Yin-Yin Siew

Abstract The Global Diabetes Compact was launched by the World Health Organization in April 2021 with one of its important goals to increase the accessibility and affordability of life-saving medicine—insulin. The rising prevalence of diabetes worldwide is bound to escalate the demand for recombinant insulin therapeutics, and currently, the majority of recombinant insulin therapeutics are produced from E. coli inclusion bodies. Here, a comprehensive review of downstream processing of recombinant human insulin/analogue production from E. coli inclusion bodies is presented . All the critical aspects of downstream processing, starting from proinsulin recovery from inclusion bodies, inclusion body washing, inclusion body solubilization and oxidative sulfitolysis, cyanogen bromide cleavage, buffer exchange, purification by chromatography, pH precipitation and zinc crystallization methods, proinsulin refolding, enzymatic cleavage, and formulation, are explained in this review. Pertinent examples are summarized and the practical aspects of integrating every procedure into a multimodal purification scheme are critically discussed. In the face of increasing global demand for insulin product, there is a pressing need to develop a more efficient and economical production process. The information presented would be insightful to all the manufacturers and stakeholders for the production of human insulins, insulin analogues or biosimilars, as they strive to make further progresses in therapeutic recombinant insulin development and production.

Selected cytotoxic chemicals can provoke the immune system to recognize and destroy malignant tumors. Most of the studies on immunogenic cell death are focused on the signals that operate on a series of receptors expressed by dendritic cells to induce tumor antigen-specific T-cell responses. Here, we explored the effects of oxaliplatin, an immunogenic cell death inducer, on the induction of stress ligands and promotion of natural killer (NK) cell-mediated cytotoxicity in human ovarian cancer cells. The results indicated that treatment of tumor cells with oxaliplatin induced the production of type I interferons and chemokines and enhanced the expression of major histocompatibility complex class I-related chains (MIC) A/B, UL16-binding protein (ULBP)-3, CD155 and TNF-related apoptosis-inducing ligand (TRAIL)-R1/R2. Furthermore, oxaliplatin but not cisplatin treatment enhanced susceptibility of ovarian cancer cells to NK cell-mediated cytolysis. In addition, activated NK cells completely abrogated the growth of cancer cells that were pretreated with oxaliplatin. However, cancer cells pretreated with the same concentration of oxaliplatin alone were capable of potentiating regrowth over a period of time. These results suggest an advantage in combining oxaliplatin and NK cell-based therapy in the treatment of ovarian cancer. Further investigation on such potential combination therapy is warranted.

Leea indica (Vitaceae) is a Southeast Asian medicinal plant. In this study, an ethyl acetate fraction of L. indica leaves was studied for its phytoconstituents using high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-microTOF-Q-MS/MS) analysis. A total of 31 compounds of different classes, including benzoic acid derivatives, phenolics, flavonoids, catechins, dihydrochalcones, coumarins, megastigmanes, and oxylipins were identified using LC-MS/MS. Among them, six compounds including gallic acid, methyl gallate, (−)-epigallocatechin-3-O-gallate, myricetin-3-O-rhamnoside, quercetin-3-O-rhamnoside, and 4′,6′-dihydroxy-4-methoxydihydrochalcone 2′-O-β-d-glucopyranoside were isolated and identified by NMR analysis. The LC-MS/MS analysis led to the tentative identification of three novel dihydrochalcones namely 4′,6′-dihydroxy-4-methoxydihydrochalcone 2′-O-rutinoside, 4′,6′-dihydroxy-4-methoxydihydrochalcone 2′-O-glucosylpentoside and 4′,6′-dihydroxy-4-methoxydihydrochalcone 2′-O-(3″-O-galloyl)-β-d-glucopyranoside. The structural identification of novel dihydrochalcones was based on the basic skeleton of the isolated dihydrochalcone, 4′,6′-dihydroxy-4-methoxydihydrochalcone 2′-O-β-d-glucopyranoside and characteristic LC-MS/MS fragmentation patterns. This is the first comprehensive analysis for the identification of compounds from L. indica using LC-MS. A total 24 compounds including three new dihydrochalcones were identified for the first time from the genus Leea.