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In vitro cellular uptake of evodiamine and rutaecarpine using a microemulsion.

Zhang YT, Huang ZB, Zhang SJ, Zhao JH, Wang Z, Liu Y, Feng NP - Int J Nanomedicine (2012)

Bottom Line: Under optimal conditions, the cellular uptake of microemulsified drugs was assayed and compared to tinctures and aqueous suspensions.Mouse skin fibroblasts rarely endocytosed evodiamine and rutaecarpine with a microemulsion as the vehicle.The microemulsion had no obvious effect on cellular morphology, suggesting there is little or no cellular toxicity associated with the administration of microemulsion on mouse skin fibroblasts.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutics, Shanghai University of Traditional Chinese Medicine, Shanghai, The People's Republic of China.

ABSTRACT

Objective: To investigate the cellular uptake of evodiamine and rutaecarpine in a microemulsion in comparison with aqueous suspensions and tinctures.

Materials and methods: A microemulsion was prepared using the dropwise addition method. Mouse skin fibroblasts were cultured in vitro to investigate the optimal conditions for evodiamine and rutaecarpine uptake with different drug concentrations and administration times. Under optimal conditions, the cellular uptake of microemulsified drugs was assayed and compared to tinctures and aqueous suspensions. Rhodamine B labeling and laser scanning confocal microscopy (LSCM) were used to explore the distribution of fluorochrome transferred with the microemulsion in fibroblasts. Cellular morphology was also investigated, using optical microscopy to evaluate microemulsion-induced cellular toxicity.

Results: The maximum cellular drug uptake amounts were obtained with a 20% concentration (v/v) of microemulsion and an 8 hour administration time. Drug uptake by mouse skin fibroblasts was lowest when the drugs were loaded in microemulsion. After incubation with rhodamine B-labeled microemulsion for 8 hours, the highest fluorescence intensity was achieved, and the fluorochrome was primarily distributed in the cytochylema. No obvious cellular morphologic changes were observed with the administration of either the microemulsion or the aqueous suspension; for the tincture group, however, massive cellular necrocytosis was observed.

Conclusion: The lower cellular uptake with microemulsion may be due to the fact that most of the drug loaded in the microemulsion vehicle was transported via the intercellular space, while a small quantity of free drug (released from the vehicle) was ingested through transmembrane transport. Mouse skin fibroblasts rarely endocytosed evodiamine and rutaecarpine with a microemulsion as the vehicle. The microemulsion had no obvious effect on cellular morphology, suggesting there is little or no cellular toxicity associated with the administration of microemulsion on mouse skin fibroblasts.

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LSCM images showing rhodamine B-labeled formulations (A) microemulsion; (B) tincture; and (C) aqueous suspension.Abbreviation: LCSM, laser scanning confocal microscopy.
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f11-ijn-7-2465: LSCM images showing rhodamine B-labeled formulations (A) microemulsion; (B) tincture; and (C) aqueous suspension.Abbreviation: LCSM, laser scanning confocal microscopy.

Mentions: The fluorescence intensity of the microemulsion group was relatively lower than that of the tincture and aqueous suspension groups (Figure 11), which may be related to the lowest uptake amount of rhodamine B with microemulsion as the vehicle. When the lipophilic rhodamine B was loaded in the microemulsion, it was difficult to release and, therefore, difficult for cells to ingest, while the free molecules of rhodamine B in the aqueous suspension were easily captured. Cells from the tincture group showed small, diffuse, and indistinct fluorescence, which may be due to the fact that the high alcohol content led to extensive cellular death and rupture, resulting in the leakage of fluorochrome out of the cells, staining the background.


In vitro cellular uptake of evodiamine and rutaecarpine using a microemulsion.

Zhang YT, Huang ZB, Zhang SJ, Zhao JH, Wang Z, Liu Y, Feng NP - Int J Nanomedicine (2012)

LSCM images showing rhodamine B-labeled formulations (A) microemulsion; (B) tincture; and (C) aqueous suspension.Abbreviation: LCSM, laser scanning confocal microscopy.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3367489&req=5

f11-ijn-7-2465: LSCM images showing rhodamine B-labeled formulations (A) microemulsion; (B) tincture; and (C) aqueous suspension.Abbreviation: LCSM, laser scanning confocal microscopy.
Mentions: The fluorescence intensity of the microemulsion group was relatively lower than that of the tincture and aqueous suspension groups (Figure 11), which may be related to the lowest uptake amount of rhodamine B with microemulsion as the vehicle. When the lipophilic rhodamine B was loaded in the microemulsion, it was difficult to release and, therefore, difficult for cells to ingest, while the free molecules of rhodamine B in the aqueous suspension were easily captured. Cells from the tincture group showed small, diffuse, and indistinct fluorescence, which may be due to the fact that the high alcohol content led to extensive cellular death and rupture, resulting in the leakage of fluorochrome out of the cells, staining the background.

Bottom Line: Under optimal conditions, the cellular uptake of microemulsified drugs was assayed and compared to tinctures and aqueous suspensions.Mouse skin fibroblasts rarely endocytosed evodiamine and rutaecarpine with a microemulsion as the vehicle.The microemulsion had no obvious effect on cellular morphology, suggesting there is little or no cellular toxicity associated with the administration of microemulsion on mouse skin fibroblasts.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmaceutics, Shanghai University of Traditional Chinese Medicine, Shanghai, The People's Republic of China.

ABSTRACT

Objective: To investigate the cellular uptake of evodiamine and rutaecarpine in a microemulsion in comparison with aqueous suspensions and tinctures.

Materials and methods: A microemulsion was prepared using the dropwise addition method. Mouse skin fibroblasts were cultured in vitro to investigate the optimal conditions for evodiamine and rutaecarpine uptake with different drug concentrations and administration times. Under optimal conditions, the cellular uptake of microemulsified drugs was assayed and compared to tinctures and aqueous suspensions. Rhodamine B labeling and laser scanning confocal microscopy (LSCM) were used to explore the distribution of fluorochrome transferred with the microemulsion in fibroblasts. Cellular morphology was also investigated, using optical microscopy to evaluate microemulsion-induced cellular toxicity.

Results: The maximum cellular drug uptake amounts were obtained with a 20% concentration (v/v) of microemulsion and an 8 hour administration time. Drug uptake by mouse skin fibroblasts was lowest when the drugs were loaded in microemulsion. After incubation with rhodamine B-labeled microemulsion for 8 hours, the highest fluorescence intensity was achieved, and the fluorochrome was primarily distributed in the cytochylema. No obvious cellular morphologic changes were observed with the administration of either the microemulsion or the aqueous suspension; for the tincture group, however, massive cellular necrocytosis was observed.

Conclusion: The lower cellular uptake with microemulsion may be due to the fact that most of the drug loaded in the microemulsion vehicle was transported via the intercellular space, while a small quantity of free drug (released from the vehicle) was ingested through transmembrane transport. Mouse skin fibroblasts rarely endocytosed evodiamine and rutaecarpine with a microemulsion as the vehicle. The microemulsion had no obvious effect on cellular morphology, suggesting there is little or no cellular toxicity associated with the administration of microemulsion on mouse skin fibroblasts.

Show MeSH
Related in: MedlinePlus