Oral Administration Of ALA Research Articles

Sodium Ferrous Citrate and 5-Aminolevulinic Acid Exert a Therapeutic Effect on Endotoxin-Induced Uveitis in Rats.

The metabolism of 5-aminolevulinic acid (ALA) is more efficient when combined with sodium ferrous citrate (SFC). Our previous study revealed that oral administration of ALA, which has anti-inflammatory properties, and SFC (ALA/SFC) immediately before lipopolysaccharide (LPS) inoculation suppressed endotoxin-induced uveitis (EIU) in rats. However, the therapeutic effect of ALA/SFC post-administration remains unexplored. Hence, this study aimed to evaluate the therapeutic efficacy of ALA/SFC on EIU in rats, which were administered with a gastric gavage of ALA/SFC (100/157 mg/kg) or prednisolone (Pred, 10 mg/kg) after 4 h of LPS inoculation. The treatment groups showed ameliorated clinical scores, inflammatory cells, protein levels in the aqueous humor (AqH), and histopathologic evaluation 24 h after LPS inoculation. Furthermore, the treatment groups had reduced tumor necrosis factor-α, nitric oxide, prostaglandin E2, and interleukin-6 levels in the AqH. ALA/SFC demonstrated an anti-inflammatory effect equivalent to that demonstrated by Pred. These findings indicate that ALA/SFC exerts a therapeutic effect on EIU in rats, indicating its clinical usefulness in uveitis treatment.

Alpha-linolenic acid improves nasal mucosa epithelial barrier function in allergic rhinitis by arresting CD4+ T cell differentiation via IL-4Rα-JAK2-STAT3 pathway

BackgroundAllergic rhinitis (AR) defined as inflammation and tissue remodeling of the nasal mucosa in atopic individuals after allergen exposure. Alpha-linolenic acid [cis-9, cis-12, cis-15-octadecatrienoic acid (18:3)] (ALA) as dietary supplementation can reduce inflammation and allergic symptoms. ObjectiveTo evaluate the potential therapeutic effect and mechanism of ALA in AR mouse model. MethodsOvalbumin sensitized AR mouse model were challenged with oral ALA administration. Nasal symptoms, tissue pathology, immune cell infiltration and goblet cell hyperplasia were investigated. Levels of IgE, TNF-β, IFN-γ, IL-2, IL-4, IL-5, IL-12, IL-13 and IL-25 were determined by ELISA in serum and nasal fluid. Quantitative RT-PCR and immunofluorescence were performed for occludin and zonula occludens-1 expression. CD3+CD4+ T-cells from peripheral blood and splenic lymphocytes were isolated and Th1/Th2 ratio were determined. Mouse naive CD4+ T cell were isolated and Th1/Th2 ratio, IL-4Rα expression, and IL5/IL13 secretion were determined. IL-4Rα-JAK2-STAT3 pathway change in AR mice were performed by western blot. ResultsOvalbumin induced AR, nasal symptoms, pathological performance, IgE, and cytokine production. ALA treated mice showed reduced nasal symptoms, nasal inflammation, nasal septum thickening, goblet cell hyperplasia, and eosinophil infiltration. In serum and nasal fluid of ovalbumin challenged mice, ALA decreased IgE, IL-4 levels, and the increase of Th2-cells. ALA prevented the disruption of the epithelial cell barrier in ovalbumin-challenged AR mice. Simultaneously, ALA prevents IL-4 induced barrier disruption. ALA treatment of AR by affecting the differentiation stage of CD4+T cells and block IL-4Rα-JAK2-STAT3 pathway. ConclusionThis study suggests that ALA has the potential therapeutic effect to ovalbumin-induced AR. ALA can affect the differentiation stage of CD4+T cells and improve epithelial barrier functions through IL-4Rα-JAK2-STAT3 pathways. Clinical implicationALA might be considered as drug candidate for improving epithelial barrier function through Th1/Th2 ratio recovery in AR.

Alpha-lipoic acid treatment improves adverse cardiac remodelling in the diabetic heart – The role of cardiac hydrogen sulfide-synthesizing enzymes

IntroductionAlpha-lipoic acid (ALA) is a licensed drug for the treatment of diabetic neuropathy. We recently reported that it also improves diabetic cardiomyopathy (DCM) in type 2 diabetes mellitus (T2DM). In this study, we present evidence supporting our hypothesis that the cardioprotective effect of ALA is via upregulation of cardiac hydrogen sulfide (H2S)-synthesizing enzymes. MethodsFollowing 12 h of overnight fasting, T2DM was induced in 23 out of 30 male Sprague-Dawley rats by intraperitoneal administration of nicotinamide (110 mg/kg) followed by streptozotocin (55 mg/kg) while the rest served as healthy control (HC). T2DM rats then received either oral administration of ALA (60 mg/kg/day; n = 7) or 40 mg/kg/day DL-propargylglycine (PAG, an endogenous H2S inhibitor; n = 7) intraperitoneally for 6 weeks after which all rats were sacrificed and samples collected for analysis. Untreated T2DM rats served as diabetic control (DCM; n = 9). ResultsT2DM resulted in weight loss, islet destruction, reduced pancreatic β-cell function and hyperglycemia. Histologically, DCM rats showed significant myocardial damage evidenced by myocardial degeneration, cardiomyocyte vacuolation and apoptosis, cardiac fibrosis and inflammation, which positively correlated with elevated levels of cardiac damage markers compared to HC rats (p < 0.001). These pathological alterations worsened significantly in PAG-treated rats (p < 0.05). However, ALA treatment restored normoinsulemia, normoglycemia, prevented DCM, and improved lipid and antioxidant status. Mechanistically, ALA significantly upregulated the expression of cardiac H2S-synthesizing enzymes and increased plasma H2S concentration compared to DCM rats (p < 0.001). ConclusionALA preserves myocardial integrity in T2DM likely by maintaining the expression of cardiac H2S-synthezing enzymes and increasing plasma H2S level.

Adjuvant Photodynamic Therapy, Mediated via Topical Versus Systemic Administration of 5-Aminolevulinic Acid for Control of Murine Mammary Tumor after Surgical Resection.

Treatment de-escalation is sought in the management of precursor lesions of early stage breast cancer, driving the appeal of adjuvant modalities to lumpectomy that reduce toxicity and minimally detract from patient quality of life. We investigate photodynamic therapy (PDT), with the photosensitizing prodrug, 5-aminolevulinic acid (ALA), as adjuvant therapy to complete resection of murine mammary tumor (propagated from TUBO cells). ALA was delivered either systemically (oral, 250 mg kg-1 ) at 5 h before 632 nm illumination or topically (20% solution) to the resection site at 10 min before light delivery to 135 J cm-2 . Treatment with either oral-ALA-PDT (oALA-PDT) or topical-ALA-PDT (tALA-PDT) to the mammary fat pad after TUBO complete resection (CR) produced long-term tumor control with 90-day complete response rates of 21% and 32%, respectively, compared to control rates of 0-5% in mice receiving only CR. Thus, CR/tALA-PDT was equipotent to CR/oALA-PDT despite ~10-fold lower levels of ALA-induced protoporphyrin XI as photosensitizer after topical versus oral-ALA administration. CR/oALA-PDT produced more vascular damage, greater proportion of tissue-resident neutrophils and stronger inflammation when compared to CR/tALA-PDT. Collectively, these data provide rationale for ongoing investigation of ALA-PDT as adjuvant therapy after lumpectomy for increased probability of local control in the treatment of breast cancer.

The sustaining of fluorescence in photodynamic diagnosis after the administration of 5-aminolevulinic acid in carcinogen-induced bladder cancer orthotopic rat model and urothelial cancer cell lines

BackgroundThe administration of 5-aminolevulic acid hydrochloride (5-ALA·HCl) 3 h (range: 2–4 h) before photodynamic diagnosis (PDD) is recommended for detecting bladder tumors. However, there is insufficient evidence on the time duration for the fluorescence of PDD after oral administration of 5-ALA. We investigated the sustainability of the photodynamic effect and protoporphyrinⅨ (PpⅨ) after 5-ALA administration in a carcinogen-induced bladder tumor rat model and bladder cancer cell lines. MethodsThe carcinogen-induced bladder tumor orthotopic rat model was established by the administration of N-butyl-N-(4-hydroxybutyl) nitrosamine. ResultsRed fluorescence was visible 2–8 h after the oral administration of 5-ALA in the carcinogen-induced bladder tumor rat model. Plasma and intratissue PpⅨ (nM) progressed to a higher level at 2 h and remained almost constant 2–8 h after oral administration of 5-ALA. The peak fluorescence intensity of PpⅨ was observed 3–4 h after the administration of 5-ALA in bladder cancer cell lines. The accumulated PpⅨ remained for 4 h after the removal of 5-ALA in UMUC3 cells. It was not clearly visible 3 h after the removal of 5-ALA in MGHU3 and T24 cells. The expression level of ferrochelatase was significantly lower in UMUC3 cells than in other cells. Our findings suggest that 5-ALA-assisted PDD (ALA-PDD) can aid in detecting non-muscle-invasive bladder cancer 2–8 h after 5-ALA administration. ConclusionUrologists might not be required to make excess effort to start ALA-PDD-assisted transurethral resection of bladder tumor after the administration of 5-ALA.

Impact of age, body mass index, and renal function for severe hypotension caused by oral 5-aminolevulinic acid administration in patients undergoing transurethral resection of bladder tumor.

Severe hypotension is a notable adverse event caused by administration of 5-aminolevulinic acid (5-ALA) during photodynamic diagnosis-assisted transurethral resection of bladder tumor (PDD-TURBT). Hypotension can be prolonged following induction of anesthesia and may require continuous administration of a vasopressor. Here, we investigated the risk factors for severe hypotension caused by oral administration of 5-ALA. A total of 128 patients with bladder tumors who underwent PDD-TURBT using 5-ALA were included in this study. Clinicopathological data were collected retrospectively and the correlations between the incidence of severe hypotension and clinicopathological factors were analyzed. Severe hypotension developed in 8 cases (6.3 %). Age ≥ 80 years, body mass index (BMI) ≥ 25 (kg/m2), and estimated glomerular filtration rate (eGFR) < 45 (mL/min/1.73 m2) were significantly correlated with severe hypotension (P = 0.003, 0.017, and 0.027, respectively). Severe hypotension developed in 1 of 89 cases (1.1 %) which have 0 or 1 risk factor, and in 3 of 31 cases (9.7 %) which have 2 risk factors, whereas it developed in 4 of 8 cases (50 %) which have all risk factors. Patients with all risk factors developed severe hypotension significantly more frequently compared with patients with 1 or fewer risk factors (P < 0.001). Age ≥ 80 years, BMI ≥ 25, and eGFR < 45 are risk factors for severe hypotension in PDD-TURBT using 5-ALA. The risk of developing severe hypotension is extremely high in patients who have all factors. Adjustment of the 5-ALA dose may be desirable in those patients.

Reduction of fatigue and anger-hostility by the oral administration of 5-aminolevulinic acid phosphate: a randomized, double-blind, placebo-controlled, parallel study

Although large populations feel fatigue, the standardized medicinal therapy is currently absent. In this study, we determined whether 5-aminolevulinic acid (5-ALA) supplementation alleviates the feeling of fatigue in healthy subjects who feel chronic physical tiredness. Males and females between ages of 20 and 64 who felt physical fatigue on a daily basis, with a visual analogue scale (VAS) for fatigue ≥ 40 mm, a T-score of Fatigue-Inertia in the Profile of Mood States—Second Edition—Adult (POMS2-A) ≥ 50, and a T-score of Vigor-Activity in POMS2-A ≤ 60 were recruited. Seventy eligible participants were randomly assigned to either a 5-ALA or a placebo group. During the 8 weeks of consumption, the subjects completed VAS questionnaires for fatigue and POMS2-A at 4-week intervals. The VAS values for overall feeling of fatigue and feeling of work-related fatigue, and the Anger-Hostility subscale of POMS2-A were decreased by 5-ALA with significant time × group interaction effects (p = 0.040, 0.020, and 0.045, respectively). Besides, the 5-ALA group showed significant differences in Fatigue-Inertia, Depression-Dejection and Total Mood Disturbance scores, when compared between pre- and post-intervention, while the placebo group did not. In conclusion, the oral administration of 5-ALA improves fatigue and negative mood in subjects who constantly feel physical fatigue.This clinical trial was registered with University hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) as UMIN000031528 on 2/3/2018.

Chitosan nanoparticles for oral photothermally enhanced photodynamic therapy of colon cancer.

Phototherapy exerts its anticancer effects by converting laser radiation energy into hyperthermia or reactive singlet oxygen (1O2). In this study, we developed chitosan nanoparticles (CS NPs) encapsulating both photothermal (IR780) and photodynamic (5-Aminolevulinic acid (5-ALA)) reagents for photothermally enhanced photodynamic therapy by noninvasive oral administration. The 5-ALA&IR780@CS NPs were stable in acidic conditions similar to the gastric environment, which greatly improved drug oral absorption and local accumulation in subcutaneous mouse colon tumors (CT-26 cells) following oral gavage. Mechanistic studies revealed that the co-delivery system can lead to photothermally enhanced photodynamic effects against cancer cells by increasing oxidative stress, including the elevation of ROS, superoxide and 1O2 production. Additionally, significant therapeutic efficacy for cancer treatment were observed in vivo after oral administration of 5-ALA&IR780@CS NPs, without causing any overt adverse effects. Our work highlights the great potential of photothermally enhanced photodynamic therapy by CS NPs for colon cancer management via oral route.

Endoscopic visualization of cancer and dysplasia in patients with ulcerative colitis following sensitization with oral 5-aminolevulinic acid.

ObjectiveEarly diagnosis of colitis‐associated cancer and dysplasia through surveillance endoscopy is vital for patients with ulcerative colitis (UC). This study aimed to evaluate the efficacy of autofluorescence endoscopy (AFE) using 5‐aminolevulinic acid (ALA) and to investigate the fluorescence signal localization pattern following 5‐ALA administration in tumorous lesions diagnosed as colitis‐associated cancer and dysplasia. The sensitivity and specificity of tumorous lesions detected by white light endoscopy (WLE) with and without AFE were evaluated.MethodsOverall, 13 endoscopic procedures were performed in 11 patients with UC using WLE and AFE following the oral administration of 5‐ALA. The biopsied lesions detected via endoscopy and resected specimens from cases underwent colectomy were assessed histopathologically. The sensitivity and specificity of detecting tumorous lesions by WLE with and without AFE were evaluated.ResultsOf the 68 lesions detected and biopsied, 63 were detected via WLE, and five were detected via AFE alone. The sensitivity of detecting colitis‐associated cancer and dysplasia via WLE combined with AFE was 36.4%, and the specificity, positive predictive value and negative predictive value were 94.2%, 57.1%, and 87.5%, respectively. Tumorous lesions displayed three types of fluorescence patterns on AFE.ConclusionsAFE using 5‐ALA can detect colitis‐associated cancer and dysplasia in patients with long‐standing UC and lesions that could not be detected via WLE. The distinctive fluorescence patterns in lesions may permit qualitative diagnoses of colitis‐associated cancer and dysplasia.

Alpha-Linolenic Acid Alleviates Dextran Sulfate Sodium-Induced Ulcerative Colitis in Mice

Ulcerative colitis (UC) is a type of inflammatory bowel disease characterized by inflammation of the large intestine, rectal bleeding, and abdominal pain. It can be alleviated by certain bioactive compounds, including α-linolenic acid (ALA), which is a bioactive component in fermented black radish (Raphanus sativus L. var. niger). The aim of this study was to evaluate the anti-inflammatory effects of ALA in dextran sulfate sodium (DSS)-induced UC in mice. UC was induced in C57BL/6 mice by allowing them to freely drink water containing 2.5% DSS for 7days, followed by oral administration of ALA (30 and 60mg/kg/day) or vehicle control for 7days. DSS-induced colitis was evaluated using the Disease Activity Index (DAI) and by measuring colon length and performing a histopathological examination. Compared to the control group, the vehicle-treated group showed a higher DAI score, shorter colon, goblet cell loss, and crypt shortening. The ALA treatment mitigated clinical signs of UC and histopathological changes. Furthermore, it mitigated intestinal inflammation by reducing the expression of ionized calcium binding adaptor molecule 1-positive macrophages in the colon. These results show that ALA alleviates DSS-induced UC by suppressing colon damage, which includes goblet cell loss, crypt shortening, and a reduction of macrophages in the colon.

Inverted papilloma of the urinary bladder shows fluorescence on photodynamic diagnosis using 5-aminolevulinic acid

Photodynamic diagnosis (PDD) of non-muscle invasive bladder cancer using 5-aminolevulinic acid (5-ALA) has recently attracted attention as a diagnostic method for observing cancer lesions based on fluorescence emission using a fluorescent endoscope. However, there are few reports of false positives associated with benign bladder neoplasms. Here, we provide report of two cases of inverted papillomas of the bladder that were fluorescent on PDD using 5-ALA. In each case, a surface-smooth, pedunculated bladder tumor was observed, which fluoresced red on PDD after oral administration of 5-ALA. Histopathological findings demonstrated inverted papilloma of the bladder. Although inverted papilloma of the bladder is usually regarded as a benign neoplasm, some recent studies have revealed that it could be a risk factor for urothelial carcinoma. Our present report may support the hypothesis that inverted papilloma of the bladder has malignant potential.

5-ALA-assistant automated detection of lymph node metastasis in gastric cancer patients

Background5-aminolevulinic acid (5-ALA) has been utilized for cancer diagnosis as a fluorescence probe. We have reported the feasibility of 5-ALA-induced protoporphyrin IX (PpIX) fluorescence for detecting lymph node (LN) metastasis in gastrointestinal malignancies. However, a major barrier to the fluorescence diagnosis has been that the evaluation has been highly dependent on the observers. In this study, we examined the validity of a developed device for automated detection without subjectivity.MethodsGastric cancer patients who received oral administration of 5-ALA (20 mg/kg) prior to surgery were enrolled. For a total of 323 LNs obtained from 64 patients, the diagnostic results of the device were compared to those of conventional histopathological examination based on hematoxylin-and-eosin-stained slides. The accuracy with the device was compared to that of stereoscopic detection with conventional fluorescence microscopy for 211 LNs from 42 patients. We used two types of image processing that we previously developed to eliminate autofluorescence of background tissues: differential and ratio methods.ResultsFor detection of metastasis in 323 LNs, the areas under the receiver operating characteristic curves with the differential method and ratio method were 0.921 and 0.909, respectively. The sensitivity, specificity, and accuracy with the differential method were 78.0%, 96.8%, and 94.4%; while those with the ratio method were 78.0%, 96.1%, and 93.8%, respectively. In 211 LN analysis, the diagnostic accuracy with the device was comparable to that of stereoscopic examination.ConclusionOur device for automated detection of LN metastasis using 5-ALA can be a useful tool for intraoperative diagnosis.

Chronic Treatment with α-Lipoic Acid Improves Endothelium-Dependent Vasorelaxation of Aortas in High-Fat Diet-Fed Mice

α-Lipoic acid (ALA) is used as a dietary supplement and known as an anti-oxidant. The present study aimed to examine whether ALA improves endothelial dysfunction in high-fat diet-fed obese mice. After feeding a high-fat diet to Institute of Cancer Research (ICR) mice for 4 weeks, the mice were maintained with a high-fat diet (group HF) or a high-fat diet containing ALA (25 mg/d, group HF + ALA) for an additional 20 weeks. Age-matched normal diet-fed mice were also used (group Normal). Chronic oral treatment with ALA did not affect various plasma parameters or body weights. As compared with the aortas of Normal mice, those from HF mice showed impaired endothelium-dependent relaxation in response to clonidine. However, such an impairment was not observed in the aortas from HF + ALA mice. The plasma levels of thiobarbituric acid reactive substances, an indicator of oxidative stress, were significantly decreased in HF + ALA mice compared with HF mice, confirming the anti-oxidative effects of ALA. In addition, when the impaired clonidine-induced vasorelaxation of aortas from normal mice under high glucose conditions was used as a model of acute oxidative stress, the vasorelaxation responses were improved in the presence of ALA at 100 µM. Our results suggested that the chronic oral administration of ALA improves endothelial dysfunction in high-fat diet-fed obese mice possibly through the reduction in oxidative stress in vivo.

Oxygen-dependent delayed fluorescence of protoporphyrin IX measured in the stomach and duodenum during upper gastrointestinal endoscopy.

Protoporphyrin IX‐triplet state lifetime technique (PpIX‐TSLT) is a method used to measure oxygen (PO2) in human cells. The aim of this study was to assess the technical feasibility and safety of measuring oxygen‐dependent delayed fluorescence of 5‐aminolevulinic acid (ALA)‐induced PpIX during upper gastrointestinal (GI) endoscopy. Endoscopic delayed fluorescence measurements were performed 4 hours after oral administration of ALA in healthy volunteers. The ALA dose administered was 0, 1, 5 or 20 mg/kg. Measurements were performed at three mucosal spots in the gastric antrum, duodenal bulb and descending duodenum with the catheter above the mucosa and while applying pressure to induce local ischemia and monitor mitochondrial respiration. During two endoscopies, measurements were performed both before and after intravenous administration of butylscopolamine. Delayed fluorescence measurements were successfully performed during all 10 upper GI endoscopies. ALA dose of 5 mg/kg showed adequate signal‐to‐noise ratio (SNR) values >20 without side effects. All pressure measurements showed significant prolongation of delayed fluorescence lifetime compared to measurements performed without pressure (P < .001). Measurements before and after administration of butylscopolamine did not differ significantly in the duodenal bulb and descending duodenum. Measurements of oxygen‐dependent delayed fluorescence of ALA‐induced PpIX in the GI tract during upper GI endoscopy are technically feasible and safe.

Heme Deficiency Causes Impaired Glycogen Synthesis in Skeletal Muscle Leading to Insulin Resistance

In vertebrates, the initial step in heme biosynthesis is the production of 5-aminolevulinic acid (ALA) by ALA synthase (ALAS). The ALAS1 gene encodes a ubiquitously expressed isozyme. Mice heterozygous null for ALAS1 (A1+/-s) experience mitochondrial dysfunction in skeletal muscle, impaired glucose tolerance (IGT) and insulin resistance (IR) past 20-weeks of age (aged A1+/-s) 1). IGT/IR in aged A1+/-s was remedied by oral administration of ALA for 1-week1). By contrast, mitochondrial dysfunction required 6-weeks of ALA administration before improvements could be observed, indicating the phenotype of IGT/ IR is not due to mitochondrial dysfunction1). We found no remarkable change in expressions and phosphorylation of proteins related to insulin signalling such as Akt and GSK3β in skeletal muscle of aged A1+/-s1). Rather, abnormal ultrastructure of glycogen granules and increased glycogen contents were observed in skeletal muscle of aged A1+/-s unlike of less than 15-weeks-old A1+/-s, and those abnormalities of glycogen were reversed after ALA-treatment for 1-week as well as IGT/IR. The quantification of glycogen contents showed that insulin-induced glycogen synthesis was impaired in skeletal muscle of aged A1+/-s, and the reduced de novo glycogen synthesis was recovered in ALA-administrated aged A1+/-s. Glycogen synthase (GS) activities were constitutively activated even at the low concentration of glucose 6-phosphate (G6P) and not augmented at the high concentration of G6P in extracts from skeletal muscle of aged A1+/-s, suggesting that GS fails to respond to allosteric activation by G6P. While, GS activities were normally regulated in those of ALA-administered aged A1+/-s. Taken together, our data suggest that impaired de novo glycogen synthesis in skeletal muscle is relevant to IGT/IR in aged A1+/-s due to constitutively activated GS without allosteric activation by G6P. Ref. 1) Saitoh et al. PLOS ONE in press. Disclosure O. Nakajima: None. S. Saitoh: Research Support; Spouse/Partner; Japan Society for the Promotion of Science, SBI Pharmaceuticals Co.,Ltd.. T. Kimura: None. T. Osaki: None. K.P. Vincent: Research Support; Self; Kora Healthcare. K. Takahashi: None. T. Tanaka: None. M. Nakajima: None.

5-aminolevulinic acid (ALA) deficiency causes impaired glucose tolerance and insulin resistance coincident with an attenuation of mitochondrial function in aged mice.

In vertebrates, the initial step in heme biosynthesis is the production of 5-aminolevulinic acid (ALA) by ALA synthase (ALAS). ALA formation is believed to be the rate-limiting step for cellular heme production. Recently, several cohort studies have demonstrated the potential of ALA as a treatment for individuals with prediabetes and type-2 diabetes mellitus. These studies imply that a mechanism exists by which ALA or heme can control glucose metabolism. The ALAS1 gene encodes a ubiquitously expressed isozyme. Mice heterozygous null for ALAS1 (A1+/-s) experience impaired glucose tolerance (IGT) and insulin resistance (IR) beyond 20-weeks of age (aged A1+/-s). IGT and IR were remedied in aged A1+/-s by the oral administration of ALA for 1 week. However, the positive effect of ALA proved to be reversible and was lost upon termination of ALA administration. In the skeletal muscle of aged A1+/-s an attenuation of mitochondrial function is observed, coinciding with IGT and IR. Oral administration of ALA for 1-week brought about only a partial improvement in mitochondrial activity however, a 6-week period of ALA treatment was sufficient to remedy mitochondrial function. Studies on differentiated C2C12 myocytes indicate that the impairment of glucose metabolism is a cell autonomous effect and that ALA deficiency ultimately leads to heme depletion. This sequela is evidenced by a reduction of glucose uptake in C2C12 cells following the knockdown of ALAS1 or the inhibition of heme biosynthesis by succinylacetone. Our data provide in vivo proof that ALA deficiency attenuates mitochondrial function, and causes IGT and IR in an age-dependent manner. The data reveals an unexpected metabolic link between heme and glucose that is relevant to the pathogenesis of IGT/IR.

Dynamics of absorption, metabolism, and excretion of 5-aminolevulinic acid in human intestinal Caco-2 cells

5-Aminolevulinic acid (ALA) is a precursor for the biosynthesis of porphyrins and heme. Although the oral administration of ALA has been widely applied in clinical settings, the dynamics of its absorption, metabolism, and excretion within enterocytes remain unknown. In this study, after enterocytic differentiation, Caco-2 cells were incubated with 200µM ALA and/or 100µM sodium ferrous citrate (SFC) for up to 72h. Both ALA and the combination of ALA and SFC promoted the synthesis of heme, without affecting the expression of genes involved in intestinal iron transport, such as DMT1 and FPN. The enhanced heme synthesis in Caco-2 cells was more pronounced under the effect of the combination of ALA and SFC than under the effect of ALA alone, as reflected by the induced expression of heme oxygenase 1 (HO-1), as well as a reduced protein level of the transcriptional corepressor Bach1. Chromatin immunoprecipitation analysis confirmed Bach1 chromatin occupancy at the enhancer regions of HO-1, which were significantly decreased by the addition of ALA and SFC. Finally, Transwell culture of Caco-2 cells suggested that the administered ALA to the intestinal lumen was partially transported into vasolateral space. These findings enhance our understanding of the absorption and metabolism of ALA in enterocytes, which could aid in the development of a treatment strategy for various conditions such as anemia.

The clinical trial on the safety and effectiveness of the photodynamic diagnosis of non-muscle-invasive bladder cancer using fluorescent light-guided cystoscopy after oral administration of 5-aminolevulinic acid (5-ALA)

ObjectiveTo examine the utility and safety of photodynamic diagnosis (PDD) after oral administration of 5-aminolevulinic acid (5-ALA) (ALA-PDD) of non-muscle-invasive bladder cancer (NMIBC) using fluorescent-light (FL)-cystoscopy. MethodsThe study was a single-arm, open-label, multi-center prospective study on ALA-PDD of NMIBC, with safety as the primary endpoint and efficacy as the secondary endpoint. Diagnostic potential was evaluated through comparisons with the conventional diagnostic method using a white-light (WL)-source. Clinically recommended doses were also examined. Oral administration of 5-ALA (1.0g/50mL) was performed 180–240min before FL-cystoscopy, and positive or negative results were judged using a WL-source and based on presence or absence of red fluorescence on exposure to a blue FL-source. ResultsRegarding safety, the adverse drug reactions were observed as grade 1 pruritus in 1 patient (0.6%). As for efficacy, specificity and positive predictability were lower than those of a WL-source, but sensitivity was higher with a FL-source than with a WL-source. The proportion of patients with tumors detected only by FL-cystoscopy was greater than the proportion of patients with tumors detected only by conventional WL-cystoscopy. Moreover, not only sensitivity, but also the proportion of patients with tumors detected only by FL-cystoscopy, was highest among patients who received 5-ALA at ≧20mg/kg/body. ConclusionsALA-PDD was shown to be safe and effective. Furthermore, diagnostic accuracy of PDD increased with increased dose of 5-ALA, and the recommended dose was determined as ≧20mg/kg/body in the present study.

Evaluating the efficacy and safety of a novel endoscopic fluorescence imaging modality using oral 5-aminolevulinic acid for colorectal tumors.

Background and study aims: Five-aminolevulinic acid (5-ALA) is being increasingly used for photodynamic diagnosis and therapy of various types of tumors including brain, urologic, and other neoplasias. The use of 5-ALA to treat Barrett’s carcinomas has been documented, but its clinical effectiveness for diagnosis of gastrointestinal tumors, particularly early cancers, remains unknown. Patients and methods: The aim of our feasibility study was to evaluate the visibility of colorectal tumors using endoscopic fluorescence imaging (EFI) after oral administration of 5-ALA. The lesions identified by direct visualization and by the spectrums produced using EFI modality with 5-ALA were compared to the clinicopathologic features of resected specimens. Results: Twenty-three patients with a total of 27 known colorectal lesions were enrolled in the study. The median tumor size was 30 mm (range 10 – 75). Eleven of the lesions were flat or depressed lesions and 16 were sessile. Red fluorescence was observed in 22 out of 27 lesions. Red fluorescence was negative in 4 out of 11 flat or depressed lesions. In comparison with histopathologic findings, the rates of red fluorescence visibility were 62.5 % in low-grade intraepithelial neoplasia, 77.8 % in high-grade neoplasia, and 100 % in submucosal carcinoma. Red fluorescence visibility increased with the degree of dysplasia. There were no significant adverse events identified in this study. Conclusions: This feasibility study using EFI with 5-ALA demonstrated high visibility of superficial colorectal neoplasia. EFI with 5-ALA appears to be a novel, safe technique for improving real-time colorectal tumor imaging.

What is the Surgical Benefit of Utilizing 5-Aminolevulinic Acid for Fluorescence-Guided Surgery of Malignant Gliomas?

The current neurosurgical goal for patients with malignant gliomas is maximal safe resection of the contrast-enhancing tumor. However, a complete resection of the contrast-enhancing tumor is achieved only in a minority of patients. One reason for this limitation is the difficulty in distinguishing viable tumor from normal adjacent brain during surgery at the tumor margin using conventional white-light microscopy. To overcome this limitation, fluorescence-guided surgery (FGS) using 5-aminolevulinic acid (5-ALA) has been introduced in the treatment of malignant gliomas. FGS permits the intraoperative visualization of malignant glioma tissue and supports the neurosurgeon with real-time guidance for differentiating tumor from normal brain that is independent of neuronavigation and brain shift. Tissue fluorescence after oral administration of 5-ALA is associated with unprecedented high sensitivity, specificity, and positive predictive values for identifying malignant glioma tumor tissue. 5-ALA-induced tumor fluorescence in diffusely infiltrating gliomas with non-significant magnetic resonance imaging contrast-enhancement permits intraoperative identification of anaplastic foci and establishment of an accurate histopathological diagnosis for proper adjuvant treatment. 5-ALA FGS has enabled surgeons to achieve a significantly higher rate of complete resections of malignant gliomas in comparison with conventional white-light resections. Consequently, 5-ALA FGS has become an indispensable surgical technique and standard of care at many neurosurgical departments around the world. We conducted an extensive literature review concerning the surgical benefit of using 5-ALA for FGS of malignant gliomas. According to the literature, there are a number of reasons for the neurosurgeon to perform 5-ALA FGS, which will be discussed in detail in the current review.