Effect of citric acid and heat treatment on the content of less-polar ginsenosides in flower buds of Panax ginseng.

Ginseng flower bud (GFB), as an inexpensive part of Panax ginseng, attracted significant attention as a beneficial functional food with medicinal potentials due to its high content of ginsenosides. A few studies focused on the utilization of heat treatment and citric acid treatment to process ginseng flowers, converting its polar ginsenosides into rare ginsenosides to improve its biological activities. Thus, in this study, we compared the changes of ginsenosides in GFB after citric acid and heat treatment by HPLC method. The results revealed that less-polar ginsenoside, Rg6 and F4, increased to 1.01 and 0.27% by heat treatment, respectively. Further, ginsenoside F2 increased to 1.13% with 1 M citric acid treatment. Furthermore, based on the combination of these two processing methods for the first time, the conversion rate of less-polar ginsenosides surged to 80%. The content of ginsenoside Rg3(s) and Rg5 increased to 1.509 and 1.871%, respectively, by simultaneous heat and citric acid treatment. Therefore, a processing approach that simultaneously performs heat and citric acid treatments has been proposed, and this considerably inexpensive and convenient processing method could be applied to the processing of GFBs and produce less-polar ginsenosides.

Evaluation of Anti-Melanogenesis Activity of Enriched Pueraria lobata Stem Extracts and Characterization of Its Phytochemical Components Using HPLC-PDA-ESI-MS/MS.

The root of Pueraria lobata (Willd.) is a widely used herbal medicine worldwide, whereas the stem of the plant is discarded or used as feed for livestock. To reuse and exploit the stem of P. lobata as a resource, we investigated its potential as a skin-whitening agent. We found that the developed, enriched P. lobata stem (PLS) extract significantly inhibited melanin production in the 3-isobutyl-1-methylxanthine-induced B16/F10 cells at a concentration of 50 µg/mL. To further confirm the mechanism of the antimelanogenic effect of the enriched PLS extracts, we examined the mRNA expression of tyrosinase, which was suppressed by the extracts. To standardize and implement effective quality control of the enriched PLS extracts, its major chemical constituents were identified by high-performance liquid chromatography-photodiode array-electrospray ionization-mass spectrometry. In total, 12 constituents were identified. In silico analysis showed that the main constituents, puerarin and daidzin, had excellent binding affinities for human tyrosinase. Collectively, our results suggest that the PLS extracts could be used as anti-pigmentation agents.

A 13-week repeated-dose oral toxicity and bioaccumulation of aluminum oxide nanoparticles in mice.

Because of an increase in the commercial applications of manufactured nanoparticles, the issue of potential adverse health effects of nanoparticles following intended or unintended exposure is rapidly gaining attention. In this study, we evaluated the toxicity of aluminum oxide nanoparticles (AlNPs, rod-type, 1.5, 3, and 6 mg/kg) after oral administration to mice for 13 weeks. Compared with the control group, the consumption of diet and drinking water and body weight gain decreased in the group treated with AlNPs. The group treated with 6 mg/kg AlNPs also showed a marked elevation in the count of white blood cells that associated with a significant decrease and increase to the proportion of eosinophils and lymphocytes, respectively. In addition, the secretion of IL-6 and monocyte chemotactic protein-1 increased in a dose-dependent manner in the treated groups. Furthermore, AlNPs showed the highest accumulation in the liver and kidneys compared with the control group, increased the lactate dehydrogenase level in the blood, and induced the development of a pathological lesion in the liver and kidneys. Taken together, we suggest that the target organs of rod-type AlNPs may be the liver, kidneys and the immune system, and the not-observed adverse effect level may be lower than 6 mg/kg.