Hedychium flavum Roxb., a medicinal, edible, and ornamental plant, is widely cultivated throughout China, India, and Southeast Asia. The rhizome from this plant has been used for food flavoring and in traditional Chinese medicine to treat diverse diseases, but the detailed constituents and bioactivities are still limited known. Therefore, phytochemical analysis by GC-MS and UHPLC-Q-Orbitrap-MS, and antioxidant, antibacterial, cytotoxic, and enzyme inhibitory activities tests have been conducted in the current study. Based on the GC-MS results, the essential oil (EO) of rhizome was mainly composed of coronarin E (20.3%), β-pinene (16.8%), E-nerolidol (11.8%), and linalool (8.5%). Among them, coronarin E was reported in H. flavum EO firstly. Furthermore, the spectrophotometric indicated rhizome had high total phenolic content (TPC, 50.08–57.42 mg GAEs/g extract) and total flavonoid content (TFC, 12.45–21.83 mg REs/g extract), no matter in water extract (WE) or in 70% ethanol extract (EE). UHPLC-Q-Orbitrap-MS was applied to further characterize composition, and 86 compounds were putatively identified from WE and EE, including 13 phenolic components. For the bioactivities, both WE and EE showed remarkable antioxidant activity by DPPH and ABTS tests, being superior to the positive control (butylated hydroxytoluene, BTH). EO revealed significant antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and Proteus vulgaris with DIZ (10.34–24.43 mm), MIC (78.13–312.50 μg/mL), and MBC (156.25–625.00 μg/mL). Moreover, EO exhibited a considerable selectivity to human tumor cell K562 (IC₅₀ = 27.16 μg/mL), and its toxicity was more than 3.5-fold different from that of non-cancerous MRC-5 cell (IC₅₀ = 95.96 μg/mL) and L929 cell (IC₅₀ = 129.91 μg/mL). A series of apoptosis analysis demonstrated that EO induced apoptosis against K562 cells in a dose-dependent manner. In enzyme inhibitory effect assays, WE and EE showed strong α-glucosidase inhibition activity, being superior to the positive control (acarbose). Besides, the EO, WE, and EE didn’t show a promising inhibition on tyrosinase (19.30–32.51 mg KAEs/g sample) and exhibited a weak inhibitory effect on cholinesterase. Based on the current results, H. flavum could be considered as a source of bioactive compounds and has high exploitation potential in the cosmetics, food, and pharmaceutical industries.

The Rev1-Polζ pathway is believed to be the major mechanism of translesion DNA synthesis and base damage-induced mutagenesis in eukaryotes. While it is widely believed that Rev1 plays a non-catalytic function in translesion synthesis, the role of its dCMP transferase activity remains uncertain. To determine the relevance of its catalytic function in translesion synthesis, we separated the Rev1 dCMP transferase activity from its non-catalytic function in yeast. This was achieved by mutating two conserved amino acid residues in the catalytic domain of Rev1, i.e. D467A/E468A, where its catalytic function was abolished but its non-catalytic function remained intact. In this mutant strain, whereas translesion synthesis and mutagenesis of UV radiation were fully functional, those of a site-specific 1, N⁶ -ethenoadenine were severely deficient. Specifically, the predominant A→G mutations resulting from C insertion opposite the lesion were abolished. Therefore, translesion synthesis and mutagenesis of 1, N⁶ -ethenoadenine require the catalytic function of the Rev1 dCMP transferase, in contrast to those of UV lesions, which only require the non-catalytic function of Rev1. These results show that the catalytic function of the Rev1 dCMP transferase is required in a lesion-specific manner for translesion synthesis and base damage-induced mutagenesis.

Alpinia galanga is widely cultivated for its essential oil (EO), which has been used in cosmetics and perfumes. Previous studies of A. galanga focussed mostly on the rhizome but seldom on the flower. Therefore, this study was designed to identify the chemical composition of A. galanga flower EO and firstly estimate its antioxidant, antibacterial, enzyme inhibitory, and anticancer activities. According to the results of the gas chromatography with flame ionization or mass selective detection (GC-FID/MS) analysis, the most abundant component of the EO was farnesene (64.3%), followed by farnesyl acetate (3.6%), aceteugenol (3.2%), eugenol (3.1%), E-nerolidol (2.9%), decyl acetate (2.4%), octyl acetate (2.0%), sesquirosefuran (1.9%), (E)-β-farnesene (1.7%), and germacrene D (1.5%). For the bioactivities, the EO exhibited moderate DPPH and ABTS radical scavenging effects with IC₅₀ values of 138.62 ± 3.07 μg/mL and 40.48 ± 0.49 μg/mL, respectively. Moreover, the EO showed strong-to-moderate antibacterial activities with various diameter of inhibition zone (DIZ) (8.79–14.32 mm), minimal inhibitory concentration (MIC) (3.13–6.25 mg/mL), and minimal bactericidal concentration (MBC) (6.25–12.50 mg/mL) values against Staphylococcus aureus, Bacillus subtilis, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, and Proteus vulgaris. Interestingly, the EO possessed remarkable α-glucosidase inhibition (IC₅₀ = 0.16 ± 0.03 mg/mL), which was equivalent to that of the positive control acarbose (IC₅₀ = 0.15 ± 0.01 mg/mL) (p > 0.05). It showed moderate tyrosinase inhibition (IC₅₀ = 0.62 ± 0.09 mg/mL) and weak inhibitory activity on acetylcholinesterase (AChE) (IC₅₀ = 2.49 ± 0.24 mg/mL) and butyrylcholinesterase (BChE) (IC₅₀ = 10.14 ± 0.59 mg/mL). Furthermore, the EO exhibited considerable selective cytotoxicity to K562 cells (IC₅₀ = 41.55 ± 2.28 μg/mL) and lower cytotoxicity to non-cancerous L929 cells (IC₅₀ = 120.54 ± 8.37 μg/mL), and it induced K562 cell apoptosis in a dose-dependent manner. Hence, A. galanga flower EO could be regarded as a bioactive natural product with great application potential in the pharmaceutical field.

The chemical composition and biological activities of the essential oil (EO) from the rhizomes of Zingiber striolatum Diels were reported for the first time. Forty-five compounds were identified, and represented 95.7% of the total composition of the EO. The predominant components of the EO were β-phellandrene (24.0%), sabinene (17.3%), β-pinene (11.4%), geranyl linalool (8.6%), terpinen-4-ol (8.3%), α-pinene (5.6%) and crypton (4.5%). The EO revealed a weak DPPH and ABTS radical-scavenging activity. The EO exhibited significant antimicrobial activity with the inhibition zones (12.86–24.62 mm) and MIC (0.78–3.12 mg/mL) against Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Candida albicans. The EO showed significant cytotoxicity against human leukemic (K562), lung cancer (A549) and prostatic carcinoma (PC-3) cell lines with the IC₅₀ values of 29.67, 48.87 and 86.05 μg/mL, respectively. Thus, the EO could be regarded as a bioactive natural product with potential for utilization in the cosmetic and pharmaceutical industry.

The chemical constituents and the antioxidant, antimicrobial, and cytotoxic activities of fresh rhizome essential oil (FR‐EO) and dry rhizome essential oil (DR‐EO) of Zingiber zerumbet (L.) Smith obtained from Southwest China were compared. Zerumbone was the predominant component in both FR‐EO and DR‐EO (75.0% and 41.9%, respectively). FR‐EO, DR‐EO, and zerumbone were all demonstrated to have significant antimicrobial capacity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Proteus vulgaris, with minimum inhibitory concentration (MIC) ranging from 31.25 to 156.25 μg/mL and minimum bactericidal concentration (MBC) ranging from 62.50 to 625.00 μg/mL. Zerumbone showed the strongest antimicrobial potential against all tested microorganisms compared with the fresh and dry rhizome essential oils. FR‐EO was found to be more active than DR‐EO against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Proteus vulgaris. FR‐EO, DR‐EO, and zerumbone all showed significant cytotoxic activity against K562, PC‐3, and A549 human tumor cell lines in a time‐ and concentration‐dependent manner. Zerumbone exhibited the strongest antiproliferative activity against all tested human tumor cell lines with an IC₅₀ of 4.21–11.09 μg/mL for 72 h incubation, as compared with the fresh and dry rhizome oils. The cytotoxic activity of FR‐EO (IC₅₀: 10.48–14.51 μg/mL for 72 h) was found to be significantly higher (p < 0.05) than that of DR‐EO (IC₅₀: 13.83–33.24 μg/mL for 72 h). FR‐EO, DR‐EO, and zerumbone exhibited selective cytotoxic activity to tumor cells, with a significantly low cytotoxicity to normal cells (MRC‐5, IC₅₀: 56.98–147.29 μg/mL). However, FR‐EO, DR‐EO, and zerumbone all exhibited weak free‐radical‐scavenging activity according to DPPH and ABTS analysis. The findings highlighted in this study show that FR‐EO provides appreciably higher content of the bioactive compound, zerumbone, and has higher antimicrobial and cytotoxic properties than DR‐EO. Thus, fresh Z. zerumbet rhizome should be preferred in cosmetic, food, and pharmaceutical applications.

Scavenger receptor class B type I (SR-BI) protein is an integral membrane glycoprotein. SR-BI is emerging as a multifunctional protein, which regulates autophagy, efferocytosis, cell survival and inflammation. It is well known that SR-BI plays a critical role in lipoprotein metabolism by mediating cholesteryl esters selective uptake and the bi-directional flux of free cholesterol. Recently, SR-BI has also been identified as a potential marker for cancer diagnosis, prognosis, or even a treatment target. Natural products are a promising source for the discovery of new drug leads. Multiple natural products were identified to regulate SR-BI protein expression. There are still a number of challenges in modulating SR-BI expression in cancer and in using natural products for modulation of such protein expression. In this review, our purpose is to discuss the relationship between SR-BI protein and cancer, and the molecular mechanisms regulating SR-BI expression, as well as to provide an overview of natural products that regulate SR-BI expression.