Anti-angiogenic and anti-tumour activities of Lignosus rhinocerus (Cooke) Ryvarden water extracts on HCT116 human colorectal carcinoma cells implanted in chick embryos

ETHNOPHARMACOLOGICAL RELEVANCE

The sclerotium of Lignosus rhinocerus (Cooke) Ryvarden is used by the local communities in Southeast Asia and China to treat cancer, asthma, fever, and other ailments based on traditional knowledge. The sclerotial water extracts were previously reported to exhibit cytotoxic, apoptotic, and immunomodulatory activities - providing a scientific basis for its use in treating cancer; however, there is still a lack of evidence on its potential anti-angiogenic activity.

AIM OF THE STUDY

This study aimed to investigate the toxicity, anti-angiogenic, and anti-tumour activities of the hot-water and cold-water extracts of L. rhinocerus using HCT116 human colorectal carcinoma cells implanted in the chick chorioallantoic membrane (CAM) model.

MATERIALS AND METHODS

The toxicity of L. rhinocerus extracts towards the chick embryos was determined 24 h post-treatment. The anti-angiogenic activity of the extracts was then investigated at 0.1-10 μg/embryo (6.7-670 μg/mL) at targeted blood vessels. The anti-tumour effect of selected extracts against the HCT116 human colorectal carcinoma cells xenografted onto the chick embryos was also studied.

RESULTS

The cold-water extracts of L. rhinocerus displayed strong in ovo toxicity (LC50: 1.2- 37.7 μg/mL) while the hot-water extracts are non-toxic up to 670 μg/mL. Among the extracts, the hot-water extracts demonstrated the highest anti-angiogenic activity with 44.0 ± 17.7% reduction of capillary diameter (relative to the saline-treated control). Moreover, treatment of the HCT116 cells xenografted onto the chick embryos with the hot-water extracts resulted in smaller tumour size and lower number of blood vessels compared to the saline-treated control.

CONCLUSIONS

The hot-water extracts of L. rhinocerus sclerotium demonstrated anti-angiogenic and anti-tumour activities but most of the cold-water extracts at similar concentrations were devoid of that. Our findings provide further scientific validation of the medicinal use of the sclerotium in treating cancer and thus, expanding our knowledge on the possible mechanism of its anti-cancer effect apart from direct cytotoxicity, induction of apoptosis and immunomodulation that have been studied thus far.

Aza-BODIPY-based polymeric nanoparticles for photothermal cancer therapy in a chicken egg tumor model

A new push-pull aza-BODIPY (AZB-CF3) derivative comprised of dimethylamino groups and trifluoromethyl moieties was successfully synthesized. This derivative exhibited broad absorption in the near-infrared region in the range from 798 to 832 nm. It also exhibited significant near-infrared (NIR) signals in low-polar solvents with emission peaks around 835-940 nm, while non-fluorescence in high-polar environments due to the twisted intramolecular charge transfer (TICT) phenomenon. The nanoprecipitation of this compound with phospholipid-based polyethylene glycol (DSPE-PEG) yielded AZB-CF3@DSPE-PEG nanoparticles (NPs) with a hydrodynamic size of 70 nm. The NPs exhibited good photostability, colloidal stability, biocompatibility, and excellent photothermal (PTT) competence with a conversion efficiency (η) of 44.9%. These NPs were evaluated in vitro and in ovo in a 4T1 breast cancer cell line for NIR light-trigger photothermal therapy. Proven in the chicken egg tumor model, AZB-CF3@DSPE-PEG NPs induced severe vascular damage (∼40% vascular destruction), showed great anticancer efficacy (∼75% tumor growth inhibition), and effectively inhibited distant metastasis via photothermal treatment. As such, this PTT-based nanocarrier system could be a potential candidate for a clinical cancer therapy approach.

Aza-BODIPY based carbonic anhydrase IX: Strategy to overcome hypoxia limitation in photodynamic therapy

Hypoxia caused by photodynamic therapy (PDT) is a major hurdle to cancer treatment since it can promote recurrence and progression by activating angiogenic factors, lowering therapeutic efficacy dramatically. In this work, AZB-I-CAIX₂ was developed as a carbonic anhydrase IX (CAIX)-targeting NIR photosensitizer that can overcome the challenge by utilizing a combination of CAIX knockdown and PDT. AZB-I-CAIX₂ showed a specific affinity to CAIX-expressed cancer cells and enhanced photocytotoxicity compared to AZB-I-control (the molecule without acetazolamide). Moreover, selective detection and effective cell cytotoxicity of AZB-I-CAIX₂ by PDT in hypoxic CAIX-expressed murine cancer cells were achieved. Essentially, AZB-I-CAIX₂ could minimize tumor size in the tumor-bearing mice compared to that in the control groups. The results suggested that AZB-I-CAIX₂ can improve therapeutic efficiency by preventing PDT-induced hypoxia through CAIX inhibition.

Hepatoprotective potential of a novel quinazoline derivative in thioacetamide-induced liver toxicity

Purpose: The compound quinazoline Q-Br, 3-(5-bromo-2-hydroxybenzylideneamino)-2-(5-bromo-2 hydroxyphenyl) 2,3-dihydroquinazoline-4(1H)-one (Q-Br) was evaluated for its antioxidant capacity and potential hepatoprotectivity against sub-chronic liver toxicity induced by thioacetamide in rats.

Materials and Methods: Rats were assigned into five groups; healthy (normal) and cirrhosis control groups were given 5% Tween 20 orally, the reference control group was given a Silymarin dose of 50 mg/kg, and low-dose Q-Br and high-dose Q-Br groups were given a daily dose of 25 mg/kg and 50 mg/g Q-Br, respectively. Liver status was detected via fluorescence imaging with intravenous injection of indocyanine green (ICG) and a plasma ICG clearance test. Liver malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were also tested. The degree of fibrosis was determined histologically by hematoxylin and eosin and Masson’s Trichrome staining. The immunohistochemistry of liver tissue inhibitor of metalloproteinase (TIMP-1), matrix metalloproteinase (MMP-2), and alpha-smooth muscle actin (α-SMA) was performed.

Results: Q-Br recorded mild antioxidant capacity, dose-dependent improvement in the liver status, and inhibition of oxidative stress compared to cirrhosis control. Histopathology notified a remarkable reduction in the degree of fibrosis. Immunohistochemistry revealed an obvious low expression of MMP-2 and α-SMA along with a higher expression of TIMP-1 in Q-Br- and Silymarin-treated livers.

Conclusion: Q-Br treatment altered the course of toxicity induced by thioacetamide suggesting significant hepatoprotective potential of Q-Br treatment.

PEGylated Aza-BODIPY Nanoparticles for Photothermal Therapy

Photothermal therapy is a promising treatment modality in the realm of cancer therapy. Photothermal nanomaterials that absorb and emit in the near-infrared range (750-900 nm) have drawn a lot of attention recently because of the deep penetration of NIR light in biological tissue. Most nanomaterials, however, are produced by encapsulating or altering the surface of a nanoplatform, which has limited loading capacity and long-term storage. Herein, we developed a stable polymer conjugated with aza-BODIPY that self-assembled to form nanoparticles (aza-BODIPY-mPEG) with better hydrophilicity and biocompatibility while retaining the dye's photothermal conversion characteristics. Aza-BODIPY-mPEG with a hydrodynamic size of around 170 nm exhibited great photostability and excellent photothermal therapy in vitro and in ovo. Aza-BODIPY-mPEG exhibits approximately 30% better anti-angiogenesis and antitumor activity against implanted xenograft human HCT116 tumor in the chick embryo compared to parent aza-BODIPY-A, altogether suggesting that aza-BODIPY-mPEG is a promising material for cancer photothermal therapy.

Differential toxicity and teratogenic effects of the hot water and cold water extracts of Lignosusrhinocerus (Cooke) Ryvarden sclerotium on zebrafish (Danio rerio) embryos

ETHNOPHARMACOLOGICAL RELEVANCE

The sclerotium of Lignosusrhinocerus (Cooke) Ryvarden is highly valued for its purported medicinal properties. The decoction and macerated materials prepared from the sclerotium are used for treating cancer and other ailments based on extensive traditional knowledge. Scientific evidence from in vitro cytototoxicity, anti-inflammatory and immunomodulatory analyses showed the effectiveness of sclerotial water extracts but toxicity assessment of such preparations has not been reported.

AIM OF THE STUDY

This study aimed to compare the differential toxicity and teratogenicity (if any) of the hot water (HW) and cold water (CW) extracts of both wild and cultivated sclerotium on zebrafish (Danio rerio) embryos.

MATERIALS AND METHODS

Zebrafish embryos were treated with varying concentrations of the sclerotial HW and CW extracts (0.3-500 μg/mL) for 72 h until hatching. The hatching, mortality and heartbeat rate of the embryos as well as the potential teratogenic effect of the extracts were assessed in embryos post-treatment with the extracts.

RESULTS

While the sclerotial HW extracts were nontoxic (LC₅₀ > 500 μg/mL), the sclerotial CW extracts delayed the hatching of the embryos up to 48 h and showed slight toxicity with LC₅₀ values of 398.4 μg/mL and 428.3 μg/mL for the cultivated and wild sclerotium, respectively. The sclerotial CW extracts also induced minor tachycardia in zebrafish larvae. Phenotypic assessment revealed that, while yolk sac edema was observed at high concentrations (300 and 500 μg/mL) of all extracts, curved trunk and bent tail were only observed in the embryos treated with CW extracts of wild sclerotium (300 and 500 μg/mL) but not for CW extracts of cultivated sclerotium at similar concentrations.

CONCLUSION

The sclerotial water extracts of L.rhinocerus prepared using different methods have varying degree of toxicity and teratogenicity in zebrafish embryos with the sclerotial CW extracts showed higher toxicity than the HW extracts.

Alternative animal models in predictive toxicology

Toxicity testing relies heavily on animals, especially rodents as part of the non-clinical laboratory testing of substances. However, the use of mammalians and the number of animals employed in research has become a concern for institutional ethics committees. Toxicity testing involving rodents and other mammals is laborious and costly. Alternatively, non-rodent models are used as replacement, as they have less ethical considerations and are cost-effective. Of the many alternative models that can be used as replacement models, which ones can be used in predictive toxicology? What is the correlation between these models and rodents? Are there standardized protocols governing the toxicity testing of these commonly used predictive models? This review outlines the common alternative animal models for predictive toxicology to address the importance of these models, the challenges, and their standard testing protocols.

Identification of potential candidate genes for lip and oral cavity cancer using network analysis

Lip and oral cavity cancer, which can occur in any part of the mouth, is the 11th most common type of cancer worldwide. The major obstacles to patients' survival are the poor prognosis, lack of specific biomarkers, and expensive therapeutic alternatives. This study aimed to identify the main genes and pathways associated with lip and oral cavity carcinoma using network analysis and to analyze its molecular mechanism and prognostic significance further. In this study, 472 genes causing lip and oral cavity carcinoma were retrieved from the DisGeNET database. A protein-protein interaction network was developed for network analysis using the STRING database. VEGFA, IL6, MAPK3, INS, TNF, MAPK8, MMP9, CXCL8, EGF, and PTGS2 were recognized as network hub genes using the maximum clique centrality algorithm available in cytoHubba, and nine potential drug candidates (ranibizumab, siltuximab, sulindac, pomalidomide, dexrazoxane, endostatin, pamidronic acid, cetuximab, and apricoxib) for lip and oral cavity cancer were identified from the DGIdb database. Gene enrichment analysis was also performed to identify the gene ontology categorization of cellular components, biological processes, molecular functions, and biological pathways. The genes identified in this study could furnish a new understanding of the underlying molecular mechanisms of carcinogenesis and provide more reliable biomarkers for early diagnosis, prognostication, and treatment of lip and oral cavity cancer.

Toxicity Effect of Bougainvillea glabra (Paper Flower) Water Extracts on Zebrafish Embryo

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Assessment of Potential Anticancer Activity of Brown Seaweed Compounds Using Zebrafish Phenotypic Assay

Despite the extensive work on anticancer drug discovery, the number of potent lead compounds that enter the preclinical and clinical trials thus far is still low due to the poor selectivity and understanding in pharmacodynamics. In view of the homology between zebrafish embryogenesis and carcinogenesis in human, zebrafish embryos can be used in the screening platform to elucidate the molecular targets of potential anticancer compounds. In the present study, the possible targets modulating the potential anticancer effects of selected brown seaweed-derived compounds (ie alginate, fucoidan, phloroglucinol, fucosterol, and fucoxanthin) were examined. Teratogenic effects induced by the compounds were observed after 72 hours post-fertilization. Fucoidan, phloroglucinol, and fucosterol were observed to significantly reduce the pigmentation of the zebrafish in a dose-dependent manner at low concentrations (fucoidan, <60 µg/mL; phloroglucinol, <10 µg/mL; fucosterol, <3 µg/mL). On the other hand, embryos treated with fucoxanthin at 200 µg/mL and 300 µg/mL exhibited either phenotypes of curved trunk or bent tail. Further validation work using dual antiplatelet therapy (DAPT) and dorsomorphin as positive controls suggest that fucoxanthin might target the Notch and bone morphogenetic protein (BMP) pathways, respectively. Findings from this exploratory study henceforth have demonstrated the utility of zebrafish embryo to accelerate the discovery of potential compounds for targeted anticancer therapy.

Recent strategies to improve boron dipyrromethene (BODIPY) for photodynamic cancer therapy: an updated review

BODIPYs are photosensitizers activatable by light to generate highly reactive singlet oxygen (¹O₂) from molecular oxygen, leading to tissue damage in the photoirradiated region. Despite their extraordinary photophysical characteristics, they are not featured in clinical photodynamic therapy. This review discusses the recent advances in the design and/or modifications of BODIPYs since 2013, to improve their potential in photodynamic cancer therapy and related areas.

Tropomyosin Receptor Kinase C Targeted Delivery of a Peptidomimetic Ligand-Photosensitizer Conjugate Induces Antitumor Immune Responses Following Photodynamic Therapy

Tropomyosin receptor kinase C (TrkC) targeted ligand-photosensitizer construct, IYIY-diiodo-boron-dipyrromethene (IYIY-I₂-BODIPY) and its scrambled counterpart YIYI-I₂-BODIPY have been prepared. IYIY-I₂-BODIPY binds TrkC similar to neurotrophin-3 (NT-3), and NT-3 has been reported to modulate immune responses. Moreover, it could be shown that photodynamic therapy (PDT) elevates antitumor immune responses. This prompted us to investigate the immunological impacts mediated by IYIY-I₂-BODIPY in pre- and post-PDT conditions. We demonstrated that IYIY-I₂-BODIPY (strong response) and YIYI-I₂-BODIPY (weak response) at 10 mg/kg, but not I₂-BODIPY control, increased the levels of IL-2, IL-4, IL-6 and IL-17, but decreased the levels of systemic immunoregulatory mediators TGF-β, myeloid-derived suppressor cells and regulatory T-cells. Only IYIY-I₂-BODIPY enhanced the IFN-γ⁺ and IL-17⁺ T-lymphocytes, and delayed tumor growth (~20% smaller size) in mice when administrated daily for 5 days. All those effects were observed without irradiation; when irradiated (520 nm, 100 J/cm², 160 mW/cm²) to produce PDT effects (drug-light interval 1 h), IYIY-I₂-BODIPY induced stronger responses. Moreover, photoirradiated IYIY-I₂-BODIPY treated mice had high levels of effector T-cells compared to controls. Adoptive transfer of immune cells from IYIY-I₂-BODIPY-treated survivor mice that were photoirradiated gave significantly delayed tumor growth (~40–50% smaller size) in recipient mice. IYIY-I₂-BODIPY alone and in combination with PDT modulates the immune response in such a way that tumor growth is suppressed. Unlike immunosuppressive conventional chemotherapy, IYIY-I₂-BODIPY can act as an immune-stimulatory chemotherapeutic agent with potential applications in clinical cancer treatment.

Chick embryo chorioallantoic membrane (CAM): an alternative predictive model in acute toxicological studies for anti-cancer drugs

The chick embryo chorioallantoic membrane (CAM) is a preclinical model widely used for vascular and anti-vascular effects of therapeutic agents in vivo. In this study, we examine the suitability of CAM as a predictive model for acute toxicology studies of drugs by comparing it to conventional mouse and rat models for 10 FDA-approved anticancer drugs (paclitaxel, carmustine, camptothecin, cyclophosphamide, vincristine, cisplatin, aloin, mitomycin C, actinomycin-D, melphalan). Suitable formulations for intravenous administration were determined before the average of median lethal dose (LD₅₀) and median survival dose (SD₅₀) in the CAM were measured and calculated for these drugs. The resultant ideal LD₅₀ values were correlated to those reported in the literature using Pearson’s correlation test for both intravenous and intraperitoneal routes of injection in rodents. Our results showed moderate correlations (r²=0.42 − 0.68, P<0.005–0.05) between the ideal LD₅₀ values obtained using the CAM model with LD₅₀ values from mice and rats models for both intravenous and intraperitoneal administrations, suggesting that the chick embryo may be a suitable alternative model for acute drug toxicity screening before embarking on full toxicological investigations in rodents in development of anticancer drugs.

Targeted PDT agent eradicates TrkC expressing tumors via photodynamic therapy (PDT)

This contribution features a small molecule that binds TrkC (tropomyosin receptor kinase C) receptor that tends to be overexpressed in metastatic breast cancer cells but not in other breast cancer cells. A sensitizer for ¹O₂ production conjugated to this structure gives 1-PDT for photodynamic therapy. Isomeric 2-PDT does not bind TrkC and was used as a control throughout; similarly, TrkC– cancer cells were used to calibrate enhanced killing of TrkC+ cells. Ex vivo, 1- and 2-PDT where only cytotoxic when illuminated, and 1-PDT, gave higher cell death for TrkC+ breast cancer cells. A 1 h administration-to-illumination delay gave optimal TrkC+/TrkC–-photocytotoxicity, and distribution studies showed the same delay was appropriate in vivo. In Balb/c mice, a maximum tolerated dose of 20 mg/kg was determined for 1-PDT. 1- and 2-PDT (single, 2 or 10 mg/kg doses and one illumination, throughout) had similar effects on implanted TrkC– tumors, and like those of 2-PDT on TrkC+ tumors. In contrast, 1-PDT caused dramatic TrkC+ tumor volume reduction (96% from initial) relative to the TrkC– tumors or 2-PDT in TrkC+ models. Moreover, 71% of the mice treated with 10 mg/kg 1-PDT (n = 7) showed full tumor remission and survived until 90 days with no metastasis to key organs.

C6-ceramide in combination with transforming growth factor-β enhances Treg cell differentiation and stable FoxP3 expression in vitro and in vivo

Ceramides, sphingosine-based lipid molecules, are generated mainly from the hydrolysis of sphingomyelin and play pivotal roles in biological processes including cell growth, differentiation, and inflammation. In this study, we investigated the effect of exogenous ceramides on the differentiation of regulatory T (Treg) cells and expression of FoxP3 gene in Treg cells. A cell-permeable C6-ceramide (C6) was capable of upregulating Treg cell differentiation when acting together with transforming growth factor-beta (TGF-β), and this induction was independent of T-cell receptor (TCR) and CD28 strength. Additionally, TGF-β/C6 treatment sustained the expression of FoxP3 gene in Treg cells, as the percentages of FoxP3(+) Treg cells in the TGF-β/C6-treated group remained high for prolonged periods compared to those in the group treated with TGF-β alone. Furthermore, C8-ceramide was also capable of sustaining Treg cell populations and FoxP3 expression, whereas C2-, C16-, and C24-ceramides did not. Importantly, adoptive transfer of the TGF-β/C6-induced Treg cells into syngenic mice showed that TGF-β/C6-induced Treg cells maintained their FoxP3 expression in vivo significantly longer periods than the TGF-β-induced Treg cells. Taken together, our findings indicate that C6 can be utilized to increase Treg cell populations and also to sustain their FoxP3 expression in the treatment of autoimmune diseases or graft rejection.

C6-ceramide enhances Interleukin-12-mediated T helper type 1 cell responses through a cyclooxygenase-2-dependent pathway

Ceramides, lipid molecules located predominantly within the plasma membrane of a cell, can function as second messengers, and have been known to carry out a number of cellular functions. T helper type 1 (Th1) immune responses are known to be involved in the cellular immunity, which is crucial in the cancer and allergy immunotherapy. This study was designed to evaluate the effects of ceramides on T helper cell responses and their underlying mechanisms. We demonstrated that a cell-permeable C6-ceramide (C6) together with IL-12 enhanced Th1 cell differentiation, whereas C6 alone had no effects, as demonstrated by the increased populations of IFN-γ expressing CD4(+) T cells and the up-regulation of IFN-γ production from CD4(+) T cells. In contrast, C2-ceramide and long chain ceramides (C16 and C24) did not affect the Th1 responses. C6 treatment was shown to increase the expression of T-bet, a master transcription factor of Th1 responses, in a dose-dependent fashion. Furthermore, C6 increased the expression of cyclooxygenase-2 (COX-2) in CD4(+) T cells. The C6-mediated increase of IFN-γ production and IFN-γ expressing CD4(+) T cell populations were significantly suppressed by a COX-2 specific inhibitor (NS-398) in a dose-dependent manner. T-bet expression was also decreased by NS-398 treatment, thereby indicating that C6 ceramide enhances Th1 responses via a COX-2 dependent pathway. This result demonstrates that C6 may be utilized in therapies for the treatment of immune diseases such cancer and allergy by enhancing the Th1 activity.

C6-ceramide facilitates IL-12-mediated T helper-1 cell differentiation through a COX-2/PGE2-dependent pathway (152.17)

Ceramides, lipid molecules that are found predominantly in the plasma membrane of a cell, can serve as a second messenger and have been known to perform a number of cellular functions. Our study was designed to investigate the effect of ceramides on T helper cell responses and their underlying mechanisms. We found that a cell-permeable C6-ceramide (C6) together with IL-12 synergistically increased the populations of IFN-γ+ T cells and up-regulated IFN-γ production from CD4+ T cells, whereas C2-ceramide and long chain ceramides (C16 and C24) did not affect. C6 treatment increased the expression of T-bet, a master transcription factor of Th1 responses, in a dose-dependent manner. Moreover, C6 induced expression of cyclooxygenase-2 (COX-2) accompanied by prostaglandin E2 (PGE2) production in CD4+ T cells. The IFN-γ+ T cells populations and IFN-γ production induced by C6 were significantly suppressed by both a COX-2 specific inhibitor (NS398) and an anti-PGE2 neutralizing antibody in a dose-dependent manner. T-bet expression was also decreased by NS398 treatment. Taken together, C6 promotes the production of PGE2 in CD4+ T cells through a COX-2 dependent mechanism, thereby facilitating Th1 cell differentiation. These results suggest that C6 can be utilized in the therapeutics of diseases such as cancer and allergic by enhancing the Th1 activity.