The Mechanism of Action of Ginkgolic Acid (15:1) against Gram-Positive Bacteria Involves Cross Talk with Iron Homeostasis

The increasing emergence of infectious diseases associated with multidrug-resistant Gram-positive pathogens has raised the urgent need to develop novel antibiotics. GA (15:1) is a natural product derived from Ginkgo biloba and possesses a wide range of bioactivities, including antimicrobial activity.

Ginkgolic Acid (GA) Inhibits the Growth of OCa by Inhibiting lncRNA MALAT1/JAK2 Axis

Objective. We aimed to observe the impact of ginkgolic acid (GA) on the proliferation and metastasis ability of ovarian cancer (OCa) cells and to further explore whether GA affects the malignant progress of OCa via regulating the lncRNA MALAT1/JAK2 axis. Methods. OCa cells SKOV3 and CAOV3 were administered with 1 ng/ml GA, 5 ng/ml GA, 10 ng/ml GA, 20 ng/ml GA, and DSMO as control, respectively. The cell proliferation and migration ability of the abovementioned cells in each group were measured by CCK-8 test and Transwell experiments. The expression levels of lncRNA MALAT1 and JAK2 protein were examined by qRT-PCR and western blot, respectively. Subsequently, in OCa cells treated with GA, lncRNA MALAT1 overexpression vector was transfected to continue to detect the proliferation activity and migration ability of each treatment group. Finally, the regulation of GA on activity of lncRNA MALAT1/JAK2 axis in OCa cells was further explored in nude mice. Results. Our data showed that the proliferation inhibition rate of cells at each ginkgolic acid concentration was higher than that of the control group ( P < 0.05 ), suggesting that GA has an inhibitory influence on the proliferation of OCa cells, in a dose-dependent way. GA was able to inhibit the proliferation rate and migration ability of OCa cells. Administration of ginkgolic acid downregulated the levels of lncRNA MALAT1 and JAK2 protein. Overexpression of lncRNA MALAT1 partially reversed the inhibited OCa proliferative capacity caused by GA treatment. Consistent with the results observed in vitro, we also found that the OCa tumor weight and volume of nude mice injected with lncRNA MALAT1 overexpression vector were enhanced and JAK2 protein level increased remarkably in comparison to the ginkgolic acid group. Conclusions. In summary, GA may exert its inhibitory effect on the proliferative and migratory capacities of OCa cells through suppressing the activity of lncRNA MALAT1/JAK2 axis.

Ginkgolic Acid Inhibits Coronavirus Strain 229E Infection of Human Epithelial Lung Cells

Since December 2019, the COVID-19 pandemic has affected more than 200 million individuals around the globe and caused millions of deaths. Although there are now multiple vaccines for SARS-CoV-2, their efficacy may be limited by current and future viral mutations. Therefore, effective antiviral compounds are an essential component to win the battle against the family of coronaviruses. Ginkgolic Acid (GA) is a pan-antiviral molecule with proven effective in vitro and in vivo activity. We previously demonstrated that GA inhibits Herpes Simplex Virus 1 (HSV-1) by disrupting viral structure, blocking fusion, and inhibiting viral protein synthesis. Additionally, we reported that GA displays broad-spectrum fusion inhibition encompassing all three classes of fusion proteins, including those of HIV, Ebola, influenza A, and Epstein Barr virus. Here, we report that GA exhibited potent antiviral activity against Human Coronavirus strain 229E (HCoV-229E) infection of human epithelial lung cells (MRC-5). GA significantly reduced progeny virus production, expression of viral proteins, and cytopathic effects (CPE). Furthermore, GA significantly inhibited HCoV-229E even when added post-infection. In light of our findings and the similarities of this family of viruses, GA holds promising potential as an effective antiviral treatment for SARS-CoV-2.

Ginkgo biloba Seeds—An Environmental Pollutant or a Functional Food

Ginkgo biloba has been cultivated in Bulgaria since the end of the 19th century. Ividual specimens can be seen in almost every park. Females of the tree are considered contaminants of the landscape because their ripe seeds have a strong odor and are not utilized. We undertook this study to clarify whether ginkgo seeds of local origin can be converted from an unwanted and unused environmental pollutant into a source of beneficial compounds. Various analytical and chromatographic methods were used to quantify the major constituents and ten biologically active compounds in methanol seed extract. The results showed that the seeds are low in proteins (5%) and fats (1%); the seeds were also rich in unsaturated fatty acids and tocopherols. About 44% of nut starch was resistant to in vitro enzymatic hydrolysis. The amount of terpene trilactones in an aqueous-methanol seed extract was significantly higher than the number of flavonoids. Ginkgotoxin and ginkgolic acid were also found. The extract demonstrated weak antimicrobial activity against thirteen microorganisms. This study revealed that seeds of locally grown Ginkgo trees can be used as a source of biologically active substances. The chemical composition show similarity to those of seeds from other geographical areas.

Natural Products, Alone or in Combination with FDA-Approved Drugs, to Treat COVID-19 and Lung Cancer

As a public health emergency of international concern, the highly contagious coronavirus disease 2019 (COVID-19) pandemic has been identified as a severe threat to the lives of billions of individuals. Lung cancer, a malignant tumor with the highest mortality rate, has brought significant challenges to both human health and economic development. Natural products may play a pivotal role in treating lung diseases. We reviewed published studies relating to natural products, used alone or in combination with US Food and Drug Administration-approved drugs, active against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and lung cancer from 1 January 2020 to 31 May 2021. A wide range of natural products can be considered promising anti-COVID-19 or anti-lung cancer agents have gained widespread attention, including natural products as monotherapy for the treatment of SARS-CoV-2 (ginkgolic acid, shiraiachrome A, resveratrol, and baicalein) or lung cancer (daurisoline, graveospene A, deguelin, and erianin) or in combination with FDA-approved anti-SARS-CoV-2 agents (cepharanthine plus nelfinavir, linoleic acid plus remdesivir) and anti-lung cancer agents (curcumin and cisplatin, celastrol and gefitinib). Natural products have demonstrated potential value and with the assistance of nanotechnology, combination drug therapies, and the codrug strategy, this “natural remedy” could serve as a starting point for further drug development in treating these lung diseases.

Ginkgolic acid induces apoptosis and autophagy of endometrial carcinoma cells via inhibiting PI3K/Akt/mTOR pathway in vivo and in vitro

Endometrial cancer (EC) is the fourth most common malignancy in women in developed countries. The prognosis of EC is extremely poor, and it is an important factor that contributes to the death of patients. Therefore, studying EC pathogenesis and therapeutic targets, and exploring effective drugs are the primary tasks to improve the prognosis of EC. In the present study, we aimed to explore the function of ginkgolic acid (GA) in EC cell apoptosis and autophagy through PI3K/Akt/mTOR signal pathway in vitro and in vivo. Firstly, MTT assay and clone formation assay were employed to analyze the Ishikawa and HEC-1-B cell viabilities and proliferation after treatment with GA. The results showed that GA inhibited endometrial cancer cell survival. Flow cytometry assay and western blot assay were applied to examine the apoptosis and apoptosis related protein Bcl-2, Bax, Cleaved caspase-3 expression levels of Ishikawa and HEC-1-B cells after treatment with GA. Next, we applied western blot assay to analyze the autophagy associated proteins LC3I, LC3II, p62 and Beclin-1 in GA treated Ishikawa and HEC-1-B cells. We found that GA promoted apoptosis and induced autophagy of endometrial cancer cells. Meanwhile, western blot assay was also used to determine the expression levels of the PI3K/Akt/mTOR signal pathway related protein and the results revealed that GA inhibited the activity of PI3K/Akt/mTOR pathway. Finally, we found that GA inhibited tumor growth in vivo through immunohistochemistry assay. In conclusion, GA induces apoptosis and autophagy of EC cells via inhibiting PI3K/Akt/mTOR pathway in vivo and vitro.

Increased SUMOylation of TCF21 improves its stability and function in human endometriotic stromal cells

Endometriosis is an estrogen-dependent disease. Our previous study demonstrated that elevated levels of transcription factor 21 (TCF21) in endometriotic tissues enhanced steroidogenic factor-1 (SF-1) and estrogen receptor β (ERβ) expression by forming a heterodimer with upstream stimulatory factor 2 (USF2), allowing these TCF21/USF2 complexes to bind to the promoters of SF-1 and ERβ. Furthermore, TCF21 contributed to the increased proliferation of endometriotic stromal cells (ESCs), suggesting that TCF21 may play a vital role in the pathogenesis of endometriosis. SUMOylation is a posttranslational modification that has emerged as a crucial molecular regulatory mechanism. However, the mechanism regulating TCF21 SUMOylation in endometriosis is incompletely characterized. Thus, this study aimed to explore the effect of TCF21 SUMOylation on its expression and regulation in ovarian endometriosis. We found that the levels of SUMOylated TCF21 were increased in endometriotic tissues and stromal cells compared with eutopic endometrial tissues and stromal cells and enhanced by estrogen. Treatment with the SUMOylation inhibitor ginkgolic acid (GA) and the results of a protein half-life assay demonstrated that SUMOylation can stabilize the TCF21 protein. A coimmunoprecipitation (Co-IP) assay showed that SUMOylation probably increased its interaction with USF2. Further analyses elucidated that SUMOylation of TCF21 significantly increased the binding activity of USF2 to the SF-1 and ERβ promoters. Moreover, the SUMOylation motifs in TCF21 affected the proliferation ability of ESCs. The results of this study suggest that SUMOylation plays a critical role in mediating the high expression of TCF21 in ESCs and may participate in the development of endometriosis.

Ginkgolic acid and anacardic acid are specific covalent inhibitors of SARS-CoV-2 cysteine proteases

Background In the urgent campaign to develop therapeutics against SARS-CoV-2, natural products have been an important source of new lead compounds. Results We herein identified two natural products, ginkgolic acid and anacardic acid, as inhibitors using a high-throughput screen targeting the SARS-CoV-2 papain-like protease (PLpro). Moreover, our study demonstrated that the two hit compounds are dual inhibitors targeting the SARS-CoV-2 3-chymotrypsin-like protease (3CLpro) in addition to PLpro. A mechanism of action study using enzyme kinetics further characterized the two compounds as irreversible inhibitors against both 3CLpro and PLpro. Significantly, both identified compounds inhibit SARS-CoV-2 replication in vitro at nontoxic concentrations. Conclusions Our finding provides two novel natural products as promising SARS-CoV-2 antivirals.

Deletion of Small Ubiquitin-like Modifier-1 Attenuates Behavioral and Anatomical Deficits by Enhancing Functional Autophagic Activities in Huntington Disease

ABSTRACTMutant HTT (mHTT) associated with Huntington disease (HD) affects the central nervous system by prominent atrophy in the striatum and promotes psychiatric, cognitive, and choreiform movements, although the exact mechanism remains obscure. Previous studies have shown that SUMO1 (Small Ubiquitin-like Modifier-1) modification of mHTT promotes cellular toxicity, but the in vivo role and functions of SUMO1 in HD pathogenesis are unclear. Here, we report that SUMO1 deletion in Q175DN HD-het knock-in mice (HD mice) prevented age-dependent HD-like motor and neurological impairments and suppressed the striatal atrophy and inflammatory response. SUMO1 deletion caused a drastic reduction in soluble mHtt levels and nuclear and extracellular mHtt inclusions, while increasing cytoplasmic inclusions in the striatum of HD mice. SUMO1 deletion also enhanced autophagic activity, characterized by augmented interactions between mHTT inclusions and a lysosomal marker (LAMP1), increased LC3B/LAMP1 interaction, and decreased sequestosome-1 (p62) and mHTT and diminished p62/LAMP1 interactions in DARPP-32–positive medium spiny neurons (MSNs) in HD mice. Depletion of SUMO1 in an HD cell model also diminished the mHtt levels and enhanced autophagy flux. In addition, the SUMOylation inhibitor ginkgolic acid strongly enhanced autophagy and diminished mHTT levels in human HD fibroblasts. These results indicate that SUMO is a critical therapeutic target in HD and that blocking SUMO may ameliorate HD pathogenesis by improving autophagy activities.