A simple HPLC method for the determination of apigenin in mouse tissues

Apigenin-Loaded PLGA-DMSA Nanoparticles: A Novel Strategy to Treat Melanoma Lung Metastasis

The flavone apigenin (APG), alone as well as in combination with other chemotherapeutic agents, is known to exhibit potential anticancer effects in various tumors and inhibit growth and metastasis of melanoma. However, the potential of apigenin nanoparticles (APG-NPs) to prevent lung colonization of malignant melanoma has not been well investigated. APG-loaded PLGA-NPs were surface-functionalized with meso-2,3-dimercaptosuccinic acid (DMSA) for the treatment of melanoma lung metastasis. DMSA-conjugated APG-loaded NPs (DMSA-APG-NPs) administered by an oral route exhibited sustained APG release and showed considerable enhancement of plasma half-life, C_max value, and bioavailability compared to APG-NPs both in plasma and the lungs. DMSA-conjugated APG-NPs showed comparably higher cellular internalization in B16F10 and A549 cell lines compared to that of plain NPs. Increased cytotoxicity was observed for DMSA-APG-NPs compared to APG-NPs in A549 cells. This difference between the two formulations was lower in B16F10 cells. Significant depolarization of mitochondrial transmembrane potential and an enhanced level of caspase activity were observed in B16F10 cells treated with DMSA-APG-NPs compared to APG-NPs as well. Western blot analysis of various proteins was performed to understand the mechanism of apoptosis as well as prevention of melanoma cell migration and invasion. DMSA conjugation substantially increased accumulation of DMSA-APG-NPs given by an intravenous route in the lungs compared to APG-NPs at 6 and 8 h. This was also corroborated by scintigraphic imaging studies with radiolabeled formulations administered by an intravenous route. Conjugation also allowed comparatively higher penetration as evident from an in vitro three-dimensional tumor spheroid model study. Finally, the potential therapeutic efficacy of the formulation was established in experimental B16F10 lung metastases, which suggested an improved bioavailability with enhanced antitumor and antimetastasis efficacy of DMSA-conjugated APG-NPs following oral administration.

Bioactive Apigenin loaded oral nano bilosomes: Formulation optimization to preclinical assessment

AIM

Diabetic (type-2) is a metabolic disease characterized by increased blood glucose level from the normal level. In the present study, apigenin (AG) loaded lipid vesicles (bilosomes: BIL) was prepared, optimized and evaluated for the oral therapeutic efficacy.

EXPERIMENTAL

AG-BIL was prepared by a thin-film evaporation method using cholesterol, span 60 and sodium deoxycholate. The prepared formulation was optimized by 3-factor and 3-level Box-Behnken design using particle size, entrapment efficiency and drug release as a response. The selected formulation further evaluated for ex-vivo permeation, in vivo pharmacokinetic and pharmacodynamics study.

RESULTS

The optimized AG bilosomes (AG-BILopt) has shown the vesicle size 183.25 ± 2.43 nm, entrapment efficiency 81.67 ± 4.87%. TEM image showed a spherical shape vesicle with sharp boundaries. The drug release study revealed a significant enhancement in AG release (79.45 ± 4.18%) from AG-BILopt as compared to free AG-dispersion (25.47 ± 3.64%). The permeation and pharmacokinetic studies result revealed 4.49 times higher flux and 4.67 folds higher AUC0-t than free AG-dispersion. The antidiabetic activity results showed significant (P < 0.05) enhancement in therapeutic efficacy than free AG-dispersion. The results also showed marked improvement in biochemical parameters.

CONCLUSION

Our findings suggested, the prepared apigenin loaded bilosomes was found to be an efficient delivery in the therapeutic efficacy in diabetes.

Tissue distribution in mice and metabolism in murine and human liver of apigenin and tricin, flavones with putative cancer chemopreventive properties

PURPOSE

The flavones apigenin and tricin, which occur in leafy vegetables and rice bran, respectively, possess cancer chemopreventive properties in preclinical rodent models. Their pharmacology is only poorly understood. We compared their tissue levels in mice in vivo and their metabolism in liver fractions in vitro.

METHODS

Mice received apigenin or tricin (0.2%) with their diet for 5-7 days, and flavone levels were compared in the plasma, liver and gastrointestinal mucosa using HPLC-UV. Flavone metabolism was investigated in murine and human liver microsomes or cytosol in vitro co-incubated with uridine 5'-diphosphoglucuronic acid or 3'-phosphoadenosine-5' phosphosulfate. Flavone metabolites were characterized by on-line HPLC-mass spectrometry.

RESULTS

After dietary administration of flavones for 7 days, levels of tricin in plasma, liver and mucosa exceeded those of apigenin by 350, 33 and 100%, respectively. Apigenin was more rapidly glucuronidated than tricin in liver microsomes, whilst tricin underwent swifter sulfonation than apigenin in liver cytosol. For either flavone the rate of glucuronidation was much faster than that of sulfonation. Flavone monoglucuronides and monosulfates were identified as metabolites in microsomal and cytosolic incubations, respectively.

CONCLUSIONS

When consumed with the diet in mice tricin seems to be more available than apigenin in blood and tissues. Differences in their glucuronidation may account for their differential availability. Thus tricin may have a pharmacokinetic advantage over apigenin. This type of information may help decide which flavonoids to select for clinical development.