Natural products generally fall into the biologically relevant chemical space and always possess novel biological activities, thus making them a rich source of lead compounds for new drug discovery. With the recent technological advances, natural product-based drug discovery is now reaching a new era. Natural products have also shown promise in epigenetic drug discovery, some of them have advanced into clinical trials or are presently being used in clinic. The histone lysine specific demethylase 1 (LSD1), an important class of histone demethylases, has fundamental roles in the development of various pathological conditions. Targeting LSD1 has been recognized as a promising therapeutic option for cancer treatment. Notably, some natural products with different chemotypes including protoberberine alkaloids, flavones, polyphenols, and cyclic peptides have shown effectiveness against LSD1. These natural products provide novel scaffolds for developing new LSD1 inhibitors. In this review, we mainly discuss the identification of natural LSD1 inhibitors, analysis of the co-crystal structures of LSD1/natural product complex, antitumor activity and their modes of action. We also briefly discuss the challenges faced in this field. We believe this review will provide a landscape of natural LSD1 inhibitors.

Glioma is the most common primary craniocerebral tumor caused by the cancerous growth of glial cells in the brain and spinal cord. Currently, standard treatment is the surgical resection followed by concurrent radiation and chemotherapy. However, the blood-brain barrier (BBB) prevents most antitumor drugs from entering the brain and reduces their efficacy, especially in low-grade glioma. Since L-type amino acid transporter 1 (LAT1) is highly expressed in glioma cells and mediates drug transport across the BBB, it is a promising target for drug delivery and treatment of glioma. Temozolomide (TMZ) is the first-line treatment for glioma, however, patients often exhibit drug resistance at advanced stage. A multikinase inhibitor and inducer of ferroptosis, sorafenib can improve the therapeutic effects of TMZ. Therefore, to optimize the glioma treatment and cross the BBB, we designed LAT1-targeting nanoparticles co-loaded with TMZ and sorafenib. Our results from both in vitro and in vivo studies confirmed that LAT1-targeting nanoparticles significantly increased the cellular uptake, cytotoxicity, accumulation at tumor site, and the anti-tumor efficacy compared to the non-target nanoparticles. Therefore, LAT1 can be used as a potential target for brain-targeted drug delivery, and sorafenib-induced ferroptosis can aid the anti-glioma efficacy of TMZ.

Original Article Hesperetin ameliorates glioblastoma by inhibiting proliferation, inducing apoptosis, and suppressing metastasis Qian Cheng, Lianzhi Mao, Hongxiang Huang, Longguang Tang, Hongyan Jiang, Yufei Zhang, Qingchun Mu

Background: Glioma is a common primary craniocerebral malignant tumor, due to the lack of specificity of imaging examination and clinical manifestations, its diagnostic accuracy is relatively low, which may result in misdiagnosis and missed diagnosis. The apparent diffusion coefficient (ADC) in magnetic resonance diffusion weighted imaging (DWI) can reflect the histological characteristics of gliomas, which can be widely applied to classify gliomas and evaluate the extent of metastasis of glioma. The present study aimed to assess the clinical value of magnetic resonance DWI in the pathological grading of glioma and its therapeutic application in clinical surgery. Methods: This article retrospectively analyzed the clinical data of 41 patients with glioma confirmed by surgical pathology results from January 1, 2019 to March 31, 2020 in the People’s Hospital of Gaozhou. Among them, 16 patients had low-grade gliomas [World Health Organization (WHO) grade I–II] and 25 patients had high-grade gliomas (WHO grade III–IV). They were subjected to conventional T1WI and T2WI plain scans, along with DWI and enhanced scans before surgery. The ADC values of the glioma parenchyma, the peritumoral edema area, the surrounding white matter, and the contralateral normal white matter were measured. We selected some tumor tissues for pathological analysis as well, and conducted pathological grading according to WHO grading standards. Results: We compared and evaluated the ADC values of the observed areas for low-grade gliomas and high-grade gliomas. The ADC values of low-grade gliomas in the tumor parenchyma, peritumoral edema, and white matter around the edema area were significantly lower than those of high-grade gliomas, and the differences were statistically significant (P<0.05). The difference in ADC values of normal white matter between the two groups of patients was not statistically significant (P=0.125). Conclusions: DWI has prognostic predictive value in the preoperative differential diagnosis and pathological classification of gliomas. This advanced technology can verify the extent of glioma infiltration in the surrounding brain tissue. It can help clinicians formulate a safer and more effective therapeutic strategy by providing accurate information on prognostic evaluation before the successful surgical intervention of gliomas.

Cerebral ischemia reperfusion injury (CIRI) after stroke is hard to treat because the blood–brain barrier (BBB) blocks most drugs, while reperfusion triggers oxidative stress, ferroptosis, and neuroinflammation. We designed a neutrophil hitchhiking lipid nanoparticle (RKH Neu@Mino) by conjugating an RKH peptide (from Akkermansia muciniphila) onto DSPE PEG maleimide and encapsulating minocycline via microfluidic assembly. The nanoparticles specifically bind to neutrophil TLR4, allowing activated neutrophils to ferry them across the BBB and into ischemic lesions. Once there, RKH Neu@Mino suppresses ROS burst, inhibits ferroptosis, and shifts microglial polarization from pro inflammatory M1 to protective M2 phenotype, thereby mitigating CIRI. This neutrophil hitchhiking strategy offers a powerful approach to overcome the BBB delivery hurdle and treat post stroke reperfusion injury.