Nanoencapsulation of usnic acid: An attempt to improve antitumour activity and reduce hepatotoxicity

Santos, Noêmia Pereira da Silva; Nascimento, Silène Carneiro do; Wanderley, Marcela Silvestre Outtes; Pontes-Filho, Nicodemos Teles de; Silva, José Figueiredo da; Castro, Célia Maria Machado Barbosa de; Pereira, Eugênia C.; Silva, Nicácio Henrique da; Honda, Nobuaki; Santos-Magalhães, Nereide Stela

doi:10.1016/j.ejpb.2006.05.018

Cited by 82 publications

(54 citation statements)

References 11 publications

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“…No toxicity in other organs such as the kidney and spleen were detected in the study. The similar pattern of toxicity was also revealed in the tumor-bearing mice (49,50). In male Wistar albino rats, usnic acid (i.p., 50 or 200 mg/kg for 5 days) induced remarkable swelling of the liver mitochondria and endoplasmic reticulum assessed by electron microscopy, although no changes in serum transaminase activity were observed, indicating that mild hepatotoxicity occurred (15).…”

Section: In Vivo Toxicity Datamentioning

confidence: 55%

“…Of note, no apparent organ-specific toxicities in the liver, spleen, or lung were observed in this report (48). In healthy male Swiss mice, treatment of usnic acid intraperitoneally for 15 mg/kg for 15 days caused no apparent general toxicity, as evidenced by the negative observations in clinical signs or changes of body weight (49,50). However, strong hepatotoxicity, including elevated serum transaminase activity and extensive liver necrosis, were observed.…”

Section: In Vivo Toxicity Datamentioning

confidence: 76%

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Review of Usnic Acid andUsnea BarbataToxicity

Guo

Shi

Fang

et al. 2008

Journal of Environmental Science and Health, Part C

125

107

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Usnic acid is a prominent secondary lichen metabolite that has been used for various purposes worldwide. Crude extracts of usnic acid or pure usnic acid have been marketed in the United States as dietary supplements to aid in weight loss. The US Food and Drug Administration (FDA) received 21 reports of liver toxicity related to the ingestion of dietary supplements that contain usnic acid. This prompted the FDA to issue a warning about one such supplement, LipoKinetix, in 2001 (http://www.cfsan.fda.gov/~dms/ds-lipo.html). Subsequently, usnic acid and Usnea barbata lichen were nominated by the National Toxicology Program (NTP) for toxicity evaluations. At present, a toxicological evaluation of usnic acid is being conducted by the NTP. This review focuses on the recent findings of usnic acid-induced toxicities and their underlying mechanisms of action. KeywordsWeight loss dietary supplement; usnic acid and Usnea barbata toxicity

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Section: In Vivo Toxicity Datamentioning

confidence: 55%

Section: In Vivo Toxicity Datamentioning

confidence: 76%

Review of Usnic Acid andUsnea BarbataToxicity

Guo

Shi

Fang

et al. 2008

Journal of Environmental Science and Health, Part C

125

107

View full text Add to dashboard Cite

show abstract

“…2-Hydroxypropyl-bcyclodextrine was found to be suitable for solubilising usnic acid (Kristmundsdottir et al 2002) and IC 50 obtained on malignant cells are in the same range of the one obtained with a diaminooctane derivative (Bazin et al 2008). A slight increase of its antitumor effect has been obtained with encapsulating this hydrophobic compound in microspheres (da Silva Santos et al 2006). However, in vivo assays show (-)-usnic acid to have a weak, if any, antitumoral effect against Lewis Lung carcinoma and P388 leukemia (Kupchan and Kopperman 1975;Takai et al 1979).…”

Section: Cytotoxic Antimutagenic and Antitumor Activities For Potentmentioning

confidence: 81%

Bioactive lichen metabolites: alpine habitats as an untapped source

2010

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International audienceLichens are fungal and algal/cyanobacterial symbioses resulting in the production of specific metabolites. Some of these are forming an available biomass for phytochemical investigations, including the assessment of biological activities of the isolated compounds. The alpine or polar region are characterised by highly stressful environmental conditions for many organisms, but lichens are among the dominating organisms in these habitats. In the performant mutual protective system, lichen fungi often accumulate high amounts of metabolites with specific physicochemical properties (UV absorbents, hydrophobicity) which help the lichens to survive. Unique secondary metabolites and polysaccharides have been isolated and tested from these organisms. Even though this has been tested until now only with a low number of compounds so far, interesting activities have been recorded. We review here some of the antimicrobial, anti-inflammatory, antiproliferative and antioxidant activities properties described. Solutions with axenic biotechnological cultivation of each symbiotic partner and particularly the mycobiont to obtain the lichen secondary metabolites are challenging to overcome the limitations for the supply of these rare compounds. Additionally, these lichens appear to harbour a diversity of culturable microorganisms from which active compounds have also been isolated recently

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“…However, this drug has found limited applications in clinics due to its poor water solubility and high hepatotoxicity [44,45]. UA encapsulation into polymer carriers [20] or complexation with functionalized polymers [11] has been shown to be a promising strategy to develop suitable dosage forms for use in humans.…”

Section: Properties Of Ua-loaded Cplla16 Microparticlesmentioning

confidence: 99%

“…The few investigations so far available on UA entrapping in micro-or nano-carriers have underlined the applicative potential of controlled UA-releasing systems since a modulation of UA release kinetics [19] and a reduction of drug hepatotoxicity [20] were found.…”

Section: Introductionmentioning

confidence: 99%