Asian Pacific Journal of Tropical Biomedicine

1-10

Authors: Mohaddese Mahboubi, Mona Mahboubi

The protection of the liver as an essential organ in the body against oxidative stress and deleterious compounds has been the subject of recent investigations. Among different compounds, medicinal plants play an important role due to their hepatoprotective effects. Taraxacum officinale or “common dandelion” is a popular plant that has been traditionally used for its hepatoprotective effects. Currently, there are limited clinical studies on its hepatoprotective effects. The aim of this review article is to evaluate the hepatoprotective effects of dandelion and its mechanism of action. We reviewed literature up to July 2019 on “Taraxacum officinale” or “dandelion” and hepatoprotection. Currently available pharmacological studies indicate that dandelion extracts have hepatoprotective effects against chemical agents due to its antioxidant and anti-inflammatory activities. The anti-inflammatory effects of dandelion, the prebiotic effects of its oligofructans, inhibitory effects against the release of lipopolysaccharides and fasting induced adipose factor, digestive enzymes, and enhancing effects of lipogenesis, reduce lipid accumulation and liver inflammation, which directly or indirectly improve the liver functions. Given emerging evidence on hepatoprotective effects of dandelion, designing large human clinical studies is essential.

18-22

Authors: Ali Alkaladi, Haytham Ali, Aaser M Abdelazim, Mohamed Afifi, Mohammed Baeshen, Ammar AL-Farga

Objective: To investigate the molecular mechanisms of the anti-obese effect of raspberry ketone against high-fat diet fed rats. Methods: Fifty adult male rats were randomly assigned to receive a standard diet, a high fat diet, and the high-fat diet and 0.5%, 1% or 2% raspberry ketone. Body weight, biochemical parameters and gene expression of CCAAT enhancer-binding protein (C/EBP)δ, fatty acid synthase (FAS), acetyl CoA carboxylase (ACC), peroxisome proliferator-activated receptor alpha (PPAR-α), hormone-sensitive lipase (HSL) and hepatic carnitine palmitoyltransferase 1 A (CPT1A) were investigated. Results: Body weight, blood glucose, insulin, total lipids, triacylglycerols, total cholesterol and low-density lipoprotein cholesterol were increased in high-fat diet fed rats. These high fat diet-induced changes were attenuated by treatment with raspberry ketone. High-density lipoprotein cholesterol was decreased in highfat diet fed rats but increased in rats treated with raspberry ketone. Molecular investigations showed induction of gene expression of C/EBP-δ, FAS, ACC, CPT1A and inhibition of gene expression of PPAR-α and HSL in high-fat diet fed rats as compared with control. Raspberry ketone treament reversed these changes except CPT1A. Conclusions: Raspberry ketone can prevent obesity induced by a high-fat diet in rats by induction of the expression of enzymes, controlling lipolysis and fatty acids β oxidation as well as inhibition of gene expressions of adipogenic factors.

33-41

Authors: Yuling Ding, Chanipa Jiratchayamaethasakul, Junseong Kim, Eun-A Kim, Soo-Jin Heo, Seung-Hong Lee

Objective: To investigate the antioxidant and anti-melanogenesis activities of an ultrasonic extract of red sea cucumber, Stichopus japonicus, collected from Jeju Island. Methods: Antioxidant activity experiments were assessed by an electron spin resonance system and a cellular model of immortalized human keratinocytes (HaCaT) to determine its radical scavenging activity and protective effects against 2,2’-azobis (2-amidinopropane) dihydrochloride (AAPH)-induced oxidative stress. Anti-melanogenic activity of the ultrasonic extract of red sea cucumber was also examined using the melanoma cell model B16F10 and mushroom tyrosinase. Following the induction by α-melanocyte-stimulating hormone, the effects of the ultrasonic extract of red sea cucumber on intracellular tyrosinase activity, melanin content and the melanogenic protein expression of microphthalmia-associated transcription factor, tyrosinase, and tyrosinase-related proteins (TRP-1, and TRP-2) were examined. Results: The ultrasonic extract of red sea cucumber significantly scavenged 2,2-diphenyl-1-picrylhydrazyl and alkyl radicals [IC50: (0.924±0.035) and (0.327±0.006) mg/mL, respectively], as well as showed a protective effect against oxidative stress and attenuated generation of intracellular reactive oxygen species on AAPH- induced HaCaT cells, with no cytotoxicity (12.5-400 μg/mL). The ultrasonic extract of red sea cucumber also exhibited a tyrosinase inhibitory effect [IC50: (2.750±0.006) mg/mL]. On α-melanocyte-stimulating hormone-stimulated B16F10 melanoma cells, the ultrasonic extract of red sea cucumber (25-200 μg/mL) significantly inhibited not only melanin synthesis and tyrosinase activity, but also protein expressions of microphthalmia-associated transcriptional factor, tyrosinase, TRP-1, and TRP-2. Conclusions: The ultrasonic extract of red sea cucumber shows antioxidant and anti-melanogenic potential and may be a natural candidate for anti-aging as well as a whitening agent in the cosmeceuticals industry.