Luteolin as an anti-inflammatory and neuroprotective agent: A brief review

https://dr.ntu.edu.sg/bitstream/10220/44137/1/Luteolin%20restricts%20dengue%20virus%20replication%20through%20inhibition%20of%20the%20proprotein%20convertase%20furin.pdf

Luteolin restricts dengue virus replication through inhibition of the proprotein convertase furin.

Background and purpose Intestinal mucositis refers to mucosal damage caused by cancer treatment, and irinotecan is one of the agents most associated with this condition. Focusing on the development of alternatives to prevent this important adverse effect, we evaluated the activity of the flavonoid luteolin, which has never been tested for this purpose despite its biological potential. Experimental approach The effects of luteolin were examined on irinotecan-induced intestinal mucositis in mice. Clinical signs were evaluated. Moreover, histological, oxidative, and inflammatory parameters were analysed, as well as the possible interference of luteolin in the anti-tumour activity of irinotecan. Key results Luteolin (30 mg·kg-1 ; p.o. or i.p.) prevented irinotecan-induced intestinal damage by reducing weight loss and diarrhoea score and attenuating the shortening of the duodenum and colon. Histological analysis confirmed that luteolin (p.o.) prevented villous shortening, vacuolization, and apoptosis of cells and preserved mucin production in the duodenum and colon. Moreover, luteolin treatment mitigated irinotecan-induced oxidative stress, by reducing the levels of ROS and LOOH and augmenting endogenous antioxidants, and inflammation by decreasing MPO enzymic activity, TNF, IL-1β, and IL-6 levels and increasing IL-4 and IL-10. Disruption of the tight junctions ZO-1 and occludin was also prevented by luteolin treatment. Importantly, luteolin did not interfere with the anti-tumour activity of irinotecan. Conclusion and implications Luteolin prevents intestinal mucositis induced by irinotecan and therefore could be a potential adjunct in anti-tumour therapy to control this adverse effect, increasing treatment adherence and consequently the chances of cancer remission.

Luteolin prevents irinotecan-induced intestinal mucositis in mice through antioxidant and anti-inflammatory properties

The flower head of Chrysanthemum morifolium Ramat. (Juhua): A paradigm of flowers serving as Chinese dietary herbal medicine.

Doxorubicin is a valuable antineoplastic drug although its clinical use is greatly hindered by its severe cardiotoxicity with dismal target therapy available. Luteolin is a natural product extracted from vegetables and fruits with a wide range of biological efficacies including anti-oxidative, anti-tumorigenic, and anti-inflammatory properties. This study was designed to examine the possible effect of luteolin on doxorubicin-induced cardiotoxicity, if any, and the mechanism(s) involved with a focus on mitochondrial autophagy. Luteolin application (10 μM) in adult mouse cardiomyocytes overtly improved doxorubicin-induced cardiomyocyte contractile dysfunction including elevated peak shortening amplitude and maximal velocity of shortening/relengthening along with unchanged duration of shortening and relengthening. Luteolin alleviated doxorubicin-induced cardiotoxicity including apoptosis, accumulation of reactive oxygen species (ROS) and loss of mitochondrial membrane potential. Furthermore, luteolin attenuated doxorubicin-induced cardiotoxicity through promoting mitochondrial autophagy in association with facilitating phosphorylation of Drp1 at Ser616, and upregulating TFEB expression. In addition, luteolin treatment partially attenuated low dose doxorubicin-induced elongation of mitochondria. Treatment of Mdivi-1, a Drp1 GTPase inhibitor, negated the protective effect of luteolin on levels of TFEB, LAMP1, and LC3B, as well as loss of mitochondrial membrane potential and cardiomyocyte contractile dysfunction in the face of doxorubicin challenge. Taken together, these findings provide novel insights for the therapeutic efficacy of luteolin against doxorubicin-induced cardiotoxicity possibly through improved mitochondrial autophagy.

Luteolin Attenuates Doxorubicin-Induced Cardiotoxicity Through Promoting Mitochondrial Autophagy.

Luteolin and luteolin-7-O-glucoside were isolated from the ethanolic extract of Dendranthema morifolium Ramat Tzvel. The structures of these analytes were identified by nuclear magnetic resonance ((1)H and (13)C NMR) and mass spectrometry. Ethanolic and water extracts contained luteolin-7-O-glucoside at 4.19 and 6.56%, respectively. However, the level of luteolin was only 0.19% in the ethanolic extract, and luteolin was not detected in the water extract. To examine the pharmacokinetics and bioavailability of luteolin and luteolin-7-O-glucoside in rats, parallel studies of luteolin (10 mg/kg, iv; and 100 mg/kg, po) and luteolin-7-O-glucoside (10 mg/kg, iv; and 1 g/kg, po) were conducted. The analytes were detected by high-performance liquid chromatography coupled with a photodiode array detector. A phenyl-hexyl (150 × 4.6 mm iv; 5.0 μm) column was used to separate the analytes from the biological samples. The pharmacokinetic data demonstrate that the areas under the concentration curves (AUCs) of luteolin were 261 ± 33 and 611 ± 89 (min μg/mL) after luteolin administration (10 mg/kg, iv; and 100 mg/kg, po, respectively). The oral bioavailability of luteolin was 26 ± 6%. The AUCs of luteolin-7-O-glucoside were 229 ± 15 and 2109 ± 350 (min μg/mL) after administration of luteolin-7-O-glucoside (10 mg/kg, iv; and 1 g/kg, po, respectively). The oral bioavailability of luteolin-7-O-glucoside was approximately 10 ± 2%. In the group that received luteolin-7-O-glucoside orally, a biotransformed luteolin product was detected, but this product was not detected in the group that received luteolin-7-O-glucoside intravenously. The biotransformation ratio of luteolin to luteolin-7-O-glucoside (the AUC ratio of metabolite/parent compound) was approximately 48.78 ± 0.12%. These results demonstrate that luteolin-7-O-glucoside is primarily hydrolyzed to luteolin in the gastrointestinal tract and then absorbed into the systemic circulation.

Yu Feng Pai

Papers

Isolation of Luteolin and Luteolin-7-O-glucoside from Dendranthema morifolium Ramat Tzvel and Their Pharmacokinetics in Rats.