• Journal of Radiation Protection and Research
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• v.32 no.2
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• pp.59-64
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• 2007

We induced the activation of melanocytes in the epidermis of C57BL/6 mice by ultraviolet B (UVB) irradiation and observed the effect of bamboo (Phyllostachys nigra var. henenis Strapf) leaf extract (BLE) on the formation, and decrease of UVB-induced epidermal melanocytes. C57BL/6 mice were irradiated by $UVB\;80mJ/cm^2(0.5mW/sec)$ daily for 7 days, and BLE was intraperitoneally or topically applied pre-or post-irradiation. For the estimation of change of epidermal melanocytes, light microscopic observation with dihydroxyphenylalanine (DOPA) stain was performed. Split epidermal sheets prepared from the ear of untreated mice exhibited 11-16 $melanocytes/mm^2$, and one week after UV irradiation, the applied areas show an increased number of strongly DOPA-positive melanocytes with stout dendrites. But intraperitoneal or topical treatment with BLE before each irradiation interrupted UVB-induced pigmentation and resulted in a marked reduction in the number of epidermal melanocytes as compared to radiation control skin. The number and size of DOPA-positive epidermal melanocytes were also significantly decreased in intraperitoneally injected or topically applicated group after irradiation with BLE at 3rd and 6th weeks after irradiation. The results of present study indicate that BLE is likely to be useful as inhibitor of UVB-induced pigmentation and depigmenting agent.

• YAKHAK HOEJI
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• v.57 no.2
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• pp.77-86
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• 2013

The neuroprotective effects of herbal ethanol extract (GP-EX) from Gynostemma pentaphyllum on dopamine neurons in animal model of Parkinson's disease (PD) were investigated. Rats and mice were administered with rotenone (2.5 mg/kg) for 28 days and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 30 mg/kg) for 5 days for the PD models, respectively and the animals were simultaneously treated with GP-EX (30 mg/kg, daily). After preparing the PD models, the animals were also administered with L-DOPA (10 mg/kg) for 14 days with or without GP-EX treatment. Treatment with GP-EX (30 mg/kg) inhibited the rotenone- and MPTP-induced neurotoxic effects in dopamine neurons of rats or mice, which was determined by the numbers of tyrosine hydroxylase-immunohistochemical staining survival cells, as well as the levels of dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid. GP-EX (30 mg/kg) also showed the protective effects on neurotoxicity which was induced by long-term administration of L-DOPA (10 mg/kg) in rotenone- and MPTP-induced animal model of PD. The used doses of GP-EX (30 mg/kg) did not produce any signs of toxicity, such as weight loss, diarrhea, or vomiting, in rats and mice during the treatment periods. These results suggest that GP-EX has the protective functions against chronic L-DOPA-induced neurotoxic reactions in dopamine neurons of rotenone- and MPTP-induced animal model of PD. Therefore, the natural GP-EX may be beneficial in the prevention of PD progress and L-DOPA-induced neurotoxicity in PD patients.

• The Korean Journal of Zoology
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• v.39 no.1
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• pp.36-46
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• 1996

An endogenous phenoloxidase (EPO) from earthworm, Lumbricus rubellus, has been purified and characterized. The purified EPO using ammonium sulfate fractionation, Blue-2, Phenyl-, and Q-sepharose chromatography steps was revealed in SDS-PAGE as a single protein banri with Mr. of 59 kl)a. A native strudure of the enzyme was examined with an in situ staining of a nondenatudng-PAGE using DL-dopa as a substrate. The result showed that a single band due to the EPO activity was located siighdy above a standard polypeptide with Mr. of 210 kl)a. These fads indicate that the EPO is an oligomeric enzyme. The presence of a monophenolase activity of the purified EPO, which hydroxylates tyrosine to dopa, was confirmed by observing dopachrome accumulation at 475 nm at PH 8.0 with a typical lag phase during 60 mm. of meausrement. A series of inhibition study has been performed for the enzyme with several divalent cation chelators such as phenyithiourea (Flu), 1, lO-phenanthroline, EDTA, and EGTA. Among them, only V'flj inhibited the enzyme with 1C0.5 of 65 MM, which indicated that copper was critical for the catalysis of EPO. The enzyme was maximally active at 35'C and pH 8.0 when L-dopa to dopachrome conversion was spectrophotometricaily monitored at 475 nm. The apparent Km values of P0 for L-opa were obtained as 1.86 mM and 13.8 mM at pH 6.5 and 8.0, respectively. The catalytic efficiencies at both pH were almost identical [(kat/Km)pH8.0/(kcat/Km)pH6.5 = O.92] while the Vmax at p11 8.0 was 6.6-fold higher than that at pH 6.5. This fact may indicate that pH affeds the catalysis at substrate and/or enzyme-substrate complex level rather than the enzyme itself. Taken together, the EPO was an oligomeric enzyme which did not require proteolysis for its activation. These results also indicated that the enzyme can exist, at least, in part as a latent form In vivo, which might be distinct from the prophenoloxidase activating system. Therefore, it is pertinent to consider that there must be certain regulatory molecules or phenomena in L. rubellus which make the 1,0 in a latent form in vivo before the foreign invasions.

• Archives of Pharmacal Research
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• v.9 no.3
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• pp.169-174
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• 1986

Bilateral lesion of nucleus accumbens septi (N, AB), one of the mesolimbic nuclei, resulted in hyperirritability and muricide including mouse eating behavior in rats. The effects of various drugs on hyperirritability and muricide induced by NAB lesion were investigated in rats. Hyperirritability in NAB rats were significantly reduced by L-DOPA L-5-HTP major and minor tranquilizers but not reduced by MA, ATP and imipriamine-like antidepressants. On the other hand, muricide in NAB rats was significantly suppressed by L-DOPA, L-5-HTP, major and minor tranquilizers, furthermore, selectively suppressed by MA, ATP and antidepressants. These results suggested that the neural mechanism for inducing muricide is distinct from for hyperirritability in NAB rats, and that muricide in NAB rats is resulted from the increasing of cholinergic activity and reduction of dopaminergic and serotonergic activity.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.10a
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• pp.97-98
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• 2003

Current study was aimed to understand an interaction between Dopa decarboxylase (DDC) and proteins that specifically binds to DDC in the silkworm, Bombyx mori. Materials and Methods: Materials-Animal: Bombyx mori Construction of GST fusion protein Preparation of lysates: Protein extracted from whole body of Bombyx mori Methods-In vitro binding assay with lysates, Peptide sequence and RACE-PCR (omitted)

• KSBB Journal
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• v.8 no.5
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• pp.488-494
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• 1993

The accumulation of benzophenanthridine alkaloids, sanguinarine, chelerythrine, chelirubine and macarpine occurred in suspension cultures of Eschscholtzia californica. To increase alkaloid production, feeding experiments with the biosynthetic precursors, tyrosine, tyramine, L-dopa, dopamine with and without elicitation were studied. In feeding experiments with various precursors, the total alkaloid production was slightly increased. The precursor feeding with elicitation, however, increased total alkaloid production several times.

• Preventive Nutrition and Food Science
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• v.5 no.3
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• pp.148-152
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• 2000

Mussel adhesive protein (MAP) was extracted from Korean Mytilus edulis and then partially purified using Sephacryl S-300 gel permeation chromatography and reversed-phase high performance liquid chromatography. As an indicator of adhesiveness, is 3,4-dihydroxyphenylalanine (DOPA) content was determined. Its DOPA/protein ratio of 0.19 was higher than those of other reports, indicating a good adhesive. The partially purified MAP was confirmed by acid-urea polyacrylamide gel electrophoresis using cetylpiridinium bromide as a cationic detergent. Sea mussel hydrolysates were prepared using three commercial proteases to provide value-added functional materials and their angiotensin converting enzyme (ACE) inhibitory activities were determined. Among hydrolysates of sea mussel, Protamex was the best and further purification would improved ACE inhibitory activity.

• BMB Reports
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• v.28 no.4
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• pp.323-330
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• 1995

Recent studies have shown that dopamine applied to cultured swimming motor neurons of Polyorchis penicillatus produces an inhibitory action by opening potassium channels through $D_2$-like receptors. In this study, it was demonstrated that dopamine found in the hydromedusa was not from exogenous sources and the content of dopamine depended on the $Ca^{2+}$ content of the dissecting media. In addition, a combination of thin layer chromatography and high performance liquid chromatography showed the presence of DOPA and DO PAC-like compounds in the jellyfish. The glyoxylic acid method for catecholamines suggested that a population of small cells, neither swimming motor neurons nor B-like neurons, had dopaminergic systems. From all these results, it is suggested here that DA synthesized from DOPA in some cells is released. being dependent on calcium concentrations, into a synaptic cleft and degraded into DOPAC after acting as an inhibitory transmitter to swimming motor neurons.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.3
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• pp.528-532
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• 2011

This study was designed to investigate the collagen metabolism and tyrosinase activity of Meretrix extracts (ME). The effect of ME on type I procollagen production and collagenase activity in human normal fibroblasts HS68 after UVB (312 nm) irradiation was measured by ELISA method. The tyrosinase activity after treatment of ME was measured as well. Type I procollagen production was recovered by ME in UVB damaged HS68 cells. The increased collagenase activity after UVB damage was significantly recovered by ME. The tyrosinase activity and L-DOPA oxidation were significantly reduced as well. However, the effects on tyrosinase activity and L-DOPA oxidation were not powerful enough to be used as whitening agents. ME showed the anti-wrinkle effects and some whitening effects in vitro. These results suggest that ME may be a useful drug as an anti-wrinkle treatments.

• Bulletin of the Korean Chemical Society
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• v.26 no.8
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• pp.1255-1259
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• 2005

Lewy bodies (LBs) are neuronal inclusions that are closely related to Parkinson's disease (PD). The filamentous component of LB from patients with PD contains biochemically altered $\alpha$-synuclein. We have investigated the effect of the oxidized products of catecholamines on the modification of $\alpha$-synuclein. When $\alpha$-synuclein was incubated with the oxidized 3,4-dihydroxyphenylalanine (L-DOPA) or dopamine, the protein was induced to be aggregated. The oxidized catecholamine-mediated $\alpha$-synuclein aggregation was enhanced by copper ion. Radical scavengers, azide and N-acetyl cysteine significantly prevented the oxidized catecholamine-mediated $\alpha$-synuclein aggregation. The results suggest that free radical may play a role in $\alpha$-synuclein aggregation. Exposure of $\alpha$-synuclein to the oxidized products of catecholamines led to the formation of dityrosine. Antioxidant dipeptides carnosine, homocarnosine and anserine significantly protected $\alpha$-synuclein from the aggregation induced by the oxidized products of catecholamines.