There effects. (32) Constant examinations on diverse parts

There are more than 200 chemical compounds
that have been documented and isolated from this plant; the foremost being the alkaloids,
phenols, flavonoids and acetogenins. Based on the in vitro studies, extracts
and phytochemicals of A. muricata
have been sorted out as anti-microbial, anti-inflammatory, anti-protozoan,
antioxidant, insecticide, larvicide, and cytotoxic to tumor cells.
Studies on the extracts and isolated compounds of A. muricata showed contraceptive, antitumor, anti-ulceric, wound
healing, hepato-protective, anxiolytic, anti-stress, anti-inflammatory,
anti-icteric and hypoglycemic activities. Furthermore, there have been clinical
studies carried out in order to boost the hypoglycemic activity of the
ethanolic extracts of A. muricata
leaves. Mechanisms of action of a few pharmacological activities have been
explicated, such as cytotoxic, antioxidant, antimicrobial, anti-nociception and
hypotensive activities. Nonetheless, some phytochemical compounds isolated from
A. muricata have shown a neurotoxic
effect in vitro and in vivo. Thus, these crude extracts and isolated compounds
requires further studies to define the magnitude of the effects, optimal
dosage, long-term safety, and potential side effects. (32)

Constant
examinations on diverse parts of the A. muricata have shown the
occurrence of varieties of phyto constituents and compounds, including flavonol
triglycosides (FTGs) alkaloids (ALKs), phenolics (PLs), megastigmanes (MGs),
cyclopeptides (CPs) and essential oils. The existence of various minerals such
as Ca, Na, Fe, K, Cu and Mg imply that regular intake of the A.
muricata fruit can help furnish essential nutrients to the human
body. However, Annona species, including A.
muricata, have been shown to be a vital source of annonaceous acetogenin
compounds (AGEs). Almost all the parts inclusive of the fruits, leaves, stems and roots of
this plant are known to be rich in flavonoids, isoquinoline alkaloids and
annonaceous acetogenins. (23,25,26,28,35,42)

Acetogenins are a
unique category of C-35/C37 secondary metabolites obtained from long chain
(C-32/C34) fatty acids in the polyketide pathway. They are basically illustrated
by combining fatty acids with  2-propanol
unit at C-2 that gives a methyl-substituted ?, ?-unsaturated ?-lactone.
Starting with the discovery of uvaricin from Uvaria accuminata in
1982,there have been several acetogenins that are identified. About 500 have
been reported from numerous parts of the plants in the Annonaceae family.
Because of the exceptional structures and broad spectrum of biological
activities, AGEs have drawn significant scientific interest of late. The active
annonaceous acetogenins have shown to be successful in inducing death in cancer
cells that are resistant to even chemotherapeutic drugs. Besides their
remarkable anti proliferative efficacy, these annonaceous acetogenins have been
endorsed to debilitating side effects such as neurotoxicity suggesting that
these components can easily traverse the blood–brain barrier and are known to
cause atypical Parkinson’s disease, thus restricting their development as new
drug entities. Various biological activities have been reported for AGEs,
including antimalarial, anti-parasitic and pesticidal activities. However, the
physiological activities of AGEs are initially characterized by the toxicity
against cancer cells and inhibitions of the mitochondrial complex I. (11)

4.    Anticancer activity:

There are plentiful reports
that signify anti-proliferative effects of various extracts of the plant and
isolated AGEs against various cancer cell lines. As mentioned earlier cancer is
categorized based on the primary tissue it occurs in. The antitumor effects of A. muricata against various cancer cell
lines are described here.

Breast Adenocarcinoma:

In the conclusions made by, Constant Anatole Pieme and
others A. muricata exhibited
anti proliferative effects on HL-60 cells by promoting loss of cell viability,
morphology changes, loss of membrane mitochondrial potential and G0/G1 phase
cell arrest. Their reports confirmed the efficacy of A. muricata as
an agent of chemotherapeutic and cytostatic activity in HL-60 cells (7). Studies have revealed
that the extracts have selective inhibition of breast cancer cells via EGFR
downregulation. An oncogene, the epidermal growth factor receptor (EGFR) is
that is often overexpressed in breast cancer (BC), along with its
overexpression has been associated with poor prognosis and drug resistance.
EGFR is therefore a rational target for BC therapy development. In addition,
experiments showed that Graviola fruit extract (GFE) reduces the growth of BC
cells utilizing xenografts mouse model studies. Moreover, GFE selectively
restrained the growth of EGFR-overexpressing human BC (MDA-MB-468) cells but
not in non-tumorigenic human breast epithelial cells (MCF-10A). These studies strengthen the
evidence that Graviola has selective anti-growth effects between cancer and
non-cancer cells (8).

Another report
on breast cancer cells by Yu-Min Koa and
colleagues supported that Graviola endorses apoptosis in ER-related
pathways. Moreover, Graviola subsided MCF-7 tumor growth while hindering
ER-cyclin D1 and Bcl-2 protein expressions in nude mice (44). It has been analyzed that Graviola also seemed
to have anti-proliferative effects of HL-60 cells via loss of cell viability,
loss of MMP, G0/G1 phase cell arrest and morphological apoptotic changes. It
was authenticated and confirmed that Graviola does indeed have
anti-proliferative and cytostatic activity in HL-60 cells by these findings
(7).

 

Lung Cancer:

Treatment
of A549 cells with AMEAE significantly elevated ROS formation, followed by
attenuation of MMP via upregulation of Bax and downregulation of Bcl-2,
accompanied by cytochrome c release to the cytosol. The incubation of A549
cells with superoxide dismutase and catalase significantly attenuated the cytotoxicity
caused by AMEAE, indicating that intracellular ROS plays a pivotal role in cell
death. The released cytochrome c triggered the activation of caspase-9 followed
by caspase-3. In addition, AMEAE-induced apoptosis was accompanied by cell
cycle arrest at G0/G1 phase. Moreover, AMEAE suppressed the induced
translocation of NF-?B from cytoplasm to nucleus. Anonna muricata also had impacts on Lewis lung carcinoma (LLC)
tumor cell lines that were examined both in
vivo as well as in vitro which
was shown in an another study by Zhao GX1
et,.al. This implies that Graviola had antitumor activity by limiting
the natural growth of the lung tumors (45). NADH oxidase inhibition in cancer
cell lines, down regulation of the P-glycoprotein pump via ATP depletion and
Cell cycle arrest at S-phase progression has shown to be affected by Graviola
through its anti-cancerous and cytotoxic mechanisms, which has been shown by
additional research.  

Liver Carcinoma

In the present
study, we researched whether different concentrations of aqueous extract of Annona muricata can activate the
caspases in Huh-7 human liver cancer cells. The activity of both caspase-9 and
caspase-3 were fundamentally lifted when Huh-7 cells were treated with 0.5
mg/ml, 1.0 mg/ml and 1.5 mg/ml of AEAML, suggesting that the plant extract has
induced apoptosis predominantly via mitochondrial-mediated intrinsic pathway.
The western blot analysis of caspases likewise demonstrated that the protein
expression of cleaved caspase-3 and -9 were dose-dependently increased upon
treatment with the AEAML. In the present study, the caspase 3 and caspase 9
expressions were increased significantly in Huh-7 cells treated with graded
increasing doses of the aqueous extract of Annona
muricata. This result suggests the involvement of caspase cascade in
aqueous extract of Annona muricata mediated
apoptosis in Huh-7 cells.

Taking everything into account, results of this
study demonstrate that the extract of Annona
muricata leaves possess good potential for use as cancer chemotherapeutic agent. Furthermore, our data indicate that the
aqueous extract of Annona muricataleaves
specifically reduce viability of hepatocellular carcinoma cell lines possibly
through G0/G1 or S phase arrest or possibly via induction of sub-G0/G1 DNA
fragmentation. Be that as it may, the mechanism of the action is still pending.
Along these lines, further investigation of the molecular mechanism(s) involved
is needed to fully understand the use of Annona
muricata as a chemopreventive food.

Pancreatic Cancer:

In PC
patients, an increased metabolic activity and glucose concentration of
malignant tumors has been linked to pancreatic tumor aggressiveness 47.
Additionally, the presence of hypoxia in PC has been associated with tumor
growth and metastasis 48,49. Indeed, the presence of hypoxic environment has
been linked to the oncogenic and metabolic transformation (i.e. glycolysis) of
PC cells that results in resistance to conventional cancer therapeutics
48,50. More specifically, it has been suggested that hypoxia can induce
resistance to gemcitabine through the activation of PI3K/Akt/NF-jB and MAPK/ERK
pathways 51, which are also related to PC progression and survival. The
activation of both of these signaling pathways was evaluated in PC cells after
treatment with Graviola extract and it was found that the extract suppressed
phosphorylation of the key molecules involved in these pathways, which
correlated with reduced viability of PC cells. Subsequently, the expression of
HIF-1a, the major transcription factor activated under hypoxic conditions, and
its ensuing downstream effects on PC cell metabolism were analyzed in Graviola
extract treated cells. The results indicated the natural product inhibited PC
cell metabolism by inhibiting the expression of HIF-1a, NF-jB, glucose
transporters (i.e. GLUT1, GLUT4), and glycolytic enzymes (i.e. HKII, LDHA), all
of which lead to the reduction of glucose uptake and ATP production by PC
cells. The overall downregulation of PC cell metabolism induced by Graviola
extract resulted in PC cell death and necrosis. In agreement with previous
studies of ATP reduction, the metabolic and therapeutic stress induced by
Graviola extract led to an acute ATP depletion, which is accompanied by increased
intracellular ROS, ultimately leading to necrosis 52–54. While necrotic
agents have not been considered beneficial in cancer therapies due to induction
of local inflammation, the process itself can lead to the activation of the
innate immune system capable of initiating anti-tumor immunity 52. It makes
it imperative to evaluate the effect of a necrosis-inducing product such as
Graviola extract in an immune competent host. In this regard, we plan to
evaluate the effect of the natural product on the progression of pancreatic
adenocarcinoma in the KrasG12DPdx1- Cre spontaneous animal model, where the
effect on the immune system can be evaluated 55,56. In order to evaluate the
potential of Graviola extract in preventing PC progression, we plan to supplement
the diet of KrasG12DPdx1-Cre mice with Graviola extract after the mice start
developing pancreatic intraepithelial neoplastic (PanIN) lesions. The effective
concentrations of Graviola metabolites after oral absorption and effects on the
immune system will be measured as well. Additional experiments will be carried
out to evaluate the potential of a combination therapy of Graviola extract with
the standard chemotherapeutic drug Gemcitabine. With the results discussed in
the present study, it is expected that minimum doses of the chemotherapeutic
drug will be needed to eradicate the malignant disease. The major bioactive
compounds identified in A. Muricata have been classified as Annonaceous
acetogenins, which inhibit mitochondrial complex I that leads to a decreased
ATP production 13–17. Although the natural extract capsules used in these
studies contained numerous compounds, the presence of Annonaceous acetogenins
was evident by the depletion of ATP production in PC cells after being
incubated with Graviola extract. Bioactivityguided fractionation for the
identification of potent bioactive (i.e. anti-tumorigenic) compounds that are
present in the Graviola extract is currently being investigated. We are also
ensuring that cytotoxic effects are specific to tumorigenic cells only, by
including the non-transformed immortalized pancreatic epithelial cell line
HPNE, which is derived from pancreatic duct (data not shown). Pancreatic tumors
develop from a complex interplay of numerous signaling pathways and Graviola
extract has shown promising anti-tumorigenic characteristics by targeting some
of these pathways all at once. Although novel glycolytic inhibitors, such as
Graviola extract, may have broad therapeutic applications 57, inhibition of
glycolysis alone may not be sufficient to eradicate tumor cells completely.
Perhaps the use of alternative medicine, like taking Graviola capsules on a
regular basis, should still be considered a supplement, not a replacement for
standard therapies.

Prostate Cancer

The activity of the water extract of leaves
of A. muricata against the benign prostatic hyperplasia
(BPH-1) cell line and rats prostates was examined where the the
anti-proliferative effects with an IC50 of 1.36 mg/mL was indicated. Bax gene
was up regulated, while Bcl-2 was suppressed. Normal histology of all the other
testes was observed. Seminal vesicle was significantly reduced in test groups
(P < .05) and showed marked atrophy with increased cellularity and the acinii, empty of secretion. Prostate of test groups were abridged with epithelial lining showing condensation, pyknotic nucleus and marginalization of the nuclear material as the characteristic of apoptosis of the glandular epithelium. Furthermore, inadequate prostatic secretion with flattening of acinar epithelial lining was observed. Thus was concluded that Annona muricata has anti-proliferative effects on BPH-1 cells and deduces the prostate size, possibly through apoptosis (5). This promising antitumor effect was also reported in an in vivo study on 7,12-dimethylbenzene anthracene (DMBA)-induced cell proliferation in the breast tissues of mice. Oral administration of the A. muricata leaves probably have protective effects towards the development of breast carcinogenesis was shown by DMBA as it induced a protective effect against DNA damage. The leaves, even at a low dosage of 30 mg/kg suppressed the initiation and promotion stage of skin papillomagenesis in mice that was induced by DMBA and croton oil, respectively (27). In xenografts studies, the oral administration of 100mg/kg bw GLE show tumor growth-inhibition in human prostate tumor. This study also validates the synergy amongst the components of Graviola leaf extract (GLE) equated to its acetogenin-enriched (AEF) fractions and flavonoid-enriched (FEF) (22). The effect of Graviola extract against the prostate cancer cell lines has also been expounded in vitro. The experiments performed to show that Graviola initiates necrosis in PC-3 cells through inhibition of cellular metabolism and tumor mobility. Further evaluation depicted the downregulation of the expression of the hypoxia-related factors and glycolytic factors following treatment in PC cells with Graviola (41) Colon Cancer: In a study performed by Jaramillo MC et al., the mechanism of action of ethyl acetate extract of A. muricata leaves against colon cancer cells (HT-29 and HCT-116) and lung cancer cells (A549) has been illustrated. The leaf extract was proficient to induce apoptosis in colon and lung cancer cells through the mitochondrial-mediated pathway. This anti-proliferative effect was alongside with cell cycle arrest in the G1 phase.(20) However, the migration and invasion of colon cancer cells were profoundly inhibited by the leaf extract. The in vivo chemo preventive potential of the ethyl acetate extract of the A. muricata leaves against azoxymethane-induced colonic aberrant crypt foci (ACF) in rats was examined by Moghadamtousi and colleages. There was a significant reduction in ACF formation in rats because of the oral administration of the extract at two doses (250 and 500 mg/kg) for 60 days, as gaged by methylene blue staining of colorectal specimens. The down-regulation of PCNA and Bcl-2 proteins and the up-regulation of Bax protein after the administration of EEAML compared with the cancer control group was depicted in the Immunohistochemistry analysis. In addition, an increase in the levels of enzymatic antioxidants and a reduction in the malondialdehyde level of the colon tissue homogenates were found, suggesting the suppression of lipid peroxidation. The growth of HT-29 cells with an IC50 value of 1.62 ± 0.24 ?g/ml after 48 h was inhibited by Annomuricin E. The cytotoxic effect of annomuricin E was supplementarily substantiated by G1 cell cycle arrest and early apoptosis induction in HT-29 cells. Annomuricin E activated mitochondria-initiated events, comprising the dissipation of the mitochondrial membrane potential and caused the leakage of cytochrome c from the mitochondria. Preceding these events, annomuricin E activated caspase 3/7 and caspase 9. Further annomuricin E, induced a time-dependent upregulation of Bax and downregulation of Bcl-2 at the mRNA and protein levels. Thus, these findings verify the usage of A. muricata leaves in ethnomedicine against cancer and emphasize annomuricin E as one of the contributing compounds in the anticancer activity of A. muricata leaves. Furthermore, Moghadamtousi and colleagues examined that ethyl acetate extract of Annona muricata leaves (EEAM) exerted a striking cytotoxic effects on HCT-116 and HT-29 cells as determined by MTT and LDH assays. After 24 h of treatment, EEAM showed the IC50 value against HT-29 and HCT-116 cells. Flow cytometric analysis illucidated the cell cycle arrest at G1 phase and also the externalization of phosphatidylserine acting as an indicator of the induction of apoptosis. EEAM treatment activated excessive accumulation of ROS followed by disruption of MMP, cytochrome c leakage and activation of the initiator and executioner caspases in both colon cancer cells. Immunofluorescence analysis portrayed the up-regulation of Bax and down-regulation of Bcl-2 proteins while treated with EEAM. Furthermore, EEAM conspicuously blocked the migration and invasion of HT-29 and HCT-116 cells (29,31). In colon cancer cells, Graviola leaves also have significant effects on cell survival potential via mitochondrial-mediated apoptosis associated with the G1 cell cycle arrest. Graviola elicits apoptosis by generating reactive oxygen species ROS and down-regulating the anti-apoptotic Bcl-2 protein, while up-regulating pro-apoptotic Bax protein. These processes subsequently steer to attenuation of mitochondrial membrane potential (MMP) and cytochrome c release. Release of cytochrome c activates apotosome and the intrinsic caspase cascade that triggers execution of apoptosis through DNA fragmentation. (30). Further studies by Yang C et, .al have shown that the Graviola leaf extract (GLE) pharmacokinetics and absorption kinetics resulting in inhibiting prostate cancer proliferation, viability and clonogenic colonies (43). Ovarian Cancer: Apart from its various medicinal properties, acetogenins in Annona muricata showed potent anti-ovarian cancer activity which selectively attack cancerous cells without harming healthy cells and preventing metastasis. Apoptosis of granulosa cells of the ovary has been initiated by this acetogenin in many organs of cancerous cells of humans. The plant had proved to be an effective anti-tumor and anti-cancer medicinal plant, and thus represents a source for new antiovarian cancer drug discovery. In vitro cytotoxicity tests were performed using MTT assay as described by Xu-jie and Chu 11. Briefly, ovarian cell line ( 5 × 104 ) was seeded in 24-wells plates (Costar, USA) and grown in RPMI1640, supplemented with 6 mM L-glutamine, 10% foetal bovine serum (FBS) (Gibco, Invitrogen, UK) and penicillin (100 units/mL) and streptomycin (100 ?g/mL), while normal fibroblasts were grown in Dulbecco's modified Eagle medium (DMEM), also supplemented with L-glutamine and FBS. Cultures were maintained in a humidified atmosphere of 5% CO2 at 37 °C. Cell cultures, in triplicates, in exponential growth were treated with the different dried fractions of the plant extract, redissolved in di-methyl sulfoxide (DMSO) and added at final concentrations of 1, 10 and 100 ?g/mL. The control cultures had 0.02% (1 ?g/mL) 0.2% (10 ?g/ mL) and 2% (100 ?g/mL) DMSO added to the medium. In 2 mL medium/well 10% MTT was added and 100 ?L of the supernatants of the 24- well plates after 24, 48 and 72 h incubations were pipetted into 96-well plates. Cell viability was measured with a 96-well plate reader. In a later stage, after identifying fractions with high cytotoxic effects, the final concentrations of extracts tested ranged from 6.25-200 ?g/mL, with final concentrations of 0.02 up to 0.2% DMSO. 2.6.2. In vivo Pilot Experiment An in vivo pilot experiment was performed with thirty Swiss albino mice consisting of all females (average weights 18-25g). In order to mimic advanced ovarian cancer, the mice were injected intraperitoneally (i.p.) with 1 x 104 OV7-96020764-CDNA-(20uL) cell line into the abdominal cavity to form ascites. Five groups of mice were examined: four control mice (no treatment), twelve mice treated with crude and pure compound from A. muricata leaf and four mice treated with doxorubicin (10 mg) after ascites had formed. Cells of ascites of two mice were frozen and stored for future experiments. To study the reduction of swollen abdomen, 5 mg/kg doxorubicin (Rubex) and the isolated compound at a final concentration of 20 mg/kg were administered i.p. Leukemia: the efficacy of ethanolic extracts of Annona muricata leaves for its cytotoxicity potential and induction of apoptosis in K562 cancer cells, was investigated. Caspase-3 activity was significantly enhanced (P<0.001) during apoptosis induced by the extract at low quantities, with the peak activity shown at 50 µg/ml. Apoptosis was confirmed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) assay. Caspase-3 activity and TUNEL results suggested that the ethanolic extract of Annona muricata induced apoptosis in the myelogenous leukemic K562 cell line. This supports the therapeutic application of Annona muricata to be considered as a natural product source for the development of pro-apoptotic drugs.>
during apoptosis induced by the extract at low quantities, with the peak
activity shown at 50 µg/ml. Apoptosis was confirmed by terminal
deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) assay.
Caspase-3 activity and TUNEL results suggested that the ethanolic extract of
Annona muricata induced apoptosis in the myelogenous leukemic K562 cell line.
This supports the therapeutic application of Annona muricata to be considered
as a natural product source for the development of pro-apoptotic drugs

Cervical Cancer:

Our
result demonstrated that polyketide derivatives from Annona muricata L. have
growth inhibitory and cytotoxic effect on cervical cancer cell line. Polyketide
derivatives from Annona muricata L. leaves performed potent cytotoxic effect on
Hela cells with IC50 value of 77,09 µg/ml. Decreasing cell viability may be
because of either cell death or cell cycle arrest. The mechanism of cell cycle
distribution is also associated with some of celuller protein especially p53
protein. p53 is a tumor suppresor protein. In this study, we observed that
polyketide derivative from Annona muricata L. treatment increased p53 level in
nucleus. Therefore, poliketide isolation may be amandable as viral inhibitor
agent and as competitor of vaccine to prevent the development of cervical
cancer. However, this speculation still needs further investigation by in
silico study. In conclusion, polyketide derivatives from Annona muricata L.
leaves indicate has potential to be developed as a co-chemotherapeutic agent on
Hela cell lines, it can exhibit potential abbility with p53 stabilization.
Further molecular target detection to investigate its cellular pathway needs to
be conducted.

Related Posts

© All Right Reserved