Conversion Of Peroxide Research Articles

Comprehensive analysis and transcript profiling of Arabidopsis thaliana and Oryza sativa catalase gene family suggests their specific roles in development and stress responses

Stress induces the generation of Reactive Oxygen Species (ROS) that ultimately hampers the growth, development, and productivity of the plant. As an antioxidant enzyme, catalase converts hydrogen peroxide to water and keeps ROS level down to protect cells from stress-induced apoptosis. Here, a genome-wide analysis of catalase gene family has been performed in two model plants- Arabidopsis thaliana and Oryza sativa. Both Arabidopsis and rice has a small family of three and four genes, respectively; that code for seven proteins each. Detailed analysis of these members in terms of their structure, duplication, chromosomal position and proteins subcellular localization, as well as expression profiling under various developmental and environmental cues, was performed. Catalase proteins were mostly found to be localized in the cytoplasm, followed by peroxisome and mitochondria. Phylogenetically plant catalases showed strong divergence from their non-plant counterparts. Expression profiling revealed that AtCAT3 and OsCATA are the constitutively expressive member; while AtCAT2, OsCATA, and OsCATC are the stress-responsive members. Moreover, an altered level of total rice catalase enzyme activity and H2O2 level was observed under various abiotic stress conditions. This indicates the stress-responsive transcriptome as well as proteome alteration of catalase in the plant.

The inhibition of hydrogen peroxide reduction at low potentials on Pt(111): Hydrogen adsorption or interfacial charge?

The hydrogen peroxide reduction reaction (HPRR) on Pt(111) has been studied for the first time in acid to neutral pH values in the absence of anion specific adsorption using the HMRDE configuration. The onset for the reduction is ca. 0.95V (RHE) for the Pt(111), irrespective of the pH value. At more negative potential values, the reduction is inhibited. It has been found that the diminution of the activity on Pt(111) occurs at the same potential value in the SHE scale for the different pH values. This indicates that this deactivation is not dependent on the hydrogen adsorption process, as has been previously suggested. However, it appears to be related to the interface water reorganization and the potential of zero free charge of the metal surface. In addition, studies in alkaline conditions suggest that the presence of adsorbed OH species promotes the total conversion of hydrogen peroxide to water.

Neutrophil granule proteins generate bactericidal ammonia chloramine on reaction with hydrogen peroxide

The neutrophil enzyme, myeloperoxidase, by converting hydrogen peroxide (H2O2) and chloride to hypochlorous acid (HOCl), provides important defense against ingested micro-organisms. However, there is debate about how efficiently HOCl is produced within the phagosome and whether its reactions with phagosomal constituents influence the killing mechanism. The phagosome is a small space surrounding the ingested organism, into which superoxide, H2O2 and high concentrations of proteins from cytoplasmic granules are released. Previous studies imply that HOCl is produced in the phagosome, but a large proportion should react with proteins before reaching the microbe. To mimic these conditions, we subjected neutrophil granule extract to sequential doses of H2O2. Myeloperoxidase in the extract converted all the H2O2 to HOCl, which reacted with the granule proteins. 3-Chlorotyrosine, protein carbonyls and large amounts of chloramines were produced. At higher doses of H2O2, the extract developed potent bactericidal activity against Staphylococcus aureus. This activity was due to ammonia monochloramine, formed as a secondary product from protein chloramines and dichloramines. Isolated myeloperoxidase and elastase also became bactericidal when modified with HOCl and antibacterial activity was seen with a range of species. Comparison of levels of protein modification in the extract and in phagosomes implies that a relatively low proportion of phagosomal H2O2 would be converted to HOCl, but there should be sufficient for substantial protein chloramine formation and some breakdown to ammonia monochloramine. It is possible that HOCl could kill ingested bacteria by an indirect mechanism involving protein oxidation and monochloramine formation.

Overcoming Multidrug Resistance through the Synergistic Effects of Hierarchical pH-Sensitive, ROS-Generating Nanoreactors.

Recently, multidrug resistance (MDR) has become a major clinical chemotherapeutic burden that robustly diminishes the intracellular drug levels through various mechanisms. To overcome the doxorubicin (Dox) resistance in tumor cells, we designed a hierarchical nanohybrid system possessing copper-substituted mesoporous silica nanoparticles (Cu-MSNs). Further, Dox was conjugated to copper metal in the Cu-MSNs framework through a pH-sensitive coordination link, which is acutely sensitive to the tumor acidic environment (pH 5.0-6.0). In the end, the nanocarrier was coated with D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS), a P-gp inhibitor-entrenched compact liposome net for obstructing the drug efflux pump. Copper ions in the framework synergize the antitumor activity of Dox by enhancing the intracellular reactive oxygen species (ROS) levels through a Fenton-like reaction-mediated conversion of hydrogen peroxide. Furthermore, intracellularly generated ROS triggered the apoptosis by reducing the cellular as well as mitochondrial membrane integrity in MDR cells, which was confirmed by the mitochondrial membrane potential (MMP) measurement. The advancement of the design and critical improvement of cytotoxic properties through free radical attack demonstrate that the proposed hierarchical design can devastate the MDR for efficient cancer treatment.

Biochemical and spectroscopic characterization of dinuclear Mn-sites in artificial four-helix bundle proteins

To better understand metalloproteins with Mn-clusters, we have designed artificial four-helix bundles to have one, two, or three dinuclear metal centers able to bind Mn(II). Circular dichroism measurements showed that the Mn-proteins have substantial α-helix content, and analysis of electron paramagnetic resonance spectra is consistent with the designed number of bound Mn-clusters. The Mn-proteins were shown to catalyze the conversion of hydrogen peroxide into molecular oxygen. The loss of hydrogen peroxide was dependent upon the concentration of protein with bound Mn, with the proteins containing multiple Mn-clusters showing greater activity. Using an oxygen sensor, the oxygen concentration was found to increase with a rate up to 0.4μM/min, which was dependent upon the concentrations of hydrogen peroxide and the Mn-protein. In addition, the Mn-proteins were shown to serve as electron donors to bacterial reaction centers using optical spectroscopy. Similar binding of the Mn-proteins to reaction centers was observed with an average dissociation constant of 2.3μM. The Mn-proteins with three metal centers were more effective at this electron transfer reaction than the Mn-proteins with one or two metal centers. Thus, multiple Mn-clusters can be incorporated into four-helix bundles with the capability of performing catalysis and electron transfer to a natural protein.

Catalase ameliorates diabetes-induced cardiac injury through reduced p65/RelA- mediated transcription of BECN1.

Catalase is an antioxidative enzyme that converts hydrogen peroxide (H2O2) produced by superoxide dismutase from highly reactive superoxide (O2 −) to water and oxygen molecules. Although recent findings demonstrate that catalase, autophagy and the nuclear factor κB (NF‐κB) signalling pathway are centrally involved in diabetic cardiomyopathy (DCM), the interplay between the three has not been fully characterized. Thus, the mechanism responsible for catalase‐mediated protection against heart injury in diabetic mice was investigated in this study, as well as the role of NF‐κB‐p65 in the regulation of autophagic flux was investigated in this study. Western blot analysis revealed that catalase inhibited NF‐κB activity and decreased LC3‐II (microtubule‐associated protein 1 light chain 3) and beclin‐1 (Atg6) expression. Furthermore, up‐regulation of autophagy was detrimental for cardiac function in diabetic mice. Catalase overexpression reduced the level of NF‐κB subunit in the nucleus, where it initiates autophagy through activation of the key autophagy gene BECN1. To evaluate the role of the NF‐κB pathway in diabetes‐induced autophagy, Bay11‐7082, an NF‐κB inhibitor, was injected into diabetic mice, which suppressed NF‐κB and attenuated diabetes‐induced autophagy and myocardial apoptosis. In agreement with the in vivo results, Bay11‐7082 also inhibited high‐glucose‐induced activation of NF‐κB and the up‐regulation of LC3‐II and beclin‐1 expression in H9c2 cells. In addition, high‐glucose‐induced activation of autophagic flux and apoptosis were largely attenuated by p65 siRNA, suggesting that catalase ameliorates diabetes‐induced autophagy, at least in part by increasing the activity of the NF‐κB pathway and p65‐mediated transcription of BECN1.

Thermal decomposition reaction in ethanol solution of deuterated acetone cyclic diperoxide and acetone diperoxide. Secondary inverse isotopic effect

The characterization by mass spectrometry and the kinetic study of the thermal decomposition reaction of deuterated acetone diperoxide (dACDP) was studied in ethanol in the 140-165 oC temperature range. The comparison with the non deuterated species (ACDP) was also made. The kinetic behavior observed for both compounds follows a pseudo first order kinetic law up to at least 86 % peroxide conversions. It could be observed that under the established experimental conditions, the dACDP decomposes ca. 1.2 times faster than the ACDP. The activation parameters were calculated for both peroxides and allowed to postulate a single process initial step, the unimolecular thermal decomposition through the O-O bond cleavage to form an intermediate biradical. The products of the acetone derived peroxides thermal decomposition support a radical-based decomposition mechanism. The changes in kinetic parameters between dACDP and ACDP were justified attending to differences in ring substituents sizes. A secondary inverse kinetic isotope effect is observed (kH/kD <1).

Non-linear hydroxyl radical formation rate in dispersions containing mixtures of pyrite and chalcopyrite particles

The formation of hydroxyl radicals was studied in mixed pyrite-chalcopyrite dispersions in water using the conversion rate of adenine as a proxy for hydroxyl radical formation rate. Experiments were conducted as a function of pH, presence of phosphate buffer, surface loading, and pyrite-to-chalcopyrite ratio.The results indicate that hydroxyl radical formation rate in mixed systems is non-linear with respect to the rates in the pure endmember dispersions. The only exception is a set of experiments in which phosphate buffer is used. In the presence of phosphate buffer, the hydroxyl radical formation is suppressed in mixtures and the rate is close to that predicted based on the reaction kinetics of the pure endmembers.The non-linear hydroxyl radical formation in dispersions containing mixtures of pyrite and chalcopyrite is likely the result of two complementary processes. One is the fact that pyrite and chalcopyrite form a galvanic couple. In this arrangement, chalcopyrite oxidation is accelerated, while pyrite passes electrons withdrawn from chalcopyrite to molecular oxygen, the oxidant. The incomplete reduction of molecular oxygen leads to the formation of hydrogen peroxide and hydroxyl radical. The galvanic coupling appears to be augmented by the fact that chalcopyrite generates a significant amount of hydrogen peroxide upon dispersal in water. This hydrogen peroxide is then available for conversion to hydroxyl radical, which appears to be facilitated by pyrite as chalcopyrite itself produces only minor amounts of hydroxyl radical. In essence, pyrite is a “co-factor” that facilitates the conversion of hydrogen peroxide to hydroxyl radical. This conversion reaction is a surface-mediated reaction.Given that hydroxyl radical is one of the most reactive species in nature, the formation of hydroxyl radicals in aqueous systems containing chalcopyrite and pyrite has implications for the stability of organic molecules, biomolecules, the viability of microbes, and exposure to dust containing the two metal sulfides may present a health burden.

Effect of residence time on micropollutant removal in WWTP secondary effluents by continuous solar photo-Fenton process in raceway pond reactors

The removal of micropollutants (MPs) in wastewater treatment plants (WWTPs) secondary effluents by solar photo-Fenton is commonly carried out with low concentrations of iron and hydrogen peroxide due to the low pollutant concentration (ngL−1). This led to two main consequences being observed: short treatment times (tens of minutes) and excess of photons when using 5cm-diameter tubular reactors. To make better use of most of the photons reaching the reactor surface, the use of raceway pond reactors (RPRs) with longer light path length was implemented successfully. However, little attention was paid to the treatment time itself and the photo-Fenton process was applied in batch mode despite filling and emptying stages being much longer than reaction time. This paper deals with the performance of the solar photo-Fenton process in RPRs operated in continuous mode to remove MPs in WWTP secondary effluents. In this regard, first the continuous degradation of a model emerging contaminant, the pesticide Acetamiprid (ACTM), was studied in a synthetic secondary effluent at pH 2.8. Next, real secondary effluents were treated at two liquid depths, 5 and 15cm and three hydraulic residence times (HRTs), 80, 40 and 20min. Reactant concentrations were 5.5mgL−1 Fe2+ and 30mgL−1 H2O2 giving rise to a treated wastewater volume of 450Lm−2day−1 for a 5cm-deep RPR operated in continuous mode at 40min HRT for 6h a day in winter, with 84% MP removal and 66% hydrogen peroxide conversion. As far as the authors know, this is the first report on the solar photo-Fenton process operated in continuous mode displaying its advantages with regard to the batch operation.

Low-waste Technology of Obtaining Epoxy Compounds. Part 1. The Technology of Epichlorohydrin Production by Peroxide Method

The proposed technological process of manufacturing epichlorohydrin, calculated on the production capacity of 50 thousand ton per year to avoid imports of epoxy resins. On the basis of the research trial of the process by liquid-phase epoxidation of allyl chloride the optimal parameters of the process are determined. The conversion of hydrogen peroxide is 99 %, the yield of the epichlorohydrin – 94 %, the selectivity is no less by 95 %. The process includes three main stages: (1) raw materials preparation, (2) liquid-phase epoxidation of allyl chloride, (3) distillation of the target product. The scheme provided for recirculation of unreacted allyl chloride and the solvent – methanol.

Intensifying the O2-dependent heterogeneous biocatalysis: Superoxygenation of solid support from H2O2 by a catalase tailor-made for effective immobilization

Besides merely destroying H2O2, an important use of the catalase reaction, H2O2→1/2 O2+H2O, is to supply O2 to oxygenation reactions. Due to convenient spatiotemporal control over O2 release, oxygenation from H2O2 is useful in particular for enzymatic reactions confined to solid supports. Because commercial catalases are difficult to immobilize, we have developed a one-step procedure of purification and immobilization of Bordetella pertussis catalase, recombinantly produced in Escherichia coli. Fusion of the catalase to a positively charged binding module enabled effective immobilization of the chimeric enzyme on anionic support (Relisorb SP 400), giving a controllable activity loading of between 5000 and 100,000 units/g support. Use of the immobilized catalase in combination with H2O2 feeding provided O2 to the reaction of glucose oxidase in solution for a range of volumetric conversion rates (0.2–1.5mM/min). Using optical sensing to measure the O2 concentration in the liquid but also in the solid phase, we showed that internal superoxygenation of the support was made possible under these conditions, resulting in an inverted (that is, negative) O2 concentration gradient between the bulk and the particle and allowing the internal O2 concentration to exceed by up to 4-fold the limit of atmospheric-pressure air saturation in solution. By tailored immobilization of B. pertussis catalase, therefore, an efficient biocatalytic system for hydrogen peroxide conversion in porous solid support was developed. This could find application for bubble-free oxygenation of O2-dependent enzymes co-immobilized with the catalase whereby enhanced internal availability of O2 would contribute to biocatalytic reaction intensification.

Chromatin remodeling regulates catalase expression during cancer cells adaptation to chronic oxidative stress

Regulation of ROS metabolism plays a major role in cellular adaptation to oxidative stress in cancer cells, but the molecular mechanism that regulates catalase, a key antioxidant enzyme responsible for conversion of hydrogen peroxide to water and oxygen, remains to be elucidated. Therefore, we investigated the transcriptional regulatory mechanism controlling catalase expression in three human mammary cell lines: the normal mammary epithelial 250MK primary cells, the breast adenocarcinoma MCF-7 cells and an experimental model of MCF-7 cells resistant against oxidative stress resulting from chronic exposure to H2O2 (Resox), in which catalase was overexpressed. Here we identify a novel promoter region responsible for the regulation of catalase expression at −1518/−1226 locus and the key molecules that interact with this promoter and affect catalase transcription. We show that the AP-1 family member JunB and retinoic acid receptor alpha (RARα) mediate catalase transcriptional activation and repression, respectively, by controlling chromatin remodeling through a histone deacetylases-dependent mechanism. This regulatory mechanism plays an important role in redox adaptation to chronic exposure to H2O2 in breast cancer cells. Our study suggests that cancer adaptation to oxidative stress may be regulated by transcriptional factors through chromatin remodeling, and reveals a potential new mechanism to target cancer cells.

Patterns of phenol oxidation process with an aqueous solution of hydrogen peroxide

This paper presents experimental data on the study of catalytic systems based on titanium silicalite (TS-1) for liquid-phase oxidation of phenol. The influence of the main parameters of the process of liquid phase oxidation of phenol with aqueous solution of hydrogen peroxide on the catalyst; the formed titanium silicalite (initial molar ratio of phenol/hydrogen peroxide, temperature) has been studied based on the basic parameters of the process, including the degree of conversion of hydrogen peroxide, the degree of conversion of phenol, the selectivity of the formation of catechol, hydroquinone and 1,4-benzoquinone, and the ratio of products in the reaction mass.

Characterization of 2‐Chlorofatty Acid Signaling Pathways

Monocytes and macrophages are key inflammatory cell mediators in the response to infection and tissue injury. Monocytes and macrophages produce a respiratory burst, resulting in the release of reactive oxygen species. Upon activation of these leukocytes, myeloperoxidase (MPO) is released. MPO catalyzes the conversion of hydrogen peroxide into hypochlorous acid (HOCl). HOCl then is able to target the vinyl ether bond of plasmalogens, an abundant class of phospholipids. This results in the production of a novel class of chlorinated lipids, including 2‐chlorofatty aldehyde (2‐ClFALD) and its oxidation product, 2‐chlorofatty acid (2‐ClFA). 2‐Chlorofatty acids have been shown to accumulate in activated human neutrophils and monocytes, as well as the plasma of rats subjected to lipopolysaccharide treatment or the cecal ligation and puncture sepsis model. The present study is designed to identify signaling mechanisms mediated by 2‐ClFA. Initial studies used dynamic mass redistribution (DMR) assays, which is a label‐free functional cell‐based technology that measures whole cell response to ligands. DMR analyses demonstrated that the 2‐ClFA, 2‐chloropalmitic acid, selectively stimulates THP‐1 cells and not HEK293 cells. Furthermore, the dose‐response for 2‐chloropalmitic acid was striking compared to the lack of response to equimolar concentrations of the non‐chlorinated fatty acid, palmitic acid. CCAAT/enhancer‐binding protein homologous protein (CHOP) mRNA increases selectively in response to 2‐chloropalmitic acid compared to palmitic acid in both RAW 264.7 and THP‐1 cells. CHOP mRNA expression in RAW 264.7 cells is inhibited by Bisindolylmaleimide, SB203580, and U0126 indicating 2‐ClFA elicited CHOP expression is PKC, p38 and MEK1/2 dependent. Thus, THP‐1 and RAW 264.7 cells are ideal cells to use for expression analysis and DMR to further elucidate the mechanisms and receptor by which 2‐ClFA elicits cell responses.Support or Funding InformationNational Institutes of Health Grant GM115553

The epoxidation of diallyl ether to allyl-glycidyl ether over the TS-1 catalyst

Research on the epoxidation of diallyl ether (DAE) to allyl-glycidyl ether with 30 wt% hydrogen peroxide and in the presence of the TS-1 catalyst is presented. In this work, methanol was tested as the solvent. The influence of the following parameters was studied: the temperature 25–80 °C, the molar ratio of DAE/H2O2 0.25:1–5:1, the solvent concentration 10–90 wt%, the content of the TS-1 catalyst 1–9 wt% and the reaction time 15–240 min. Because the effective conversion of hydrogen peroxide was relatively low during the studies, after establishing the most beneficial conditions for the epoxidation of DAE, the influence of an addition of the chosen inorganic salt—KH2PO4 on the effective conversion of hydrogen peroxide and other functions characterized this process was also tested.

Assessment of tick antioxidant responses to exogenous oxidative stressors and insight into the role of catalase in the reproductive fitness of the Gulf Coast tick, Amblyomma maculatum.

As obligate blood-sucking ectoparasites, to avoid tissue damage, ticks must neutralize the reactive oxygen species (ROS) generated from uptake and digestion of a bloodmeal. Consequently, ticks utilize a battery of antioxidant molecules, including catalase (CAT), an enzyme that converts hydrogen peroxide (H2 O2 ) into water and oxygen. Here, we investigated the tick antioxidant machinery by exogenous injection of sublethal doses of H2 O2 or paraquat. The relative transcript levels of selected Amblyomma maculatum antioxidant targets in tissues were determined by quantitative reverse transcriptase PCR following treatment. The results showed 2-16-fold increases in target antioxidant gene transcripts, signifying the ability of Am. maculatum to regulate its antioxidant machinery when exposed to increased ROS levels. Next, RNA interference was used to determine the functional role of CAT in haematophagy, redox homeostasis and reproductive fitness. CAT gene silencing was confirmed by transcript depletion within tick tissues; however, CAT knockdown alone did not interfere with tick haematophagy or phenotype, as confirmed by the resulting differential expression of antioxidant genes, thereby indicating an alternative mechanism for ROS control. Interestingly, double stranded RNA of CAT gene (dsCAT) and the CAT inhibitor, 3-aminotriazole, together reduced tick reproductive fitness via a marked reduction in egg mass and larval eclosion rates, highlighting a role for CAT in tick redox-homeostasis, making it a potential target for tick control.

Nano-Fenton Reactors as a New Class of Oxidative Stress Amplifying Anticancer Therapeutic Agents.

Cancer cells, compared to normal cells, are under oxidative stress associated with an elevated level of reactive oxygen species (ROS) and are more vulnerable to oxidative stress induced by ROS generating agents. Thus, manipulation of the ROS level provides a logical approach to kill cancer cells preferentially, without significant toxicity to normal cells, and great efforts have been dedicated to the development of strategies to induce cytotoxic oxidative stress for cancer treatment. Fenton reaction is an important biological reaction in which irons convert hydrogen peroxide (H2O2) to highly toxic hydroxyl radicals that escalate ROS stress. Here, we report Fenton reaction-performing polymer (PolyCAFe) micelles as a new class of ROS-manipulating anticancer therapeutic agents. Amphiphilic PolyCAFe incorporates H2O2-generating benzoyloxycinnamaldehyde and iron-containing compounds in its backbone and self-assembles to form micelles that serve as Nano-Fenton reactors to generate cytotoxic hydroxyl radicals, killing cancer cells preferentially. When intravenously injected, PolyCAFe micelles could accumulate in tumors preferentially to remarkably suppress tumor growth, without toxicity to normal tissues. This study demonstrates the tremendous translatable potential of Nano-Fenton reactors as a new class of anticancer drugs.

Binding of Cimetidine to Balb/C Mouse Liver Catalase; Kinetics and Conformational Studies.

Catalase is responsible for converting hydrogen peroxide (H2O2) into water and oxygen in cells. This enzyme has high affinity for hydrogen peroxide and can protect the cells from oxidative stress damage. Catalase is a tetramer protein and each monomer contains a heme group. Cimetidine is a histamine H2 receptor blocker which inhibits acid release from stomach and is used for gasterointestinal diseases. In this research, effect of cimetidine on the activity of liver catalase was studied and the kinetic parameters of this enzyme and its conformational changes were investigated. Cell free extract of mouse liver was used for the catalase assay. The activity of the catalase was detected in the absence and presence of cimetidine by monitoring hydrogen peroxide reduction absorbance at 240 nm. The purified enzyme was used for conformational studies by Fluorescence spectrophotometry. The data showed that cimetidine could inhibit the enzyme in a non-competitive manner. Ki and IC50 values of the drug were determined to be about 0.75 and 0.85 uM, respectively. The Arrhenius plot showed that activation energy was 6.68 and 4.77 kJ/mol in the presence and absence of the drug, respectively. Fluorescence spectrophotometry revealed that the binding of cimetidine to the purified enzyme induced hyperchromicity and red shift which determined the conformational change on the enzyme. Cimetidine could non-competitively inhibit the liver catalase with high affinity. Binding of cimetidine to the enzyme induced conformational alteration in the enzyme.

Novel mild synthesis of high-added-value p-hydroxyphenyl acetic acid and 3,4-dihydroxyphenyl acetic acid using the acidic clay/hydrogen peroxide catalytic system

Acid-activated clays KSF and KSF/0 were successfully used in the hydrogen peroxide conversion of phenyl acetic acid to high-added phenolic compounds: p -hydroxyphenyl acetic acid and 3,4-dihydroxyphenyl acetic acid, endowed with a powerful antioxidant capacity. The catalytic conversion enhancement could be correlated to the total surface acidity and the high iron content of the catalysts KSF/0 and KSF, respectively. The synthetic route described here was conducted under mild conditions with very low degree of mineralization and without significant Fe ion leaching observations. The synthesis reaction is operationally simple and could find application for industrial purposes.

Color reduction of melanin by lysosomal and peroxisomal enzymes isolated from mammalian cells.

Lysosomes and peroxisomes are organelles with many functions in all eukaryotic cells. Lysosomes contain hydrolytic enzymes (lysozyme) that degrade molecules, whereas peroxisomes contain enzymes such as catalase that convert hydrogen peroxide (H2O2) to water and oxygen and neutralize toxicity. In contrast, melanin is known as a helpful element to protect the skin against harmful ultraviolet rays. However, a high quantity of melanin leads to hyperpigmentation or skin cancer in human. New materials have already been discovered to inhibit tyrosinase in melanogenesis; however, melanin reduction does not suggest their preparation. In this study, we report that the color intensity because of melanin decreased by the cellular activation of lysosomes and peroxisomes. An increase in the superficial intensity of lysosome and peroxisome activities of HeLa cells was observed. In addition, a decrease in the amount of melanin has also been observed in mammalian cells without using any other chemical, showing that the process can work in vivo for treating melanin. Therefore, the results of this study indicate that the amount of melanin decreases by the lysosome and peroxisome activity after entering the cells, and functional organelles are effective in color reduction. This mechanism can be used in vivo for treating melanin.