ABSTRACT
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.
Subject(s)
Malpighiaceae/chemistry , Plant Extracts/pharmacology , Skin Pigmentation/drug effects , Ultraviolet Rays , Animals , Ascorbic Acid/pharmacology , Body Water/drug effects , Body Weight/drug effects , Gene Expression , Mice , Mice, Hairless , Mice, Knockout , Skin/drug effects , Skin/radiation effects , Skin Pigmentation/radiation effectsABSTRACT
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.
Subject(s)
Ascorbic Acid/pharmacokinetics , Food-Drug Interactions , Fruit/chemistry , Intestinal Absorption , Malpighiaceae/chemistry , Plant Preparations/pharmacology , Vitamins/pharmacokinetics , Adult , Area Under Curve , Ascorbic Acid/blood , Ascorbic Acid/urine , Beverages , Dose-Response Relationship, Drug , Flavonoids/pharmacology , Humans , Japan , Male , Plant Preparations/chemistry , Reference Values , Vitamins/blood , Vitamins/urine , Young AdultABSTRACT
To investigate the physiological functions of polyphenols from acerola (Malpighia emarginata DC.) fruit, the effects on melanogenesis were studied. The crude polyphenol concentrated extract from acerola (C-AP) was used to examine the skin-lightening effect on brownish guinea pigs which had been subjected to controlled UVB irradiation. The results show that C-AP significantly lightened the UVB-irradiated skin pigmentation. Furthermore, treatment with C-AP reduced the content of melanin in B16 melanoma cells, suggesting that the in vivo skin-lightening effect of C-AP was due to the suppression of melanin biosynthesis in melanocytes. In addition, we found that C-AP could effectively inhibit mushroom tyrosinase activity, the main constituents responsible for this effect being thought to be such anthocyanins as cyanidin-3-alpha-O-rhamnoside (C3R) and pelargonidin-3-alpha-O-rhamnoside (P3R). This result indicates that the skin-lightening effect of C-AP can be partly attributed to the suppression of melanogenesis through the inhibition of tyrosinase activity in melanocytes. An oral ingestion of C-AP may therefore be efficacious for reducing UVB-induced hyper-pigmentation by inhibiting the tyrosinase in melanocytes.
Subject(s)
Flavonoids/chemistry , Fruit/chemistry , Magnoliopsida/chemistry , Phenols/chemistry , Plant Extracts/pharmacology , Skin Pigmentation/drug effects , Skin/drug effects , Ultraviolet Rays , Administration, Oral , Agaricales/enzymology , Animals , Cell Line, Tumor , Epidermis/drug effects , Epidermis/metabolism , Epidermis/radiation effects , Female , Guinea Pigs , Melanins/metabolism , Melanosomes/drug effects , Melanosomes/metabolism , Melanosomes/radiation effects , Mice , Monophenol Monooxygenase/antagonists & inhibitors , Plant Extracts/administration & dosage , Polyphenols , Skin/cytology , Skin/metabolism , Skin/radiation effects , Skin Pigmentation/radiation effects , Ultraviolet Rays/adverse effectsABSTRACT
A crude acerola polyphenol fraction (C-AP) was prepared by subjecting an acerola extract to a C18 cartridge column, and eluting the adsorbed fraction with ethanol containing 10% of acetic acid. C-AP appeared in a previous study to have an inhibitory effect on alpha-glucosidase and particularly on maltase activities. To elucidate the antihyperglycemic effect of C-AP further, we examined the regulation by C-AP of glucose uptake in Caco-2 cell; this resulted in the inhibition of glucose uptake. We next conducted single administration tests of glucose and maltose to ICR mice to investigate whether C-AP really controlled the intestinal glucose absorption in an animal body. The results showed that C-AP significantly suppressed the plasma glucose level after administering both glucose and maltose, suggesting that C-AP had a preventive effect on hyperglycemia in the postprandial state. The mechanism for this effect is considered to have been both suppression of the intestinal glucose transport and the inhibition of alpha-glucosidase. Despite such a preventive effect, the therapeutic effect of C-AP on hyperglycemia appeared to be low from the experiment with KKAy mice.
Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Flavonoids/pharmacology , Fruit/chemistry , Hypoglycemic Agents/pharmacology , Malpighiaceae/chemistry , Phenols/pharmacology , Animals , Blood Glucose/drug effects , Caco-2 Cells , Cells, Cultured , Diabetes Mellitus, Type 2/blood , Disease Models, Animal , Flavonoids/administration & dosage , Flavonoids/chemistry , Glucose/metabolism , Glucose/pharmacokinetics , Glucose/pharmacology , Glucose Tolerance Test , Humans , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/chemistry , Intestinal Absorption/drug effects , Intestinal Mucosa/metabolism , Male , Maltose/metabolism , Maltose/pharmacology , Mice , Mice, Inbred ICR , Mice, Obese , Molecular Structure , Phenols/administration & dosage , Phenols/chemistry , Polyphenols , Stereoisomerism , Time FactorsABSTRACT
Two anthocyanins, cyanidin-3-alpha-O-rhamnoside (C3R) and pelargonidin-3-alpha-O-rhamnoside (P3R), and quercitrin (quercetin-3-alpha-O-rhamnoside), were isolated from acerola (Malpighia emarginata DC.) fruit. These polyphenols were evaluated based on the functional properties associated with diabetes mellitus or its complications, that is, on the radical scavenging activity and the inhibitory effect on both alpha-glucosidase and advanced glycation end product (AGE) formation. C3R and quercitrin revealed strong radical scavenging activity. While the inhibitory profiles of isolated polyphenols except quercitrin towards alpha-glucosidase activity were low, all polyphenols strongly inhibited AGE formation.
