Acerola exosome-like nanovesicles to systemically deliver nucleic acid medicine via oral administration.

Extracellular vesicles derived from mammalian cells could be useful carriers for drug delivery systems (DDSs); however, with regard to clinical application, there are several issues to be overcome. Acerola (Malpighia emarginata DC.) is a popular health food. In this study, the feasibility of orally administered nucleic acid drug delivery by acerola exosome-like nanoparticles (AELNs) was examined. AELNs were recovered from acerola juice using an affinity column instead of ultracentrifugation. MicroRNA (miRNA) was sufficiently encapsulated in AELNs by 30-min incubation on ice and was protected against RNase, strong acid, and base treatments. The administration of an AELN/miRNA mixture in cells achieved downregulation of the miRNA's target gene, and this mixture showed cytoplasmic localization. AELNs orally delivered small RNA to the digestive system in vivo. The target gene-suppressing effect in the small intestine and liver peaked 1 day after administration, indicating potential for use as an oral DDS for nucleic acid in the digestive system.

Acerola (Malpighia emarginata DC.) Juice Intake Suppresses UVB-Induced Skin Pigmentation in SMP30/GNL Knockout Hairless Mice.

BACKGROUND/AIMS: Acerola (Malpighia emarginata DC.) is a fruit that is known to contain high amounts of ascorbic acid (AA) and various phytochemicals. We have previously reported that AA deficiency leads to ultraviolet B (UVB)-induced skin pigmentation in senescence marker protein 30 (SMP30)/gluconolactonase (GNL) knockout (KO) hairless mice. The present study was undertaken to investigate the effects of acerola juice (AJ) intake on the skin of UVB-irradiated SMP30/GNL KO mice. RESEARCH DESIGN/PRINCIPAL FINDINGS: Five-week old hairless mice were given drinking water containing physiologically sufficient AA (1.5 g/L) [AA (+)], no AA [AA (-)] or 1.67% acerola juice [AJ]. All mice were exposed to UVB irradiation for 6 weeks. UVB irradiation was performed three times per week. The dorsal skin color and stratum corneum water content were measured every weekly, and finally, the AA contents of the skin was determined. The skin AA and stratum corneum water content was similar between the AA (+) and AJ groups. The L* value of the AA (+) group was significantly decreased by UVB irradiation, whereas AJ intake suppressed the decrease in the L* value throughout the experiment. Moreover, in the AJ group, there was a significant decrease in the expression level of dopachrome tautomerase, an enzyme that is involved in melanin biosynthesis. CONCLUSION: These results indicate that AJ intake is effective in suppressing UVB-induced skin pigmentation by inhibiting melanogenesis-related genes.

Absorption and excretion of ascorbic acid alone and in acerola (Malpighia emarginata) juice: comparison in healthy Japanese subjects.

It has been suggested that some food components, such as bioflavonoids, affect the bioavailability of ascorbic acid in humans. Since little is known in Japan about the effective intake of this dietary requirement, we tested young Japanese males after the ingestion of commercial ascorbic acid or acerola (Malpighia emarginata DC.) juice to compare the quantities absorbed and excreted. Healthy Japanese subjects received a single oral dose of ascorbic acid solution (50, 100, 200 or 500 mg) and received distilled water as a reference at intervals of 14 d or longer. All subjects were collected blood and urine until 6 h after ingestion and evaluated for time-dependent changes in plasma and urinary ascorbic acid levels. Predictably, the area under the curve (AUC) values in plasma and urine after ingestion increased dose-dependently. Next, each subject received diluted acerola juice containing 50 mg ascorbic acid. Likewise, their plasma and urinary ascorbic acid concentrations were measured. In plasma, the AUC value of ascorbic acid after ingestion of acerola juice tended to be higher than that from ascorbic acid alone. In contrast, the urinary excretion of ascorbic acid at 1, 2 and 5 h after ingestion of acerola juice were significantly less than that of ascorbic acid. These results indicate that some component of acerola juice favorably affected the absorption and excretion of ascorbic acid.

Isolation and characterization of a novel flavonoid possessing a 4,2''-glycosidic linkage from green mature acerola (Malpighia emarginata DC.) fruit.

The novel flavonoid, leucocyanidin-3-O-beta-D-glucoside, possessing a 4,2''-glycosidic linkage was isolated from green mature acerola (Malpighia emarginata DC.) puree and given the trivial name "aceronidin." To examine the functions of aceronidin, its antioxidative activity and both its alpha-glucosidase and alpha-amylase inhibition activities, as a potential inhibitor of the sugar catabolic enzyme, were evaluated against those of taxifolin, catechin, isoquercitrin and quercitrin which each have a similar structure. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical quenching activity of aceronidin was stronger than that of alpha-tocopherol and comparable to that of flavonoids. In the yeast alpha-glucosidase inhibitory assay, aceronidin showed significantly greater inhibition than the other flavonoids tested. In the human salivary alpha-amylase inhibitory assay, aceronidin showed inhibition activity. Taken together, these results indicate aceronidin to be a potent antioxidant that may be valuable as an inhibitor of sugar catabolic enzymes.