11: Plants that kill and heal Flashcards
Calabar bean (monograph)
- SCIENTIFIC NAME:
- PART USED:
- MODE OF ADMINISTRATION:
- BIOACTIVE COMPOUND:
- COMPOUND CLASS:
- USES:
- SCIENTIFIC NAME: physostigma venenosum
- PART USED: bean
- MODE OF ADMINISTRATION: tincture, extract
- BIOACTIVE COMPOUND: physostigmine
- COMPOUND CLASS: indole alkaloid
- USES: trial by ordeal, glaucoma
what is the bioactive compound in physostigma venenosum?
- what does it do?
- it acts as what? –> what?
- stimulates which nervous system? –> effects?
- treat what?
- physostigmine!
- causes death by paralytic asphyxia
- is a reversible inhibitor of acetylcholinesterase: causes prolonged and exaggerated effects of ACh
- stimulates all PSNS nerves: contraction of pupils, bronchi, intestinal smooth muscle
- ability to contract pupil led to its use to treat glaucoma: leading cause of blindness in adults
THE IRIS (on exam!!)
- physostigmine stimulates PSNS = _____________
- is a _________ agent
- is a _________ drug
- what does it do? (6 steps ish)
- parasympathomimetic!
- cholinergic agent
- miotic drug! cause miosis (constriction of pupils)
- increases ACh by inhibiting acetylcholinesterase –> increase PSNS –> contracts sphincter muscles –> leads to miosis (constricted) –> decreases intraocular pressure in people with glaucoma –> prevents damage to optic nerve and retina
what is glaucoma?
- what compound can help?
- how to apply?
- blocked drainage canal –> fluid builds up in the eye = milky lens + increase intraocular pressure = damages retina = blindness!
- physostigmine can relieve intraocular pressure by contracting pupil
- applied through eye drops!
(not in exam)
deadly nightshade (monograph)
- SCIENTIFIC NAME:
- PART USED:
- MODE OF ADMINISTRATION:
- BIOACTIVE COMPOUND:
- COMPOUND CLASS:
- USES:
- SCIENTIFIC NAME: atropa belladonna
- PART USED: foliage and berries
- MODE OF ADMINISTRATION: tincture and extract
- BIOACTIVE COMPOUND: atropine
- COMPOUND CLASS: tropane alkaloid
- USES: cyclopegic + bradychardia
THE IRIS (on exam)
- atropine inhibits PSNS = _________
- is an ____________ agent
- is a _________ drug
HOW?
- parasympatholytic (against PSNS)
- anticholinergic agent
- mydriatic drug
- causes sympathetic stimulation + constriction of radial muscles = pupil dilates! (opposite to physostigmine)
ATROPINE
- causes what?
- act as what?
- inhibits which nervous system?
- treat what?
- causes death by central depression (coma) –> shuts things down
- atropine is a muscarinic cholinergic blocking agent: inhibits effects of ACh on muscarinic recptors
- inhibits all parasympathetic nerves: dilates pupils, bronchi, intestinal smooth muscle, etc.
- ability to dilate pupil led to its use before eye examinations and to treat certain eye conditions like uveitis
castor bean (monograph)
- SCIENTIFIC NAME:
- PART USED:
- MODE OF ADMINISTRATION:
- BIOACTIVE COMPOUND:
- COMPOUND CLASS:
- USES:
- SCIENTIFIC NAME: ricinus communis
- PART USED: bean
- MODE OF ADMINISTRATION: extract
- BIOACTIVE COMPOUND: ricin
- COMPOUND CLASS: lectin (glycoprotein)
- USES: poison + biological/chemical weapon –> can kill you
ricin mechanism of action (ON EXAM!)
- inhibits what? how?
- is a WHAT? –> 2 types
- ricin is which type?
- inhibits protein synthesis by specifically and irreversibly inactivating ribosomes
- is a ribosome inactivating protein (RIP!)
1. type 1 RIPs (monomer): ie wheat and barley, are not poisonous
2. type 2 RIPs (dimer): ie castor bean –> most potent cytotoxic agents in nature - ricin = heterodimeric type 2 RIP
mechanism of action of ricin/type ___ what? 5 steps
KNOW THIS!
type 2 ribosome inactivating protein!
1. B chain binds to terminal galactose on cell surface receptors and the whole toxin is endocytosed
*B-chain allows to bring a-chain (actual toxic part) into cells!
2. whole toxin reaches Golgi complex and exploits retrograde transport to translocate to the ER (cause usually ER to Golgi complex)
3. separation of A and B chains in ER by protein disulfide isomerase
4. followed by escape of A chain to the cytosol through sec61 translocon
5. in cytosol, A chain depurinates adenine 4324 of a-sarcin loop in 60S ribosomal subunit and inhibits protein synthesis irreversibly
castor oil
- made by extracting what from what?
- can a process deactivate ricin?
- castor oil used as ______ in (4) ish
- natural remedy for ______ since ancient egypt
*** rich in __________ –> act as what?
- reduces __________ when applied topically
- extracting oil from castor beach
- heating process deactivates ricin (when extracting oil)
- used as additive on foods, medications and cosmetics + as an industrial lubricant
- constipation
- ricinoleic acid: MUFA that acts as humectant
- inflammation
rosary pea (monograph):
- other common name?
- SCIENTIFIC NAME:
- PART USED:
- MODE OF ADMINISTRATION:
- BIOACTIVE COMPOUND:
- COMPOUND CLASS:
- USES:
(lobser eye)
- SCIENTIFIC NAME: abrus precatorius
- PART USED: breah
- MODE OF ADMINISTRATION: crushed seed
- BIOACTIVE COMPOUND: abrin (similar to ricin)
- COMPOUND CLASS: lectin (glycoprotein)
- USES: poison, chemical/biological weapon
what are lectins? + 2 characteristics
- most are inactivated through (2)
- what foods are high in lectins and need to be (2) to reduce lectin content
- 2 major forms of lectin + describe + examples (ON EXAM)
carbohydrate-binding proteins that are toxic and ubiquitous in nature
- most are inactivated by proper processing and preparation
- grains and legumes (babies of plants) are particularly high in lectins and need to be cooked or fermented to reduce lectin content
1. PROLAMINE: toxic lectins that serve as storage proteins (ie gluten)
2. AGGLUTININ: class of lectins that induce clumping of red blood cells (ie ricin, wheat germ agglutinin)
- what are prolamines?
- what is the most studied prolamine? –> partially digested by what into (2) describe the first one
- lectins characterized by high content of aa proline
- gluten is the most studied prolamine –> digested by our proteases to gliadin and glutenin
GLIADIN: - can cross gut barrier and activate both the innate and adaptive system
- signals zonulin release from enterocyte that can loosen tight junctions
*ZONULIN is a protein that modulates the permetability of tight junctions btw cells of wall of digestive tract
*gliadin “tricks” immune/endothelial system into opening tight junctions by signaling for zonulin release (opens up gates so big molecules can enter the castle through tight junctions)
(needs to know this! Zonulin = name of prof’s future son lol)
increasing zonulin levels have been linked with which disease? (a lot) why?
- celiac disease, T1D, IBD/colitis, multiple sclerosis, obesity, IR, T2D, PCOS
- no surprising bc all foreign invaders are being let into the castle
what is the second type of lectin (apart from prolamine)?
- which “plant” is the best studied?
- what grains are high in that?
- resistant to (2)
- does 2 things
- binds directly to what? (3) (bold)
AGGLUTININS!
- wheat germ agglutinin (WGA)
*part of plant’s natural defence mechanisms against fungi and insects
- GMO grans are high in WGA
*agglutinins are small and remain intact
- resistant to low pH and proteolytic enzymes
- not directly toxic to enterocytes but can increase gut permeability and is a well-known stimulator of innate and adaptive immune system
(BOLD): WGA binds directly to 2 sugars found on cell membrane (N-acetylglucosamine) and N-acetylneuraminic acid) + binds to epidermal growth factor (EGF) receptor and causes tight junctions to open (zonulin not needed)
*EGF also internalize WGA into enterocytes and into bloodstream
what are the 4 steps of what WGA does to intestinal permeability and consequences
- agglutinin/WGA bind with epidermal growth factor (EGF) receptors –> signal for tight junctions to open
- lysosome or endosome/the agglutinin/WGA is endocytosed
- WGA also interacts with sugars on cell-membrane –> both are also endocytosed
- leads to a build up of WGA in lysosomes –> finds its way in the bloodstream –> it’s a large molecule that shouldn’t be there = immune system goes haywire
AGGLUTININS
- WGA is (2)
- can pass through what? through which process?
- binds to what (ex?)
- WGA can bind to what and is capable of inhibiting what?
- pro-inflammatory and neurotoxic
- (BOLD) can pass through BBB through a process called absortive endocytosis
- binds to N-acetylneuraminic acids on surface of brain neural membranes (such as GANGLIOSIDES)
- (BOLD) can bind to myelin sheath and is capable of inhibiting Nerve Growth Factor
- agglutinins from other plants have been shown to have similar effects (examples on slides)
curare (monograph)
- SCIENTIFIC NAME:
- PART USED:
- MODE OF ADMINISTRATION:
- BIOACTIVE COMPOUND:
- COMPOUND CLASS:
- USES:
- SCIENTIFIC NAME: chondrodendron tomentosum
- PART USED: bark/woody stem
- MODE OF ADMINISTRATION: extract, injection
- BIOACTIVE COMPOUND: tubocurarine
- COMPOUND CLASS: complex alkaloid
- USES: smoking withdrawal symptoms + spider bite antidote + used as anesthetic!
*paralyzes you without making you faint = still conscious
explain curare’s mechanism of action
- what bioactive compound? blocks what receptor where?
- acts as what?
- antidote?
- has no effect when ________
- tubocurarine blocks nicotinic acetylcholine receptor (nAChR) at the neuromuscular junction –> ie blocks Ach
- competitive antagonist of ACh: occupies same position on receptor as ACh, but with greater affinity!
- antidote for curare poisoning is an acetylcholinesterase inhibitor such as physostigmine (calabar bean)
- no effect when ingested! (has to be through blow dard)
foxglove (monograph)
- SCIENTIFIC NAME:
- PART USED:
- MODE OF ADMINISTRATION:
- BIOACTIVE COMPOUND:
- COMPOUND CLASS:
- USES:
- SCIENTIFIC NAME: digitalis purpurea
- PART USED: leaves
- MODE OF ADMINISTRATION: extract
- BIOACTIVE COMPOUND: digoxin
- COMPOUND CLASS: cardiac glycoside
- USES: irregular heartbeats: atrial fibrillation
foxglove
- overdose of that causes so many symptoms
- when do poisonings occur?
- overdose of digitalis causes nausea, vomiting, diarrhea, drooling, abnormal heart rate, weakness, collapse, dilated pupil, tremors, seizures and death
- poisonings occur mostly in children younger than 6 yo who chew the flowers and taste the nectar
digitalis mechanism of action
- acts as what? –> reduces what?
- by promoting what?, digitalis causes more …
- [bioactive compound of digitalis] inhibits what? in myocardium –> causes what?
- act as diuretic to reduce fluid retention, a symptom of heart disease
- by promoting regular heartbeat, digitalis causes more blood to reach kidneys, where excess fluids are removed rather than accumulated in the body
- digoxin inhibits sodium potassium ATPase in myocardium –> inhibition causes a decrease in heart rate and increase in stroke volume
explain the effects of digoxin on Na+/K+ ATPase (2 steps)
- inhibits Na+/K+ ATPase –> indirectly increases Ca+ concentration (bc potassium can get in and Na can’t get out and Ca2+ needs Na+ to go from out to in, so that Ca+ can get out)
- increased intracellular calcium causes more calcium to be released by sarcoplasmic reticulum –> making more calcium available to bind to troponin-C which increases contractility (inotropy)
