Nicotinamide mononucleotide (NMN) is a nucleotide that is most recognized for its role as an intermediate of nicotinamide adenine dinucleotide (NAD+) biosynthesis. Although the biosynthetic pathway of NMN varies between eukaryote and prokaryote, two pathways are mainly followed in case of eukaryotic human—one is through the salvage pathway using nicotinamide while the other follows phosphorylation of nicotinamide riboside. Due to the unavailability of a suitable transporter, NMN enters inside the mammalian cell in the form of nicotinamide riboside followed by its subsequent conversion to NMN and NAD+. This particular molecule has demonstrated several beneficial pharmacological activities in preclinical studies, which suggest its potential therapeutic use. Mostly mediated by its involvement in NAD+ biosynthesis, the pharmacological activities of NMN include its role in cellular biochemical functions, cardioprotection, diabetes, Alzheimer’s disease, and complications associated with obesity. The recent groundbreaking discovery of anti-ageing activities of this chemical moiety has added a valuable essence in the research involving this molecule. This review focuses on the biosynthesis of NMN in mammalian and prokaryotic cells and mechanism of absorption along with the reported pharmacological activities in murine model.

BCL-X L and BCL-2 are important targets for cancer treatment. BCL-X L specific proteolysis-targeting chimeras (PRO-TACs) have been developed to circumvent the on-target platelet toxicity associated with BCL-X L inhibition. However, they have minimal effects on cancer cells that are dependent on BCL-2 or both BCL-X L and BCL-2. Here we report a new series of BCL-PROTACs. The lead PZ703b exhibits high potency in inducing BCL-X L degradation and in inhibiting but not degrading BCL-2, showing a hybrid dual-targeting mechanism of action that is unprecedented in a PROTAC molecule. As a result, PZ703b is highly potent in killing BCL-X L dependent, BCL-2 dependent, and BCL-X L /BCL-2 dual-dependent cells in an E3 ligase (VHL)dependent fashion. We further found that PZ703b forms stable {BCL-2:PROTAC:VCB} ternary complexes in live cells that likely contribute to the enhanced BCL-2 inhibition by PZ703b. With further optimization, analogues of PZ703b could potentially be developed as effective antitumor agents by co-targeting BCL-X L and BCL-2.

Cancer is one of the deadly diseases which is characterized by unchecked cell division or abnormal cell growth due to the incapability of cell cycle arrest. As the treatment for this is to kill the cancerous cells the main challenge for scientists is to direct the cell killing to cancerous cells while leaving the normal cells unharmed. Antibody-drug conjugates (ADC) are one such targeted anti-cancer therapy. It is an effective drug delivery system that utilizes the targeting action of antibody along with cell death by potent cytotoxic agent, linked up with one another by a linker molecule and thus helps to reduce toxicity to non-target cells, ensure broad therapeutic window and overcome multi-drug resistance. Multiple parameters like total antibody (conjugated and unconjugated antibody), conjugated antibody, conjugated drug, unconjugated antibody and unconjugated (free) drug are needed to be analyzed to find out the behavior as well as safety and efficacy of ADCs. With 2 FDA approved drugs (Kadcylca and Adcetris) and more than 40 drugs undergoing clinical trial this field has gained pace in recent years. Some challenges still persist in this field like reducing immunogenic response to antibodies, ensuring the ADC homogeneity and antibody-drug ratio, selection of appropriate targets, successful conjugation of drug to antibody, securing the stability of linkers in systemic circulation as well as improvement of oral bioavailability. With the advent of stable linkers, cytotoxic drugs having higher potency and better conjugation capability with the linker and antibodies having high specificity, these ADCs can overcome the limitations of cancer treatment. This review focuses on the criteria for proper construction of ADC, conjugation techniques, the target choices, the underlying mechanism of action and pharmacokinetic considerations associated with ADC.

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In view of the results, the copper and zinc complexes of indomethacin may be used as better substitutes of the parent indomethacin owing to their minimal side effects with additional pharmacological effects.