Triphala is novel dietary or natural chemopreventive
formulation. Triphala has been used for centuries in
Ayurvedic medicine to treat various types of
gastrointestinal-related disorders; however, the molecular
mechanisms of triphala have not been studied yet. In the
present studies, it has demonstrated that aqueous extract of
triphala is effective in inhibiting the growth of pancreatic
cancer cells in culture as well as in the In vivo model. The
results reveal that Triphala treatment drastically reduces the
survival of Capan-2 and BxPC-3 human pancreatic cancer
cells in a dose- dependent manner. On the other hand,
Triphala failed to cause any cytotoxic effects on the growth
of HPDE-6 near normal pancreatic epithelial cells.
Suppression of pancreatic cancer cell growth by Triphala in
studied model was due to induction of apoptosis, which in.
turn was associated with generation of ROS. Pretreatment of
Capan-2 cells with antioxidant NAC blocked ROS
generation and completely protected the cells from Triphalainduced
apoptosis. The results also demonstrate that
Triphala treatment caused DNA damage resulting in the
activation of ATM and ERK leading to stabilization.
Blocking ERK activation by MEK-1/2 inhibitor U0126 or
p53 activation by pifithrin-a completely protected Capan-2
(wild type p53) cells from Triphala-induced apoptosis.
Similarly, U0126 treatment blocked Triphala-induced
apoptosis in BxPC-3 (mutated p53) cells, suggesting ERK as
a molecular target of Triphala in pancreatic cancer cells.
Further, orally feeding 50 mg/kg or 100 mg/kg Triphala to
nude mice significantly retarded the growth of Capan-2
pancreatic tumor xenograft. Tumors from Triphala treated
mice demonstrated increased apoptosis in the tumor cells,
which was due to the activation of ERK and p53. To the best
of our knowledge, this is the first study to report the
molecular mechanism of the chemotherapeutic effects of
Triphala against pancreatic cancer.
Reactive oxygen species (ROS) are the known mediators of
intracellular signaling cascades. Excessive production of
ROS nonetheless leads to oxidative stress, loss of cell
function and apoptosis or necrosis 14-17. Our results reveal
that Triphala-induced apoptosis in pancreatic cancer cells is
initiated by ROS generation, the effect of which can be
blocked by antioxidant NAC. Several previous studies
including those from our laboratory have implicated ROS as
a possible mechanism for DNA damage and induction of
apoptosis [15, 17, 18]. DNA damage plays a critical role in
maintaining genomic integrity. Tumor cells exhibit genetic
instability causing functional inactivation of p53 that plays
an important role in DNA damage checkpoint pathways. In
response to DNA damage, p53 is stabilized through
phosphorylation at Ser 15 by ATM 19-21. The effects of
Triphala are compatible with this assertion. The results do
indicate that Triphala treatment causes DNA damage as
depicted by increased phosphorylation of H2A.X at Ser 139,
an indicator for the presence of DNA double-strand breaks.
Pancreatic tumor growth inhibition and induction of
apoptosis In vivo was observed by the oral administration of
50 mg/kg or 100 mg/kg Triphala 5 times a week the results
were consistent with previous studies where Triphala was
shown to be effective in suppressing the growth of Barc- 95
(mouse thymic lymphoma) xenograft in mice22. Although,
pharmacokinetics of Triphala in humans has not been
determined, it has been used safely for centuries in the
Ayurvedic medicinal system in India for the treatment of
various gastrointestinal-related disorders. The effective dose
of Triphala in our animal model for suppressing tumor
growth, if extrapolated to humans ranges from 4 to 8 grams
per day for a person weighing 70 kg. These doses of Triphala
come within the dose range already being used by humans in
countries such as India.
Triphala churna is a powdered preparation of three
myrobalan fruits, Emblica officinalis (Amla), Terminalia
chebula (Haritaki) and Terminalia belerica (Bibhitaki) in
equal proportions. This fruit formulation has been
extensively used in the traditional Indian system of
medicine, Ayurveda for the treatment of several disorders of
the gastrointestinal and cardiovascular systems [23-26]. In
addition, THL is also consumed by the people of Indian
subcontinent for its high nutritional value [26]. Recently, it
has been demonstrated that THL can inhibit the growth of
carcinogen induced stomach cancer, murine thymic
lymphoma and human pancreatic cancer in mice. However,
there is no mention in these reports regarding the effects of
THL on tumor angiogenesis [25-28].
High performance liquid chromatography (HPLC) has
revealed gallic acid (GA), ellagic acid (EA) and chebulinic
acid (CI) to be the major constituents of THL [24, 26]. The
plasma levels of GA and EA after oral intake of fruits
containing these two compounds, and thereby their
bioavailability has been reported to be poor 29. As THL has
been shown to inhibit malignant tumor growth in animals25-
28, therefore there is a possibility that other bioactive
compounds present in THL mediate its anti-tumor effects in
these animals.
The cytotoxic effects of aqueous extract of Triphala, an
ayurvedic formulation, were investigated on human breast
cancer cell line (MCF-7) and a transplantable mouse thymic
lymphoma (barcl-95). The viability of treated cells was
found to decrease with the increasing concentrations of
Triphala. On the other hand, treatment of normal breast
epithelial cells, MCF-10 F, human peripheral blood
mononuclear cells, mouse liver and spleen cells, with similar
concentrations of Triphala did not affect their cytotoxicity
significantly. The drug treatment was found to induce
apoptosis in MCF-7 and barcl-95 cells in vitro as determined
by annexin-V fluorescence and proportion of apoptotic cells
was found dependent on Triphala concentration. MCF-7
cells treated with Triphala when subjected to single cell gel
electrophoresis, revealed a pattern of DNA damage,
characteristic of apoptosis. Studies on Triphala treated MCF-
7 and barcl-95 cells showed significant increase in
intracellular reactive oxygen species (ROS) in a
concentration dependent manner. ROS increase was,
however, found to be insignificant in MCF-10 F as well as in
murine spleen and liver normal cells. In vivo, direct oral
feeding of Triphala to mice (40 mg/kg body weight)
transplanted with barcl-95 produced significant reduction in
tumor growth as evaluated by tumor volume measurement. It
was also found that apoptosis was significantly higher in the
excised tumor tissue of Triphala fed mice as compared to the
control, suggesting the involvement of apoptosis in tumor
growth reduction. These results suggest that Triphala
possessed ability to induce cytotoxicity in tumor cells but
spared the normal cells. The differential effect of Triphala on
normal and tumor cells seems to be related to its ability to
evoke differential response in intracellular ROS generation.
The differential response of normal and tumor cells to
Triphala in vitro and the substantial regression of
transplanted tumor in mice fed with Triphala points to its
potential use as an anticancer drug for clinical treatment [3].
The presence of elemental contents is suggests that triphala
as a whole is rich in Mg, K, Ca, Fe, and Zn, though Se
(Selenium) is also present in significant amounts. There
appears to be an association between Se deficiency and
protein malnutrition disease, multiple sclerosis, cancer and
heart disease. It has been suggested that Se (Selenium) as
glutathione peroxidase inhibits the replication of tumour
viruses and prevents the malignant transformation of cells
30. The triphala and its three constituents have shown V
content in the range 1-2 μg/g, which has been suggested to
play vital role in the treatment of cancer and diabetes [31].
In the recent past, there has been growing interest in
exploiting the biological activities of different ayurvedic
medicinal herbs, owing to their natural origin, cost
effectiveness and lesser side effects [32, 33]. Triphala is one of
the ayurvedic medicinal herbal formulations prescribed by
most health care practitioners. It is used as colon tonic,
laxative, eye rejuvenator, anti-inflammatory, anti-viral etc.
Triphala is gentle for people of all ages, from children to
seniors and hence is recommended for everybody [34].
Triphala has been tested as an antioxidant and also as a
radioprotector in mice [25, 35]. In the recent study, it is tested
the in vitro antioxidant activity under y-radiation induced
conditions. In order to understand the factors responsible for
the antioxidant and radio protection activity, free radical
reactions and phytochemical analysis of triphala were carried
out.