Antiatherogenic effect of guava leaf extracts inhibiting leucocyte-type 12-lipoxygenase activity

Kawakami, Yuki; Hosokawa, Tomoyoshi; Morinaka, Tomoko; Irino, Shioka; Hirano, Seishiro; Kobayashi, Hirokazu; Yoshioka, Akiko; Suzuki-Yamamoto, Toshiko; Yokoro, Miyuki; Kimoto, Masumi; Tsuji, Hideaki; Yamashita, Hiromi; Doi, Shinobu; Yutani, Chikao; Kato, Ryuichi; Itabe, Hiroyuki; Kanada, Teruyuki; Hada, Takahiko; Takahashi, Yoshitaka

doi:10.1016/j.foodchem.2011.10.011

Cited by 14 publications

(12 citation statements)

References 28 publications

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“…Ligurosides A ( 1 ) and B ( 2 ) exhibited significant inhibitory effects, with IC 50 values of 1.7 and 0.7 μM, respectively. The inhibitory potency of liguroside A was comparable to that of quercetin (IC 50 value of 1.6 μM) used as a positive control [ 3 ]. p -Coumaric acid, as a part of the catabolites believed to be produced from ligurosides by intestinal microflora after Qing Shan Lu Chui consumption showed no inhibition on leukocyte-type 12-LOX activity.…”

Section: Resultsmentioning

confidence: 99%

“…Oxidative modification of low-density lipoprotein is the first key step in the development of atherosclerosis, and the role of leukocyte-type 12-lipoxygenase (LOX) in this process has been established using leukocyte-type 12-LOX-knockout mice [ 1 , 2 ]. We previously reported that guava leaf extracts showed anti-atherogenic activity by inhibiting leukocyte-type 12-LOX activity [ 3 ]. Chinese teas derived from various kinds of plants are drunk for health benefits in parts of South China such as the province of Sichuan.…”

Section: Introductionmentioning

confidence: 99%

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Two New Monoterpene Glycosides from Qing Shan Lu Shui Tea with Inhibitory Effects on Leukocyte-Type 12-Lipoxygenase Activity

et al. 2013

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We evaluated the inhibitory effect of 12 Chinese teas on leukocyte-type 12-lipoxygenase (LOX) activity. Tea catechins such as epigallocatechin gallate have been known to exhibit leukocyte-type 12-LOX inhibition. Qing Shan Lu Shui, which contains lower catechin levels than the other tested teas, suppressed leukocyte-type 12-LOX activity. To characterize the bioactive components of Qing Shan Lu Shui, leukocyte-type 12-LOX inhibitory activity–guided fractionation of the aqueous ethanol extract of the tea was performed, resulting in the isolation of two new monoterpene glycosides: liguroside A (1) and B (2). The structures of compounds 1 and 2 were characterized as (2E,5E)-7-hydroperoxy-3,7-dimethyl-2,5-octadienyl-O-(α-l-rhamnopyranosyl)-(1″→3′)-(4′″-O-trans-p-coumaroyl)-β-d-glucopyranoside and (2E,5E)-7-hydroperoxy-3,7-dimethyl-2,5-octa-dienyl-O-(α-l-rhamnopyranosyl)-(1″→3′)-(4′″-O-cis-p-coumaroyl)-β-d-glucopyranoside, respectively, based on spectral and chemical evidence. Ligurosides A (1) and B (2) showed inhibitory effects on leukocyte-type 12-LOX activity, with IC50 values of 1.7 and 0.7 μM, respectively.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Two New Monoterpene Glycosides from Qing Shan Lu Shui Tea with Inhibitory Effects on Leukocyte-Type 12-Lipoxygenase Activity

et al. 2013

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“…As seen on Figure 2B, the trunk bark extract proved to be active at concentrations as low as 10 µg mL −1 , displaying an IC 50 value of 29.0 ± 2.3 µg mL −1 . Ellagic acid derivatives, particularly ellagic acid (1), have been ascribed as anti-inflammatory agents interfering with several inflammatory mediators [30], and while there are no reports on the specific inhibitory effects towards 5-LOX, Kawakami et al [31] recorded a concentration-dependent inhibition against the 12-lipoxygenase isoform.…”

Section: Effects On No Levels and Inflammatory Cytokines In Lps-stimumentioning

confidence: 99%

Inhibition of Proinflammatory Enzymes and Attenuation of IL-6 in LPS-Challenged RAW 264.7 Macrophages Substantiates the Ethnomedicinal Use of the Herbal Drug Homalium bhamoense Cubitt & W.W.Sm

Suksungworn

Andrade

Oliveira

et al. 2020

IJMS

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Commonly used to treat skin injuries in Asia, several Homalium spp. have been found to promote skin regeneration and wound healing. While ethnobotanical surveys report the use of H. bhamoense trunk bark as a wound salve, there are no studies covering bioactive properties. As impaired cutaneous healing is characterized by excessive inflammation, a series of inflammatory mediators involved in wound healing were targeted with a methanol extract obtained from H. bhamoense trunk bark. Results showed concentration-dependent inhibition of hyaluronidase and 5-lipoxygenase upon exposure to the extract, with IC50 values of 396.9 ± 25.7 and 29.0 ± 2.3 µg mL−1, respectively. H. bhamoense trunk bark extract also exerted anti-inflammatory activity by significantly suppressing the overproduction of interleukin 6 (IL-6) in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages at concentrations ranging from 125 to 1000 µg mL−1, while leading to a biphasic effect on nitric oxide (NO) and tumor necrosis factor alpha (TNF-α) levels. The phenolic profile was elucidated by HPLC-DAD, being characterized by the occurrence of ellagic acid as the main constituent, in addition to a series of methylated derivatives, which might underlie the observed anti-inflammatory effects. Our findings provide in vitro data on anti-inflammatory ability of H. bhamoense trunk bark, disclosing also potential cutaneous toxicity as assessed in HaCaT keratinocytes.

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“…It is found in many foods, including vegetables, tea, fruits and wine [15]. Quercetin is an effective inhibitor of lipoxygenases [16]. It also exhibits a broad range of pharmacological activities such as anti-inflammatory, anti-oxidant [17], anti-tumor, immunomodulatory [18], anti-ulcer [19] and vasodilator [20] effects.…”

Section: Introductionmentioning

confidence: 99%

Quercetin Protects against Diabetes-Induced Exaggerated Vasoconstriction in Rats: Effect on Low Grade Inflammation

et al. 2013

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Vascular complications are the leading cause of morbidity and mortality in patients with diabetes. Quercetin is an important flavonoid with antioxidant and anti-inflammatory activity. Here, the effect of quercetin on diabetes-induced exaggerated vasoconstriction in insulin deficient and insulin resistant rat models was investigated. Insulin deficiency was induced by streptozotocin while, insulin resistance by fructose. Rats were left 8 weeks or 12 weeks after STZ or fructose administration respectively. Quercetin was daily administered in the last 6 weeks. Then, tail blood pressure (BP) was recorded in conscious animals; concentration-response curves for phenylephrine (PE) and KCl were studied in thoracic aorta rings. Non-fasting blood glucose level, serum insulin level, insulin resistance index, serum tumour necrosis factor-α (TNF-α) and serum C-reactive protein (CRP) were determined. Nuclear transcription factor-κB (NF-κB) was assessed by immunofluorescence technique. Histopathological examination was also performed. The results showed that quercetin protected against diabetes-induced exaggerated vasoconstriction and reduced the elevated blood pressure. In addition, quercetin inhibited diabetes associated adventitial leukocyte infiltration, endothelial pyknosis and increased collagen deposition. These effects were accompanied with reduction in serum level of both TNF-α and CRP and inhibition of aortic NF-κB by quercetin in both models of diabetes. On the other hand, quercetin did not affect glucose level in any of the used diabetic models. This suggests that the protective effect of quercetin is mediated by its anti-inflammatory effect rather than its metabolic effects. In summary, quercetin is potential candidate to prevent diabetic vascular complications in both insulin deficiency and resistance via its inhibitory effect on inflammatory pathways especially NF-κB signaling.

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Antiatherogenic effect of guava leaf extracts inhibiting leucocyte-type 12-lipoxygenase activity

Cited by 14 publications

References 28 publications

Two New Monoterpene Glycosides from Qing Shan Lu Shui Tea with Inhibitory Effects on Leukocyte-Type 12-Lipoxygenase Activity

Two New Monoterpene Glycosides from Qing Shan Lu Shui Tea with Inhibitory Effects on Leukocyte-Type 12-Lipoxygenase Activity

Inhibition of Proinflammatory Enzymes and Attenuation of IL-6 in LPS-Challenged RAW 264.7 Macrophages Substantiates the Ethnomedicinal Use of the Herbal Drug Homalium bhamoense Cubitt & W.W.Sm

Quercetin Protects against Diabetes-Induced Exaggerated Vasoconstriction in Rats: Effect on Low Grade Inflammation

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