Page 23 - Drug Discovery and Development: Prospects and Challenges

Drug Discovery and Development: Prospects and Challenges / 13

Brothers and sisters,
Ladies and Gentlemen,

In Vitro and In Vivo Studies

In the initial step of drug discovery, all potential lead compounds
undergo in vitro pharmacology testing. Various preliminary testing
is available, including chemical reactions, enzymes reaction, and
cell/ microbial culture tests. In vitro studies using chemical reactions,
such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis-(3-
ethylbenzothiazoline-6-sulfonate (ABTS), and lipid peroxidation are
normally used for the antioxidant assay. In addition, enzyme assays,
such as a-glucosidase and a-amylase assays, are conducted for anti-
diabetic testing.
The cell line experiment is an important step to analyse in vitro
pharmacology activity, which explains the mechanism of action of
the drug in detail, including protein and gene expression, as well as
a cytotoxic activity but it cannot fully replace animal testing in the
drug development process. This is because in vitro studies lack certain
information regarding substance safety, toxicity, pharmacokinetics, and
metabolic pathway.
There is a wide range of cells that are available for bioassay testing,
such as the RAW 264.7 cell lines for anti-inflammatory assay. In this
study, the murine RAW 264.7 cells were induced with pro-inflammatory
Lipopolysaccharide (LPS). LPS plays an important role in inducing the
inflammatory, which leads to various inflammatory diseases, and it is a
compound of the cellular wall of Gram-negative bacteria (Takeuchi &
Akira, 2010). The formation of nitric oxide (NO) produced by the cells
was determined using the Griess reagent. It was postulated that excessive
production of NO plays a critical role in the pathogenesis of inflammation
(Bahiense et al., 2017). This method showed a clear response of RAW
264.7 macrophages towards the inflammatory agent by producing NO,
which will be inhibited by an anti-inflammatory agent. The following
sections describe our previous and on-going research studies on drug
discovery and development, which involves anti-cancer/cytotoxicity,
anti-hyperglycemic, anti-obesity, and wound healing.