Pomolic acid in persimmon peel suppresses the increase in glycerol-3 phosphate dehydrogenase activity in 3T3-L1 adipocytes.

Persimmon peels, though usually discarded, are useful sources of nutraceuticals. In this study, persimmon peel-derived pomolic acid was found to suppress the increase in the activity of glycerol-3 phosphate dehydrogenase, a neutral fat synthesis-related enzyme, in 3T3-L1 adipocytes, whereas oleanolic and ursolic acids did not exert this effect. Therefore, persimmon peel may be an effective functional food material.

Hepatic fatty acid biosynthesis in KK-Ay mice is modulated by administration of persimmon peel extract: A DNA microarray study.

SCOPE: Previously, we showed that the intake of a persimmon peel (PP) extract altered hepatic gene expression associated with the insulin signaling pathway and enhanced tyrosine phosphorylation of insulin receptors in nonobese type 2 diabetic Goto-Kakizaki rats. Our objective was to evaluate the effect of fat-soluble PP extract on obese type 2 diabetic KK-Ay mice with insulin resistance. METHODS AND RESULTS: KK-Ay mice were fed a diet mixed with 0.1% of the extract for 8 weeks. The total ketone body levels in the plasma of PP extract-fed mice were significantly lower than those in the normal diet-fed mice. Hepatic nonesterified palmitic acid content was higher in the PP extract-fed mice than in normal diet-fed mice. The hepatic gene expression profiles of the treated mice indicated upregulation of fatty acid synthesis and downregulation of inflammation-associated genes, predicting SREBP-1c and PPARγ activation. CONCLUSION: These results suggest that the PP extract enhances hepatic fatty acid synthesis via SREBP-1c and PPARγ, as well as anti-inflammatory activity in KK-Ay mice.

Redundant mechanisms are involved in suppression of default cell fates during embryonic mesenchyme and notochord induction in ascidians.

During embryonic induction, the responding cells invoke an induced developmental program, whereas in the absence of an inducing signal, they assume a default uninduced cell fate. Suppression of the default fate during the inductive event is crucial for choice of the binary cell fate. In contrast to the mechanisms that promote an induced cell fate, those that suppress the default fate have been overlooked. Upon induction, intracellular signal transduction results in activation of genes encoding key transcription factors for induced tissue differentiation. It is elusive whether an induced key transcription factor has dual functions involving suppression of the default fates and promotion of the induced fate, or whether suppression of the default fate is independently regulated by other factors that are also downstream of the signaling cascade. We show that during ascidian embryonic induction, default fates were suppressed by multifold redundant mechanisms. The key transcription factor, Twist-related.a, which is required for mesenchyme differentiation, and another independent transcription factor, Lhx3, which is dispensable for mesenchyme differentiation, sequentially and redundantly suppress the default muscle fate in induced mesenchyme cells. Similarly in notochord induction, Brachyury, which is required for notochord differentiation, and other factors, Lhx3 and Mnx, are likely to suppress the default nerve cord fate redundantly. Lhx3 commonly suppresses the default fates in two kinds of induction. Mis-activation of the autonomously executed default program in induced cells is detrimental to choice of the binary cell fate. Multifold redundant mechanisms would be required for suppression of the default fate to be secure.

Hepatic gene expression of the insulin signaling pathway is altered by administration of persimmon peel extract: a DNA microarray study using type 2 diabetic Goto-Kakizaki rats.

Persimmon (Diospyros kaki) is a very popular fruit in East Asian countries, but its peels are not consumed despite the fact that they contain many antioxidants such as carotenoids and polyphenols. We prepared a fat-soluble extract from persimmon peel (PP) and fed type 2 diabetic Goto-Kakizaki (GK) rats an AIN-93G rodent diet supplemented with persimmon peel extract (PP diet) for 12 weeks. Compared with the control AIN-93G diet, the PP diet significantly reduced plasma glutamic-pyruvate transaminase activity, with accumulation of ß-cryptoxanthin in the liver. DNA microarray analysis revealed that the PP diet altered hepatic gene expression profiles. In particular, expression of insulin signaling pathway-related genes was significantly enriched in differentially expressed gene sets. Moreover, Western blotting analysis showed an increase in insulin receptor beta tyrosine phosphorylation in rats fed the PP diet. These data suggest that the PP diet improves insulin resistance in GK rats.

Preparing a carotenoid polyphenol-enriched extract from the peel of persimmon, Diospyros kaki L.f.

The use of persimmon (Diospyros kaki L.f.) as a possible functional food material has not garnered widespread popularity. We conducted the present study and found that a fat-soluble extract obtained from the peel contained a large amount of carotenoids; beta-cryptoxanthin accounted for more than 50% of the total carotenoids identified. The extract also contained 6 polyphenolic aglycons.