• Korean Journal of Pharmacognosy
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• v.51 no.4
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• pp.255-263
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• 2020

Ginsenosides are considered to be the most important ingredients in ginseng. They are chemically converted by endogenous organic acids contained in ginseng and the heat applied during red ginseng processing. During this procedure, various converted ginsenosides are produced through hydrolysis of substitute sugars of ginsenosides and forming double bonds through dehydration in the dammarane skeleton. In order to study the conversion mechanism of protopanaxadiol-type ginsenosides during the heat treatment process of ginseng, we purified the three final converted ginsenosides by heating fresh ginseng for a long time. The three isolated ginsenosides were identified as 25(OH)-ginsenoside Rg5, 25(OH)-ginsenoside Rz1 and 25(OH)-ginsenoside Rg3 through NMR spectrum analysis. As a result of quantification of ginseng heated at 100 ℃ for 0 to 6 days by HPLC/UV and TLC methods, the content of 25(OH)-ginsenosides tended to increase in proportion to the time exposed to heat. In particular, the content of 25(OH)-ginsenosid Rg5 was confirmed to be noticeably increased.

• Journal of Microbiology and Biotechnology
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• v.28 no.3
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• pp.391-396
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• 2018

It is well known that Korean red ginseng has various biological activities. However, there is little knowledge about the antiviral activity of Korean red ginseng and its ginsenosides. In this study, we addressed whether oral administration of ginsenoside-Rb2 and -Rg3 is able to protect against rotavirus (RV) infection. The protective effect of ginsenosides against RV infection was examined using an in vivo experiment model in which newborn mice (10-day-old) were inoculated perorally (p.o.) with $1.5{\times}10^6$ plaque-forming units/mouse of RV strain SA11. When various dosages of ginsenoside-Rb2 (25-250 mg/kg) were administered 3days, 2 days, or 1 day before virus challenge, treatment with this ginsenoside at the dosage of 75 mg/kg 3days before virus infection most effectively reduced RV-induced diarrhea. In addition, consecutive administration of ginsenoside-Rb2 (75 mg/kg) at 3 days, 2 days, and 1 day before virus infection was more effective than single administration on day -3. The consecutive administration of ginsenoside-Rb2 also reduced virus titers in the bowels of RV-infected mice. In an experiment to compare the protective activity between ginsenoside-Rb2 and its two hydrolytic products (20(S)- and 20(R)-ginsenoside-Rg3), 20(S)-ginsenoside-Rg3, but not 20(R)-ginsenoside-Rg3, prevented RV infection. These results suggest that ginsenoside-Rb2 and its hydrolytic product, 20(S)-ginsenoside-Rg3, are promising candidates as an antiviral agent to protect against RV infection.

• Journal of Ginseng Research
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• v.34 no.3
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• pp.246-253
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• 2010

Ginsenoside $Rg_3$ ($Rg_3$), one of the active ingredients in Panax ginseng, attenuates NMDA receptor-mediated currents in vitro and antagonizes NMDA receptors through a glycine modulatory site in rat cultured hippocampal neurons. In the present study, we examined the neuroprotective effects of $Rg_3$ on 24-hydroxycholesterol (24-OH-chol)-induced cytotoxicity in vitro. The results showed that $Rg_3$ treatment significantly and dose-dependently inhibited 24-OH-chol-induced cell death in rat cultured cortical neurons, with an $IC_{50}$ value of $28.7{\pm}7.5\;{\mu}m$. Furthermore, the $Rg_3$ treatment not only significantly reduced DNA damage, but also dose-dependently attenuated 24-OH-chol-induced caspase-3 activity. To study the mechanisms underlying the in vitro neuroprotective effects of $Rg_3$ against 25-OH-chol-induced cytotoxicity, we also examined the effect of $Rg_3$ on intracellular $Ca^{2+}$ elevations in cultured neurons and found that $Rg_3$ treatment dose-dependently inhibited increases in intracellular $Ca^{2+}$, with an $IC_{50}$ value of $40.37{\pm}12.88\;{\mu}m$. Additionally, $Rg_3$ treatment dose-dependently inhibited apoptosis with an $IC_{50}$ of $47.3{\pm}14.2\;{\mu}m$. Finally, after confirming the protective effect of $Rg_3$ using a terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay, we found that $Rg_3$ is an active component in ginseng-mediated neuroprotection. These results collectively indicate that $Rg_3$-induced neuroprotection against 24-OH-chol in rat cortical neurons might be achieved via inhibition of a 24-OH-chol-mediated $Ca^{2+}$ channel. This is the first report to employ cortical neurons to study the neuroprotective effects of $Rg_3$ against 24-OH-chol. In conclusion, $Rg_3$ was effective for protecting cells against 24-OH-chol-induced cytotoxicity in rat cortical neurons. This protective ability makes $Rg_3$ a promising agent in pathologies implicating neurodegeneration such as apoptosis or neuronal cell death.

• Preventive Nutrition and Food Science
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• v.14 no.3
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• pp.201-207
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• 2009

In an effort to improve ginsenoside bioavailability, the ginsenosides of fermented red ginseng were examined with respect to bioavailability and physiological activity. The results showed that the fermented red ginseng (FRG) had a high level of ginsenoside metabolites. The total ginsenoside contents in non-fermented red ginseng (NFRG) and FRG were 35715.2 ${\mu}g$/mL and 34822.9 ${\mu}g$/mL, respectively. However, RFG had a higher content (14914.3 ${\mu}g$/mL) of ginsenoside metabolites (Rg3, Rg5, Rk1, CK, Rh1, F2, and Rg2) compared to NFRG (5697.9 ${\mu}g$/mL). The skin permeability of RFG was higher than that of NFRG using Franz diffusion cells. Particularly, after 5 hr, the skin permeability of RFG was significantly (p<0.05) higher than that of NFRG. Using everted instestinal sacs of rats, RFG showed a high transport level (10.3 mg of polyphenols/g sac) compared to NFRG (6.67 of mg of polyphenols/g sac) after 1 hr. After oral administration of NFRG and FRG to rats, serum concentrations were determined by HPLC. Peak concentrations of Rk1, Rh1, Rc, and Rg5 were approximately 1.64, 2.35, 1.13, and 1.25-fold higher, respectively, for FRG than for NFRG. Furthermore, Rk1, Rh1, and Rg5 increased more rapidly in the blood by the oral administration of FRG versus NFRG. FRG had dramatically improved bioavailability compared to NFRG as indicated by skin permeation, intestinal permeability, and ginsenoside levels in the blood. The significantly greater bioavailability of FRG may have been due to the transformation of its ginsenosides by fermentation to more easily absorbable forms (ginsenoside metabolites).