Final Exam Flashcards
(225 cards)
1
Q
How many cancer drugs are natural products or synthetic analogs of the natural products?
A
More than 60%.
2
Q
What was the first step that the National Cancer Institute in the US performed regarding anticancer natural products?
A
Collect different plant materials, extract the biomass with methanol/dichloromethane (1:1), and then with water to give organic and aqueous extracts.
3
Q
What was the second step that the National Cancer Institute in the US performed regarding anticancer natural products?
A
Assigned a number to each extract and then proceeded to screen for anti-cancer activity in cell culture models.
4
Q
What was the third step that the National Cancer Institute in the US performed regarding anticancer natural products?
A
Bioassay guided purification of compounds that have anticancer activity. Compounds were further tested in animal models for their anticancer efficacy and dose tolerance.
5
Q
What was the final step that the National Cancer Institute in the US performed regarding anticancer natural products?
A
Further modification and chemical synthetic procedures were applied to produce better derivatives that could be more bioavailable and less toxic.
6
Q
What does taxol target?
A
Tubulin
7
Q
How does taxol target tubulin?
A
Inhibits the depolarization of tubulin. This stabilizes the tube, so chromosomes cannot separate and thus cell division cannot occur.
8
Q
What was taxol derived from?
A
From the bark of the Pacific yew tree.
9
Q
What cancers is taxol used for?
A
Treatment of breast, lung, and ovarian cancer, as well as Kaposi’s sarcoma.
10
Q
When was it discovered that the bark extract that taxol was derived from had cytotoxic activity? By who?
A
In 1964, by Dr. Wall and Dr. Wani.
11
Q
What confirmed the initial anticancer activity of taxol?
A
Mouse melanoma model and animal models against MX-1 mammary, LX-1 lung, and CX-1 colon tumors.
12
Q
What did Dr. Horwitz find about taxol cytotoxicity?
A
Found the mechanism of action the natural compound as she was able to demonstrate that taxol was able to bind to a cell’s microtubule assembly and inhibited cell division by stabilizing microtubules, preventing shrinkage, and thus blocking the segregation of chromosomes.
13
Q
What was the challenge with the production of taxol?
A
Isolation of taxol from the pacific yew bark was difficult and synthesizing the compound was complex.
14
Q
What did the slow isolation of taxol do to clinical trials?
A
Clinical development was slow.
15
Q
How did clinical trials become possible for taxol?
A
When they extracted a precursor of taxol from the common yew taxus baccata, which was then converted by chemical synthesis to Taxol.
16
Q
What was the precursor for Taxol?
A
10-deacetyl-baccatin lll
17
Q
What was the challenge with the solubilization and delivery of taxol?
A
It was difficult to formulate Taxol into a delivery system acceptable for human use.
18
Q
What was taxol soluble in?
A
It was soluble in 75% polyethylene glycol.
19
Q
What was the issue with the solution of taxol in polyethylene glycol?
A
When the formula was used against B16 andP388 tumors, it produced poor results.
20
Q
How was the solubilization of taxol fixed?
A
The drug was formulated in an ethanol, cremophor, and saline solution to a concentration of 0.3 to 0.6 mg/mL.
21
Q
Where were preclinical toxic effects of taxol observed?
A
Mostly in tissues with a high cell turnover, such as hematopoietic, lymphatic, gastrointestinal, and reproductive tissues.
22
Q
What was the promising treatment finding of taxol?
A
Researchers at John Hopkins reported a promising clinical finding that the Taxol treatment resulted in partial or complete responses in 30% of patients with advanced ovarian cancer.
23
Q
When was taxol approved for cancer treatment?
A
December 1992
24
Q
When was taxol approved for breast cancer treatment?
A
1994
25
What is the best-selling cancer drug ever manufactured?
Taxol
26
What plant does vincristine and vinblastine come from?
The Madagascar periwinkle
27
How was the periwinkle plant discovered for medicinal use?
Native people used the plant extract to help in the treatment of diabetes as well as treating long-term flu-like symptoms in children (helped in treating Hodgkin's lymphoma).
28
What did the initial screening of the periwinkle plant reveal?
The extract inhibited the growth of certain types of cancer cells.
29
How were the two compounds of the periwinkle plant discovered?
Via a bioassay-guided isolation.
30
What is the periwinkle plant a source for?
Over 150 active alkaloids.
31
How do alkaloids make up the periwinkle plant?
In an extremely low amount (0.0002%).
32
What was the first plant extract approved for medicinal use?
Vincristine and vinblastine.
33
When was vincristine and vinblastine approved for medicinal use?
July 1963
34
What were vincristine and vinblastine initially approved as?
Oncovin
35
Why was vincristine and vinblastine approved quickly for medicinal use?
It was shown to be well-tolerated in children ALREADY (native use) and therefore, companies put money into it to get it approved/further trials.
36
What is vincristine and vinblastine used for?
Treatment of non-Hodgkin's lymphoma as part of the chemotherapy regimen CHOP, Hodgkin's lymphoma as well as a chemotherapy regimen in acute lymphoblastic leukemia (ALL) and nephroblastoma.
37
What are the side effects of vincristine and vinblastine?
Chemotherapy-induced peripheral neuropathy, low sodium in blood causing headache, constipation, and hair loss.
38
What are symptoms of peripheral neuropathy?
Progressive and enduring tingling numbness, pain and hypersensitivity to cold starting in the hands and feet (could move to arms and legs).
39
What do vincristine and vinblastine target?
Target tubulin dimers in fast dividing cancer cells.
40
What is the mechanism of action for vincristine and vinblastine?
Destabilizes the tube by inhibiting tubulin polymerization, which forces the cells to undergo apoptosis.
41
What is the downside of the mechanism of action for vincristine and vinblastine?
It also targets healthy proliferating cells too.
42
Where is camptothecin (CPT) isolated from?
The wood and bark of the happy (or cancer) tree native of southern China and Tibet.
43
What culture was CPT used in?
Treating cancer in TCM.
44
What are the derivatives of CPT?
Topotecan and irinotecan (CPT-11).
45
What are the derivatives of CPT used for?
Metastatic colon cancer.
46
What is the mechanism of action of CPT?
Binds to topo I and DNA complex, resulting in a stabilized ternary complex. This prevents DNA re-ligation and therefore causes DNA damage = apoptosis.
47
What are the side effects of CPT?
Diarrhea, nausea, vomiting, weakness, and low WBC/RBC counts.
48
What plant was effective in treating warts?
Rhizomes of Podophyllon peltatum (mayapple).
49
What extract was used for mayapple?
Ethanolic extract
50
What exhibited anti-cancer activity in mayapple?
Lignan glycosides.
51
What extract of mayapple obtained the anti-cancer derivatives?
Benzaldehyde
52
What compounds of mayapple were marked as anticancer drugs?
Etoposide (VP-16) and teniposide (VM-26).
53
When were etoposide (VP-16) and teniposide (VM-26) approved?
1983
54
What is etoposide (VP-16) and teniposide (VM-26) used for?
Treatment of lung cancer, lymphoma, glioblastoma.
55
What is the mechanism of action for etoposide (VP-16) and teniposide (VM-26)?
Topisomerase inhibitors binding to complex I and DNA that leads to DNA damage and apoptosis.
56
What are tetracyclines derived from?
Fungi
57
What is the most widely used tetracycline in medicine?
Doxorubicin
58
What is doxorubicin derived from?
Streptomyces peucetus
59
What is doxorubicin used in?
Intravenous injection used for breast cancer, bladder cancer, Kaposi's sacroma, lymphoma, and acute lymphocytic leukemia.
60
What is the mechanism of action of doxorubicin?
It inhibits DNA synthesis by intercalating in DNA double helix and thus inducing cell death in dividing cells.
61
What are the side effects of doxorubicin?
Cardiotoxicity where is can lead to congestive heart failure.
62
How does doxorubicin cause cardiomyopathy?
Inducing oxidative stress, downregulation of genes for contractile proteins, and p53-mediated apoptosis.
63
What are 3 mechanisms of action for chemotherapy drufs?
1. Tubulin targeting = taxol/periwinkle
2. Topoisomerase inhibitor = V-16/CPT
3. DNA-intercalating drugs = doxorubicin
64
How is plant material first identified?
By field botanist as species and family.
65
Why is a field botanist important in plant material identification?
Important to authenticate plant material.
66
Where are plant samples collected from?
1. Aerial parts (leaves, stem or stem bark, flowers, or buds)
2. Roots
3. Timber or heartwood (inner timber) of large trees
67
Why are samples air-dried?
It helps to dry out the cell so they can break the hard cell wall and cellulose to reach the components that they want to isolate.
68
Why is dehydration of plant extracts performed at lower temperatures?
Through osmosis, this action occurs way faster. No water surrounds the plant, so water will flow accordingly.
69
What is a faster way to dehydrate plant extracts?
Lyophilizers, which is freeze-drying them.
70
After drying plant extracts, what happens next?
The dried biomass is ground carefully.
71
How fine do you want the powder?
Very fine, as the increase in surface area helps for a better extraction.
72
What are the two solvents generally used for extractions?
Water or ethanol.
73
What is the solvent extraction process for herbal medicines or natural extracts for commercial availability?
Water or ethanol.
74
What is the solvent extraction process for plant extract used for traditional medicines or ethnobotanical purposes?
The extraction process is used exactly as used by the tradition or ethnic practice which is mainly boiling or col extraction with different incubation periods or conditions.
75
What is the solvent extraction process for natural products?
Many different methods.
76
What is the simplest solvent extraction process for natural products?
Cold extraction at room temperature using different solvents with increasing polarity sequentially.
77
Give the step-wise solvent extraction process (soft extraction).
1. Powder mixed with solvents and stirred at room temp
2. Hexane first
3. Separate the hexane extract
4. Mix the biomass pellet with chloroform to kill the cells
5. Separate the chloroform extract
6. Mix/stir with ethyl acetate and separate the extract
7. Same with acetone
8. Same with methanol
9. Finally mix and stir with water
78
What is a batch extraction?
Extracting the solute from one immiscible layer in to other by shaking the two layers until equilibrium is attained, after which the layers are allowed to settle before sampling. It's done slowly and with increasing polarity.
79
What does water extract?
Salt, phosphate, and sugar (polar compounds).
80
What does ethanol extract?
Lipophilic compounds (non-polar).
81
Why would an soft extraction be performed?
To maintain/preserve most of the natural product.
82
What happens in a hot solvent extraction?
1. Powdered biomass added to a round bottom flask with the solvent
2. Heated gently under reflux
83
What solvents are used in a hot solvent extraction?
Ethanol or ethanol-water extraction.
84
What does supercritical fluid extraction do?
It uses gases that behave as liquids under pressure to solubilize natural products from biomass.
85
What gas is normally used for supercritical fluid extraction?
Carbon dioxide
86
What is the main advantage of supercritical fluid extractions?
The CO2 or any gas used with automically evaporate when the extraction process is done, leaving behind a clean extract.
87
How to increase the polarity of supercritical fluid extraction solvent?
Adding modifying agents like methanol or dichloromethane.
88
What is the most widely used method for extraction of plant natural products?
Soxhlet extraction
89
Soxhlet extraction
It uses an continuous extraction by solvents (boiling and condensing) of increasing polarity.
90
Explain the process of a soxhlet extraction.
1. Biomass powder is placed in a Soxhlet thimble of filter paper
2. Solvent is continuously refluxed below (boil and vaporized)
3. Apparatus will empty is content into a round bottom flask
4. The solvent vapors rise through a tube and condense in the condenser, returning as liquid solvent to the Soxhlet extractor chamber
5. As the solvent drips onto the sample in the thimble, it dissolves any soluble compounds
6. Once the chamber fills with the solvent-extract mixture, the liquid siphons back down into the flask below, repeating the extraction cycle.
91
What are lipophilic compounds extracted by?
Non-polar solvents like petrol, ethyl acetate, chloroform, and dichloromethane
92
What are hydrophilic compounds extracted by?
Polar solvents like acetone, methanol, and water.
93
What is done regardless of extraction technique?
Extracts are concentrated under vacuum using a rotary evaporator to remove the solvent.
94
How to remove solvents from extracts with volatile compounds?
Use a liquid nitrogen blow drying procedure.
95
What class of natural compounds must be extracted using specific protocols?
Alkaloids or monoterpenes.
96
How are alkaloids present as salt in biomass treated? What does this do?
With aqeuous ammonia that leads to the alkaloids becoming free bases.
97
What are the free base alkaloids extracted with?
Dichloromethane or ethyl acetate.
98
How is the dichloromethane layer with free bases separated?
Removed and mixed with aqueous acid like 2M hydrochloric acid.
99
What form are the free base alkaloids transferred from the dichloromethane to aqueous phase?
As a hydrochlorid salt.
100
How is the acidic layer extracted? What does this give?
Basified resulting in the precipitation of alkaloids. The precipitate can again be extracted using organic solvents to get pure alkaloids.
101
What are essential oils?
Special extracts from aromatic plants.
102
What do essential oils contain?
Volatile plant secondary metabolites.
103
What are types of volatile chemicals?
Terpenes and phenylpropenes.
104
How are volatile chemicals extracted?
By steam distillation and recovered after condensation by water-cooled condenser.
105
Explain how steam distillation works.
1. Biomass powder is boiled in water or the steam is passed through the dry plant material to directly vaporize volatile compounds
2. Condensed on other end
106
What are the two layers of the condensed liquid in a steam distillation of essential oil?
1. Upper layer = essential oil
2. Bottom layer = hydrosol containing water with some polar compounds
107
What is a cold press extraction of essential oils?
Peels of citrus fruits are mechanically peeled in cold conditions to yield pharmaceutical grade essential oil.
108
Phytochemical screening
Identifies the chemicals present in plant extracts and determines their relative abundance.
109
What are classical qualitative or quantitative methods of phytochemical screening?
Precipitation, colour of secondary metabolites or colour development reactions, odors, etc.
110
What do the classical qualitative or quantitative methods of phytochemical screening require?
Adequate amounts of the extract.
111
What is an instrumental analytical technique or chromatography based technique of phytochemical screening?
Physical method of seperating components of a mixture based on their distribution in stationary and mobile phases.
112
What is the stationary phase that was initially used in chromatography?
Cellulose, kieselguhr, and aluminum oxide.
113
What is the stationary phase that is used now in chromatography?
Silica gel and its derivatives (cyno, diol, amide, etc.).
114
How are the stationary phase materials positioned?
1. Layered on a glass plate in thin layer chromatography
2. Packed in columns in liquid chromatography
115
How does chromatography work?
1. Solute interacts with two phases (stationary and mobile)
2. Depending on different compounds with different affinities for the phases
3. Compounds are separated and eluted with mobile phase at a different time or with a different polarity composition
NOTE: those that are less soluble move slower to the end of the column
116
What are types of chromatography?
1. Thin layer
2. Liquid
3. High performance liquid
4. Gas
5. Liquid
117
What does the dragedroff's test test? Positive?
Alkaloids, forming a red precipitate if found.
118
What does the liebermann burchard's test test? Positive?
Phytosterols, and the formation of a brrwon ring at the water-chloroform interphase if found.
119
What does the foam test test? Positive?
Saponins and a foam is produced for ten minutes if found.
120
What does the ferric chloride test test? Positive?
Phenols with a bluish-black colour forming if found.
121
Where is pancratistatin found in?
Hawaiian spider lily
122
What can pancratistatin not do?
Because of the OH in its structure it cannot intercalate with DNA, not a topoisomerase inhibitor, OR tubulin targeter.
123
What is pancratistatin shown to do?
Induce apoptosis in cancer cell lines but is non-toxic to normal cell lines.
124
What did PST do in hepatoma cells at high concentrations?
Cytostatic effect = slowing down or stopping cell growth by inhibiting cell division. Cancer cells were not dead but not dividing.
125
What did PST do in hepatoma cells at low concentrations?
All cells were dead, showing that it can trigger apoptosis.
126
What natural compound showed a homeopathic effect?
PST because the more it was diluted, the better effect it had on cells.
127
What was the best concentration of PST on hepatoma cells?
0.5 uM
128
How did they determine that PST did not target DNA?
Using cultured jurkat cells (human leukemia cells) there was no indiciation of DNA damage with PST. However, when using VP-16, a DNA targeting drug, there was a greater appearance of y-H2AX staining.
129
What did PST do to a cultured jurkat cell versus healthy lymphocytes?
Jurkat = Great apoptosis with time
Lymphocytes = normal apoptosis underwent (did not increase greatly)
130
What did PST do in ex vivo leukemia samples?
An Annexin-V staining which indicates apoptosis was indicative in the jurkat and the leukemia samples. Untreated there was no apoptosis.
131
What ex vivo leukemia samples were tested against PST?
AML, ALL, CLL, CMML, and MLS
132
Was PST harmful to non-cancerous PBMCs (normal blood cells)?
PST was not attacking the healthy lymphocytes whereas it indicated great apoptosis of leukemia samples.
133
How did PST compare to taxol and VP-16 to breast cancer cells or healthy human memory epithelial cells?
PST exhibited a greater selectivity compared to the most used chemotherapy agents.
134
How did normal, healthy cells do following the exposure and removal of PST?
Normal healthy fibroblast cells treated with PST versus untreated had no big difference in survival/numbers. Both were able to divide at the same rate.
135
What does PST do to human colon carcinoma cell lines?
It induces apoptosis in the cancer cells reducing their viability in a dose-dependent manner.
136
Does PST target the mitochondria?
Yes it does.
137
How does PST target the mitochondria?
It causes mitochondrial membrane potential collapse in cancer cells.
138
How was PST shown to target mitochondria?
1. JC-1 staining of colon carcinoma cells treated with PST showed less fluorescence than untreated ones
2. Cytochrome C was increased in the PST treated cells, indicating apoptosis
3. Cancer cells mutated without a functional mitochondria = PST with these cell lines had no effect, so this mean its targets the mitochondria
139
How to make a dysfunctional mitochondria in the lab?
Slowly mutate the mitochondrial DNA with ethidium bromide, which makes the mitochondrial dysfunctional = mito free cells.
140
Is PST caspase-independent or dependent apoptosis?
PST induces caspase-independent apoptosis.
141
How was PST shown to induce caspase-independent apoptosis?
Pre-treatment with pan-caspase inhibitor (z-VAD-fmk) did not inhibit PST induced cell death. Also, AIF was released (an apoptosis inducing factor that is caspase-independent).
142
What is a caspase inhibitor?
z-VAD-fmk
143
What did xenograft mice with PST show?
Their weight was controlled well, similar to the normal mice, and the tumor volume growth was stopped.
144
How to change the structure of PST?
Took the precursor and modified the OH groups via enzymes.
145
What are PST analogues?
SVTH-5,6,7 or JCTH-1,2,3,4.
146
What did Fleming discover?
Lysozyme
147
What is a lysozyme?
An enzyme with weak antibacterial properties that inhibit bacterial growth through the digestion of the cell wall.
148
Where are lysozymes?
Found in the ECM in our body, so our fingernails, hair, saliva, skin, and tears.
149
What was the first antibiotic?
Penicillin
150
What can the overuse of penicillin lead to?
Bacterial resistance
151
How was penicillin discovered?
1. Fleming grew bacteria on petri dishes and treated them with a material to test their anti-bacterial activity
2. His plates were contaminated with fungus
3. Around the fungus was a clear ring, which indicated an inhibition of bacteria growth
4. Activity based purification of the fungus (HPLC) had the isolated compound being penicillin
152
How does penicillin act as an antibiotic?
It inhibits the formation of cell wall in bacteria by inhibiting synthesis of peptidoglycan by blocking transpeptidases (enzymes like peptidyltransferase).
153
What are analogs of penicillin?
Methicillin, ampicillin, carbenicillin, and azlocillin.
154
What plant did Dr. Tu use?
Artemisia annua
155
What was the plant extract Dr. Tu discovered effective in?
Treating P. berghei (parasite that causes malaria).
156
What pure compound did Dr. Tu find in artemisia annua? Benefit?
Dihydroartemisinin and artemisinin which greatly improved water solubility and treatment efficacy.
157
How did Dr. Tu test artemisia annua?
First clinical trial was with the total extract.
158
What is an antimalarial natural compound?
Artemisinin
159
What is an antibacterial natural compound?
Penicillin
160
How does the anti-malarial mechanism of artemisinin work?
1. Secondary metabolite dihydroartemisinin
2. Comes into contact with haem (associated with the hemoglobin of the RBC)
3. Iron (II) oxide breaks the endoperoxide ring
4. Produces free radicals that in turn damage susceptible proteins = death of the parasite
161
How does artemisinin behave in cancerous situations?
It targets both the healthy and cancerous cells, but healthy cells can withstand (oxidative stress).
162
What to do with artemisinin and cancer?
Clinical trial because the compound is already well-tolerated (used for humans to treat malaria).
163
What anticancer natural compounds target oxidative stress vulnerability of cancer cells?
Piperlongumine, curcumin, and synthetic analogues.
164
What analgoue of PST does better than itself?
SVTH-7 displayed 100x more anti-caner activity.
165
What is EC50?
The concentration of a drug that gives half-maximal response (kills half the cells).
166
What was the EC50 of SVTH-7?
5 uM
167
How did the synthetic compounds of PST work against cancer lines compared to current chemotherapies?
Had a much better effect, reducing the viability of the cancer cell lines to below 50 in various cell lines. It did better than GEM and taxol.
168
How did PST analogues perform at higher concentrations?
Still toxic but didn't affect healthy cells.
169
How did PST analogues do in cancer cells (lymphoma) and healthy blood cell lines (quantitative)?
Cancer = Indicated apoptosis at various stages
Healthy = Blue portion of graphs indicated that the cells were not dying
170
How did PST analogues do in cancer cells (lymphoma) (qualitative)?
Cancer = Apoptosis as cell numbers decreased on the microscope
171
What factors did PST analogues activate? When?
1. Casapase-3 after 6 hours
2. Caspase-8 (comes first)
172
What did the PST analogues do to the mitochondrial potential in cancer cells versus health ones?
Cancer = great decrease in MMP
Healthy = no difference in potential even after 48 hours
THEREFORE SELECTIVITY OF CANCER CELLS.
173
How did the cancer cells appear via fluorescence with PST analogues versus taxol?
PST analogues = little to no fluorescence with SVTH-5,6,7, indicating mitochondrial collaspe
Taxol = fluorescence appears still indicating that the mito was in tact
174
What happened to the cancer cell lines with PST analogues when blocked with Z-VAD-FMK?
There was a reduction in the amount of apoptosis normally produced, almost back to control, indicating that PST analogues were caspase-dependent apoptosis
175
How does BCl2 relate to cancer?
Bcl2 is overexpressed in cancer cells to protect the mitochondrial potential (resist depolarization) and prevent opening up.
176
What happened when BCl2 was upregulated in cancer cell lines with PST analogues (viability and mitochondrial potential)?
Viability = decreased, inhibition of cell death
Potential = increased and exemplified polarization of the mitochondria
NOTE: shows that PST targets the mitochondria
177
Why is paraquat used as a positive control for ROS studies?
Known to induce oxidative stress selectively.
178
What happened to the ROS levels of cancer cell lines with PST analogues (PQ comparison)?
Cancer = increased to the levels of PQ in most cases (but increase is all that matters)
179
What did PST analogues do to oxygen consumption in cancer cell lines (AMA comparison)?
Cancer = Low oxygen consumption levels, not as low as AMA = MEANS disfunctions mitochondria
180
What does AMA do?
It blocks complex 3 which leads to no oxygen consumption.
181
What PST analogues performed the best in the oxygen consumption assay?
SVTH-5,6,7
182
How did cytochrome c levels appear with PST analogues in cancer cells?
Levels increased over time indicated that the mitochondria was opening up.
183
What happened to lab-induced dysfunctional mitochondria with PST analogues? What does this mean?
No apoptosis with TTFA (complex 2 blocker) + SVTH-7 or AMA (small with AMA and SVTH-7), indicating that there needs to be a hyperpolarized functional mitochondria in cancer cells to target. The SVTH compounds compete from a complex 2/3 spot.
184
What does TTFA block?
Complex 2
185
What happened to cancer cells treated with PST analogues when TTFA was added?
Increase in viability and caspase-3 not activated meaning that PST analogues target complex 2 in the mitochondria. Happened for AMA as well.
186
What are the targets in the mitochondria for PST analogues?
Complex 2 and 3
187
What happend to mitochondrial polarization in cancer cells with TTFA/AMA with PST analogues?
The mitochondiral polarization was recovered when the blockers were added.
188
How did the mito appear with and without the blockers with added PST analogues?
With blockers = mitochondria of cancer cells were protected and in tact
Without blockers = mitochondria collapsed
189
How did the PST analogues do in xenograft mice?
SVTH-5,6,7 dissipated the tumor (inhibit the growth) and were well-tolerated (body weight still gaining).
190
What were some difficulties with creating curcumin analogs?
There is a very vulnerable bond that is single bond between double bond oxygen, that if it breaks the compound is no longer curcumin.
191
What compounds of PST were patented?
SVTH-5,6,7
192
How many derivatives of curcumin were developed?
10 (compound A-J).
193
When did curcumin show anti-cancerous activity?
At high concentrations.
194
What compound of curcumin performed the best in cancer cell lines?
Compound A, 10x more activity than native curcumin
195
How did compound A perform in healthy cells?
Well-tolerated (little to none apoptosis).
196
How did compound A compare to positive chemotherapy drugs in triple negative cancer cell lines?
It performed 10 times better in inducing apoptosis and even in small doses (0.5 uM).
197
Did all the cancer cell lines perform the same to compound A?
No, there was some variability.
198
Was the compound A targeting mitochondrial? If yes, how?
Yes, it was destabilizing the mt potential in cancer cells ONLY.
199
What concentration of compound A was able to destabilize mt potential?
1 uM
200
What were the effects of compound A when Bcl2 was overexpressed?
Apoptosis was usually inhibited (some sort of extent).
201
Did compound A induce oxidative stress in cancer cells?
Yes, it was done selectively. When an anti-oxidant was used, this effect was blocked (NAC) and cell death did not occur.
202
How do curcumin analogs induce apoptosis?
Dependent on the productive of oxidative stress.
203
What genes were different in cancer and normal cells when curcumin was used?
Cancer = pro-oxidative ones were upregulated
Normal = pro-oxidative ones were donwregulated
204
How did compound A do when piperlongumine was addded?
The compound was more potent, increasing apoptosis of cancer cell lines than without.
205
What did compound A do to xenograft tumors?
Reduced tumor size very greatly.
206
What did a combination of PST analogues and PL do to cancer cell lines?
Performed the best when 0.1 uM SVTH-6 and 5uM PL was combined, even more than enhancing as there were barely any cancer cells left behind. PL did a great job in this reduction.
207
How did the combination of SVTH-6 and PL do to healthy cells?
Slightly toxic but not too much (well-tolerated). There was still a great amount of healthy cells alive.
208
How did the SVTH-6 and PL do in pancreatic and ovarian cell lines?
The combination worked the best in reducing cancer cell numbers.
209
What materials were activated with the combination of PL and SVTH-6 in cancer cells?
Pro-caspase 3, thus caspase dependent apoptosis.
210
What did the combination of PL and SVTH-6 do to the mitochondrial potential of cancer cells?
Combination was much more effective in decreasing the mitochondrial potential with SVTH-6 doing a lot of the work. Great fluorescence was seen.
211
What did the combination of PL and SVTH-6 do to the mitochondrial potential of healthy cells?
Nuceli keep in tact, so cells were well-tolerated to this mixture.
212
What did the combination of PL and SVTH-6 do to the oxygen consumption of cancer cells?
Increased further with SVTH-6 doing most of the work.
213
What did the combination of PL and SVTH-6 increase in cancer cells?
Increased the amount of cytochrome C and AIF released, thus mitochondria was opening up.
214
What happened to the cancer cells treated with a combination of PL and SVTH-6 when NAC was added?
Their effects were greatly reduced (PL mainly causes oxidative stress) with greater cell vibiality and less oxidative stress observed.
215
What happened to the cancer cells depolarization treated with a combination of PL and SVTH-6 when NAC was added?
Was blocked when NAC was used.
216
What is oxaliplatin similar to? Use?
Similar to cisplatin where it induces DNA damage.
217
How did cancer cell lines react to oxaliplatin?
Dose-dependent toxicity.
218
What happened to cancer cells when oxaliplatin was used in combination with PL?
Enhancement of the chemo's effects:
1. Greater apoptosis of cancer cells
2. Induces oxidative stress, more ROS
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How did PL affect oxaliplatin?
More than additive effects was synergistic. This is because the effects of the two were 54.7% in colon cancer, separate they were 19 and 23 which didn't add up.
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What is the conclusion of the PL and oxaliplatin study?
You don't have to use large concentrations of the toxic drugs because at small concentrations (10 nM), PL can increase the efficacy and act as non-toxic too.
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What happened with oxa and PL when NAC was used in cancer cells?
Depolarization didn't occur as the NAC blocked mitochondrial effects (in tact).
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What did oxa and PL do to tumor size?
Reduced them greatly together; not much difference when used separately.
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How does oxaliplatin target cells in high doses?
In high doses it induces DNA damage which causes apoptosis.
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How does oxaliplatin target cells in low doses?
Increases ROS/oxidative stress which will lead to caspase 3 activation that causes apoptosis via cyto C and Bcl-2.
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How does PL target cells?
Increases ROS/oxidative stress which will lead to caspase 3 activation that causes apoptosis via PERK pathway.
