Expression of a New hemA Gene from Agrobacterium radiobacter in Escherichia coli for 5-Aminolevulinate Production

A new hemA gene encoding 5-aminolevulinate (ALA) synthase was cloned from Agrobacterium ra- diobacter zju-0121. The ALA synthase catalyzes the pyridoxal phosphate-dependent condensation of succinyl coen- zyme A (succinyl-CoA) and glycine to produce ALA. Four plasmids carrying the A, radiobacter hemA gene were transformed into different E. coli strains. The effects of both genetic and physiological factors on the expression of ALA synthase and ALA production were studied. The results indicated that the final intracellular activity of ALA synthase and the production of ALA in different expression systems varied largely. Among them, the recombinant E. coli BL21 (DE3) harboring the expression plasmid pET28-A. R-hemA was the most suitable one. The effects of isopropyl-β-D-thiogalactopyranoside (IPTG) addition time, IPTG concentration, culture temperature and the initial concentration of precursors and glucose on the ALA production were also evaluated. The expressed ALA synthase accounted for about 23.7% of the intracellular soluble protein. The highest specific activity of ALA syn- thase was 13.8nmol·min-1·mg-1 of intracellular soluble protein. In the batch culture of the recombinant E. coli, the extracellular ALA concentration reached 0.9 g·L-1.

Establishment of a nonradioactive assay for 2′5′oligoadenylate synthetase and its application in chronic hepatitis C patients receiving interferon-α

IM To establish a nonradioactive assay for 2′5′ oligoadenylate synthetase (25 AS) and to measure the 25AS in peripheral blood mononuclear cell (PBMC) extracts of patients with chronic hepatitis C before IFNα injection, 24 hours and one month after the first injection.METHODS 25AS in cell extracts of PBMCs from 10 normal persons and 15 chronic hepatitis C patients were determined with PEI cellulose thinlayer chromatography.RESULTS The assay of 25AS in human PBMC was found to be rapid, sensitive, specific and reliable. The 25AS activity of PBMC in normal persons was in a quite low level (20%), and it was increased about tenfolds after stimulation of IFN (197%), (P<001). In 15 chronic hepatitic C patients, the basal levels of 25AS before IFN treatment were higher than those of normal persons, being much higher in the group showing poor response to IFN treatment, but 24h after the first injection of IFNα the 25AS level showed a more rapid and much greater rise in those patients with a good response.CONCLUSION 25AS may be a useful parameter of biological response during the IFN therapy..

Human intestinal acyl-CoA synthetase 5 is sensitive to the inhibitor triacsin C

AIM:To investigate whether human acyl-CoA synthetase 5(ACSL5) is sensitive to the ACSL inhibitor triacsin C.METHODS:The ACSL isoforms ACSL1 and ACSL5 from rat as well as human ACSL5 were cloned and recombinantly expressed as 6xHis-tagged enzymes.Ni 2+-affinity purified recombinant enzymes were assayed at pH 7.5 or pH 9.5 in the presence or absence of triacsin C.In addition,ACSL5 transfected CaCo2 cells and intestinal human mucosa were monitored.ACSL5 expression in cellular systems was verified using Western blot and immunofluorescence.The ACSL assay mix included TrisHCl(pH 7.4),ATP,CoA,EDTA,DTT,MgCl 2,[9,103 H] palmitic acid,and triton X-100.The 200 μL reaction was initiated with the addition of solubilized,purified recombinant proteins or cellular lysates.Reactions were terminated after 10,30 or 60 min of incubation with Doles medium.RESULTS:Expression of soluble recombinant ACSL proteins was found after incubation with isopropyl betaD-1-thiogalactopyranoside and after ultracentrifugation these were further purified to near homogeneity with Ni 2+-affinity chromatography.Triacsin C selectively and strongly inhibited recombinant human ACSL5 protein at pH 7.5 and pH 9.5,as well as recombinant rat ACSL1(sensitive control),but not recombinant rat ACSL5(insensitive control).The IC50 for human ACSL5 was about 10 μmol/L.The inhibitory triacsin C effect was similar for different incubation times(10,30 and 60 min) and was not modified by the N-or C-terminal location of the 6xHis-tag.In order to evaluate ACSL5 sensitivity to triacsin C in a cellular environment,stable human ACSL5 CaCo2 transfectants and mechanically dissected normal human intestinal mucosa with high physiological expression of ACSL5 were analyzed.In both models,ACSL5 peak activity was found at pH 7.5 and pH 9.5,corresponding to the properties of recombinant human ACSL5 protein.In the presence of triacsin C(25 μmol/L),total ACSL activity was dramatically diminished in human ACSL5 transfectants as well as in ACSL5-rich human intestinal mucosa.CONCLUSION:The data strongly indicate that human ACSL5 is sensitive to triacsin C and does not compensate for other triacsin C-sensitive ACSL isoforms.

Specific activation of 2'-5'oligoadenylate synthetase gene promoter by hepatitis C virus-core protein:A potential for developing hepatitis C virus targeting gene therapy

AIM： TO examine whether 2＇-5＇oligoadenylate synthetase （OAS） gene promoter can be specifically activated by hepatitis C virus （HCV）-core protein. METHODS： Human embryo hepatic cell line L02 was transfected with pcDNA3.1-core plasmid and selected by G418. Expression of HCV-core was detected by reverse transcription polymerase chain reaction and Western blotting. The OAS promoter sequence was amplified from the genomic DNA and inserted into pGL3-basic vector. The resultant pGL3-OAS-Luci plasmid was transiently transfected into L02/core cells and luciferase activity was assayed. I^ESULTS： L02/core cell line stably expressing HCV- core protein was established. The pGL3-OAS-Luci construct exhibited significant transcriptional activity in the L02/core cells but not in the L02 cells. CONCLUSION： HCV-core protein activates the OAS gene promoter specifically and effectively. Utilization of OAS gene promoter would be an ideal strategy for developing HCV-specific gene therapy.

REGULATION OF THE INTERFERON-INDUCIBLE PROTEIN KINASE PKR AND 2'5' OLIGOADENYLATE SYNTHETASE BY A CATALYTICALLY INACTIVE PKR MUTANT THROUGH COMPETITION FOR DOUBLE-STRANDED RNA BINDING

The interferon-inducible double-stranded RNA-dependent protein kinase PKR has been suggested to function as a turnour suppressor gene product.Catalytically inactive mutants of PKR give rise to a tumourigenic phenotype when overexpressed in NIH-3T3 fibroblasts and this has been attributed to a dominant negative effect on only inhibits the protein kinase activity of wild-type PKR but is also inhibitory towards another dotlblestranded RNA-dependent enzyme,the 40kDa form of 2'5'oligoadenylate synthetase. Inhibition of both wile-type PKR or 2'5' oligoadenylate synthetase is reversed by adding higher concentrations of double-stranded RNA. These results suggest competition between PKR K296R and wild-type PKR or 2'5' oligoadenylate synthetase for limiting amounts of dublestranded RNA. Moreover,the data imply that the tumourigenic effect of this PKR mutant could be due to inhibition of additional pathways requiring low levels of double-strandeed RNA for activation and cannot be unambiguously attributed to inhibition of endogenous PKR itself.

Effects of Illumination Intensity, 5-aminolevulinic Acid Concentration and Their Interaction on Chlorophyll Fluorescence Parameters and Yield of Summer Maize

[Objective] This study aimed to investigate the influence of illumination intensity, 5-aminolevulinic acid （ALA） concentration and their interaction on chlorophyll fluorescence parameters and yield of summer maize. [Method] Two illumination intensity levels and five ALA concentrations were applied in the experiment using 2x5 completely balanced program. The two illumination intensity levels were natural light （So） and 60% shade （SO, and five ALA concentrations were 0, 1, 10, 25 and 50 mg/L. [Result] The relative chlorophyll content of leaf （SPAD）, the optimal/maximal quantum yield of PS II （Fv/Fm）, the photochemical quenching coefficient （qP）, electron transport rate （ETR）, grain number per cob and grain weight per cob in $1 treatment were significantly reduced compared with that in So. However, the non- photochemical quenching coefficient （qN） was significantly increased. The responses of these parameters to ALA were different under So and $1 treatments. The SPAD, Fv/Fm, qP, ETR, grain number and grain weight per cob were firstly increased, but then decreased following the raise of ALA concentration, ranging from 0 to 50 mg/L, whereas qN showed opposite trend. The effect of the interaction of illumination in- tensity and ALA concentration on these parameters was significant （P〈0.05）. Under natural light, summer maize could obtain higher SPAD, Fv/Fm, qP and ETR and lower qN combined with low concentration of ALA. However, high concentration of ALA was needed under shading to get the same results. [Conclusion] Soaking seed in suitable concentration of ALA can reduce the yield loss of summer maize caused by short-term shading in seedling stage.

Clinical applications of 5-aminolevulinic acid-mediated fluorescence for gastric cancer

5-aminolevulinic acid(ALA) is a naturally occurring amino acid that is a protoporphyrin IX(Pp IX) precursor and a next-generation photosensitive substance. After exogenous administration of ALA, Pp IX specifically accumulates in cancer cells owing to the impaired metabolism of ALA to Pp IX in mitochondria, which results in a red fluorescence following irradiation with blue light and the formation of singlet oxygen. Fluorescence navigation by photodynamic diagnosis(PDD) using ALA provides good visualization and detection of gastric cancer lesions and is a potentially valuable diagnostic tool for gastric cancer for evaluating both the surgical resection margins and extension of the lesion. Furthermore, PDD using ALA might be used to detect peritoneal metastases during preoperative staging laparoscopy, where it could provide useful information for the selection of a therapeutic approach. Another promising application for this modality is in the evaluation of lymph node metastases. Photodynamic therapy(PDT) using ALA to cause selective damage based on the accumulation of a photosensitizer in malignant tissue is expected to be a non-invasive endoscopic treatment for superficial early gastric cancer. ALA has the potential to be used not only as a diagnostic agent but also as a therapeutic drug, resulting in a new strategy for cancer diagnosis and therapy. Here, we review the current use of PDD and PDT in gastric cancer and evaluate its future potential beyond conventional modalities combined with a light energy upconverter, a light-emitting diode and nearinfrared rays as light sources.

Recent advances in photodynamic diagnosis of gastriccancer using 5-aminolevulinic acid

Photodynamic diagnosis based on 5-aminolevulinic acidinduced protoporphyrin IX has been clinically applied in many fields based upon its evidenced efficacy and adequate safety. In order to establish a personalized medicine approach for treating gastric cancer patients, rapid intraoperative detection of malignant lesions has become important. Feasibility of photodynamic diagnosis using 5-aminolevulinic acid for gastric cancer patients has been investigated, especially for the detection of peritoneal dissemination and lymph node metastasis. This method enables intraoperative realtime fluorescence detection of peritoneal dissemination, exhibiting higher sensitivity than white light observation without histopathological examination. The method also enables detection of metastatic foci within excised lymph nodes, exhibiting a diagnostic accuracy comparable to that of a current molecular diagnostics technique. Although several complicating issues still need to be resolved, such as the effect of tissue autofluorescence and the insufficient depth penetration of excitation light, this simple and rapid method has the potential to become a useful diagnostic tool for gastric cancer, as well as urinary bladder cancer and glioma.

Effects of Exogenous 5-Aminolevulinic Acid and 24-Epibrassinolide on Cd Accumulation in Rice from Cd-Contaminated Soil

High grain-Cd-accumulating rice variety Yongyou 9 was planted in Cd-contaminated farmland in Taizhou City, Zhejiang Province, China to study the effects of 5-aminolevulinic acid(ALA) and24-epibrassinolide(EBR) on Cd accumulation in brown rice. Results showed that the exogenous ALA and EBR had no significant effects on agronomic traits, soil pH and total Cd content in soil, but had some effects on the available Cd content in soil, and significantly influenced the Cd accumulation in the different parts of rice. Results also showed that 100 mg/L exogenous ALA significantly reduced the Cd accumulation in brown rice to blow the food safety standard(0.2 mg/kg), and also significantly reduced the Cd contents in the roots and culm of rice. However, 200 mg/L exogenous ALA treatment increased the Cd content in brown rice remarkably. In addition, 0.15 mg/L EBR treatment increased Cd accumulation in roots, culm, leaves and brown rice notably, whereas 0.30 mg/L exogenous EBR treatment reduced the Cd accumulation in brown rice properly, but it was not significant. Therefore,proper concentration of ALA can effectively reduce the Cd accumulation in brown rice, which can be used as an effective technical method for the safe production of rice in Cd polluted farmland.

Improved 5-Aminolevulinic Acid Production with Recombinant Escherichia coli by a Short-term Dissolved Oxygen Shock in Fed-batch Fermentation

5-Aminolevulinic acid （ALA） is a common precursor for tetrapyrrole compounds in all kinds of organ isms and has wide applications in agriculture and medicines. In this study, a new strategy, i.e. short-term dissolved oxygen （DO） shock during aerobic fermentation, was introduced to produce 5-aminolevulinic acid with a recombi-nant E. coli. Effects of duration time of DO shock operation on plasmid concentration, intracellular ALA synthase （ALAS） activity and ALA production were investigated in Erlenmeyer shake flasks. The results indicated that both ALAS activity and ALA yield were enhanced in an anaerobic operation of 45 rain in the early exponential phase during fermentation, while they decreased when the anaerobic operation time was further increased to 60 rain. The DO shock protocol was confirmed with the fed-batch fermentation in a 15 L fermenter and the ALA production achieved 9.4 g.L-1 （72 mmol.L-1）, which is the highest yield in the fermentation broth reported up to now.

Insight into 5-aminolevulinic acid-induced modulation of cellular antioxidant metabolism to confer salinity and drought tolerance in maize

The current study investigated the comparative oxidative damage in twomaize seedlings induced by saline,drought,and combined stress and the ameliorative role of two different doses(20 and 80μM)of 5-aminolevulinic acid(ALA)against the above-mentioned stresses.Hydroponically grown 10-day-old maize(Zea mays,var.BARI Hybrid Maize-7(BHM-7)and BARI Hybrid Maize-9(BHM-9))seedlings were exposed to 12 dS/m of saline solution,200 mM mannitol-induced drought stress alone and their combined stress for 7 days.Result revealed that individual stresses retard the plant growth to some degrees,however,their combined stress has more detrimental effects,which might be correlated with lipid peroxidation(MDA)-induced oxidative stress in seedlings,enhanced Na+/K+ratio,and augmented generation of superoxide(O_(2)•^(−))and hydrogen peroxide(H_(2)O_(2)).In contrast,exogenous ALA supplementation at 20μM concentration markedly recovered from chlorosis and growth inhibition,substantially scavenged reactive oxygen species(ROS)and MDA by preserving ionhomeostasis and relaxing oxidative stress,also,by boosting catalase(CAT)and glutathione S-transferase(GST),and exclusively via depressing the activity of lipoxygenase(LOX)antioxidant enzyme.On the contrary,80μM ALA made things worse,nevertheless,higher activities shown by other antioxidant enzymes,like,superoxide dismutase(SOD),ascorbate peroxidase(APX),peroxidase(POD),and glutathione peroxidase(GPX),which were related to lessen the oxidative damage by highly produced O_(2)•^(−)and H_(2)O_(2) under combined stress.Non-denaturing gel electrophoresis was done for further confirmation.However,ALA importantly increased the photosynthetic pigment contents in both genotypes irrespective of doses.Nevertheless,GST might have assisted the plants to escape from the herbicidal effect by detoxification.However,in the combined stress condition,high ALA concentration may have some positive role to play.Our findings also showed that BHM-9 performed better than BHM-7.Therefore,ALA at lower concentration was effective for single stress of saline and drought,while higher concentration can improve plant survival under combined stress.

Study on Insecticidal Activities and Effect on Three Kinds of Enzymes by 5-Aminolevulinic Acid on Oxya chinensis

Insecticidal activities and effects on three enzymic activities caused by 5-aminolevulinic acid （ALA） on Oxya chinensis were studied. Fourth-instar nymphs of O. chinensis were treated with different doses ofALA （A1,250 mM; A2, 450 mM; A3,750 mM; A4, 1 000 mM）. Mortality and the activities of acetylcholinesterase （ACHE）, glutathione S-transferase （GSTs）, and glutathione peroxidase （GPx） were determinated. The mortality of O. chinensis rose with an increasing dose of ALA. The mortality of high-dose treatments A3 and A4 reached 66.19 and 80.21%, respectively. The value of LD50 was 3.61 （3.29-3.93） mg·g^-1 body weight （95% confidence interval）. Biochemical studies showed that the activities of AChE and GPx in the A4 treatment declined by 51.53 and 42.82% in the female, and 42.65 and 43.85% in the male compared to the control, respectively, and the degree of decline reached a significant level at P 〈 0.05. Meanwhile, the GSTs activities of O. chinensis enhanced with increasing dose of ALA. The GSTs activities of female and male O. chinensis in the A4 treatment remarkably increased by 171.05 and 97.42% compared to the control （P〈 0.05）. ALA had an obviously toxic effect on O. chinensis. Moreover, ALA caused the photoinactivation of AChE and GPx, which induced nerve transmission blocking and the capability to defend oxidation damage declining. Meanwhile, a high dose of ALA could activate GSTs, which caused a feedback inhibition of the insect to the phototoxic substance.

A Photosensitivity Insecticide, 5-Aminolevulinic Acid, Exerts EffectiveToxicity to Oxya chinensis (Orthoptera: Acridoidea)

5-Aminolevulinic acid （ALA）, a major photosensitivity insecticide, has attracted increasing attention as a new type of highly efficient, environmental friendly pesticide to be used to control the pest. To examine whether or not ALA acts effectively to grasshopper, Oxya chinensis and elucidate the detoxification mechanism of ALA, the susceptibility to ALA was assessed in O. chinensis and two major metabolic detoxification enzymes including glutathione S-transferases （GSTs） and general esterases （ESTs）-specific activities were compared in different development stages and different body sections of O. chinensis treated by ALA and the control. The results showed that the ALA exhibited obvious toxicity to the grasshopper in different development stages. In the low-dose treatment （0.0597 mmol L-1）, the mortalities of O. chinensis reached a significant level （55.5% in the 1st instar nymphs, 61.4% in the 2nd instar nymphs, 71.4% in the 3rd instar nymphs, and 64.4% in the 4th instar nymphs. But, there was no dose-dependent toxic effect. Thereby, we proposed that ALA has the potential for acting as photosensitivity insecticide for controlling O. chinensis. GSTs activity assays using CDNB and DCNB as substrates indicated that the thorax and abdomen of the different instar nymphs treated by ALA showed 1.52-5.56 fold significantly increased GSTs activities compared with the control. However, for the ESTs-specific activity assay, there was no significant difference between O. chinensis treated by ALA and the control within different instar nymphs, when a-NA, a-NB and b-NA were used as substrates. Therefore, GSTs-mediated metabolic detoxification as evidenced by significantly increased GSTs activities might contribute to protect against oxidative damage and oxidative stress by ALA in O. chinensis.

The Role of 5-Aminolevulinic Acid (5-ALA) and Sleep

Objective: To determine if there is a relationship between the administration of the dietary supplement containing 5-Aminolevulinic Acid (5-ALA) and sleep. Methods: A double-blind, randomized parallel-group study was conducted. It was a 4-month study of 40 participants between the ages of 40 and 70. Males and females were recruited equally. There were 20 in each group who had existing sleep disorders. The tool used to measure participant sleep improvement included the Pittsburgh Insomnia Rating Scale-20 Question (PIRS-20). Improved sleep is reflected when the total PIRS-20 score is lower. Results: Improvement in sleep in the group taking 50 mg 5-ALA, compared to controls, was significant. The mean change, from baseline through week 6, was -5.67 units less on the sleep scale than the control group with a p value of 0.001. The mean change from week 6 to week 10 when the participant was no longer taking the supplement was 4.55 units higher than the control group with a p value of 0.062, which is of borderline significance. Conclusions: There is a relationship between the administration of dietary supplements containing 5-ALA and sleep. The results of this study suggest that 5-ALA is associated with improved sleep. The mechanism for sleep improvement needs to be explored. Further research is warranted.

Development of a Photodynamic Diagnosis Method for Oral Squamous Cell Carcinoma Using 5-Aminolevulinic Acid and a Luminescence Plate Reader

Purpose: To establish a simple and accurate photodynamic diagnosis (PDD) method for oral squamous cell carcinoma (OSCC). Methods: OSCC cell lines HSC-2, HSC-3, HSC-4, and Sa3, and normal human oral keratinocytes (HOK) were used. First, we examined the amount of cells needed to detect differences in fluorescence intensities for PDD. OSCC cell lines were adjusted to concentrations of 1 × 104 (104), 1 × 105 (105), and 1 × 106 (106) cells/ml. The experimental groups comprised a group with 5-aminolevulinic acid (5-ALA (+)), and a group without 5-ALA (5-ALA (-)). For each OSCC cell line, 100 μl of each concentration of cells of the 5-ALA groups was seeded onto fluorescence plates, and fluorescence intensity was measured at 60-min intervals for 240 min. Results are expressed as the ratio of fluorescence intensity in 5-ALA (+) to 5-ALA (-). As cells at the concentration of 106 cells/ml provided the clearest results, fluorescence intensities of all cell lines were measured using this concentration at 20-min intervals for 700 min using the same methods. Results: The 5-ALA (+) to (-) ratio increased in a cell concentration-dependent manner at 240 min;the ratio was highest with 106 cells/ml and lowest with 104 cells/ml. With 106 cells/ml in the 5-ALA (+) group, fluorescence intensity increased in a metabolic time-dependent manner;the increase was highest in HSC-2 cells, followed by HSC-4 cells, HSC-3 cells, Sa3 cells, and HOK. Fluorescence intensity was significantly enhanced after 40 min in HSC-2, HSC-3, and HSC-4 cells, after 60 min in Sa3 cells, and after 100 min in HOK compared to the 5-ALA (-) group (P < 0.05). Moreover, fluorescence intensity was significantly increased in OSCC cell lines compared to HOK after 40 min. Conclusion: Early detection of OSCC is possible by screening only microplate reader measurements of fluorescence intensity for PDD.

Photodynamic Therapy of Cancer Cells with Methanesulfonate Salts of 5-Aminolevulinic Acid and Its Derivatives

A series of 5-aminolevulinic acid and its alkylester methanesulfonates was exploited to photodynamic therapy（PDT） of human lymphocytic cells, U-937 in vitro. The PDT efficiency is influenced by the concentration and incubation time. Generally, for ALA and its alkylester methanesulfonates, the cell survival rate decreases and the accumulation ability of PplX increases with the concentration and incubation time. We found that the longer carbon chain methanesulfonates（C5-S, C6-S, C8-S） exhibit better PDT effect than ALA methanesulfonate. This possibly provides a promising route to the clinical application ofPplX-mediated PDT to cancer cell.

5-Aminolevulinic Acid (5-ALA): Analysis of Preclinical and Safety Literature

Problem: 5-ALA has been used for many years at relatively high dose amounts in single doses for photodynamic therapy and immunofluorescence of tumors. An analysis of compiled data relating to safety and any side-effects about the use of 5-ALA at low doses has not yet been published. Purpose: This report analyzes data about the safety of the use of 5-Aminolevulinic Acid (5-ALA) in low doses as a supplement over an extended period of time. Methods: This investigation is a systematic analysis of the current literature ((Medline, and SBI) and snowballing techniques) related to the safety and efficacy of 5-ALA in animals and humans. Clinical trials in progress using 5-ALA were also analyzed. Constant comparative analyses were used to synthesize the findings. Results: The safety of low-dose 5-ALA as a supplement has been demonstrated by animal and human studies. The results suggest that none of the investigations document the presence of symptoms or abnormal laboratory results of clinical significance. The minor laboratory changes documented were judged not clinically significant.

OPTIMIZATIONS FOR 5-AMINOLEVULINIC ACID BASED PHOTODYNAMIC THERAPY IN PURGING LEUKEMIA CELL HL60

Objective To optimize experimental parameters for the photosensitization of 5-aminolevulinic acid (ALA) in promyelocytic leukemia cell HL60 and compare them with normal human peripheral blood mononuclear cell (PBMC). Methods ALA incubation time, wavelength applied to irradiate, concentration of ALA incubated, irradiation fluence may modulate the effect of 5-aminolevulinic acid based Photodynamic Therapy (ALA-PDT).The high-pressure mercury lamps of 400W served as light source, the interference filter of 410nm, 432nm, 545nm, 577nm were used to select the specific wavelength. Fluorescence microscope was used to detect the fluorescence intensity and location of protoporphyrin IX (PpIX) endogenously produced by ALA. MTT assay was used to measure the survival of cell. Flow cytometry with ANNEXIN V FITC kit (contains annexin V FITC, binding buffer and PI) was used to detect the mode of cell death. Results ① 1mmol/L ALA incubated 1×105/mL HL60 cell line for 4 hours, the maximum fluorescence of ALA induced PpIX was detected in cytomembrane. ② Irradiated with 410nm for 14.4J/cm2 can result in the minimum survivability of HL60 cell. ③ The main mode of HL60 cell death caused by ALA-PDT is necrosis. Conclusion ALA for 1mmol/L, 4 hours for dark incubation time, 410nm for irradiation wavelength, 14.4J/cm2 for irradiation fluence were the optimal parameters to selectively eliminate promyelocytic leukemia cell HL60 by ALA based PDT. The photosensitization of ALA based PDT caused the necrosis of HL60 cell, so it could be used for inactivation of certain leukemia cells.

Arsenic Induced Inhibition of δ-aminolevulinate DehydrataseActivity in Rat Blood and its Response To Meso2,3-dimercaptosuccinic Acid andMonoisoamyl DMSA

Objective The objective of this study was to investigate arsenic induced changes in blood 8-aminolevulinic acid dehydratase (ALAD) after in vitro and in vivo exposure to this element and its response to co-administration of meso 2,3-dimercaptosuccinic acid (DMSA) and monoisoamyl DMSA (MiADMSA) either individually or in combination. Methods Rat whole blood was exposed to varying concentrations (0.1, 0.2 and 0.5 mmol/L) of arsenic (III) or arsenic (V), to assess their effects on blood ALAD activity. Varying concentrations of MiADMSA and DMSA (0.1,0.5 and 1.0 mmol/L) were also tried in combination to determine its ability to mask the effect of arsenic induced (0.5 mmol/L) inhibition of blood ALAD in vitro. In vitro and in vivo experiments were also conducted to determine the effects of DMSA and MiADMSA either individually or in combination with arsenic, on blood ALAD activity and blood arsenic concentration. Results In vitro experiments showed significant inhibition of the enzyme activity when 0.1-0.5 mmol/L of arsenic (III and V) was used. Treatment with MiADMSA increased ALAD activity when blood was incubated at the concentration of 0.1 mmol/L arsenic (III) and 0.1 mmol/L MiADMSA. No effect of 0.1 mmol/L MiADMSA on ALAD activity was noticed when the arsenic concentration was increased to 0.2 and 0.5 mmol/L. Similarly, MiADMSA at a lower concentration (0.1 mmol/L) was partially effective in the turnover of ALAD activity against 0.5 mmol/L arsenic (III), but at two higher concentrations (0.5 and 1.0 mmol/L) a complete restoration of ALAD activity was observed. DMSA at all the three concentrations (0.1,0.5 and 1.0 mmol/L) was effective in restoring ALAD activity to the normal value. Conclusions The results thus suggest that arsenic has a distinct effect on ALAD activity. Another important toxicological finding of the present study, based on in vivo experiments further suggests that combined administration of DMSA and MiADMSA could be more beneficial for reducing blood ALAD inhibition and blood arsenic concentration than the individual treatment.

5-Aminolevulinic Acid Improves Water Content and Reduces Skin Wrinkling

5-Aminolevulinic acid (ALA) is a natural amino acid that is used as a raw material for the biosynthesis of red-blood-cell hemoglobin in humans and animals. ALA is the subject of research in a wide range of human health care fields, including skin care and medicine. This study investigated whether and to what extent cosmetics containing ALA (skin lotions and creams) improved facial-skin condition in women. As such, a double-blind controlled experiment was conducted among 45 women aged 47.0 ± 1.72 years. Participants were divided into two intervention groups, including those who used cosmetics containing ALA (C-ALA, n = 22) and those who used cosmetics without ALA (W-ALA, n = 23). Specifically, participants were instructed to use their assigned cosmetics twice per day (morning and evening) after washing their faces before each application. Inner skin condition and skin-water content were evaluated via VISIA-Evolution and Multi Display Devices at baseline and after four and eight weeks of use. The experiment lasted for a total of eight weeks. A baseline comparison at week four showed that skin moisture content increased significantly for the C-ALA group (p = 0.021). Further, wrinkling significantly decreased at week four among participants in the C-ALA group who were evaluated as having many wrinkles at baseline (p = 0.034). These findings suggest that cosmetics containing ALA have moisturizing effects and reduce wrinkling caused by dryness.