-GA-RGD nanomedicine was characterized by dynamic latter scattering (DLS) and transmission electron microscopy (TEM). After esterase treatment, active pterostilbene (PS) sustainably released from the PS-GA-RGD nanomedicine within 48 h, as indicated by an in vitro release study. In comparison with native PS, the formed PS-GA-RGD nanomedicine caused minimal cytotoxicity towards RAW 264.7 and HCEC cells in the 0-20 µM range and did not delay wound healing of HCEC monolayer within 6 h. Furthermore, PS-GA-RGD nanomedicine effectively reduced the intracellular reactive oxygen species (ROS) level in H2O2 challenged RAW264.7 macrophages and remarkably suppressed the secretion of inflammatory cytokines (e.g., NO, TNF-α, and IL-6) in lipopolysaccharide (LPS) activated RAW264.7 macrophages. Ocular tolerance to the proposed PS-GA-RGD nanomedicine was good after a single instillation in in vivo ocular irritation tests. Overall, the proposed PS-GA-RGD nanomedicine had potent anti-oxidant capacity and anti-inflammatory efficacy, which may be a promising ophthalmic formulation for the management of dry eye.

Components synergy between stilbenes and emodin derivatives contributes to hepatotoxicity induced by Polygonum multiflorum.

Polygonum multiflorum Thunb. (PM) is a famous traditional Chinese medicine with liver tonic effect, but arousing great concerns for hepatotoxicity issue. In this study, we elucidated the contribution of the two major compounds, emodin-8-O-ß-D-glucoside (EG) and 2,3,5,4´-tetrahydroxyl diphenylethylene-2-O-glucoside (TSG), in PM-induced liver injury.Based on LC-MS, the two concerned compounds were detected simultaneously in the sera of patients with PM-induced liver injury. In the lipopolysaccharide (LPS)-mediated inflammatory stress rat model, by the analysis of plasma biochemistry and liver histopathology, we observed that the solo treatment of EG, not TSG, could induce significant liver injury; and the combined administration of EG and TSG caused more severe liver injury than that of EG.Metabolomics analysis revealed that the EG-triggered liver injury was associated with significant disturbances of sphingolipids and primary bile acids metabolism pathways. In the combined administration group, much more disturbances in EG-triggered metabolic pathways, as well as alterations of several additional pathways such as retinol metabolism and vitamin B6 metabolism, were observed.Taken together, we considered EG was involved in the idiosyncratic liver injury of PM, and TSG played a synergetic role with EG, which contributed to the understanding of the hepatotoxic basis of PM.

Pterostilbene supplements carry the risk of drug interaction via inhibition of UDP-glucuronosyltransferases (UGT) 1A9 enzymes.

Pterostilbene (PT) is a natural stilbene common in small berries and food supplements, possessing numerous pharmacological activities. However, whether PT can affect the activities of UDP-glucuronosyltransferases (UGT) enzymes remains unclear. The aim of the present study was to investigate the effect of PT on UGT activities and to quantitatively evaluate the food-drug interaction potential due to UGT inhibition. Our data indicated that PT exhibited potent inhibition against HLM, UGT1A6, UGT1A9, UGT2B7, and UGT2B15, moderate inhibition against UGT1A1, UGT1A3, UGT1A8, and UGT2B4, negligible inhibition against UGT1A4, UGT1A7, UGT1A10, and UGT2B17. Further kinetic investigation demonstrated that PT exerted potent noncompetitive inhibition 4-MU glucuronidation by UGT1A9, with IC50 and Ki values of 0.92 µM and 0.52 ± 0.04 µM, respectively. Quantitative prediction study suggested that coadministration of PT supplements at 100 mg/day or higher doses may result in at least a 50% increase in the AUC of drugs predominantly cleared by UGT1A9. Thus, the coadministration of PT supplements and drugs primarily cleared by UGT1A9 may result in potential drug interaction, and precautions should be taken when coadministration of PT supplements and drugs metabolized by UGT1A9.

Substituent enhanced fluorescence properties of star α-cyanostilbenes and their application in bioimaging.

A series of star α-cyanostilbenes with D-π-A structures comprising triphenylamine as the donor, the cyanovinyl group as the acceptor and different substituents on the terminal phenyl rings were synthesized and characterized. The influence of the substituents on the photophysical, electrochemical and thermal properties of the star molecules was investigated in detail. A strongly electron withdrawing nitro substituent on the phenyl ring (NTBTNPA) increased the absorption and emission maxima, the Stokes shift, and the difference between the ground and excited state dipole moments and decreased the fluorescence quantum yield, fluorescence lifetime and band gap energy between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). This molecule (i.e., NTBTNPA) also showed aggregation-induced enhanced emission; it showed emission at 608 nm in pure DMF and displayed red-shifted emission at 625 nm and new emission at 706 nm in a DMF/water (50 : 50) binary mixture. Aggregation of this molecule in different DMF/water mixtures was confirmed by the dynamic light scattering method. The HOMO, LUMO and band gap energy values of all the star molecules calculated theoretically using density functional theory (DFT) were in good agreement with the experimentally determined values. The biocompatibility of NTBTNPA was tested with two Gram positive and two Gram negative bacteria and also with a fungus. Based on the photophysical properties, NTBTNPA was used as a fluorophore for bio-imaging application of a fungus, Rhizoctonia solani, as a model and the results obtained were excellent.

Protective effects of polydatin in free and nanocapsulated form on changes caused by lipopolysaccharide in hippocampal organotypic cultures.

BACKGROUND: Polydatin (PD) is a compound, originally isolated from the root and rhizome of the Chinese herb Polygonum cuspidatum. To date, various biological properties of this compound, such as analgesic, anti-pyretic or diuretic effects, have been shown. Recently, anti-oxidant and anti-inflammatory properties have been widely postulated, yet PD instability and low bioavailability limit its beneficial actions. Therefore, it has been suggested that an encapsulation process may be a promising strategy for overcoming these limitations and increasing the therapeutic efficacy of PD. METHODS: We examined the effects of PD in two forms, including free and in PD-loaded polymeric nanocapsules, on lipopolysaccharide (LPS)-induced changes in hippocampal organotypic cultures. RESULTS: Our results indicated that free and encapsulated PD diminished cell death processes and attenuated the secretion of pro-inflammatory cytokines induced by LPS administration. Additionally, PD in both forms strongly inhibited the production of nitric oxide and down-regulated the level of iNOS enzyme in LPS-stimulated hippocampal cultures. CONCLUSION: Taken together, our study showed that PD exerts anti-inflammatory and anti-oxidant properties in LPS-treated hippocampal organotypic cultures. Furthermore, we show that the encapsulation procedure preserved the features of the free form of this compound, and therefore, the polymeric nanocapsules containing PD may be used as a novel and promising delivery system in therapeutic strategies.

Prenylated stilbenes and flavonoids from the leaves of Cajanus cajan.

Three new prenylated stilbenes, named as cajanusins A-C (1-3), and one new natural product cajanusin D (4), along with six known derivatives (5-10) were isolated from the leaves of Cajanus cajan. Their structures were fully elucidated by means of extensive spectroscopic methods and comparison with data in the reported literatures. The new compounds of 1 and 2 were evaluated for in vitro cytotoxic activities against a panel of human cancer cell lines.

Antioxidant, anti-tyrosinase and anti-melanogenic effects of (E)-2,3-diphenylacrylic acid derivatives.

During our continued search for strong skin whitening agents over the past ten years, we have investigated the efficacies of many tyrosinase inhibitors containing a common (E)-ß-phenyl-α,ß-unsaturated carbonyl scaffold, which we found to be essential for the effective inhibition of mushroom and mammalian tyrosinases. In this study, we explored the tyrosinase inhibitory effects of 2,3-diphenylacrylic acid (2,3-DPA) derivatives, which also possess the (E)-ß-phenyl-α,ß-unsaturated carbonyl motif. We synthesized fourteen (E)-2,3-DPA derivatives 1a-1n and one (Z)-2,3-DPA-derivative 1l' using a Perkin reaction with phenylacetic acid and appropriate substituted benzaldehydes. In our mushroom tyrosinase assay, 1c showed higher tyrosinase inhibitory activity (76.43 ±â€¯3.53%, IC50 = 20.04 ±â€¯1.91 µM) with than the other 2,3-DPA derivatives or kojic acid (21.56 ±â€¯2.93%, IC50 = 30.64 ±â€¯1.27 µM). Our mushroom tyrosinase inhibitory results were supported by our docking study, which showed compound 1c (-7.2 kcal/mole) exhibited stronger binding affinity for mushroom tyrosinase than kojic acid (-5.7 kcal/mole). In B16F10 melanoma cells (a murine cell-line), 1c showed no cytotoxic effect up to a concentration of 25 µM and exhibited greater tyrosinase inhibitory activity (68.83%) than kojic acid (49.39%). In these cells, arbutin (a well-known tyrosinase inhibitor used as the positive control) only inhibited tyrosinase by 42.67% even at a concentration of 400 µM. Furthermore, at 25 µM, 1c reduced melanin contents in B16F10 melanoma cells by 24.3% more than kojic acid (62.77% vs. 38.52%). These results indicate 1c is a promising candidate treatment for pigmentation-related diseases and potential skin whitening agents.

Attributes of Polygonum multiflorum to transfigure red biotechnology.

A vast array of plant-based compounds has enriched red biotechnology to serve the human health and food. A peculiar medicinal plant which was an element of traditional Chinese medicine for centuries as a liver and kidney tonic, for life longevity and hair blackening, is Polygonum multiflorum Thunb. (PM) which is popularly known as "He shou wu" or "Fo-ti" and is rich in chemical components like stilbenes, quinones, and flavonoids which have been used as anti-aging, anti-alopecia, anti-cancer, anti-oxidative, anti-bacterial, anti-hyperlipidemia, anti-atherosclerosis, and immunomodulating and hepatoprotective agents in the modern medicine. The health benefits from PM are attained since long through commercial products such as PM root powder, extract, capsules, tincture, shampoo, and body sprays in the market. Currently, the production of these pharmaceuticals and functional foods possessing stilbenes, quinones, and flavonoids is through cell and organ cultures to meet the commercial demand. However, hepatotoxic effects of PM-based products are the stumbling blocks for its long-term usage. The current review encompasses a comprehensive account of bioactive compounds of PM roots, their biological activities as well as efficacy and toxicity issues of PM ingredients and future perspectives.

A 14-day repeat dose oral gavage range-finding study of a first-in-class CDI investigational antibiotic, in rats.

Drug resistant bacteria are winning the fight over antibiotics with some bacteria not responding to any antibiotics, threatening modern medicine as we know it. The development of new, effective and safe antibiotics is critical for addressing this issue. Ramizol, a first-in-class styrylbenzene based antibiotic, is an investigational drug indicated for Clostridium difficile infections (CDI). The objective of this range-finding study was to evaluate the potential general toxicity (based on toxicological endpoints selected) and toxicokinetics of Ramizol in male and female rats that may arise from repeated exposure via oral gavage over a test period of at least 14 days at doses of 50 mg/kg, 500 mg/kg and 1500 mg/kg. There were no mortalities in this study and no Ramizol-related clinical observations. Additionally, there were no changes in mean body weight, body weight gain, food consumption or food efficiency for male and female rats attributable to Ramizol administration. The observed pharmacokinetic behavior showed the presence of Ramizol in plasma at 24 hours post-dosing combined with increasing AUC(0-24) values during the course of this study in groups administered 1500 mg/kg/day, which suggests that at least some dosing groups will show accumulation of compound during repeated dose studies. These toxicology results have shown Ramizol is well-tolerated at very high concentrations in rats and support the further drug development of Ramizol as a first-in-class antibiotic for the treatment of CDI.

Enhanced local cancer therapy using a CA4P and CDDP co-loaded polypeptide gel depot.

Cancer combination therapy based on drug co-delivery systems provides an effective strategy for enhancing treatment efficacy and reducing side effects. In this work, a new strategy through co-delivery of combretastatin A4 disodium phosphate (CA4P) and cisplatin (CDDP) was developed for the local treatment of colon cancer, through an in situ thermo-gelling hydrogel (mPEG-b-PELG). The results indicated that this material possessed concentration-dependent thermogelling properties and tunable in vivo biodegradability. Also, the drug loaded gel could regulate the in vitro drug release behaviors of both CDDP and CA4P, which promoted the in vivo vessel disrupting effects of CA4P compared with a free drug after local treatment for 48 h. Although the drug co-loaded gel induced less in vitro cell death compared with the free drug co-treated group, this drug co-loaded gel depot showed the highest antitumor efficacy compared with the other experimental groups after peritumoral injection toward C26 tumor bearing mice.

Two new stilbenoids from aerial parts of Flickingeria fimbriata.

Two new stilbenoids, named 2,3 -dimethoxyl-7-hydroxyl-1,4-phenanthrenedione (1) and 2-methoxyl-3-methyl-7-hydroxyl-9,10-dihydro-1,4-phenanthrenedione (2), together with two known stilbenoids including densiflorol B (3) and ephemeranthoquinone (4), were isolated from aerial parts of Flickingeria fimbriata (Bl.) Hawkes. The structures of two new compounds were elucidated by extensive spectroscopic analysis, including HRESIMS, 1H and 13C NMR, DEPT, HMBC, COSY, HMQC, NOESY. All the compounds were obtained from this genus for the first time. In addition, they all exhibited moderate cytotoxic activities against HepG2 cell lines.