(24R)-pseudo-ginsenoside HQ (R-PHQ) and (24S)-pseudo-ginsenoside HQ (S-PHQ) are the main metabolites of (20S)-ginsenoside Rh₂ (Rh₂) in vivo. In this study, we found that Rh₂, R-PHQ, and S-PHQ upregulated the innate and adaptive immune response in cyclophosphamide (CTX) induced-immunocompromised mice as evidenced by the number of leukocytes, cellular immunity, and phagocytosis of macrophages. Spleen T-lymphocyte subpopulations and the serum cytokines level were also balanced in these immunosuppressed mice. Furthermore, co-administration with R-PHQ or S-PHQ did not compromise the antitumor activity of CTX in the hepatoma H22-bearing mice. Treatment with R-PHQ and S-PHQ clearly induced the apoptosis of tumor cells, significantly increased the expression of Bax, and remarkably inhibited the expression of Bcl-2 and vascular endothelial growth factor (VEGF) in H22 tumor tissues. The anti-tumor activity of R-PHQ and S-PHQ could be related to the promotion of tumor apoptosis and inhibition of angiogenesis and may involve the caspase and VEGF signaling pathways. This study provides a theoretical basis for further study on R-PHQ and S-PHQ.

In this study, the protective effects of pseudoginsengenin DQ (PDQ) on cisplatin (CDDP)-induced nephrotoxicity were assessed, with a primary investigation into the mechanisms involved. Our results showed that pretreatment with PDQ remarkably restored levels of blood urea nitrogen (BUN) and creatinine (CRE), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β). Meanwhile, PDQ decreased the CDDP-induced overexpression of heme oxygenase 1 (HO-1), cytochrome P450 E1 (CYP2E1), TNF-α, nuclear factor-kappa B (NF-κB), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) in renal tissues. Hoechst 33258 and TdT-mediated dUTP nick-end labeling (TUNEL) staining showed that CDDP-induced renal tubular cell apoptosis was apparently inhibited by PDQ. Western blotting showed that PDQ reversed the CDDP-induced (1) downregulation of Sirtuin-1 (Sirt-1), nuclear-related factor 2 (Nrf2), and Bcl-2, and (2) upregulation of NF-κB, Nox-4, Bax, caspase-9, and caspase-3. In addition, PDQ enhanced the antitumor activity of cisplatin in Lewis lung cancer xenograft tumor model mice. In conclusion, we found that PDQ exerted a renal protective effect against CDDP-induced acute nephrotoxicity via Sirt1/NF-κB and the caspase signaling pathway without compromising the antitumor activity of CDDP, which provides a new potential strategy for the clinical treatment of cancer and presents a new medicinal application of PDQ.

Suppressive effects of ginsenoside Rh₂ (Rh₂), (24R)-pseudo-ginsenoside HQ (R-PHQ), and (24S)-pseudo-ginsenoside HQ (S-PHQ) against lipopolysaccharide (LPS)-induced depression-like behavior were evaluated using the forced swimming test (FST) and tail suspension test (TST) in mice. Pretreatment with Rh₂, R-PHQ, and S-PHQ significantly decreased immobility time in FST and TST with clear dose-dependence, and significantly downregulated levels of serum tumor necrosis factor-α and interleukin-6, and upregulated superoxide dismutase activity in the hippocampus of LPS-challenged mice. Furthermore, R-PHQ and S-PHQ significantly increased the expression of the brain-derived neurotrophic factor (BDNF), tropomyosin-related kinase B (TrkB), sirtuin type 1 (Sirt1), and nuclear-related factor 2, and inhibited the phosphorylation of inhibitor of κB-α and nuclear factor-κB (NF-κB) in the hippocampus of LPS-challenged mice. Additionally, the antidepressant-like effect of R-PHQ was found related to the dopaminergic (DA), γ-aminobutyric acid (GABA)ergic, and noradrenaline systems, while the antidepressive effect of S-PHQ was involved in the DA and GABAergic systems. Taken together, these results suggested that Rh₂, R-PHQ, and S-PHQ produced significant antidepressant-like effects, which may be related to the BDNF/TrkB and Sirt1/NF-κB signaling pathways.

Panax ginseng Meyer cv. Silvatica (PGS), which is also known as “Lin-Xia-Shan-Shen” or “Zi-Hai” in China, is grown in forests and mountains by broadcasting the seeds of ginseng and is harvested at the cultivation age of 15–20 years. In this study, four new dammarane-type triterpenoids, ginsengenin-S1 (1), ginsengenin-S2 (2), ginsenoside-S3 (3), ginsenoside-S4 (4), along with one known compound were isolated from pearl knots of PGS. Ginsengenin-S2 significantly alleviated oxidative damage when A549 cells were exposed to cigarette smoke (CS) extract. In addition, ginsengenin-S2 could inhibit the CS-induced inflammatory reaction in A549 cells. Protective effects of ginsengenin-S2 against CS-mediated oxidative stress and the inflammatory response in A549 cells may involve the Nrf2 and HDAC2 pathways.

A fully quantitative theory of the relationship between protein conformation and optical spectroscopy would facilitate deeper insights into biophysical and simulation studies of protein dynamics and folding. In contrast to intense bands in the far-ultraviolet, near-UV bands are much weaker and have been challenging to compute theoretically. We report some advances in the accuracy of calculations in the near-UV, which were realised through the consideration of the vibrational structure of the electronic transitions of aromatic side chains.

Treatment for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes Covid-19, may well be predicated on knowledge of the structures of protein of this virus. However, often these cannot be determined easily or quickly. Herein, we provide calculated circular dichroism (CD) spectra in the far- and near-UV, and infra-red (IR) spectra in the amide I region for experimental structures and computational models of SARS-CoV-2 proteins. The near-UV CD spectra offer greatest sensitivity in assessing the accuracy of models.