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Genomics and Applied Biology
, 2012, Vol.3 No.2 8-21
http://gab.sophiapublisher.com
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important physiological role in the regulation of
enzymes. There are many examples of pathological
conditions in which uncontrolled proteolytic activity
of host enzymes leads to irreversible tissue destruction
(e.g., in inflammatory processes, including rheumatoid
arthritis and periodontitis), or to tumor growth and
metastasis. In addition to host proteinases, exogenous
proteinases from infectious agents such as bacteria,
viruses or protozoa play a role in the onset and
perpetuation of infection, suggesting the potentially
therapeutic application for proteinase inhibitors in
combating diseases.Therapeutic possibilities of plant
PIs in the treatment of a wide range of disorders, such
as pancreatitis, shock, allergy and inflammation
associated with enhanced proteolytic activities had
resulted in several kallikrein trypsin inhibitor-based
drugs (Richardson, 1977; Park and Ohba, 2004).
Epidemiological studies indicate decreased occurrence
of breast, colon, and prostates cancers in vegetarian
populations suggested the role of plant PIs in
preventing these cancers (Birk, 1993), which has
eventually led to extensive studies of plant PIs as
cancer chemo preventive agents (Troll and Kennedy,
1993). Plant PIs are found active in regulating human
physiological processes, e.g. cell signaling/migration,
digestion, fertilization, growth, differentiation,
immunological defense, wound healing and apoptosis,
have great potential in therapeutic applications
(Abdel-Meguid et al., 2000; Leung et al., 2000).
Purified homodimeric trypsin inhibitor of 54kD from
Clausena lansium
seed inhibited trypsin with no
inhibitory activity on chymotrypsin and proteinase K.
However,
Clausena lansium
trypsin inhibitor inhibited
the uptake of MTT by human leukemia HL60 and
hepatoma Hep G2 cells. The activity of HIV-1 reverse
transcriptase was reduced in the presence of the
inhibitor (Ng et al., 2003).Two molecular species of
oryzacystatin (OC), OC-I and OC-II were investigated
to haveantiviral action against herpes simplex virus
type 1 (HSV-1)
in vitro
and
in vivo
. In the mouse
modelwith
HSV-1-induced
keratitis
and
encephalopathy, topical administration of OC-I to
cornea produced a significant decrease in
virusproduction and improvementin survival rates
(Aoki et al., 1995). Kunitz trypsin inhibitors act on
platelet aggregation, blood coagulation, fibrinolysis
and inflammation. Due to its ability to block enzymes,
plant Kunitz inhibitors are useful as tools in the study
of biochemical processes of these phenomenon
(Sampaio et al., 1996, Souza-Pinto et al., 1995).
Serine proteinase inhibitor isolated from
Leucaena
leucocephala
seeds has shown to inhibit plasmin,
human plasma kallikrein, trypsin, chymotrypsin and
Factor XIIa but not factor Xa (Oliva et al., 2000).
Soybean derived KTI inhibits LPS-induced
up-regulation of cytokine expression possibly through
suppression of ERK1/2 and p38 kinase-mediated
NFkappaB activation. These findings may identify
anti-inflammatory properties of KTI at the level of
gingival fibroblasts and suggest the use of KTI in
modulating inflammation, including periodontal
disease (Kobayashi et al., 2005).The Bowman-Birk
trypsin-chymotrypsin inhibitor from soybean has been
described as a potential chemopreventive agent of
cancer. Effects of inhibitor were compared with two
variants of pea seed protease inhibitors, rTI1B and
rTI2B homologous to BBI but differing in inhibitory
activity, on the growth of human colorectal
adenocarcinoma HT29 cells. Significant and
dose-dependent decrease in the growth of HT29 cells
was observed using these proteinase inhibitors
(Clemente et al., 2005).Squash family inhibitors are
the smallest protein serine protease inhibitors,
composed of 30 amino acid residues. Squash family
inhibitors (from the seeds of bitter gourd, squash,
gourd and luffa) were examined on serine proteases
associated with blood coagulation. Five of them
prolonged the activated thromboplastin time of human
plasma. All inhibitors inhibited the amidolytic
activities of factor XIIa, plasma kallikrein, factor Xa,
but not to the same extent with factor XIa, IXa, VIIa
and thrombin. The extension of activated partial
thromboplastin time by inhibitors appeared to
correspond to their inhibitory potencies for factor XIIa
(Hayashi et al., 1994). Siritapetawee and Thammasirirak
(2011) investigated biological effect of
Artocarpus
heterophyllus
(jackfruit) latex on human blood
coagulation. They demonstrated the serine protease
inhibitory property of a heteromultimeric glycoprotein
(HSGPL1) purified from jackfruit latex. This protein
affects the intrinsic factors of human blood coagulation
by prolonging the activated partial thrombin time (APTT)
and inhibiting blood coagulation factors XIa and α-XIIa.
In addition, this protein was provisionally identified as a