Phloretin-loaded fast dissolving nanofibers for the locoregional therapy of oral squamous cell carcinoma

Nam, Suyeong,Lee, Song Yi,Cho, Hyun-Jong Elsevier 2017 JOURNAL OF COLLOID AND INTERFACE SCIENCE - Vol.508 No.-

<P><B>Abstract</B></P> <P>Fast dissolving nanofiber (NF) composed of poly(vinyl alcohol) (PVA) and <SMALL>D</SMALL>-α-tocopheryl polyethylene glycol succinate (TPGS) was developed for locoregional delivery of phloretin to oral cancers. PVA/TPGS/phloretin NF with 321nm mean diameter and >90% drug entrapment efficiency was fabricated by an electrospinning method. Transformation of drug from crystalline to amorphous state was identified by solid-state studies. NF structure was changed to nanoparticles after its dispersing in the aqueous medium. PVA/TPGS/phloretin NF exhibited fast wetting property and smaller hydrodynamic size of dispersion, compared with PVA/phloretin NF. The amphiphilic property of TPGS also contributed to the improved drug release from PVA/TPGS/phloretin NF. The anticancer activities of phloretin, <I>via</I> the inhibition of glucose uptake into the cancer cells, in NFs were assessed in YD-9 cells (oral squamous cell carcinoma from buccal cheek). The antiproliferation efficacy of PVA/TPGS/phloretin NF was significantly higher than that of phloretin solution and PVA/phloretin NF (<I>p</I> <0.05). Higher apoptotic events were also observed in PVA/TPGS/phloretin NF group rather than phloretin solution and PVA/phloretin NF groups (<I>p</I> <0.05). All these results support that PVA/TPGS/phloretin NF can be a promising fast dissolving formulation for the treatment of oral cancers.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Production of Human Metabolites of Phloretin by Bacterial CYP102A1 Peroxygenase

Jang HAN SOL,Mok JIAE,Kim JEONG-HOON,Nguyen NGOC ANH,Yun CHUL-HO 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.10

Phloretin, the major polyphenol in apples, is interesting because of its beneficial effects on human health. It is mainly found as a form of glucoside, phlorizin. However, the metabolic pathway of phloretin in humans has not been reported. Therefore, identifying phloretin metabolites in human liver microsomes (HLMs) and the human cytochrome P450 enzymes to make them is interesting. Here, the roles of human liver P450s for phloretin oxidation were examined using HLMs and recombinant human liver P450s. One major metabolite of phloretin in HLMs was 3-OH phloretin, which is the same product of a bacterial CYP102A1-catalyzed reaction of phloretin. The catalytic efficiency of a CYP3A4-catalyzed reaction is 1.8-fold higher than a reaction catalyzed by CYP2C19. Whole-cell biotransformation with CYP3A4 was achieved 0.16 mM per hour productivity for 3-OH phloretin. Phloretin was a potent inhibitor of CYP3A4-catalyzed testosterone 6β-hydroxylation activity. Antibodies against CYP3A4 inhibited up to 90% of the microsomal activity of phloretin 3-hydroxylation. Thus, CYP3A4 majorly contributes to the human liver microsomal phloretin 3-hydroxylation, and CYP2C19 has a minor role.

플로레틴(Phloretin)의 혈관내피수축 융합효과와 관련기전 연구

방준석,제현동,민영실 중소기업융합학회 2020 융합정보논문지 Vol.10 No.10

이 실험에서 뇌졸중, 심혈관계 질환 등에 대해 치료 활성이 기대되는 플로레틴(phloretin) – 사과나무 잎과 개살구의 주성분 - 에서의 쥐의 대동맥에서 ROCK(Rho연관 인산화효소) 불활성화를 통해 혈관수축을 억제한다는 기전을 확인하고자 한다. 개체에서 분리되고 내피가 유지되거나 손상된 동맥의 고리 조각은 2개의 금속 고리로 근운동기록기(myograph) 수조 안에 현수되었고 아래쪽 고리는 수조바닥에 고정되었고 위쪽 고리는 등장력 변환기에 연결되었고 등장력 변환기의 전기적 신호는 생리측정기에 표시되었다. 재미있게도 플로레틴은 수축약 (fluoride, phorbol ester)에 의한 혈관 수축을 억제하여 ROCK 또는 MEK(마이토겐 활성화 단백질 키나제 키나제) 비활성화 같은 경로가 혈관이완에 관여할 수 있음을 보였다. 따라 서 phloretin은 내피가 완전한 혈관에서의 내피에 의존적인 작용 외에 추가적으로 내피에 비의존적으로 평활근에서 ROCK 또는 MEK 활성 감소에 참여하여 결과적으로 평활근에서 액틴-미오신 상호작용을 억제하여 혈관을 이완하는 것으로 관찰되 었다. 또한 phloretin은 thromboxane A2 유도수축을 억제하고 ROCK 및 MEK 억제를 포함하는 기전있음을 주장합니다. This study tried to observe the ability to inhibit vasocontriction in phloretin - the primary ingredient of apple tree leaves and the Manchurian apricot – through ROCK(Rho-associdated, coiled-coil containing protein kinase) inactivation in rat aortae. A piece of artery that was separated from Sprague-Dawley male rats and retained or damaged the endothelium was suspended in myograph tank with two metal rings, the lower ring fixed to the bottom of the tank, and the upper ring connected to the isotonic force transducer. Interestingly, phloretin inhibited fluoride- or phorbol ester-provoked contraction implying that additional pathways dissimilar from endothelial nitric oxide synthesis such as ROCK or MEK (mitogen activated protein kinase kinase) inactivation might be involved in the vasorelaxation. Therefore, this study provides that phloretin participates in the reduction of ROCK or MEK activity in smooth muscle in addition to the endothelial-dependent action of the endotheliuim in complete blood vessels, and consequently inhibits actin-myosin interaction in smooth muscle. Furthermore, phloretin inhibited thromboxane A2-induced contraction suggesting the mechanism including inhibition of ROCK and MEK.

사과 추출물과 phloretin에 의한 항염증 활성

김근호(Geun-Ho Kim),이은주(Eun-Joo Lee),류승민(Seung-Min Ryu),손호용(Ho-Yong Sohn),김종식(Jong-Sik Kim) 한국생명과학회 2021 생명과학회지 Vol.31 No.2

본 연구에서는 풋사과의 열수추출물(GAHW)과 에탄올추출물(GAE), 그리고 애사과 열수추출물(UAHW)을 제조하고 LPS로 활성화된 RAW264.7세포주를 이용하여 이들의 항염증 활성을 연구하였다. 모든 추출물이 세포생존율에는 영향을 미치지 않고 nitric oxide (NO) 생산을 저해하였으며, iNOS의 발현도 감소시켰다. 반면, UAHW만이 COX-2의 발현을 저해하였다. 또한 모든 추출물이 모든 MAPKs의 인산화를 감소시켰다. 모든 추출물이 ROS의 생산을 농도의존적으로 감소시켰으며, GAHW와 GAE에 의해 HO-1의 발현이 증가됨을 확인하였다. 또한, 사과 flavonoid인 phloretin과 phloridzin의 항염증 활성을 연구하였다. Phloretin은 농도의존적으로 NO의 생산을 저해하였으나, phloridzin은 NO 생산에 아무 영향이 없었다. 또한, phloretin은 iNOS와 COX-2 단백질의 발현을 감소시킨 반면, phloridzin은 두 단백질 발현에 영향을 주지 못하였다. 따라서, 이러한 연구결과는 사과 추출물은 MAPK 경로와 HO-1 경로를 조절함으로써 항염증 활성을 가지며, phloretin이 사과의 항염증 활성을 담당하는 파이토케미칼의 하나가 될 수 있음을 제시한다. In the present study, we prepared hot water extracts of green apple (GAHW) and unripe apple (UAHW), and ethanol extract of green apple (GAE), and investigated their anti-inflammatory activities in LPS-activated RAW264.7 cells. All extracts dramatically suppressed nitric oxide (NO) production in a dose-dependent manner in LPS-stimulated RAW264.7 cells without affecting cell viability. In addition, all extracts decreased the expression of iNOS, whereas UAHW only reduced the expression of COX-2. All extracts suppressed the phosphorylation of MAPKs (p38, ERK, and JNK) indicating all extracts show their anti-inflammatory activities via regulating MAPK pathway. Furthermore, all extracts reduced the production of reactive oxygen species in a dose-dependent manner and they increased the expression of heme oxygenase-I (HO-I) whereas UAHW could not. We also investigated whether apple flavonoids phloretin and phloridzin can have their anti-inflammatory activities in same in vitro model. Phloretin dramatically decreased NO production in a dose dependent manner without affecting cell viability, whereas phloridzin have no effects. Phloretin also reduced the expression of iNOS as well as COX-2, whereas phloridzin could not. Overall, these results suggest that apple extracts have their anti-inflammatory activities via regulating MAPKs and HO-1 pathways, and apple flavonoid phloretin can be one of phytochemicals responsible for anti-inflammatory effect of apple.

Protective Effects of a New Phloretin Derivative against UVB-Induced Damage in Skin Cell Model and Human Volunteers

Shin, Seoungwoo,Kum, Hyunwoo,Ryu, Dehun,Kim, Minkyung,Jung, Eunsun,Park, Deokhoon MDPI 2014 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.15 No.10

<P>The phenolic compound phloretin is a prominent member of the chemical class of dihydrochalcones. Phloretin is specifically found in apple and apple juice and known for its biological properties. We were particularly interested in its potential dermo-cosmetic applications. However, practical limitations of phloretin do exist due to its poor water-solubility. Phloretin was sulfonated with sulfuric acid (98%, wt) and mixed with saturated salt water to produce phloretin 3',3-disulfonate in order to increase its water-solubility. Here we reported the photoprotective effect of phloretin 3',3-disulfonate (PS), a new semi-synthetic derivative of phloretin. Results showed that PS attenuated cyclobutane pyrimidine dimer (CPDs) formation, glutathione (GSH) depletion and apoptosis induced by ultraviolet B (UVB). The photoprotective effect of PS is tightly correlated to the enhancement of nucleotide excision repair (NER) gene expression. Furthemore, PS had inhibitory effects on UVB-induced release of the inflammatory mediators, such as IL-6 and prostaglandin-E<SUB>2</SUB>. We also confirmed the safety and clinical efficacy of PS on human skin. Overall, the results demonstrated significant benefits of PS on the protection of keratinocytes against UVB-induced injuries and suggested its potential use in skin photoprotection.</P>

AFB₁ 대사에서 phloretion의 이중 활성 효과

임대원,이광,고상상,진효연,은상용,최병민,김복량 圓光大學校 醫科學硏究所 2008 圓光醫科學 Vol.23 No.1

Aflatoxm B₁(AFB₁) is a potent hepatocarcinogen in experimental animals and a hazard to human health in several parts of the world. AFB₁ is activated to its ultimate carcinogenic intermediate, AFB₁-8,9-epoxide, by cytochrome P450(CYP) 1A2 and CYP3A4 in human liver and the intermediate is decomposed by several glutathione S-transferase(GST) including GSTA2, GSTM1 and GSTP1. In this study, we investigated the effects of phloretin on the enzyme systems which are involved in the activation and detoxification of AFB₁. The metabolic intermediate of AFB₁ was measured with HPLC. We found that phloretin could strongly inhibit the activities of CYP 3A4 and CYP1A2 in a dose dependent manner. Phloretin induced the antioxidant-response element(ARE)-mediated gene expression, including GSTs. The expressions of GSTA2, T1, M1, and GSTP1 were induced by 10μM phloretin. The decomposition of AFB₁-8,9-epoxide was measured with GSH conjugating activity of the epoxide. The rate was increased to 1.5 fold when HepG2 cells were treated by 10μM phloretin for 12h. In the mean while, the total GST activitives toward CDNB in HepG2 cells were not changed by the treatment with phloretin. The results demonstrate that phloretin has strong chemopreventive effects against AFB₁ toxicity through the inhibition of AFB₁ activation and induction of GSTs.

In vitro and in vivo production of phloretin glucosides by using Bacillus licheniformis glycosyltransferase

Ramesh Prasad Pandey,Le Tai Feng,Mi Kyoung Kim,Jae Kyung Sohng 한국당과학회 2012 한국당과학회 학술대회 Vol.2012 No.1

A novel GT1 family glycosyltransferase, YjiC from Bacillus licheniformis ATCC 14580 has been PCR amplified, cloned, and expressed in E. coli BL21 (DE3) expression host. The expression of 396 amino acid long gene generated ~45 kDa N-terminal his-tag protein. The protein has been purified and used for the in vitro glycosylation of phloretin. Moreover, the enzyme was also applied for the in vivo glycosylation of the same phloretin molecule. The in vitro and in vivo study found that YjiC can glycosylate at different positions of hydroxyl groups of phloretin molecule very efficiently with conversion rate of ~98%. Four different products has been identified from the in vitro as well as in vivo reaction as phloretin-2’-glucoside, phloretin-4’-glucoside, and two different diglucosides of phloretin. All the products have been confirmed by TLC, HPLC, LC-MS, and former two products has been further confirmed by NMR analysis.

Phloretin promotes osteoclast apoptosis in murine macrophages and inhibits estrogen deficiency-induced osteoporosis in mice

Lee, E.J.,Kim, J.L.,Kim, Y.H.,Kang, M.K.,Gong, J.H.,Kang, Y.H. G. Fischer 2014 Phytomedicine Vol.21 No.10

Bone-remodeling imbalance induced by increased osteoclast formation and bone resorption is known to cause skeletal diseases such as osteoporosis. The reduction of estrogen levels at menopause is one of the strongest risk factors developing postmenopausal osteoporosis. This study investigated osteoprotective effects of the dihydrochalcone phloretin found in apple tree leaves on bone loss in ovariectomized (OVX) C57BL/6 female mice as a model for postmenopausal osteoporosis. OVX demoted bone mineral density (BMD) of mouse femurs, reduced serum 17β-estradiol level and enhanced serum receptor activator of NF-κB ligand (RANKL)/osteoprotegerin ratio with uterine atrophy. Oral administration of 10mg/kg phloretin to OVX mice for 8 weeks improved such effects, compared to sham-operated mice. Phloretin attenuated TRAP activity and cellular expression of β3 integrin and carbonic anhydrase II augmented in femoral bone tissues of OVX mice. This study further examined that osteogenic activity of phloretin in RANKL-differentiated Raw 264.7 macrophages into mature osteoclasts. Phloretin at 1-20μM stimulated Smac expression and capase-3 activation concurrently with nuclear fragmentation of multi-nucleated osteoclasts, indicating that this compound promoted osteoclast apoptosis. Consistently, phloretin enhanced bcl-2 induction but diminished bax expression. Furthermore, phloretin activated ASK-1-diverged JNK and p38 MAPK signaling pathways in mature osteoclasts, whereas it dose-dependently inhibited the RANKL-stimulated activation of ERK. Therefore, phloretin manipulated ASK-1-MAPK signal transduction leading to transcription of apoptotic genes. Phloretin was effective in preventing estrogen deficiency-induced osteoclastogenic resorption.

Phloretin Ameliorates Succinate-Induced Liver Fibrosis by Regulating Hepatic Stellate Cells

Cong Thuc Le,Giang Nguyen,박소영,Hanh Nguyen Dong,조윤경,이재호,임승순,최대호,조은희 대한내분비학회 2023 Endocrinology and metabolism Vol.38 No.4

Background: Hepatic stellate cells (HSCs) are the major cells which play a pivotal role in liver fibrosis. During injury, extracellular stimulators can induce HSCs transdifferentiated into active form. Phloretin showed its ability to protect the liver from injury, so in this research we would like to investigate the effect of phloretin on succinate-induced HSCs activation in vitro and liver fibrosis in vivo study. Methods: In in vitro, succinate was used to induce HSCs activation, and then the effect of phloretin on activated HSCs was examined. In in vivo, succinate was used to generated liver fibrosis in mouse and phloretin co-treated to check its protection on the liver. Results: Phloretin can reduce the increase of fibrogenic markers and inhibits the proliferation, migration, and contraction caused by succinate in in vitro experiments. Moreover, an upregulation of proteins associated with aerobic glycolysis occurred during the activation of HSCs, which was attenuated by phloretin treatment. In in vivo experiments, intraperitoneal injection of phloretin decreased expression of fibrotic and glycolytic markers in the livers of mice with sodium succinate diet-induced liver fibrosis. These results suggest that aerobic glycolysis plays critical role in activation of HSCs and succinate can induce liver fibrosis in mice, whereas phloretin has therapeutic potential for treating hepatic fibrosis. Conclusion: Intraperitoneal injection of phloretin attenuated succinate-induced hepatic fibrosis and alleviates the succinate-induced HSCs activation.

Phloretin Inhibits Phorbol Ester–Induced Tumor Promotion and Expression of Cyclooxygenase-2 in Mouse Skin: Extracellular Signal-Regulated Kinase and Nuclear Factor-jB as Potential Targets

신준완,Kundu, Joydeb Kumar,Young-Joon Surh 한국식품영양과학회 2012 Journal of medicinal food Vol.15 No.3

The present study investigated the effect of phloretin [20,40,60-trihydroxy-3-(4-hydroxyphenyl)-propiophenone] on 12-O-tetradecanoylphorbol 13-acetate (TPA)–induced cyclooxygenase-2 (COX-2) expression and tumor promotion in mouse skin and explored the underlying molecular mechanisms. Topical application of phloretin significantly inhibited 7,12-dimethylbenz[a]anthracene-initiated and TPA-promoted mouse skin carcinogenesis. Pretreatment with phloretin on the dorsal skin of mice inhibited TPA-induced COX-2 expression in a dose-dependent manner. To elucidate the molecular mechanism underlying COX-2 inhibition by phloretin, we examined its effect on TPA-induced activation of nuclear factor-jB (NF-jB), a ubiquitous transcription factor responsible for TPA-induced COX-2 expression in mouse skin. Topically applied phloretin decreased the TPA-induced DNA binding of NF-jB. In addition, phloretin inhibited the phosphorylation as well as the catalytic activity of extracellular signal-regulated kinase (ERK), which was previously found to activate NF-jB and induce COX-2 expression in TPA-treated mouse skin. Taken together, the inhibitory effects of phloretin on TPA-induced NF-jB activation and COX-2 expression through the modulation of ERK signaling may partly account for its antitumor-promoting effect on mouse skin carcinogenesis.