Ultrastructural changes in Tritrichomonas foetus after treatments with AlPcS4 and photodynamic therapy

Anti-trichomonad activities of different compounds from foods, marine products, and medicinal plants: a review

Human trichomoniasis, caused by the pathogenic parasitic protozoan Trichomonas vaginalis, is the most common non-viral sexually transmitted disease that contributes to reproductive morbidity in affected women and possibly to prostate cancer in men. Tritrichomonas foetus strains cause the disease trichomoniasis in farm animals (cattle, bulls, pigs) and diarrhea in domestic animals (cats and dogs). Because some T. vaginalis strains have become resistant to the widely used drug metronidazole, there is a need to develop alternative treatments, based on safe natural products that have the potential to replace and/or enhance the activity of lower doses of metronidazole. To help meet this need, this overview collates and interprets worldwide reported studies on the efficacy of structurally different classes of food, marine, and medicinal plant extracts and some of their bioactive pure compounds against T. vaginalis and T. foetus in vitro and in infected mice and women. Active food extracts include potato peels and their glycoalkaloids α-chaconine and α-solanine, caffeic and chlorogenic acids, and quercetin; the tomato glycoalkaloid α-tomatine; theaflavin-rich black tea extracts and bioactive theaflavins; plant essential oils and their compounds (+)-α-bisabolol and eugenol; the grape skin compound resveratrol; the kidney bean lectin, marine extracts from algae, seaweeds, and fungi and compounds that are derived from fungi; medicinal extracts and about 30 isolated pure compounds. Also covered are the inactivation of drug-resistant T. vaginalis and T. foetus strains by sensitized light; anti-trichomonad effects in mice and women; beneficial effects of probiotics in women; and mechanisms that govern cell death. The summarized findings will hopefully stimulate additional research, including molecular-mechanism-guided inactivations and human clinical studies, that will help ameliorate adverse effects of pathogenic protozoa.

Comparison of the synergistic anticancer activity of AlPcS4 photodynamic therapy in combination with different low‑dose chemotherapeutic agents on gastric cancer cells

Limited cellular delivery and internalization efficiency of Al(III) phthalocyanine chloride tetrasulfonic acid (AlPcS₄) induce poor penetration ability in cells and a slight photodynamic therapy (PDT) effect on gastric cancer. The combination treatment of AlPcS₄/PDT with low-dose chemotherapeutic agents may provide a promising treatment strategy to increase the weak delivery efficiency of AlPcS₄, reducing the dose of chemical agents without reducing efficacy, and improving apoptosis-inducing abilities, thereby increasing the antitumor effects and decreasing the noxious side effects on gastric cancer. We investigated and compared the synergistic antitumor growth effect on gastric cancer cells by combining AlPcS₄/PDT treatment with different low-dose chemotherapeutic agents, namely, 5-fluorouracil (5-FU), doxorubicin (DOX), cisplatin (CDDP), mitomycin C (MMC), and vincristine (VCR). The inhibitory effect was increased in treatments that combined AlPcS₄/PDT with all the aforementioned low-dose chemotherapeutic agents, to a different extent. An evident synergistic effect was obtained in the combination treatment of AlPcS₄/PDT with low-dose 5-FU, DOX, and MMC by increasing AlPcS₄ intracellular uptake ability, improving apoptosis-inducing abilities, and prolonging apoptosis-inducing time. The low-dose chemotherapeutic agents prolonged the apoptosis-inducing period of AlPcS₄/PDT, and AlPcS₄/PDT quickly improved apoptosis-inducing abilities of chemotherapy even at low doses. Generally, the combination treatment of AlPcS₄/PDT with low-dose chemotherapeutic agents had significant antitumor growth effects in addition to a low dark-cytotoxicity effect on gastric cancer, thereby representing an effective and feasible therapy method for gastric cancer.

AlPcS4-PDT for gastric cancer therapy using gold nanorod, cationic liposome, and Pluronic® F127 nanomicellar drug carriers

Purpose

As a promising photodynamic therapy (PDT) agent, Al(III) phthalocyanine chloride tetrasulfonic acid (AlPcS₄) provides deep penetration into tissue, high quantum yields, good photostability, and low photobleaching. However, its low delivery efficiency and high binding affinity to serum albumin cause its low penetration into cancer cells, further limiting its PDT effect on gastric cancer. In order to improve AlPcS₄/PDT effect, the AlPcS₄ delivery sys tems with different drug carriers were synthesized and investigated.

Materials and methods

Gold nanorods, cationic liposomes, and Pluronic^® F127 nanomicellars were used to formulate the AlPcS₄ delivery systems. The anticancer effect was evaluated by CCK-8 assay and colony formation assay. The delivery efficiency of AlPcS₄ and the binding affinity to serum proteins were determined by fluorescence intensity assay. The apoptosis and necrosis ability, reactive oxygen species and singlet oxygen generation, mitochondrial transmembrane potential and ([Ca²⁺]_i) concentration were further measured to evaluate the mechanism of cell death.

Results

The series of synthesized AlPcS₄ delivery systems with different drug carriers improve the limited PDT effect in varying degrees. In contrast, AlPcS₄ complex with gold nanorods has significant anticancer effects because gold nanorods are not only suitable for AlPcS₄ delivery, but also exhibit enhanced singlet oxygen generation effect and photothermal effect to induce cell death directly. Moreover, AlPcS₄ complex with cationic liposomes shows the potent inhibition effect because of its optimal AlPcS₄ delivery efficiency and ability to block serum albumin. In addition, AlPcS₄ complex with Pluronic F127 exhibits inferior PDT effect but presents lower cytotoxicity, slower dissociation rate, and longer retention time of incorporated drugs; thus, F127–AlPcS₄ is used for prolonged gastric cancer therapy.

Conclusion

The described AlPcS₄ drug delivery systems provide promising agents for gastric cancer therapy.

DNA analysis of cattle parasitic protozoan Tritrichomonas foetus after photodynamic therapy

Photodynamic therapy (PDT) is a modality of therapy that involves the activation of photosensitive substances and the generation of cytotoxic oxygen species and free radicals to promote the selective destruction of target tissues. This study analyzed the application of PDT to Tritrichomonas foetus, a scourged and etiological agent of bovine trichomoniasis, a sexually transmitted infectious disease. As it is an amitochondrial and aerotolerant protozoan, it produces energy under low O₂ tension via hydrogenosome. T. foetus from an axenic culture was incubated with photosensitizer tetrasulfonated aluminium phthalocyanine and then irradiated with a laser source (InGaAIP) at a density of 4.5Jcm^-2. The DNA integrity of the control and treated group parasites was analyzed by conventional gel electrophoresis and comet assay techniques. In previous results, morphological changes characterized by apoptotic cell death were observed after T. foetus was submitted to PDT treatment. In the treated groups, T. foetus DNA showed a higher concentration of small fragments, about 200pb, in gel electrophoresis after PDT. In the comet assay, the DNA tail percentage was significantly higher in the treated groups. These results demonstrate that PDT leads to DNA fragmentation with changes in nuclear morphology and apoptotic features.

Tritrichomonas foetus infection in cat - first detection in Poland

Tritrichomonas foetus, a parasite of cattle reproductive system, has been recently discovered as a cause of disease in cats in many countries. T. foetus infects and colonizes cat's ileum, caecum, colon and can lead to enteritis. This paper presents the first clinical case of cat intestinal trichomonosis caused by T. foetus in Poland. The material for this study was a smear collected from a 6-month-old male British Shorthair cat. The presence of parasitic protozoan was determined via microscopic examination and confirmed by amplification of T. foetus rDNA using polymerase chain reaction (PCR) technique. In the first PCR reaction, a DNA of Trichomonadidae was identified and in the second PCR, T. foetus was detected. The T. foetus positive products from the second PCR reaction were sequenced. Interpretation of the sequencing results of obtained amplicons by comparing them with the GenBank database proved that the causative agent, in this case, was T. foetus.

In vitro photodynamic therapy against Foncecaea pedrosoi and Cladophialophora carrionii

Photodynamic therapy (PDT) has been originally developed for cancer treatment, but recently, it has been successfully employed against microorganisms, including fungi. Chromoblastomycosis is a subcutaneous fungal infection that is recalcitrant to conventional antifungal drug therapy. The most frequent species involved are Foncecaea pedrosoi and Cladophialophora carrionii. The present study aimed to verify the efficacy in vitro of PDT employing methylene blue (MB) as a photosensitiser and Light emmiting diode (LED) (InGaAl) as the light source. Methylene blue at the concentrations of 16, 32 and 64 μg/mL and LED (InGalP) were employed for 15 min against spores of two isolates of F. pedrosoi and two isolates of C. carrionii. The spores were plated on Sabouraud Dextrose agar and the number of colony forming units was counted after 7-10 days of incubation at 37 °C. The PDT with MB and LED was efficient in reducing the growth of all samples tested. Better results were obtained for the concentration of 32 μg/mL of MB. The treatment proved to be highly effective in killing the samples of F. pedrosoi and Cladophialophora pedrosoi tested in vitro. PDT arises as a promising alternative for the treatment of this subcutaneous infection.

Intestinal Tritrichomonas foetus infection in cats in Switzerland detected by in vitro cultivation and PCR

Tritrichomonas foetus, a parasite well known for its significance as venereally transmitted pathogen in cattle, has recently been identified as a cause of chronic large-bowel diarrhea in domestic cats in the US, UK, and, more recently, also in Norway. In a period of 3 months (October to December 2007), 45 cats of Switzerland suffering from chronic diarrhea were investigated for intestinal infections, including a search for trichomonads. A commercially available in vitro culture system was used to screen for infection, complemented with a PCR and subsequent amplicon sequencing to support speciation. The PCR is based upon amplification of a sequence derived from the internal transcribed spacer region 1 (ITS1) on the ribosomal RNA gene (rRNA) using primers designed to detect a broad range of genera and species belonging to the family of Trichomonadidae. The method was furthermore adapted to the uracil DNA glycosylase (UDG) system in order to prevent carry-over contamination and it included a recombinant internal control to track for inhibitory reactions. Eleven out of the 45 cats were culture-positive, as revealed by microscopic identification of trichomonadid organisms. One of the isolates was subjected to scanning electron microscopy and findings revealed the presence of three flagella, thus placing the isolate into the gender Tritrichomonas sp. PCR and subsequent amplicon sequencing were carried out with ten of the 11 isolates. A total homology with published T. foetus sequences was confirmed in all of the cases. T. foetus therefore appears to range among those organisms that can cause chronic diarrhea in cats in Switzerland.

Photodynamic Therapy: Porphyrins and Phthalocyanines as Photosensitizers

The present work is focussed on the principles of photodynamic therapy (PDT), emphasizing the photochemical mechanisms of reactive oxygen species formation and the consequent biochemical processes generated by the action of reactive oxygen species on various biological macromolecules and organelles. This paper also presents some of the most used photosensitizers, including Photofrin, and the new prototypes of photosensitizers, analysing their physicochemical and spectroscopic properties. At this point, the review discusses the therapeutic window of absorption of specific wavelengths involving first- and second-generation photosensitizers, as well as the principal light sources used in PDT. Additionally, the aggregation process, which consists in a phenomenon common to several photosensitizers, is studied. J-aggregates and H-aggregates are discussed, along with their spectroscopic effects. Most photosensitizers have a significant hydrophobic character; thus, the study of the types of aggregation in aqueous solvent is very relevant. Important aspects of the coordination chemistry of metalloporphyrins and metallophthalocyanines used as photosensitizers are also discussed. The state-of-the-art in PDT is evaluated, discussing recent articles in this area. Furthermore, macrocyclic photosensitizers, such as porphyrins and phthalocyanines, are specifically described. The present review is an important contribution, because PDT is one of the most auspicious advances in the therapy against cancer and other non-malignant diseases.