Pluronic F-127: An Efficient Delivery Vehicle for 3-(1'-hexyloxy)ethyl-3-devinylpyropheophorbide-a (HPPH or Photochlor)

To determine the impact of delivery vehicles in photosensitizing efficacy of HPPH, a hydrophobic photosensitizer was dissolved in various formulations: 1% Tween 80/5% dextrose, Pluronic P-123 and Pluronic F-127 in 0.5%, 1% and 2% phosphate buffer solutions (PBS). HPPH was also conjugated to Pluronic F-127, and the resulting conjugate (PL-20) was formulated in PBS. Among the different delivery vehicles, only Pluronic P-123 displayed significant vehicle cytotoxicity, whereas Pluronic F127 was nontoxic. Compared to PL-20, HPPH formulated in Tween80 and Pluronic F-127 showed higher cell-uptake, but lower long-term retention in Colon26 cell compared to PL-20. The higher retention of PL-20 was similarly observed during in vivo uptake with BALB/c mice baring Ct26 tumors. In contrast to the in vitro uptake experiments, PL-20 showed slightly higher uptake compared to HPPH formulated in Tween or Pluronic-F127. A significant difference in pharmacokinetic profile was also observed between the HPPH-Pluronic formulation and PL-20. Under similar in vivo treatment parameters (drug dose 0.47 µmol kg^-1 , light dose: 135 J cm^-2 at 24 h post-injection of PS), HPPH formulated either in Tween or Pluronic F-127 formulation showed similar in vivo PDT efficacy (20-30% tumor cure on day 60), whereas PL-20 showed 40% tumor cure (day 60).

A bioactivatable self-quenched nanogel for targeted photodynamic therapy

Photodynamic therapy has attracted significant attention due to its localized treatment advantage. However, the non-specific distribution of photosensitizers and the subsequent potential toxicity caused by sunshine exposure hinder its wide adoption in cancer treatment. To minimize these unwanted effects and improve its efficacy, we developed a bioactivatable self-quenched nanogel, which remains in its inactive state in healthy tissues. Anti-EGFR Affibody decorated nanogels can effectively target head and neck cancer and release activated pheophorbide A in a reducing environment, such as in the tumor stroma and cytoplasm. Consequently, the EGFR targeted nanogel coupled with NIR irradiation alleviates tumor burden by 94.5% while not inducing systemic toxicity.

Pre-clinical compartmental pharmacokinetic modeling of 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH) as a photosensitizer in rat plasma by validated HPLC method

A second-generation chlorin-based photosensitizer, 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH) has shown tremendous therapeutic potential in clinical trials in the treatment of esophageal cancer. Herein, we have developed and validated a bioanalytical method for estimation of HPPH in rat plasma using High Performance Liquid Chromatography (HPLC) with a photo diode array (PDA) detector. The method was applied for carrying out pharmacokinetic study of HPPH. Further pharmacokinetic modeling was carried out to understand the compartment kinetics of HPPH. The developed method was fully validated as per the United States Food and Drug Administration (US-FDA) guidelines for bioanalytical method validation. The linearity of the method was in the range of 250-8000 ng mL-1, and the plasma recovery was found to be 70%. Pharmacokinetic parameters were evaluated and compared via non-compartment analysis and compartment modeling after the intravenous (i.v.) bolus administration in rats using Phoenix WinNonlin 8.0 (Certara™, USA). From the obtained results, we hypothesize that the HPPH complies with two compartmental pharmacokinetic model. Furthermore, it was observed that HPPH has the rapid distribution from the central compartment to peripheral compartment along with slow elimination from peripheral compartment.

N-(2-hydroxypropyl)methacrylamide polymer conjugated pyropheophorbide-a, a promising tumor-targeted theranostic probe for photodynamic therapy and imaging

Tumor-targeted photodynamic therapy (PDT) using polymeric photosensitizers is a promising therapeutic strategy for cancer treatment. In this study, we synthesized a pHPMA conjugated pyropheophorbide-a (P-PyF) as a cancer theranostic agent for PDT and photodynamic diagnostics (PDD). Pyropheophorbide-a has one carboxyl group which was conjugated to pHPMA via amide bond yielding the intended product with high purity. In aqueous solutions, P-PyF showed a mean particle size of ∼200 nm as it forms micelle which exhibited fluorescence quenching and thus very little singlet oxygen (¹O₂) production. In contrast, upon disruption of micelle strong fluorescence and ¹O₂ production were observed. In vitro study clearly showed the PDT effect of P-PyF. More potent ¹O₂ production and PDT effect were observed during irradiation at ∼420 nm, the maximal absorbance of pyropheophorbide-a, than irradiation at longer wavelength (i.e., ∼680 nm), suggesting selection of proper absorption light is essential for successful PDT. In vivo study showed high tumor accumulation of P-PyF compared with most of normal tissues due to the enhanced permeability and retention (EPR) effect, which resulting in superior antitumor effect under irradiation using normal xenon light source of endoscope, and clear tumor imaging profiles even in the metastatic lung cancer at 28 days after administration of P-PyF. On the contrary irradiation using long wavelength (i.e., ∼680 nm), the lowest Q-Band, exhibited remarkable tumor imaging effect with little autofluorescence of background. These findings strongly suggested P-PyF may be a potential candidate-drug for PDT/PDD, particularly using two different wavelength for treatment and detection/imaging, respectively.

Soy Leaf Extract Containing Kaempferol Glycosides and Pheophorbides Improves Glucose Homeostasis by Enhancing Pancreatic β-Cell Function and Suppressing Hepatic Lipid Accumulation in db/db Mice

This study investigated the molecular mechanisms underlying the antidiabetic effect of an ethanol extract of soy leaves (ESL) in db/db mice. Control groups (db/+ and db/db) were fed a normal diet (ND), whereas the db/db-ESL group was fed ND with 1% ESL for 8 weeks. Dietary ESL improved glucose tolerance and lowered plasma glucose, glycated hemoglobin, HOMA-IR, and triglyceride levels. The pancreatic insulin content of the db/db-ESL group was significantly greater than that of the db/db group. ESL supplementation altered pancreatic IRS1, IRS2, Pdx1, Ngn3, Pax4, Ins1, Ins2, and FoxO1 expression. Furthermore, ESL suppressed lipid accumulation and increased glucokinase activity in the liver. ESL primarily contained kaempferol glycosides and pheophorbides. Kaempferol, an aglycone of kaempferol glycosides, improved β-cell proliferation through IRS2-related FoxO1 signaling, whereas pheophorbide a, a product of chlorophyll breakdown, improved insulin secretion and β-cell proliferation through IRS1-related signaling with protein kinase A in MIN6 cells. ESL effectively regulates glucose homeostasis by enhancing IRS-mediated β-cell insulin signaling and suppressing SREBP-1-mediated hepatic lipid accumulation in db/db mice.

9-Hydroxypheophorbide α-mediated photodynamic therapy induces matrix metalloproteinase-2 (MMP-2) and MMP-9 down-regulation in Hep-2 cells via ROS-mediated suppression of the ERK pathway

BACKGROUND

Photodynamic therapy (PDT) is a promising treatment modality for malignant diseases through the generation of reactive oxygen species (ROS). In this study, we assessed the change of migration and invasion of HEp-2 cells after sublethal doses of 9-hydroxypheophorbide α (9-HPbD)-mediated PDT in vitro, and explored the role of ROS in 9-HPbD-PDT-induced anti-metastatic effects in HEp-2 cells.

METHODS

Following PDT, ROS were measured by a fluorescence microscope in both the presence and absence of glutathione (GSH) pretreatment. Wound healing assay, cell migration assay, and matrigel invasion assay were used to evaluate the cellular migration and invasion. Western blot was performed to investigate the signaling pathways that may have been involved.

RESULTS

ROS were rapidly generated in 9-HPbD-loaded HEp-2 laryngeal cancer cells by the activation of a diode laser and were significantly inhibited by a 6-h GSH pretreatment. Wound healing assay, cell migration assay, and matrigel invasion assay showed that sublethal PDT significantly suppressed the migration and invasion of HEp-2 cells. GSH decreased the ability of PDT to inhibit the invasion of HEp-2 cells. Western blot analysis showed that PDT significantly inhibited the phosphorylation of MEK1/2 and ERK1/2, and significantly suppressed the expression of MMP-2 and MMP-9 after 24h following the implementation of sublethal PDT, and these efficacies of PDT could be abrogated by GSH pretreatment.

CONCLUSIONS

9-HPbD-PDT attenuated the migration and invasion of HEp-2 cells in vitro, which may be related to the down-regulated expression of MMP-2 and MMP-9 via ROS-mediated-inhibition of phosphorylation in the ERK/MEK signaling pathway.

Synergistic effects of photodynamic therapy with HPPH and gemcitabine in pancreatic cancer cell lines

BACKGROUND AND OBJECTIVE

Photodynamic therapy (PDT) is a potential treatment for pancreatic cancer. A second-generation photosensitizer, 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide (HPPH) has a long wavelength absorption, high-tumor selectivity, and shorter duration of skin photosensitivity. We investigated the efficacy of PDT with HPPH and gemcitabine in inducing cell death in multiple pancreatic cancer cell lines.

METHODS

We used three pancreatic cancer cell lines (PANC-1, MIA PaCa-2, and BXPC-3) incubated with HPPH concentration of 0, 0.005, 0.01, 0.025, 0.05, 0.1, 0.25, and 0.5 µg/ml for 6 hours, followed by photoradiation at a light dose of 60 J/cm(2). Afterwards, each cell line was treated with gemcitabine at concentrations of 0, 1, 10, and 100 µM and incubated for another 96 hours. Cell death was detected with SYTOX green staining. We also assessed the difference in cytotoxicity in adding gemcitabine before and after PDT.

RESULTS

HPPH-PDT can effectively induce cell death in all cell lines in a dose-dependent manner, with a 100% of cell death at the 0.5 µg/ml HPPH concentration. In contrast, monotherapy with gemcitabine alone (100 µM) only achieved <45% cell death. Combining gemcitabine to HPPH-PDT resulted in synergistic cytotoxic effect with 20-50% more cell death across all cell lines. There was no difference in cytotoxicity in adding gemcitabine before or after PDT.

CONCLUSION

This is the first study on HPPH-PDT for pancreatic cancer. HPPH-PDT-induced cell death occurs in a dose-dependent manner. HPPH-PDT and gemcitabine have synergistic effects in inducing cell death in multiple pancreatic cancer cell lines.

[Rational prophylaxis of purulent-septic complications of the soft tissue in ambulatory-outpatient conditions]

The results of investigation are adduced, concerning impact of ultraviolet irradiation and electric field of ultrahigh frequency in conjunction with local application of 1% ethanol solution of chlorophyllipt, using bandage, on prevention of purulent-septic complications occurrence with the soft tissues affection. There were operated on 107 patients. In 56 patients the proposed scheme of purulent-septic complications prophylaxis was applied. This permits to exclude the systemic application of antibiotics for prophylaxis after "clean" operations performance.

Enhanced apoptotic effect of combined modality of 9-hydroxypheophorbide alpha-mediated photodynamic therapy and carboplatin on AMC-HN-3 human head and neck cancer cells

Photodynamic therapy (PDT) has been developed as an effective treatment for malignant disease. Carboplatin (CBDCA), a less nephrotoxic analog of cisdiamminedichloroplatinum (cisplatin), has been widely used for the treatment of multiple malignancies. In this study, we investigated the cytotoxic and apoptotic effect of combined modality of 9-hydroxypheophorbide alpha (9-HPbD)-mediated PDT and CBDCA on AMC-HN-3 human head and neck cancer cell line in vitro. The attached AMC-HN-3 cells were incubated with CBDCA (0.04 mg/ml) for 24 h at 37 degrees C and followed by photosensitization with 9-HPbD for 6 h and laser irradiation with 670 nm diode laser at an intensity of 2.0 J/cm(2) for activating 9-HPbD for 15 min. Then MTT reduction assay and Hoechst 33342 and propidium iodide (PI) double staining were used respectively to measure the cytotoxicity and nuclear morphology at 24 h after PDT. Expression of caspase-3, -9 and poly(ADP-ribose) polymerase (PARP) was detected at 0, 3, 6 and 12 h after irradiation through Western blotting techniques. Compared with PDT and CBDCA alone groups, there was more cytotoxicity and enhanced apoptotic cell death in combination groups. The peaked expression of cleaved form of caspase-3, -9 and PARP occurred approximately 3 h after PDT. There was stronger expression of cleaved caspase-3, -9 and PARP in combination groups than that in PDT or CBDCA alone groups. This study demonstrates that the combined modality resulted in enhanced apoptotic cell death as well as cytotoxic effect on AMC-HN-3 cells in vitro, which suggests the feasibility of combined modality and the possibility of reducing the effective dosage of 9-HPbD and CBDCA and lowering the side effects on normal cells.

Light delivery over extended time periods enhances the effectiveness of photodynamic therapy

PURPOSE

The rate of energy delivery is a principal factor determining the biological consequences of photodynamic therapy (PDT). In contrast to conventional high-irradiance treatments, recent preclinical and clinical studies have focused on low-irradiance schemes. The objective of this study was to investigate the relationship between irradiance, photosensitizer dose, and PDT dose with regard to treatment outcome and tumor oxygenation in a rat tumor model.

EXPERIMENTAL DESIGN

Using the photosensitizer HPPH (2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide), a wide range of PDT doses that included clinically relevant photosensitizer concentrations was evaluated. Magnetic resonance imaging and oxygen tension measurements were done along with the Evans blue exclusion assay to assess vascular response, oxygenation status, and tumor necrosis.

RESULTS

In contrast to high-incident laser power (150 mW), low-power regimens (7 mW) yielded effective tumor destruction. This was largely independent of PDT dose (drug-light product), with up to 30-fold differences in photosensitizer dose and 15-fold differences in drug-light product. For all drug-light products, the duration of light treatment positively influenced tumor response. Regimens using treatment times of 120 to 240 min showed marked reduction in signal intensity in T2-weighted magnetic resonance images at both low (0.1 mg/kg) and high (3 mg/kg) drug doses compared with short-duration (6-11 min) regimens. Significantly greater reductions in pO(2) were observed with extended exposures, which persisted after completion of treatment.

CONCLUSIONS

These results confirm the benefit of prolonged light exposure, identify vascular response as a major contributor, and suggest that duration of light treatment (time) may be an important new treatment variable.

Low-dose dietary chlorophyll inhibits multi-organ carcinogenesis in the rainbow trout

We recently reported that chlorophyll (Chl) strongly inhibits aflatoxin B(1) preneoplasia biomarkers in rats when administered by co-gavage (Simonich et al., 2007. Natural chlorophyll inhibits aflatoxin B1-induced multi-organ carcinogenesis in the rat. Carcinogenesis 28, 1294-1302.). The present study extends this by examining the effects of dietary Chl on tumor development, using rainbow trout to explore ubiquity of mechanism. Duplicate groups of 140 trout were fed diet containing 224 ppm dibenzo[a,l]pyrene (DBP) alone, or with 1000-6000 ppm Chl, for 4 weeks. DBP induced high tumor incidences in liver (51%) and stomach (56%), whereas Chl co-fed at 2000, 4000 or 6000 ppm reduced incidences in stomach (to 29%, 23% and 19%, resp., P<0.005) and liver (to 21%, 28% and 26%, resp., P<0.0005). Chlorophyllin (CHL) at 2000 ppm gave similar protection. Chl complexed with DBP in vitro (2Chl:DBP, K(d1)=4.44+/-0.46 microM, K(d2)=3.30+/-0.18 microM), as did CHL (K(d1)=1.38+/-0.32 microM, K(d2)=1.17+/-0.05 microM), possibly explaining their ability to inhibit DBP uptake into the liver by 61-63% (P<0.001). This is the first demonstration that dietary Chl can reduce tumorigenesis in any whole animal model, and that it may do so by a simple, species-independent mechanism.

Excretion of causative PCDFs congeners of Yusho by one year intake of FBRA in patients with Yusho

Thirty-eight years have passed since the outbreak of Kanemi rice oil poisoning, namely, Yusho in the western Japan. However, even now the patients with Yusho have been still suffering from several objective and subjective symptoms. In order to improve or, if possible, to cure the such symptoms, the most important therapeutic treatment is considered to actively excrete the causative agents, that is, polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) from the bodies of the patients and to reduce their body burdens. In rats, dietary fiber and chlorophyll have been shown to promote the fecal excretion of dioxins and to reduce their levels in rat liver. In this study, we examined whether such kinds of effect were also observed by FBRA, which was the health food and relatively rich with dietary fiber and chlorophyll, in eighteen patients with Yusho, which were divided into two groups, namely group A, ten patients (Male: 3 and Female: 7) with the mean age of 67.7 years old and group B, eight patients (Male: 4 and Female: 4) with the mean age of 64.1 years. Respective mean concentrations of the three PCDF congeners, that is, 2,3,4,7,8-PenCDF, 1,2,3,4,7,8-HxCDF and 1,2,3,6,7,8-HxCDF in the blood on whole weight basis just before initiating this study were as follows; group A: 1.36, 0.491 and 0.150 pg/g, and group B: 0.571, 0.159 and 0. 064 pg/g. Contamination levels of these PCDF congeners in group A were 2 to 3 times higher than those in group B. Group A took 7.0 to 10.5g of FBRA after each meal and tree times a day for the first one year and for second one year, they did not take FBRA any more. Group B took FBRA with the same manner as the group A only for the second one year. The concentrations of these PCDFs congeners in the blood of groups A and B were also measured at the end of first and second year, respectively. Assuming that the lipid content of the blood is 0.3% in order to convert their concentrations on whole weight basis to those on lipid weight basis and also that the body fat is contaminated with these PCDF congeners at their concentrations on lipid weight basis and the content of body fat is 20% of the body weight (60 kg), we computed the average amounts in the net excretion of these PCDF congeners from the body of the patients due to the intake of FBRA in groups A and B. As a result, in group A, 120, 372 and 96 ng/patient of 2,3,4,7,8-PenCDF, 1,2,3,4,7,8-HxCDF and 1,2,3,6,7,8-HxCDF, respectively, were excreted from the body of the patients. In group B, however, 36 ng/patient of 2,3,4,7,8-PenCDF only was excreted, but other two PCDF congeners were not. Accordingly, promotive excretion of theses PCDF congeners from the patients with Yusho seemed much effective in group A, of which their concentrations in the blood were much higher than those of group B.

Natural chlorophyll inhibits aflatoxin B1-induced multi-organ carcinogenesis in the rat

Chemoprevention by chlorophyll (Chl) was investigated in a rat multi-organ carcinogenesis model. Twenty-one male F344 rats in three gavage groups (N = 7 rats each) received five daily doses of 250 microg/kg [(3)H]-aflatoxin B(1) ([(3)H]-AFB(1)) alone, or with 250 mg/kg chlorophyllin (CHL), or an equimolar amount (300 mg/kg) of Chl. CHL and Chl reduced hepatic DNA adduction by 42% (P = 0.031) and 55% (P = 0.008), respectively, AFB(1)-albumin adducts by 65% (P < 0.001) and 71% (P < 0.001), respectively, and the major AFB-N(7)-guanine urinary adduct by 90% (P = 0.0047) and 92% (P = 0.0029), respectively. To explore mechanisms, fluorescence quenching experiments established formation of a non-covalent complex in vitro between AFB(1) and Chl (K(d) = 1.22 +/- 0.05 microM, stoichiometry = 1Chl:1AFB(1)) as well as CHL (K(d) = 3.05 +/- 0.04 microM; stoichiometry = 1CHL:1AFB(1)). The feces of CHL and Chl co-gavaged rats contained 137% (P = 0.0003) and 412% (P = 0.0048) more AFB(1) equivalents, respectively, than control feces, indicating CHL and Chl inhibited AFB(1) uptake. However, CHL or Chl treatment in vivo did not induce hepatic quinone reductase (NAD(P)H:quinone oxidoreductase) or glutathione S-transferase (GST) above control levels. These results are consistent with a mechanism involving complex-mediated reduction of carcinogen uptake, and do not support a role for phase II enzyme induction in vivo under these conditions. In a second study, 30 rats in three experimental groups were dosed as in study 1, but for 10 days. At 18 weeks, CHL and Chl had reduced the volume percent of liver occupied by GST placental form-positive foci by 74% (P < 0.001) and 77% (P < 0.001), respectively compared with control livers. CHL and Chl reduced the mean number of aberrant crypt foci per colon by 63% (P = 0.0026) and 75% (P = 0.0004), respectively. These results show Chl and CHL provide potent chemoprotection against early biochemical and late pathophysiological biomarkers of AFB(1) carcinogenesis in the rat liver and colon.

Inactivation of methicillin-resistant Staphylococcus aureus (MRSA) by liposome-delivered photosensitising agents

The uptake of two photosensitising agents (hematoporphyrin and chlorophyll a) by a highly pathogenic bacterium, namely methicillin-resistant Staphylococcus aureus (MRSA), has been studied by using unilamellar liposomes of different size, fluidity and electric charge as carriers. Optimal results are obtained by using hematoporphyrin embedded in fluid cationic vesicles composed by the monocationic lipid N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium methylsulfate (DOTAP), which yield an endocellular concentration of photosensitiser much higher than that obtained by incubation of the cells with the free porphyrin, yet promote a tighter binding and a more efficient photoinactivation of MRSA. Apparently, the photosensitiser is successfully transferred from the liposome to the bacterial cells when the presence of the tetrapyrrolic derivative does not appreciably perturb the native three-dimensional organisation of the lipid vesicle, such as it occurs with hematoporphyrin. On the other hand, chlorophyll, which causes a marked structural alteration of the DOTAP vesicles as shown by electron microscopy and fluorescence anisotropy measurements, does not show any detectable photocytotoxicity toward MRSA, contrary to what observed for the free dye.

Tumor Vascular Response to Photodynamic Therapy and the Antivascular Agent 5,6-Dimethylxanthenone-4-Acetic Acid: Implications for Combination Therapy

PURPOSE

Photodynamic therapy (PDT) is a clinically approved treatment for a variety of solid malignancies. 5,6-Dimethylxanthenone-4-acetic acid (DMXAA) is a potent vascular targeting agent that has been shown to be effective against a variety of experimental rodent tumors and xenografts and is currently undergoing clinical evaluation. We have previously reported that the activity of PDT against transplanted mouse tumors is selectively enhanced by DMXAA. In the present study, we investigated the in vivo tumor vascular responses to the two treatments given alone and in combination.

EXPERIMENTAL DESIGN

Vascular responses to (i) four different PDT regimens using the photosensitizer 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH) at two different fluences (128 and 48 J/cm(2)) and fluence rates (112 and 14 mW/cm(2)), (ii) 5-aminolevulinic acid (ALA)-sensitized PDT (135 J/cm(2) at 75 mW/cm(2)), (iii) DMXAA at a high (30 mg/kg) and low dose (25 mg/kg), and (iv) the combination of HPPH-PDT (48 J/cm(2) at 112 mW/cm(2)) and low-dose DMXAA were studied in BALB/c mice bearing Colon-26 tumors.

RESULTS

PDT-induced changes in vascular permeability, determined using noninvasive magnetic resonance imaging with a macromolecular contrast agent, were regimen dependent and did not predict tumor curability. However, a pattern of increasing (4 hours after treatment) and then decreasing (24 hours after) contrast agent concentrations in tumors, seen after high-dose DMXAA or the combination of PDT and low-dose DMXAA, was associated with long-term cure rates of >70%. This pattern was attributed to an initial increase in vessel permeability followed by substantial endothelial cell damage (CD31 immunohistochemistry) and loss of blood flow (fluorescein exclusion assay). Low dose-rate PDT, regardless of the delivered dose, increased the level of magnetic resonance contrast agent in peritumoral tissue, whereas treatment with either DMXAA alone, or PDT and DMXAA in combination resulted in a more selective tumor vascular response.

CONCLUSIONS

The observed temporal and spatial differences in the response of tumor vessels to PDT and DMXAA treatments could provide valuable assistance in the optimization of scheduling when combining these therapies. The combination of PDT and DMXAA provides therapeutically synergistic and selective antitumor activity. Clinical evaluation of this combination is warranted.

Promotive excretion of causative agents of Yusho by one year intake of FBRA in Japanese people

Thirty-six years have passed since the outbreak of Kanemi rice oil poisoning, namely, Yusho in the western Japan. However, even now the patients with Yusho have been still suffering from several objective and subjective symptoms. In order to improve or, if possible, to cure the such symptoms, the most important therapeutic treatment is considered to actively excrete the causative agents, that is, polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) from the bodies of the patients and to reduce their body burdens. In rats, dietary fiber and chlorophyll have been shown to promote the fecal excretion of dioxins and to reduce their levels in rat liver. In this study, we examined whether such kinds of effect were also observed by FBRA, which was the health food and relatively rich with dietary fiber and chlorophyll, in nine married Japanese couples. As a result, concentrations of PCDFs and PCDDs on the lipid weight basis in the blood of the FBRA-intake group in which they took 7.0 to 10.5g of FBRA after each meal and three times a day for one year were more lowered than those in the blood of the non-intake group; Blood levels of PCDFs and PCDDs in the FBRA-intake group were decreased by 41.0 and 37.2%, respectively, and those decreases were 33.7 and 29.4% in the non-intake group. Their total body burdens just before and one year after the study were calculated on the assumptions that the body fat was also contaminated with these dioxins at their blood levels on the lipid weight basis and the content of body fat was 20% of the body weight. Then, we computed the average amounts in excretion of PCDFs and PCDDs from the body in both the FBRA-intake and non-intake groups. Consequently, the amounts of excretion of PCDFs and PCDDs in the FBRA-intake group were 1.81 and 1.74 times, respectively, greater than those in the non-intake group. Therefore, FBRA seemed to promote the fecal excretion of causative agents of Yusho, from the human body. We also expect FBRA to reduce their body burdens of patients with Yusho and to improve some objective and subjective symptoms of Yusho patients.

[Investigation of the drug "Mamoclam" for the treatment of patients with fibroadenomatosis of the breast]

The clinical trial of a new drug "mamoclam" was carried out in patients with benign breast disease. The drug contains omega-3 polyunsaturated fatty acids, iodine and chlorophyll derivatives and is produced from the brown sea alga laminaria. The study involved 33 patients (mean age 42.5 +/- 1.1 yrs). Two tablets were administered thrice a day for three months. Examination included clinical evaluation of symptoms of mastopathy and dysalgomenorrhea, breast sonography and mammography. Therapeutic response presented as reduced mastalgia, premenopausal syndrome, dysmenorrhea and algomenorrhea, breast cyst regression as well as attenuated pain associated with benign breast disease and palpation. Positive response was reported in 94%. The drug should be recommended for benign breast disease treatment.

Photodynamic therapy for the treatment of intranasal tumors in 3 dogs and 1 cat

Three dogs and 1 cat with intranasal tumors were treated with pyropheophorbide-a-hexyl ether-based photodynamic therapy (PDT). PDT was well tolerated by all the animals, and no adverse effects from photosensitizer injection, such as cutaneous photosensitization, were observed. Facial swelling was observed in all animals after each PDT treatment but resolved spontaneously within 72 hours after treatment. All animals had a decrease in severity of epistaxis, frequency of sneezing, and amount of nasal discharge after PDT. Clinical signs were controlled for variable time, although long-term responses were comparable with radiation therapy in 2 animals. This small case series demonstrates another application for PDT in veterinary medicine. On the basis of these findings. further studies are warranted to define the role of PDT in the management of intranasal tumors in dogs and cats.

Ceramic-based nanoparticles entrapping water-insoluble photosensitizing anticancer drugs: a novel drug-carrier system for photodynamic therapy

A novel nanoparticle-based drug carrier for photodynamic therapy is reported which can provide stable aqueous dispersion of hydrophobic photosensitizers, yet preserve the key step of photogeneration of singlet oxygen, necessary for photodynamic action. A multidisciplinary approach is utilized which involves (i) nanochemistry in micellar cavity to produce these carriers, (ii) spectroscopy to confirm singlet oxygen production, and (iii) in vitro studies using tumor cells to investigate drug-carrier uptake and destruction of cancer cells by photodynamic action. Ultrafine organically modified silica-based nanoparticles (diameter approximately 30 nm), entrapping water-insoluble photosensitizing anticancer drug 2-devinyl-2-(1-hexyloxyethyl) pyropheophorbide, have been synthesized in the nonpolar core of micelles by hydrolysis of triethoxyvinylsilane. The resulting drug-doped nanoparticles are spherical, highly monodispersed, and stable in aqueous system. The entrapped drug is more fluorescent in aqueous medium than the free drug, permitting use of fluorescence bioimaging studies. Irradiation of the photosensitizing drug entrapped in nanoparticles with light of suitable wavelength results in efficient generation of singlet oxygen, which is made possible by the inherent porosity of the nanoparticles. In vitro studies have demonstrated the active uptake of drug-doped nanoparticles into the cytosol of tumor cells. Significant damage to such impregnated tumor cells was observed upon irradiation with light of wavelength 650 nm. Thus, the potential of using ceramic-based nanoparticles as drug carriers for photodynamic therapy has been demonstrated.

Berberis aetnensis C. Presl. extracts: antimicrobial properties and interaction with ciprofloxacin

Previous research showed that berberine-containing Berberis species synthesise the substances 5'-methoxyhydnocarpin-D (5'-MHC-D) and pheophorbide a, which have no antimicrobial activity but inhibit the expression of multidrug resistant efflux pumps (MDRs) in Staphylococcus aureus and potentiate the action of berberine. The MDR pumps extrude synthetic and natural antimicrobials from bacterial cells. We searched for these compounds in Berberis aetnensis C. Presl. (Berberidaceae), an endemic plant of the volcano Mount Etna. This work confirms the presence of pheophorbide a and permits us to hypothesise the presence of 5'-MHC-D in leaf extracts. In fact, the activity of ciprofloxacin was improved when two chromatographic fractions isolated from leaf extracts were added. These results are indicative of the presence of MDR pump inhibitors. Moreover, crude extracts were tested on several micro-organisms and showed antimicrobial activity mainly against Gram-positive bacteria and yeasts.

The breast cancer resistance protein protects against a major chlorophyll-derived dietary phototoxin and protoporphyria

The breast cancer resistance protein (BCRPABCG2) is a member of the ATP-binding cassette family of drug transporters and confers resistance to various anticancer drugs. We show here that mice lacking Bcrp1Abcg2 become extremely sensitive to the dietary chlorophyll-breakdown product pheophorbide a, resulting in severe, sometimes lethal phototoxic lesions on light-exposed skin. Pheophorbide a occurs in various plant-derived foods and food supplements. Bcrp1 transports pheophorbide a and is highly efficient in limiting its uptake from ingested food. Bcrp1(-/-) mice also displayed a previously unknown type of protoporphyria. Erythrocyte levels of the heme precursor and phototoxin protoporphyrin IX, which is structurally related to pheophorbide a, were increased 10-fold. Transplantation with wild-type bone marrow cured the protoporphyria and reduced the phototoxin sensitivity of Bcrp1(-/-) mice. These results indicate that humans or animals with low or absent BCRP activity may be at increased risk for developing protoporphyria and diet-dependent phototoxicity and provide a striking illustration of the importance of drug transporters in protection from toxicity of normal food constituents.

2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH) in a nude rat glioma model: implications for photodynamic therapy

BACKGROUND AND OBJECTIVE

In this study, we evaluated 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-alpha (HPPH or Photochlor) as a photosensitizer for the treatment of malignant gliomas by photodynamic therapy (PDT).

STUDY DESIGN/MATERIALS AND METHODS

We performed in vivo reflection spectroscopy in athymic rats to measure the attenuation of light in normal brain tissue. We also studied HPPH pharmacokinetics and PDT effects in nude rats with brain tumors derived from stereotactically implanted U87 human glioma cells. Rats implanted with tumors were sacrificed at designated time points to determine the pharmacokinetics of HPPH in serum, tumor, normal brain, and brain adjacent to tumor (BAT). HPPH concentrations in normal brain, BAT and tumor were determined using fluorescence spectroscopy. Twenty-four hours after intravenous injection of HPPH, we administered interstitial PDT treatment at a wavelength of 665 nm. Light was given in doses of 3.5, 7.5 or 15 J/cm at the tumor site and at a rate of 50 mW/cm.

RESULTS

In vivo spectroscopy of normal brain tissue showed that the attenuation depth of 665 nm light is approximately 30% greater than that of 630 nm light used to activate Photofrin, which is currently being evaluated for PDT as an adjuvant to surgery for malignant gliomas. The t1/2 of disappearance of drug from serum and tumor was 25 and 30 hours, respectively.

CONCLUSION

Twenty-four hours after injection of 0.5 mg/kg HPPH, tumor-to-brain drug ratios ranged from 5:1 to 15:1. Enhanced survival was observed in each of the HPPH/PDT-treated animal groups. These data suggest that HPPH may be a useful adjuvant for the treatment of malignant gliomas.

In vitro and in vivo efficacy of photofrin and pheophorbide a, a bacteriochlorin, in photodynamic therapy of colonic cancer cells

This study was designed to investigate the efficacy of photodynamic therapy (PDT) in treating colonic cancer in a preclinical study. Photofrin, a porphyrin mixture, and pheophorbide a (Ph a), a bacteriochlorin, were tested on HT29 human colonic tumor cells in culture and xenografted into athymic mice. Their pharmacokinetics were investigated in vitro, and the PDT efficacy at increasing concentrations was determined with proliferative, cytotoxic and apoptotic assessments. The in vivo distribution and pharmacokinetics of these dyes (30 mg/kg, intraperitoneal) were investigated on HT29 tumor-bearing nude mice. The inhibition of tumor growth after a single 100 J/cm2 PDT session was measured by the changes in tumor volume and by histological analysis of tumor necrosis. PDT inhibited HT29 cell growth in culture. The cell photodamage occurred since the time the concentrations of Ph a and Photofrin reached 5.10(-7) M (or 0.3 microg/mL) and 10 microg/mL, respectively. A photosensitizer dose-dependent DNA fragmentation was observed linked to a cleavage of poly(ADP-ribose) polymerase and associated with an increased expression of mutant-type p53 protein. PDT induced a 3-week delay in tumor growth in vivo. The tumor injury was corroborated by histological observation of necrosis 48 h after treatment, with a correlated loss of specific enzyme expression in most of the tumor cells. In conclusion, PDT has the ability to destroy human colonic tumor cells in vitro and in vivo. This tumoricidal effect is likely associated with a p53-independent apoptosis, as HT29 cells express only mutated p53. The current study suggests a preferential use of Photofrin in PDT of colonic cancer because it should be more effective in vivo than Ph a as a consequence of better tumor uptake.

Investigation of genotoxic and antigenotoxic activities of chlorophylls and chlorophyllin in cultured V79 cells

Chlorophyll and its derivatives are examples of plant compounds (purified and/or extracted) which appear to protect DNA from damage caused by chemical or physical agents, although some studies have identified clastogenic activity of these compounds. This study was carried out to assess the genotoxic activity of chlorophyll-a (Chl-a), -b (Chl-b) and chlorophyllin (Chl) and their antigenotoxic activity against the DNA damage induced by methyl methanesulphonate (MMS) under conditions of simultaneous, pre-, post-treatment, and simultaneous treatment after pre-incubation of the chemical with MMS. The micronucleus (MN) test was used in binucleated cells (induced by cytochalasin-B) of a mammalian cell line (V79). The three concentrations of Chl-a, Chl-b or Chl (0.1375, 0.275, 0.55microM) were not genotoxic and the genotoxic action of MMS (400microM) decreased (74-117%) under all treatment conditions. The results showed that there was no significant difference among the treatment types, the concentration or the nature of chlorophyll used. The data obtained suggest that Chl-a, Chl-b and Chl when associated with the DNA damaging agent, MMS, may protect the DNA by desgenotoxic action and/or by bio-antigenotoxic mechanisms, with the similar efficiency.

[Optimal treatment parameters for damage of chicken comb vessels using chlorophyll derivative IV in photodynamic therapy]

OBJECTIVE

To define the optimal treatment parameters of chlorophyll derivative IV (CPD4) in photodynamic therapy(PDT) of port wine stains(PWS) by observing the morphological changes of chicken combs.

METHODS

102 animals were divided into 6 groups at random, including 3 control groups(given no treatment, given light without photosensitizer or given photosensitizer without light) and 3 experimental groups treated with different CPD4 dosages(5, 7.5, 10, 12.5, 15 mg/kg body weight), power density(50, 100, 150, 200 mW/cm2), energy density (15, 30, 45, 60, 120, 135, 180 J/cm2) and different intervals between CPD4 injection and irradiation (immediately, 5, 10, 20, 30, 60, 120, 180, 240 minutes). The main emitting peak of light source was at 650 nm, and CPD4 was injected intravenously, then the appearance of chicken comb was recorded everyday. The prepared sections were stained with HE. The histological changes of chicken comb were observed by light microscope.

RESULTS

The control animals showed no significant comb changes, while the PDT could cause blanching of the chicken comb in the experimental group. The histologic changes included damage of erythrocytes and endothelial cells, vascular rupture, hemorrhage or disappearance, denaturation of perivascular collagen fiber and local necrosis of chicken combs. The treatment parameters which caused the most obvious blanching of the chicken comb were 7.5-10 mg/kg body weight of CPD4 dosage, 100-150 mW/cm2 of power density, 60-90 J/cm2 of energy density, and the intervals between CPD4 injection and irradiation were 0-20 minutes.

CONCLUSION

CPD4 in PDT can cause selective damage of dermal capillaries in chicken comb and blanching of the chicken comb with optimal treatment parameters. The results will offer the basis for further investigation of clinic treatment parameters.

Quantitative determination of cholesterol 5alpha-, 7alpha-, and 7beta-hydroperoxides in rat skin

An assay method for determination of cholesterol 5alpha-, 7alpha-, and 7beta-hydroperoxides (ChOOHs) in rat skin using high-performance liquid chromatography (HPLC) with a chemiluminescence detector has been developed. In the assay method, free form and free plus ester forms of ChOOHs could be separately determined by HPLC in combination with the treatment of a tissue extract by cholesterol esterase. Lower limits of quantitation for cholesterol 5alpha-, 7alpha-, and 7beta-hydroperoxides were 0.2, 0.1, and 0.5 nmol/g skin, respectively. This assay method showed that (i) good absolute recoveries of ChOOHs from rat skin (80-90% of radiolabeled ChOOHs added to rat skin); (ii) negligible autoxidation of cholesterol caused by the assay procedure (<9.4x10(-5)% of radiolabeled cholesterol added to rat skin); and (iii) good correlation between ChOOHs added to rat skin and ChOOHs determined, indicating this assay method is applicable to quantify ChOOHs in rat skin. By using this assay method, we observed that (i) cholesterol 5alpha-hydroperoxide was detected in skin of rats pretreated with oral doses of pheophorbide a and subsequent visible irradiation; (ii) concentrations of cholesterol 7-hydroperoxides in skin of rats in an ambient light room were not significantly different from those in a dark room for 12 weeks; and (iii) ultraviolet light B irradiation markedly enhanced the concentrations of cholesterol 7-hydroperoxides in the skin of rats.

Effect of cuprofilin on experimental atherosclerosis

The effect of Cuprofilin, a newly synthesized C.(II)-chlorophyll complex, was assessed in rats with experimental atherosclerosis. The study was focused on changes in serum cholesterol, lipids, and triglycerides concentration as well as on serum and abdominal aorta Cu and Zn values. It has been ascertained that after 90 d in animals fed a rich lipid diet there was a statistically significant increase in serum cholesterol, triglycerides, and lipid concentration (p < 0.01). A significant augmentation of serum Cu values (p < 0.01) accompanied by a marked lowering of the same element in abdominal aorta (p < 0.01) was also found, as compared to the results registered in the control group. However, Cuprofilin, administered for 90 d in the group of animals with experimental atherosclerosis, significantly decreased the serum cholesterol, triglycerides, and serum lipid values (p < 0.01), increased copper content in aortic tissue (p < 0.01) and lowered serum copper concentration (p < 0.01) as compared to the untreated group. Moreover, in the aorta of administered animals the lipid infiltration has been demonstrated to be significantly diminished vs the untreated group.

Lipid-associated methylpheophorbide-a (hexyl-ether) as a photodynamic agent in tumor-bearing mice

Liposomes are a potential system for more selective delivery of photosensitizers (PS) to tumors. Pheophorbides are one series of new PS under investigation for use in photodynamic therapy. The pharmacokinetics, anti-tumor response and normal tissue effects of methylpheophorbide-a-(hexyl-ether) (MPH) associated with negatively charged phospholipid vesicles composed of high and low transition temperature lipids were determined in mice. In some preparations monosialoganglioside, which is known to impart long circulation time to liposomes was also included. Normally water-insoluble MPH could be quantitatively incorporated in multilamellar liposomes up to at least 20 mol MPH/mol lipid% for most liposome compositions and sonicated to form clear suspensions. Evidence from electron microscopy and entrapment of aqueous space markers indicated that the particles formed by sonication were not standard liposomes. Anti-tumor responses to light treatment (135 J/cm2, 665 nm argon-dye laser) 24 h after MPH (0.4 mumol/kg) administration were slightly but significantly greater (P < 0.05) for lipid associated MPH compared to MPH solubilized in Tween 80. There were no major differences in tumor uptake and tumor cell photosensitization between lipid or Tween 80 formulations of MPH, whereas, dependent on lipid composition and time after MPH administration, the doses of light required to cause occlusive vascular damage were increased for the lipid formulations. Pharmacokinetic studies showed rapid dissociation between lipids and MPH in vivo. Lipid formulations are useful for solubilizing MPH and may improve the therapeutic effects of this PS.

Induction of glomerular injury by singlet oxygen

The role of the reactive oxygen species (ROS) in the induction of tissue injury has been well documented. Regarding glomerular injury, the focus of past studies has been on superoxide, hydrogen peroxide, hydroxyl radical and C10-. However, whether singlet oxygen, an exceptionally reactive oxygen metabolite, may cause glomerular lesions has not been investigated. In the present study we documented the effects of locally generated singlet oxygen in the kidney. To generate singlet oxygen, kidneys were perfused with the pigment pheophorbide a, which was followed by exposure to light. One hour after irradiation, severe morphological damage of the glomerular cell had developed. Extensive deposits of fibrin and accumulation of platelets were seen in the glomerular capillary lumina. By contrast, kidneys not exposed to light showed no, or only minimal, abnormalities. Glomerular injury was not inhibited by pretreatment with superoxide dismutase. These results suggest that singlet oxygen produced by pheophorbide a by photodynamic reaction leads to tissue injury in vivo.

[Use of correlation analysis of clinical and laboratory data in the treatment of patients with chronic suppurative maxillary sinusitis]

In order to objectivize clinical and laboratory data, we applied P. V. Terentyev's method of correlation analysis as modified by A. N. Zosimov when examining 60 adolescents with chronic purulent maxillary sinusitis. This approach was necessary to choose an adequate method for evaluating the therapeutic efficacy. Analysis of correlations between clinical parameters, blood profile and immune data demonstrated different relationships before and after therapy. The mathematical and graphical models proposed make it possible to evaluate objectively each type of treatment, the results being in agreement with clinical observations. These models can help predict the course of disease.

[Evaluation of the efficacy of photodynamic therapy on experimental hepatocellular carcinoma--using local injection of photosensitizer]

The effect on photodynamic therapy (PDT) of using pheophorbide-a as a photosensitizer and Nd: YAG laser (Q-switch) was evaluated. Two hundred micrograms (0.1 ml) of pheophorbide-a was injected into tumors that had been subcutaneously implanted into the backs of nude mice (BALB/c-nu). Interstitial Nd: YAG laser irradiation (Q-switch; mean power 0.5 W, duration 10 min.) was performed 72 hours after pheophorbide-a injection. Forty-eight hours after laser irradiation, the areas of tumor necrosis were measured; these were larger in the group with the injection of pheophorbide-a than in those without. The areas of tumor necrosis after Nd: YAG laser irradiation at a higher mean power (Q-switch; mean power 2 W, control temperature 43-43.5 degrees C, duration 10 min.) were also measured. Again, the areas were larger in the group injected with pheophorbide-a. These results show that the injection of pheophorbide-a and interstitial irradiation using Nd: YAG laser induce a photodynamic reaction, and that this combination is useful in the treatment of deep-seated tumors.

[Can chlorophyll reduce fecal odor in colostomy patients?]

The effect of 75 mg chlorophyll tablets thrice daily was studied in 28 colostomy patients. The investigation was carried out as a randomized, double-blind, cross-over study. The effect of chlorophyll did not differ from that of a placebo in the patients' subjective assessment of the unpleasant odour.

New method of photosensitizer accumulation for photodynamic therapy in an experimental liver tumor

A new sensitizing method of photodynamic therapy for malignant tumors and its effects was studied. Prepared for the study were pheophorbide a (Phd), dissolved in an oily contrast medium, Lipiodol (LPD-Phd), and water-soluble pheophorbide a (W-S Phd) as sensitizers, and VX-2 tumor in rabbit livers. The Phd distribution was compared after intraarterial (i.a.) administration of LPD-Phd or W-S Phd and intravenous (i.v.) administration of W-S Phd. Phd was extracted with methanol at 24 h after injection, and the supernatant absorbance was measured at 670 nm by spectrophotometry. The tumor showed higher values of Phd than did the liver with LPD-Phd i.a. and W-S Phd i.a. (P less than .01). Conversely, the tumor accumulated less Phd than did the liver with W-S Phd i.v. (P less than .05). We subsequently produced severe photo-destruction in a Walker tumor in a Sprague-Dawley rat liver with slight damage to adjacent liver tissue using LPD-Phd i.a. and Nd-YAG dye laser irradiation at 670 nm. The intraarterial administration of a photosensitizer may make it possible to treat liver tumors by photodynamic therapy.

Therapeutic effect of chlorophyll-a in the treatment of patients with chronic pancreatitis

The favorable clinical effects of water-soluble form of chlorophyll-a in the treatment of patients with chronic relapsing pancreatitis are described. 1) 34 cases were treated with chlorophyll-a infusion and fairly favorable effect was obtained in 23 cases and some favorable effect, in 9 cases. 2) The most disgusting symptom of pancreatitis, the abdominal pain disappeared in a week or so with infusion of 5--20 mg of chlorophyll-a per day for 1--2 weeks, in all the effective cases. 3) Patients have become well controlled by intermittent administration of chlorophyll-a, even when they had recurrences. 4) 5 cases which had difficulty in the treatment by trasylol, were also successfully treated with chlorophyll-a. 5) In all the cases treated with chlorophyll-a, no unfavorable side-effect, such as of allergic, or photosensitive, or hepatotoxic nature, was hitherto observed.

The effects of intravenously administered chlorophyll-A on naturally occurring serum protease inhibitors in rabbits

Effects of intravenously administered protease inhibitors on naturally occurring serum inhibitors were investigated in rabbits. Water-dispersed chlorophyll-a, trasylol and leupeptin were tested as exogenous protease inhibitors in the experiments. From the results of experiments, it was concluded that: 1) Pretreatment with chlorophyll-a infusion into rabbits, most effectively prevented the rapid consumption of naturally occurring serum protease inhibitors after successive trypsin infusion, and the duration of its action was observed longest when compared with other exogenous inhibitors, such as trasylol or leupeptin. 2) Final therapeutic effects of these exogenous protease inhibitors seem to have depended upon the disappearing way of the administered inhibitors from the blood in certain period of time, as well as upon biochemical potency of their inhibiting activity.