• Korean Journal of Pharmacognosy
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• v.52 no.1
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• pp.19-25
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• 2021

We previously reported that lonicerin isolated from Lonicera japonica methanolic extract had potent neuro-protective activities in neuronal cell death injured by excessive glutamate. In this study, we tried to confirm the neuroprotective activities of L. japonica extract and lonicerin in glutamate injured HT22 cells and establish mechanisms of neuroprotective action of lonicerin. We used HT22 cell death injured by glutamate as a bioassay system. The compound decreased reactive oxygen species increased by excessive glutamate treatment in HT22 cells. Also, Ca2+ concentration was decreased by lonicerin treatment. This compound made mitochondrial membrane potential maintain to normal condition. Lonicerin also increased not only glutathione reductase but also peroxidase to the control level. And this compound increased amount of glutathione, an endogenous antioxidant. These results indicated that lonicerin isolated from L. japonica showed potent neuroprotective activity through the anti-oxidative pathway.

• Natural Product Sciences
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• v.15 no.3
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• pp.121-124
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• 2009

Phytochemical investigation of the aerial parts of Lonicera etrusca resulted in the isolation of three iridoids including two aglycones, loganin aglycone (log-1) (1) and lonicerin (log-2) (2), and the known common glycoside loganin (4). The study also afforded a coumarin derivative, 7-hydroxycoumarin (3), and a flavonoid glycoside, luteolin-7-O-$\beta$-D-glucoside (5). The structures were determined utilizing physical, chemical and spectral methods.

• Natural Product Sciences
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• v.17 no.3
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• pp.221-224
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• 2011

A $CH_3Cl$ extract from the flower of Lonicera japonica (Lauraceae) significantly protected primary cultures of rat cortical cells injured by the excitotoxic amino acid, L-glutamate. Loganin (1), secoxyloganin (2), caffeic acid (3) rutin (4), hyperoside (5), quercetin-3-O-glucoside (6), lonicerin (7), kaempferol-3-O-rutinoside (8), luteolin-7-O-b-D-glucopyranoside (9), quercetin (10) and luteolin (11) were isolated by bioactivity-guided fractionation from the $CH_3Cl$ fraction and further separated using chromatographic techniques. Caffeic acid, lonicerin, kaempferol-3-O-rutinoside, quercetin and luteolin had significant neuroprotective activities against glutamate-induced neurotoxicity in primary cultures of rat cortical cells at concentrations ranging from $0.1{\mu}M$ to $10.0\;{\mu}M$.

• Korean Journal of Pharmacognosy
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• v.25 no.1
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• pp.24-27
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• 1994

Two flavonoids, diosmetin 7-0-glucoside and lonicerin, and an iridoid, vogeloside have been isolated from the aerial parts of Lonicera japonica(Caprifoliaceae). The structures of these isolates have been determined by chemical transformations and interpretation of the spectral data. This is the first report of the isolation of diosmetin 7-O-glucoside from this plant.

• Archives of Pharmacal Research
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• v.18 no.2
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• pp.133-135
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• 1995

Previously, we reported that the n-butanol fraction of Lonicera japonica showed anti-flammatory activity in mice and rats. Several constituents such a loniceroside A and B, flavonoids and iridoids were isolated from this fraction. In this investigation, the anti-inflammatory activity of the major constituents of L. japonica was studied. Loniceroside A, lonicerin and loganin showed anti-inflammatory activity comparable to aspirin.

• Natural Product Sciences
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• v.10 no.1
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• pp.35-39
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• 2004

Aldose reductase (AR), the key enzyme of the polyol pathway, is known to play important roles in the diabetic complications. The inhibitors of AR, therefore, would be potential agents for the prevention of diabetic complications. In order to clarify the structural requirements of flavonoids for aldose reductase inhibitory activity, thirty flavonoids were examined. Among the thirty flavonoids, flavonols such as quercetin (5), reyneutrin (7), quercitrin (9), isoquercitrin (11), and avicularin (14) were found to exhibit much stronger AR inhibition. Lonicerin (10), amentoflavone (27) and sophoraflavanone B (30) were also showed strong inhibitory activity. Especially, quercitrin and reyneutrin exhibited the most inhibitory potency on rat lens (RL) AR. The results suggested that flavonol having the 7-hydroxyl and/or catechol moiety at the B ring exhibit strong activity. In addition, flavonols having 3-O-monosaccharide also showed stronger inhibition than free flavonols at the 3-position. These results suggested that quercitrin and reyneutrin are attributed to be the promising compounds for the prevention and/or treatment of diabetic complications.