Design and synthesis of cantharidin derivative DCZ5418 as a TRIP13 inhibitor with anti-multiple myeloma activity in vitro and in vivo

Natural product cantharidin can inhibit multiple myeloma cell growth in vitro, while serious adverse effects limited its clinical application. Therefore, the structural modification of cantharidin is needed. Herein, inspired by the structural similarity of the aliphatic endocyclic moiety in cantharidin and TRIP13 inhibitor DCZ0415, we designed and synthesized DCZ5418 and its nineteen derivatives. The molecular docking study indicated that DCZ5418 had a similar binding mode to TRIP13 protein as DCZ0415 while with a stronger docking score. Moreover, the bioassay studies of the MM-cells viability inhibition, TRIP13 protein binding affinity and enzyme inhibiting activity showed that DCZ5418 had good anti-MM activity in vitro and definite interaction with TRIP13 protein. The acute toxicity test of DCZ5418 showed less toxicity in vivo than cantharidin. Furthermore, DCZ5418 showed good anti-MM effects in vivo with a lower dose administration than DCZ0415 (15 mg/kg vs 25 mg/kg) on the tumor xenograft models. Thus, we obtained a new TRIP13 inhibitor DCZ5418 with improved safety and good activity in vivo, which provides a new example of lead optimization by using the structural fragments of natural products.

Integrative analysis of the molecular signature of target genes involved in the antitumor effects of cantharidin on hepatocellular carcinoma

BACKGROUND

Cantharidin (CTD) is the active ingredient of Chinese medicine, which has been traditionally used in multiple cancers treatment, especially in hepatocellular carcinoma (HCC). However, a comprehensive analysis of the CTD-related molecular mechanism is still necessary to understand its functions in HCC treatment. This study aimed to reveal the novel molecular targets and regulatory networks of CTD in HCC.

METHODS

A model of H22 tumour-bearing mice was constructed, and the function of CTD in tumour growth was evaluated. An integrated approach of CTD associated transcriptional profiling and biological systems analysis was used to identify key regulators involved in antitumour pathways. The identified differential expression patterns were supported by the results of Gene Ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyse, and by protein-protein interaction (PPI) network construction. The relationships between gene expression and tumour immunity were evaluated using Tumour Immune Estimation Resource (TIMER). Prognostic value was analyzed with Kaplan-Meier plotter.

RESULTS

In the present study, the therapeutic effect of CTD on HCC was evaluated in vivo. We obtained the CTD-related transcriptional profiles, systematically and intuitively illustrated its possible pharmacological mechanisms in HCC through multiple targets and signalling pathways. These results revealed that the CTD-related differentially expressed genes were involved in autophagy, transcription factors (TFs) related transcriptional regulation, fatty acid metabolism and immune response in HCC. We found that MAPT, TOP2A, CENPF and MEFV were hub genes of CTD targets involved in autophagy regulation. Totally, 14 TFs have been confirmed to be critical for transcriptional regulation, and 33 TF targets were identified as the hub genes in transcriptional mis-regulation pathway in cancer. These TFs were associated with the immune response and immune cell infiltration. In addition, the downregulated genes were significantly enriched in metabolic regulation pathways, especially fatty acid metabolism after CTD treatment. Furthermore, the network of CTD associated miRNAs with these fatty acid metabolism-related targets was constructed in HCC.

CONCLUSIONS

Taken together, our results comprehensively elucidated that CTD could act on multiple targets in HCC therapy, affecting autophagy, transcriptional regulation, the immune response and fatty acid metabolism. Our results provide a foundation for the study of the molecular mechanistic of CTD and its clinical application in the treatment of HCC.

Cantharidin analogue alleviates dextran sulfate sodium-induced colitis in mice by inhibiting the activation of NF-κB signaling

Ulcerative colitis is a chronic inflammatory disease with a remitting-relapsing clinical course, it has evolved into a global burden given its high incidence worldwide. Cantharidin (CTD) derivatives are a class of compounds whose structures characterized with a 7-oxabicyclo [2.2.1]heptane core. Though potent cytotoxicity CTD and its derivatives showed, their clinical usage as anti-cancer drugs was limited by the toxicity in organs. In order to find new CTD analogues with good activity and lower toxicity, 21 CTD analogues with or without alkynyl substitution at C5 position of 7-oxabicyclo [2.2.1]heptane core were synthesized, some compounds showed better in vitro anti-inflammatory activity compared to CTD and norcantharidin (NCTD). Based on the structure-activity relationship results of in vitro experiment, analogue 3i was chosen for further study. Results from the acute toxicity in mice showed that 3i was hypotoxic with the single-dose MTD (maximum tolerated dose) for oral administration is over 1852 mg/kg, at least 35-fold lower than that of NCTD. Mechanism study indicated that 3i could potently inhibit TNF-α induced activation of NF-κB signaling by down-regulation the expression levels of phosphor- IKK, IκBα, and NF-κB p65, and alleviated dextran sulfate sodium-induced colitis in mice. This study indicated that CTD analogues with alkynyl substitution at C5 position of 7-oxabicyclo [2.2.1]heptane core is a kind of new compounds with good anti-inflammatory activity and lower toxicity in vivo, and might be used as therapeutic agents for inflammatory diseases.

Blister Beetle Dermatitis Outbreaks in Mali

INTRODUCTION

Meloidae are distributed in temperate and arid regions but are also common in subtropical and tropical savannahs. These insects contain cantharidin, a vesicant substance that can cause poisoning by ingestion and dermatitis by direct contact.

MATERIAL AND METHODS

We describe recurrent Meloidae-related dermatitis outbreaks and their health impact by analyzing medical consultation records and meteorological data.

RESULTS

Between 2015 and 2019, dermatitis outbreaks took place at a French military base at the end of the rainy season, from July to August, with 100 cases reported in 2015, 74 in 2017, 100 in 2018, and 36 in 2019. In 2017, the incidence rate was 4.4% for the base's population. Initial medical consultations represented 31.5% of total medical care activity. Meloidae were identified as Cyaneolytta fryi.

CONCLUSIONS

These outbreaks of burn-like lesions, although clinically benign, can place a considerable burden on the medical activity of health care facilities. The diagnosis of Meloidae dermatitis is exclusively anamnestic and clinical and requires reported contact with the insect. The treatment protocol is that of standard burn care, and the best preventive measure is to avoid bright white lights. Military personnel, foreign workers, and travelers venturing into the Sahel should be warned of the risks associated with these beetles.

Cantharidin-Podophyllin-Salicylic Acid Formulation as a First-Line Treatment for Plantar Warts? A Case Report with Multiple Plantar Warts of Human Papillomavirus Biotype 27 and Previous Failed Treatments

BACKGROUND Plantar warts are benign skin tumors caused by the human papillomavirus (HPV). There are multiple treatments, but none ensure absolute success. Successful treatment depends on several factors, such as the location, number of lesions, HPV biotype, and the patient's health condition. This report presents a 53-year-old woman who had multiple recalcitrant plantar warts with HPV biotype 27 that were treated using a cantharidin-podophyllin-salicylic acid (CPS) formulation after 2 failed treatments. CASE REPORT A 53-year-old woman was seen on October 25, 2021. She had 6 plantar warts due to HPV biotype 27, which was confirmed by polymerase chain reaction using a sample of hyperkeratosis scales obtained from the wart after debridement. Five cryotherapy sessions were applied, without clinical improvement. Two sessions of nitric-acid-zinc complex were then applied, from which the patient reported severe pain, without clinical improvement. Finally, 3 sessions of CPS formulation were applied, and the HPV remitted in all warts. CONCLUSIONS Conservative treatments, such as cryotherapy, have not been effective in a case of multiple recalcitrant plantar warts. The combined action of the 3 compounds of CPS formulation was key in the resolution of this case. Plantar wart treatment should be easy to apply, effective, fast, and efficient. In cases of recalcitrant or numerous warts, treatment should be more aggressive from the beginning if the patient's lifestyle allows it. It would be interesting to conduct randomized clinical trials to find out which patients could be indicated for the CPS formulation as a first line of treatment.

Development of Glycyrrhetinic Acid and Folate Modified Cantharidin Loaded Solid Lipid Nanoparticles for Targeting Hepatocellular Carcinoma

Cantharidin (CTD) is the major component of anticancer drugs obtained from Mylabris Cichorii and has a good inhibitory effect on several cancers, including hepatocellular carcinoma (HCC) and breast cancer. However, due to its toxicity, oral administration can cause various adverse reactions, limiting its clinical application. The aim of this work was to design glycyrrhetinic acid (GA)- and/or folate (FA)-modified solid lipid nanoparticles (SLNs) for the encapsulation of CTD to target HCC. Four CTD-loaded SLNs (cantharidin solid lipid nanoparticles (CSLNs), glycyrrhetinic acid-modified cantharidin solid lipid nanoparticles (GA-CSLNs), folate-modified cantharidin solid lipid nanoparticles (FA-CSLNs), and glycyrrhetinic acid and folate-modified cantharidin solid lipid nanoparticles (GA-FA-CSLNs)) were prepared by the emulsion ultrasonic dispersion method, and their physicochemical parameters were determined (particle size and distribution, morphology, zeta-potential, entrapment efficiency, drug loading, and hemolysis). Additionally, the antitumor activities of the four SLNs were evaluated comprehensively by tests for cytotoxicity, cell migration, cell cycle, apoptosis, cellular uptake, competition suppression assay, and in vivo tumor suppression assay. Four SLNs showed spherical shapes and mean diameters in the range of 75–110 nm with size dispersion (PDI) within the range of 0.19–0.50 and zeta-potential approximately –10 mV. The entrapment efficiency of CTD in SLNs was higher than 95% for all tested formulations, and no hemolysis was observed. Compared to GA-CSLNs or CSLNs, GA-FA-CSLNs and FA-CSLNs showed stronger cytotoxicity on hepatocellular carcinoma cells (HepG2), and the cytotoxicity of GA-FA-CSLNs on hepatocyte cells (L-02) was remarkably reduced compared with other formulations. GA-FA-CSLNs and FA-CSLNs also increased the inhibition of HepG2 cell migration, and FA-CSLNs had the highest apoptosis rate. The cell cycle results indicated that HepG2 cells were arrested mainly in the S phase and G2/M phase. Analysis of competition inhibition experiments showed that GA and FA ligands had targeted effects on HepG2 cells. The in vivo tumor inhibition experiment showed that GA-FA-CSLNs and FA-CSLNs had excellent tumor inhibition ability—their tumor inhibition rates were 96.46% and 89.92%, respectively. Our results indicate that GA-FA-CSLNs and FA-CSLNs have a promising future in the therapeutic intervention of HCC.

Anticancer Attributes of Cantharidin: Involved Molecular Mechanisms and Pathways

Cancer is a preeminent threat to the human race, causing millions of deaths each year on the Earth. Traditionally, natural compounds are deemed promising agents for cancer treatment. Cantharidin (CTD)-a terpenoid isolated from blister beetles-has been used extensively in traditional Chinese medicines for healing various maladies and cancer. CTD has been proven to be protein phosphatase 2A (PP2A) and heat shock transcription factor 1 (HSF-1) inhibitor, which can be potential targets for its anticancer activity. Albeit, it harbors some toxicities, its immense anticancer potential cannot be overlooked, as the cancer-specific delivery of CTD could help to rescue its lethal effects. Furthermore, several derivatives have been designed to weaken its toxicity. In light of extensive research, the antitumor activity of CTD is evident in both in vitro as well as in vivo cancer models. CTD has also proven efficacious in combination with chemotherapy and radiotherapy and it can also target some drug-resistant cancer cells. This mini-review endeavors to interpret and summarize recent information about CTD anticancer potential and underlying molecular mechanisms. The pertinent anticancer strength of CTD could be employed to develop an effective anticarcinogenic drug.

Cantharidin for molluscum contagiosum

Question I see numerous children with molluscum contagiosum (MC), and my reassurance that these lesions will disappear without treatment falls on deaf ears. Parents and children always want those lesions gone. They are also worried about other children contracting the infection. What therapies exist for this viral condition, and is cantharidin an appropriate and safe choice for the treatment of MC in children?Answer Molluscum contagiosum is a very common skin condition caused by the MC virus. While it is known to be self-limiting and it resolves in 6 to 18 months with no long-term effects, treatment methods have been studied for children. Local treatment with cantharidin is suggested every 3 to 4 weeks, and at least 2 treatments are usually needed. Local erythema, burning sensation, and blisters are common side effects that should be considered.

Efficacy and Safety of Topical Cantharidin Treatment for Molluscum Contagiosum and Warts: A Systematic Review

BACKGROUND AND OBJECTIVE

Topical cantharidin is routinely used for the treatment of molluscum contagiosum and warts. The objective of this systematic review is to assess the efficacy and safety of topical cantharidin treatment for molluscum contagiosum and warts.

METHODS

We performed a systematic review of studies assessing topical cantharidin treatment of molluscum contagiosum or warts. We searched the databases of Cochrane, EMBASE, GREAT, LILACS, MEDLINE, and Scopus. Two authors performed the study selection and data extraction.

RESULTS

Twenty studies (1958-2018) met inclusion/exclusion criteria. Twelve studies assessed warts, and eight studies assessed molluscum contagiosum. Overall, 1752 patients were included (range 0.3-62 years; specified in 15 studies). Clearance rates with topical cantharidin for molluscum contagiosum were variable (range 15.4-100%). Significant clearance of warts with maintenance of clearance was demonstrated with topical cantharidin alone. Topical cantharidin in combination with podophyllotoxin and salicylic acid demonstrated efficacy for plantar warts (pediatric and adult; clearance rate range 81-100%; four studies had 100% clearance), with the majority clearing after a single treatment. Satisfaction with cantharidin therapy was high, especially in molluscum contagiosum. Pain (7-85.7%), blistering (10-100%), and hyper-/hypopigmentation (1.8-53.3%) were the most commonly occurring adverse effects with cantharidin treatment.

CONCLUSION

Topical cantharidin demonstrated clearance of warts, particularly in combination with podophyllotixin and salicylic acid, and modest benefit for pediatric molluscum contagiosum with good tolerability and safety.

Cantharidin is Superior to Trichloroacetic Acid for the Treatment of Non-mucosal Genital Warts: A Pilot Randomized Controlled Trial

Condyloma Acuminatum is a sexually transmitted viral disease caused by the human papilloma virus (HPV). It is the most common viral sexually transmitted disease. In this randomized controlled trial, cantharidin was found to be more effective and better tolerated than trichloroacetic acid for the treatment of these lesions. Patients treated with cantharidin healed with less scarring than those treated with TCA (P<0.034), had less pain during treatment (P<0.01), and required fewer treatments to eradicate warts (P<0.01) when compared to Trichloroacetic acid.

Treatment of molluscum contagiosum in adult, pediatric, and immunodeficient populations

BACKGROUND

Molluscum contagiosum is a viral infection of the skin that is widely considered to be a self-resolving disease that can be treated with benign neglect. However, the clinical reality is that the disease can vary widely by anatomic site and by recalcitrance to treatment and remains a significant cause of morbidity worldwide.

OBJECTIVE

The purpose of this review was to compile an updated resource for clinicians that addresses the management of the broad spectrum of molluscum cases that may be encountered.

METHODS

A comprehensive PubMed search was performed to identify publications on the treatment of molluscum infection, including presentations that may be rare or difficult.

RESULTS

The specific clinical scenario of molluscum must be considered when selecting the optimal therapy because certain treatments can be more effective for specific patient subpopulations.

CONCLUSION

Further attention must be directed toward standardizing treatment for molluscum infection based on patient age and immune status.

Anticancer effects of cantharidin in A431 human skin cancer (Epidermoid carcinoma) cells in vitro and in vivo

Cantharidin (CTD), a potential anticancer agent of Traditional Chinese Medicine has cytotxic effects in different human cancer cell lines. The cytotoxic effects of CTD on A431 human skin cancer (epidermoid carcinoma) cells in vitro and in A431 cell xenograft mouse model were examined. In vitro, A431 human skin cell were treated with CTD for 24 and 48 h. Cell phase distribution, ROS production, Ca²⁺ release, Caspase activity and the level of apoptosis associated proteins were measured. In vivo, A431 cell xenograft mouse model were examined. CTD-induced cell morphological changes and decreased percentage of viable A431 cells via G0/G1 phase arrest and induced apoptosis. CTD-induced G0/G1 phase arrest through the reduction of protein levels of cyclin E, CDK6, and cyclin D in A431 cells. CTD-induced cell apoptosis of A431 cells also was confirm by DNA gel electrophoresis showed CTD-induced DNA fragmentation. CTD reduced the mitochondrial membrane potential and stimulated release of cytochrome c, AIF and Endo G in A431 cells. Flow cytometry demonstrated that CTD increased activity of caspase-8, -9 and -3. However, when cells were pretreated with specific caspase inhibitors activity was reduced and cell viability increased. CTD increased protein levels of death receptors such as DR4, DR5, TRAIL and levels of the active form of caspase-8, -9 and -3 in A431 cells. AIF and Endo G proteins levels were also enhanced by CTD. In vivo studies showed that CTD significantly inhibited A431 cell xenograft tumors in mice. Taken together, these in vitro and in vivo results provide insight into the mechanisms of CTD on cell growth and tumor production. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 723-738, 2017.

Medium throughput biochemical compound screening identifies novel agents for pharmacotherapy of neurofibromatosis type 1

The variable manifestation of phenotypes that occur in patients with neurofibromatosis type 1 (NF1) includes benign and malignant neurocutaneous tumors for which no adequate treatment exists. Cell-based screening of known bioactive compounds library identified the protein phosphatase 2A (PP2A) inhibitor Cantharidin and the L-type calcium channel blocker Nifedipine as potential candidates for NF1 pharmacotherapy. Validation of screening results using human NF1-associated malignant peripheral nerve sheath tumor (MPNST) cells showed that Cantharidin effectively impeded MPNST cell growth, while Nifedipine treatment significantly decreased local tumor growth in an MPNST xenograft animal model. These data suggest that inhibitors of PP2A, as well as calcium channel blockers, might be used in broader MPNST preclinical studies as single agents or in combinatorial therapeutic strategies.

Therapeutic relevance of the protein phosphatase 2A in cancer

Chromosomal Instability (CIN) is regarded as a unifying feature of heterogeneous tumor populations, driving intratumoral heterogeneity. Polo-Like Kinase 1 (PLK1), a serine-threonine kinase that is often overexpressed across multiple tumor types, is one of the key regulators of CIN and is considered as a potential therapeutic target. However, targeting PLK1 has remained a challenge due to the off-target effects caused by the inhibition of other members of the polo-like family. Here we use synthetic dosage lethality (SDL), where the overexpression of PLK1 is lethal only when another, normally non-lethal, mutation or deletion is present. Rather than directly inhibiting PLK1, we found that inhibition of PP2A causes selective lethality to PLK1-overexpressing breast, pancreatic, ovarian, glioblastoma, and prostate cancer cells. As PP2A is widely regarded as a tumor suppressor, we resorted to gene expression datasets from cancer patients to functionally dissect its therapeutic relevance. We identified two major classes of PP2A subunits that negatively correlated with each other. Interestingly, most mitotic regulators, including PLK1, exhibited SDL interactions with only one class of PP2A subunits (PPP2R1A, PPP2R2D, PPP2R3B, PPP2R5B and PPP2R5D). Validation studies and other functional cell-based assays showed that inhibition of PPP2R5D affects both levels of phospho-Rb as well as sister chromatid cohesion in PLK1-overexpressing cells. Finally, analysis of clinical data revealed that patients with high expression of mitotic regulators and low expression of Class I subunits of PP2A improved survival. Overall, these observations point to a context-dependent role of PP2A that warrants further exploration for therapeutic benefits.

Cantharidin in Dermatology

Cantharidin is natural toxin produced by the blistering beetle. It has both vesicant and keratolytic features by inducing acanthloysis through targeting the desmosomal dense plaque, leading to detachment of the desmosomes from the tonofilaments. There are two available liquid preparations for dermatologic use, Canthacur (0.7% cantharidin) and Canthacur PS (1% cantharidin 30%/salicylic acid/2% podophylotoxin). The former preparation is indicated for the treatment of common warts, periungual warts, and molluscum contagiosum, while the more potent latter preparation is indicated only for plantar warts. Both preparations provide painless applications with outcomes similar to other treatment modalities for warts and molluscum contagiosum; however, neither is approved by the Food and Drug Administration (FDA). The lack of FDA approval could be related to its toxic effects following oral ingestion, which include ulceration of the gastrointestinal and genitourinary tracts, along with electrolyte and renal function disturbance in humans and animals. The mechanism of action, dermatologic indications, application techniques, and complications of cantharidin preparations are discussed.

[Application of cantharidin, podophyllotoxin, and salicylic acid in recalcitrant plantar warts. A preliminary study]

INTRODUCTION

Plantar warts often are refractory to any treatment and can last for decades in adults. Recalcitrant warts are defined as those that have persisted for more than two years, or after at least two treatment modalities.

METHODS

A total of 15 consecutive patients with recalcitrant plantar warts were included in this preliminary study. The treatment consisted of applying one to two sessions that comprised compounding 1% cantharidin, 5% of podophyllotoxin, and 30% salicylic acid (CPS), with an interval between applications of four weeks.

RESULTS

With treatment and subsequent follow-up for six months, there was complete eradication of lesions in 15 patients, eight (53.3%) required a single application of the solution, and seven (46.7%) two applications, with no side effects. Patient satisfaction related to treatment was measured by a visual analog scale (VAS) of 10 cm in length, with an average score 9.73 ± 0.46, and all said they would proceed with the treatment again if necessary.

CONCLUSIONS

Topical treatment by compounding is safe, effective, and a promising therapeutic modality when applied in recalcitrant plantar warts.

Cantharidin for the treatment of molluscum contagiosum: a prospective, double-blinded, placebo-controlled trial

Our aim was to study the effects and safety of cantharidin in the treatment of molluscum contagiosum (MC), we conducted a prospective, double-blinded, placebo-controlled, randomized clinical trial to evaluate the safety and efficacy of topical cantharidin for treatment of pediatric MC in an academic ambulatory care center. Twenty-nine children aged 5-10 with a diagnosis of MC were enrolled to receive treatment with cantharidin or placebo. The main outcome measure was complete clearance of all molluscum lesions. In contrast to previous retrospective observational studies, the performance of cantharidin treatment over 2 months was not substantially better than the performance of placebo. The scope of follow-up was limited to five visits over 2 months of treatment. A longer follow-up period might have captured a greater effect of cantharidin. Over a 2 month period, the magnitude of the cantharidin treatment effects in the target population are, at best, not large. This study provided objective unbiased estimates of the magnitude of cantharidin treatment effects and provided important prospective safety data. Our subjects experienced minimal side effects when treated with cantharidin.

Cantharidin: a comprehensive review of the clinical literature

BACKGROUND

Cantharidin is a topical vesicant that causes intraepidermal acantholysis with clinical application that includes the removal of warts, molluscum contagiosum (MC), calluses, and acquired perforating dermatoses.

OBJECTIVE

To provide a comprehensive literature review of the efficacy and safety of cantharidin in the management of various cutaneous conditions.

METHODS

A PubMed search was conducted using the term "cantharidin" combined with "warts", "plantar warts", "verruca vulgaris", "periungal", "subungual", "topical treatment", "topical therapy for warts", molluscum contagiosum", "perforating collagenosis," and "acantholysis."

RESULTS

A total of 749 articles were identified and 37 articles met inclusion criteria for this review. The majority of studies show that cantharidin is an effective and safe treatment for removal of warts and MC. Several studies also show potential novel applications of cantharidin in acquired perforating dermatosis, acute herpes zoster, and leishmaniasis. Adverse effects are generally mild but common and should be monitored, particularly in the pediatric population.

LIMITATIONS

There is a paucity of high-powered clinical studies involving the use of cantharidin.

CONCLUSION

Topical cantharidin is a safe and effective treatment for warts, molluscum contagiosum, and callus removal, with promising uses in perforating dermatoses and leishmaniasis.

Cantharidin-mediated ultrastructural and biochemical changes in mitochondria lead to apoptosis and necrosis in murine Dalton's lymphoma

Cantharidin, a type of terpenoid, is the blistering agent of blister beetles frequently used in traditional medicine. The isolation and anticancer activity of cantharidin from blister beetles, Mylabris cichorii has been recently reported by us. This study deals with changes in mitochondrial structure and function and understanding their significance in the underlying mechanism(s) in cantharidin-mediated antitumor effects in Dalton's lymphoma (DL) bearing mice. Cantharidin treatment caused the appearance of abnormal mitochondrial features which included roundish mitochondria with thickened membranes, irregularity in cristae, and appearance of small and large size vacuoles in mitochondria of DL cells. Cantharidin treatment resulted in a decrease in mitochondrial reduced glutathione, succinate dehydrogenase activity, mitochondrial membrane potential, and induced apoptosis and necrosis in DL cells. The decrease/release of mitochondrial cytochrome c were also observed after cantharidin treatment. Flow cytometry-based cell cycle analysis showed a time-dependent accumulation of the sub-G0 population of DL cells, thus, confirming the involvement of apoptosis in tumor cells in cantharidin-mediated antitumor activity. These finding signify that the apoptosis induced by cantharidin in DL cells should involve mitochondrial-dependent pathways. It is suggested that these cantharidin-mediated changes in mitochondria may play a crucial role in its antitumor activity.

Experimental study on the inhibitory effect of sodium cantharidinate on human hepatoma HepG2 cells

BACKGROUND

[corrected] Cantharidin, and its derivatives can not only inhibit the proliferation of tumor cells, but can also induce tumor cell apoptosis. It shows cantharidin exhibits a wide range of reactivity in anticancer. The objective of this paper was to study the inhibitory effect of sodium cantharidinate on human hepatoma HepG2 cells.

MATERIALS AND METHODS

MTT assay was used to detect the proliferation of HepG2 cells, and immunohisto-chemical method was used to detect the change in VEGF, protein level, and to determine the inhibitory effect of sodium cantharidinate on human hepatoma HepG2 cells.

RESULTS

As results, sodium cantharidinate significantly inhibited the growth of HepG2 cells in a time-and dose-dependent manner.

CONCLUSION

We conclude that sodium cantharidinate has an inhibitory effect on human hepatoma HepG2 cells.

[Comparative study of antitumor activity of cantharidin and cantharis peptides]

OBJECTIVE

To prepare cantharidin and cantharidin peptides from Mylabris and compare their antitumor activity.

METHODS

Cantharis peptides was prepared by bionic enzymolysis approach and cantharidin was prepared by alkaline water supersonic extraction. The inhibitory effects of both compounds on BEL-7402 cells proliferation of human liver cancer were tested by Prestoblue method. The influence of both compounds on the grown of tumor, thymus, spleen of S180 tumor-bearing mice were detected.

RESULTS

Cantharis peptides and cantharidin could inhibit the proliferation of BEL-7402 cells (P < 0.05) in vivo, and the inhibitory effect of cantharis peptide was 12.54% lower than that of cantharidin. At the same time, they could inhibit the grown of S180 sarcoma (P < 0.05), and the inhibitory effect of cantharidin was higher than that of cantharis peptides (5.93%). Furthermore, cantharis peptides could't inhibit the grown of thymus and spleen.

CONCLUSION

Both cantharis peptides and cantharidin have antineoplastic activity, but cantharidin peptides have no immunosuppression.

Antitumor effect of blister beetles: an ethno-medicinal practice in Karbi community and its experimental evaluation against a murine malignant tumor model

ETHNOPHARMACOLOGICAL IMPORTANCE

The blister beetles Epicauta hirticornis and Mylabris cichorii are used as a folk medicine by the Karbi tribe in Karbi Anglong district of Assam, India for the treatment of different human ailments, including cancer cases.

AIM OF THE STUDY

It includes field survey related to zoo-therapeutic aspects of two blister beetles in Karbi community, isolation of bio-active compound and evaluation of its antitumor potential with possible mode of action against murine Ehrlich ascites carcinoma (EAC).

MATERIALS AND METHODS

The main bio-active compound of blister beetles was isolated from ethyl acetate extract and the structure was confirmed as cantharidin using NMR, IR, Mass and X-ray diffractometer. The effect of cantharidin on apoptosis, necrosis, autophagy and the apoptosis related signaling pathways were determined using different bioassays, including cell cycle analysis, mitochondrial membrane potential, western blot analysis of cytochrome c, caspases 9, 3/7 assays, and lactate dehydrogenase (LDH) assay.

RESULTS

Cantharidin induced apoptosis, necrosis and autophagy cell death in EAC cells. The decrease in mitochondrial membrane potential was observed, which may help to release cytochrome c from mitochondria to cytosol. Cantharidin treatment caused up-regulation of caspases 9 and -3/7 and a decrease in LDH activity in EAC cells.

CONCLUSION

The major bioactive compound of these blister beetles is cantharidin which induces severe apoptosis in EAC cells involving mitochondrial intrinsic pathway. Cantharidin-mediated inhibition of LDH activity may lead to short supply of NAD(+) and cut off energy and anabolic supply to cancer cells.

Adjunctive trichloroacetic acid therapy enhances squaric acid response to verruca vulgaris

Squaric acid dibutyl ester (SADBE) is a commonly used treatment for verruca vulgaris of childhood. Few studies, however, have examined the role of SADBE in combination with other topical therapies for warts. We sought to determine if trichloroacetic acid 50% (TCA) and/or cantharidin 0.7% improve therapeutic response to SADBE. A retrospective chart review of 74 patients who were treated for warts at a pediatric dermatology practice in 2010 was performed. Cox regression analysis was used to identify determinants of 100% response to SADBE and found that number of warts was most important (P=0.002). Trichloroacetic acid + SADBE resulted in 100% clearance of warts in all subjects with the shortest time-to-clearance (hazard ratio [HR]: 2.45, 95% confidence interval [CI]: 1.14-5.25, P=0.02). In contrast, addition of cantharidin did not improve response to SADBE (HR: 1.13, 95% CI: 0.60-2.13, P=0.59) or TCA + SADBE (HR: 1.16, 95% CI: 0.65-2.07, P=0.61). These results suggest that combination treatment with TCA 50% and SADBE significantly improves the consistency and speed of SADBE-induced clearance of warts.

Insect natural products and processes: new treatments for human disease

In this overview, some of the more significant recent developments in bioengineering natural products from insects with use or potential use in modern medicine are described, as well as in utilisation of insects as models for studying essential mammalian processes such as immune responses to pathogens. To date, insects have been relatively neglected as sources of modern drugs although they have provided valuable natural products, including honey and silk, for at least 4-7000 years, and have featured in folklore medicine for thousands of years. Particular examples of Insect Folk Medicines will briefly be described which have subsequently led through the application of molecular and bioengineering techniques to the development of bioactive compounds with great potential as pharmaceuticals in modern medicine. Insect products reviewed have been derived from honey, venom, silk, cantharidin, whole insect extracts, maggots, and blood-sucking arthropods. Drug activities detected include powerful antimicrobials against antibiotic-resistant bacteria and HIV, as well as anti-cancer, anti-angiogenesis and anti-coagulant factors and wound healing agents. Finally, the many problems in developing these insect products as human therapeutic drugs are considered and the possible solutions emerging to these problems are described.

Spanish flies in the veterinary pharmacy in Skara--their medicinal use yesterday and to day

In the Veterinary Museum in Skara there is also an Animal Pharmacy. One bottle originating from the 18th century is labelled Tinct. Canthar. and thus contained an extract of Spanish flies. The active substance in such a tincture is cantharidin. The use and effects of this remedy in veterinary as well as human medicine are described. The use of cantharidin in the 18th century was linked to the predominant believe that illness was caused by imbalance of the four humours of the body. Its blistering effect was thought to "draw" superfluous liquid from the body. Its pronounced toxicity made its use to disappear, but it could still be found to be used in veterinary medicine as a blister and by undiscerning people as an aphrodisiac. Recent studies has shown cantharidin to possess antitumour effect--something that Dioscorides noted in his texts from around A.D. 40-80!

Cantharidin reverses multidrug resistance of human hepatoma HepG2/ADM cells via down-regulation of P-glycoprotein expression

Multidrug resistance (MDR) is a serious obstacle encountered in cancer treatment. In this study, we established an in vitro multiple drug resistant HepG2 cell line (HepG2/ADM), and characterized its MDR. This model was used to screen potential candidate chemosensitisers from over 200 purified naturally occurring compounds extracted from plants and animals. Cantharidin was found to have a significant reversal on MDR in our model. Further, our results showed that Cantharidin could significantly inhibit P-gp (P-glycoprotein) expression, mRNA transcription, as well as MDR1 promoter activity. These results suggest that Cantharidin is a novel and potent MDR reversal agent and may be a potential adjunctive agent for tumor chemotherapy.

Plantar warts: a focus on treatment modalities

Plantar warts are a common problem frequently seen by dermatologists and other practitioners with an interest in skin disease management. The diagnosis is often straightforward, but the treatment is difficult and lengthy. The available treatment options are reviewed.

Effect of cantharidin, cephalotaxine and homoharringtonine on "in vitro" models of hepatitis B virus (HBV) and bovine viral diarrhoea virus (BVDV) replication

The effect as antiviral agents versus viral hepatitis B and C of three compounds purified from natural products commonly used as remedies in traditional Chinese medicine, cantharidin, cephalotaxine and homoharingtonine, was investigated. To assess the activity of these compounds against flavivirus, we used bovine viral diarrhoea virus (BVDV) as a surrogate for hepatitis C virus (HCV). Anti-BVDV activity was determined by reduction in BVDV-RNA production and protection of infected embryonic bovine trachea (EBTr) cells against the cytopathic effect of BVDV. The effect versus hepatitis B virus (HBV) was investigated by measuring HBsAg and HBV-DNA release from hepatoblastoma HepG2 2.2.15 cells infected with HBV. As positive control we used the standard anti-HBV and anti-HCV drugs, lamivudine and ribavirin, respectively. Up to 100 microM lamivudine and ribavirin did not induce cell toxicity, whereas they induced dose-dependent anti-HBV and anti-BVDV effects, respectively. In the same range, cantharidin, cephalotaxine and homoharringtonine induced toxicity in EBTr cells and had no protective effect against BVDV. In contrast, they were able to inhibit HBV production at concentrations 10- to 100-fold lower than those inducing cell toxicity, which suggests that they are useless for the treatment of infection by flaviviruses, but potentially useful in combined therapy against hepatitis B.

Combination topical treatment of molluscum contagiosum with cantharidin and imiquimod 5% in children: a case series of 16 patients

The objective of this study was to assess the efficacy and tolerability of combination therapy for molluscum contagiosum (MC) with topical cantharidin and imiquimod 5%. A prospective case series of 16 paediatric patients with a mean age of 4.8 years had cantharidin applied to lesions by a dermatologist, followed by home treatment with imiquimod 5% cream nightly for an average of 5 weeks. This regimen resulted in >90% of lesions clearing in 12 patients, with half of these being totally clear. Two patients had 80-90% of lesions resolve. Two patients had 30-50% clearance of lesions at the end of the treatment period. One patient found the cantharidin reaction too strong. The mean number of imiquimod 250 mg sachets used was 4.25. In conclusion, this study suggests that combination therapy using cantharidin and imiquimod for treatment of MC in children is effective and well tolerated.

Pediatric molluscum contagiosum: optimal treatment strategies

Pediatric molluscum contagiosum virus (MCV) is a common pox viridae infection that represents a common public health issue. The spread of the virus among children is rapid and easy. The virus produces a number of substances that block immune response formation in the infected host. Despite the benign and self-limited nature of the condition, one-third of children have symptoms from, or secondary reactions to the infection, including pruritus, erythema and, occasionally, inflammation and pain. Patients with pruritus autoinoculate the virus through scratching, thereby exacerbating their conditions. While adults cope well with unanesthetized curettage of lesions, children require less painful therapeutic options. The options for therapy are manifold. Therapy should begin with gentle skin care and antipruritics to prevent symptoms, and to prevent the spread of the disease. Therapies with good efficacy and low risk of pain for the patient include in-office usage of cantharidin and the use of local anesthetics, such as topical lidocaine (lignocaine) preparations in combination with the curettage of visible lesions. Alternatively, cryosurgery can be performed to eradicate lesions in-office. At-home therapeutics are often preferred by parents and children, and include imiquimod, retinoids, and alpha-hydroxy acids. Although a variety of such at-home therapies are available, none are as effective or as rapid acting as in-office therapy. Further research in large clinical trials is required to increase knowledge on prevention, optimal treatment, and long-term outcome with this disease.

Serine/threonine protein phosphatase inhibition enhances the effect of thymidylate synthase inhibition

PURPOSE

The serine/threonine protein phosphatases 1 (PP1) and 2A (PP2A) are key enzymes in regulating entry into the cell cycle, mitosis and apoptosis. Inhibition of PP1 and PP2A is associated with enhanced S-phase entry culminating in G(2)/M arrest and apoptotic cell death. Thymidylate synthase (TS) is a key regulatory enzyme in DNA synthesis, inhibition of which is often a first-line treatment for colorectal carcinoma. In this study the effect of combining PP inhibition with TS inhibition in two colorectal cell lines was examined.

METHODS

Cantharidin and nolatrexed were used to inhibit PP and TS activity, respectively. The MTT cytotoxicity assay and cell cycle analysis were performed following single-drug treatment of HT29 and HCT116 colorectal cell lines. The median effect method was used to determine a combination index (CI), where drug antagonism was indicated by a CI>1.1, additivity by a CI between 0.9 and 1.1, and synergism by a CI<0.9.

RESULTS

Both cell lines were equally sensitive to cantharidin alone (GI(50) values 5.4 and 7.3 micro M), which induced a significant increase in the S-phase population of both cell lines within 6 h with a concomitant increase in DNA synthesis. This response culminated in G(2)/M cell cycle arrest within 24 h and subsequent cell death. In response to nolatrexed alone, HT29 cells were more sensitive than HCT116 cells (GI(50) 1.9 micro M vs 9.8 micro M), with G(1)/S-phase cell cycle arrest occurring within 24 h in both cell lines. In HT29 cells, this was followed by cell death, whereas in HCT116 cells, a proportion of cells died following arrest but the predominant event was re-entry into the cell cycle. The simultaneous exposure of HT29 cells to the combination of nolatrexed and cantharidin in drug molar ratios of 1:1 and 1:2.5 for 72 h was synergistic producing composite CIs of 0.88 and 0.87, respectively. The sequence of nolatrexed followed by cantharidin 24 h later resulted in greater synergism (CI values of 0.75, 0.52, 0.55, 0.68 for molar ratios of 10:1, 1:1, 1:2.5, 1:10), whereas the reverse sequence was antagonistic, suggesting that the point of interaction is downstream of TS inhibition. In HCT116 cells only additive and antagonistic interactions were observed for any of the treatment combinations. The lack of synergism in these cells may be caused by the reduced sensitivity of these cells to nolatrexed as a single agent.

CONCLUSION

The effect of TS inhibition can be enhanced by the inhibition of serine/threonine protein phosphatases.

Ken and Katie caterpillar: helpful props for treatment of molluscum contagiosum

A hand-made prop that aids in the efficient treatment of molluscum contagiosum with curettage or cantharidin is described. Small bandages or pieces of tape are affixed to a tongue depressor prior to the procedure so that they may be placed quickly over the treated molluscum. This improves time management and helps to reduce patient anxiety.

Cantharidin revisited: a blistering defense of an ancient medicine

Cantharidin, a vesicant produced by beetles in the order Coleoptera, has a long history in both folk and traditional medicine. In dermatology, topical cantharidin has long been used to treat warts and molluscum. In 1962, cantharidin lost Food and Drug Administration (FDA) approval owing to the failure of its manufacturers to submit data attesting to cantharidin's efficacy. However, it is expected that the FDA will soon include cantharidin on its "Bulk Substances List," which would permit physicians or pharmacists to compound cantharidin to be used in the office for individual patients. A comprehensive discussion of the origins, folk uses, current FDA status, current dermatologic uses, and effects of cantharidin poisoning has been compiled herein. No cases of systemic intoxication or scarring have been reported with the proper use of cantharidin by a physician. Cantharidin is a safe and valuable medication and should be readded to the dermatologic therapeutic armamentarium.

Childhood molluscum contagiosum: experience with cantharidin therapy in 300 patients

BACKGROUND

Molluscum contagiosum (MC) is a common cutaneous infection in children. Cantharidin, a chemovesicant that is highly effective in treating MC, has lost favor with some physicians because of concerns over its safety.

OBJECTIVE

We attempted to determine the safety, efficacy, and parental satisfaction of cantharidin therapy for MC in children who were treated in a pediatric dermatology clinic at a large referral hospital.

METHODS

A total of 537 charts of children who presented with MC were reviewed. We found 300 children who were treated with cantharidin and who had parents available for telephone interview, which was performed in addition to chart review.

RESULTS

With cantharidin therapy, 90% of patients experienced clearing and 8% improved. The average number of treatment visits was 2.1. Blisters occurred at sites of application in 92% of patients. Temporary burning, pain, erythema, or pruritus was reported in 6% to 37% of patients. No major side effects were reported, and no patients experienced secondary bacterial infection. A total of 95% of parents reported they would proceed with cantharidin therapy again.

CONCLUSION

To our knowledge ours is the largest retrospective series of childhood MC treated with cantharidin. In these patients the therapy was extremely effective and well tolerated, and parental satisfaction was high. Cantharidin is a safe and effective therapy for MC in children.

Pulsed-dye laser versus conventional therapy in the treatment of warts: a prospective randomized trial

BACKGROUND

The clinical management of verrucae vulgaris is often challenging, and no ideal treatment currently exists. Early studies suggested that pulsed-dye laser (PDL) therapy might be highly effective in the treatment of verrucae, although more recent reports have been less optimistic. Previous studies have been retrospective or have consisted of a series of patients treated with PDL alone.

OBJECTIVE

Our objective was to prospectively evaluate the efficacy of PDL therapy versus conventional therapy with liquid nitrogen cryotherapy or cantharidin in the treatment of warts.

METHODS

Forty healthy adult patients with verrucae were randomized to receive either PDL (585 nm) therapy or conventional therapy. All enrollees also performed home therapy. Patients were eligible for up to 4 treatment sessions at 1-month intervals. Warts were individually counted and measured at the time of each treatment session. Complete response was defined as complete absence of verrucae with the presence of dermatoglyphics, and partial response was defined as a 50% or greater reduction in wart size.

RESULTS

A total of 194 warts were evaluated by the conclusion of the study. Complete response was noted in an average of 70% of the warts treated with conventional therapy and in 66% of those in the PDL group; this was statistically insignificant. Partial response was observed in an average of 82% of the warts in patients treated with conventional therapy and 87% in the PDL group. Verruca vulgaris responded more readily than verruca plantaris in both treatment groups. The mean number of treatments to achieve success was similar in both groups.

CONCLUSION

The PDL is an efficacious form of therapy for verrucae, as is conventional therapy. PDL therapy should be considered among the better established approaches in the treatment of warts, although data from this trial suggest that this approach is probably not superior.

Office therapy for human papillomavirus infection in nongenital sites

The many different treatment possibilities for the eradication of warts provide evidence that no single method that is completely effective has been found. Although the various methods described herein are usually successful therapies for warts, they are all associated with treatment failures and side effects. Until the perfect cure for warts is discovered, the physician must evaluate every wart carefully before deciding on a course of action.

Cantharis in the early treatment of minor burns

The analgesic action of the homeopathic preparation Cantharis in the treatment of minor burns was assessed in a series of 34 patients. Under double blind conditions no statistically significant difference was found between Cantharis and a placebo.

Treatment of plantar warts in children with a salicylic acid-podophyllin-cantharidin product

One hundred and twenty-one children with plantar warts were treated with a topical preparation containing salicylic acid, 30%; podophyllin, 5%; and cantharidin, 1%. One hundred patients or their families were reached 6 months to 1 year later. This treatment was effective in 81 cases.