Violacein
The violet pigment violacein is an indole derivative isolated primarily
from bacteria of the genus Chromobacterium , which live in
tropical and subtropical soil and water (Soliev et al., 2011). Bacteria
which are found in a variety of natural environments, including marine,
freshwater, and soil environments, could be able to produce violacein
pigment. This bisindole is a secondary metabolite associated with
biofilm production in the majority of violacein-producing bacterial
strains isolated from nature. Violacein synthesis by C. violaceumhas been shown to be a useful indicator of quorum-sensing molecules and
their inhibitors, and it is easy to monitor. The secondary metabolite
violacein acts as a toxic sentinel, protecting against a variety of
potential bacterial predators and competitors (Choi et al., 2015).Janthinobacterium lividum and Chromobacterium violaceumhad antipredator activity against bacterivorous nanoflagellates,
indicating a protective function (Chatragadda & Dufossé, 2021).Pseudoalteromonas luteoviolacea is the sole marine bacterium
producing violet pigment. Shewanella violacea , a deep-sea
microorganism isolated from Ryukyu Trench sediments at a depth of 5110
m, also produced a violet pigment that was recently demonstrated to be a
new alkylated indigoidine. The bacteria were isolated from seawater at
Cape Muroto in Kochi Prefecture, Japan. Among the bacteria isolated, 13
strains of gram negative, rod-shaped bacteria produced a purple pigment
similar to violacein (Yada et al., 2008).
Furthermore, violacein is extremely important in cosmetics, textiles,
agriculture, and drug discovery. In the pharmaceutical industry,
violacein has been used as an immunosuppressive, antinociceptive,
analgesic, and antipyretic. According to animal studies, violacein
pigment has been applied in ulcer rat models; it decreased
gastrointestinal inflammation, perhaps through COX-1-mediated
mechanisms. On the other hand, when violacein was injected directly into
the intra-peritoneal cavity, it was discovered to have immune modulatory
effects through controlling cytokine production; it let down the
expression of IL-6 and TNF but increased the expression of IL-1.
Non-specific toxicity is normally a drawback of chemotherapeutics, but
violacein has been shown to induce apoptosis and have anti-tumor
activity against unrepeatable particular tumour lamina lines, such as
cancer lamina lines. Violacein seems to have antibiotic potential
because of its strong antibacterial properties. Additionally, when
combined with other antibiotics, the impact is more successful at
killing bacteria than using antibiotics alone (Choi et al., 2015).
Anti-protozoan, anti-cancer, anti-viral, antibacterial (both G+ and G-),
and antioxidant properties have been discovered. Staphylococcus
aureus, Neisseria meningitidis, Streptococcus sp., Bacillussp, Mycobacterium and Pseudomonas , among others is all
inhibited by the antibacterial action. Based on these characteristics,
violacein appears to be commercially viable for medicinal applications,
and it has even been proposed for use in dermatology. Due to its
toxicity in VERO and FRhK-4 cells, it has been claimed that violacein
should be considered an in vitro genotoxic chemical to mammalian cells,
although more research is needed before making any conclusions on
violacein’s future therapeutic potential (Hakvåg et al., 2009).