Topic 5: Endocrine System & Phytomedicines Flashcards
Progesterone
precursor to other steroid hormones including androgens, estrogens, and glucocorticoids
produced by the corpus luteum and the placenta
Uses of Progesterone
female contraceptives
prevent spontaneous abortion
treat menstrual disorders
Estrogens
-substance that exerts agonistic biological effects on he estrogenic receptors
Sources of endogenous estrogens
- ovaries, testes and placenta
- estradiol (E2) is more potent endogenous human estrogen
- estrone (E1) is a weaker estrogen formed in fat cells
Effects of Estrogen
- stimulate growth and maturation of long bones
- stimulate secondary sexual characteristics
- influence course and length of menstrual cycle
Uses of Estrogens
- female contraceptives
- menstrual disorders
- menopausal symptoms
- osteoporosis in post-menopausal women
- estrogen deficiency
Androgens
- agents that stimulates the development of male sex characteristics
- testosterone is an androgen
- androsterone is a testosterone metabolite (found in male urine)
Sources of Endogenous Androgens
- interstitial cells of testes
- ovary
Androgen Therapeutic Uses
- cryptochism (non-descended testes)
- hypogonadism (inadequate gonadal function in males)
- menorrhagia (excessively prolonged or heavy menses)
- testosterone deficiency
Glucocorticoid Sources
- adrenal cortex
- adrenal glands secrete cortisol- the most potent endogenous glucocorticoid
Uses of Glucocorticoid
- anti inflammatory
- immunosuppressant
- treatment of cortisol deficiency
Glucocorticoids (molecules)
- hydrocortisone
- cortisone
- prednisone
- prednisolone
- methylpredisolone
Glucocorticoid Mechanism of Action
Down regulates cytokine production which reduces inflammation: Steroid binding of glucocorticoid receptor (GR) in cell cytoplasm results in activation of receptor and translocation to the nucleus where regulatory region of certain genes are effected including negative regulation for genes that code for a number of cytokines.
Also reduces protaglandin production which reduces inflammation: Blocks conversion of phospholipid to arachidonic acid which blocks the formation of prostaglandins
Immunosuppressant Uses of Glucocorticoids
oral administration:
- systemic lupus erythematous
- idiopathic thrombocytopenis purpurea
Replacement Therapy for Glucocorticoid Deficiency
Oral administration:
- congenital adrenal hyperplasia
- panhypopituitarism
Dioscorea Mexicana
Source of diosgenin Common Name: wild yam Geography: Mexico Habit: Herbaceous climber Plant part Used: rhizomes Ethnomedical Uses: anti inflammatory, fish poisons, etc.
Diosgenin
Steroid
Use in modern medicine (derivatives included):
- female contraceptive (progesterone & estrogen)
-anti inflammatories & immunosuppressants (glucocorticoids)
-horomone replacement for estrogen, androgen, or cortisol deficiency
Diosgenin Chemical Derivatives
progesterone, which is then synthesized into:
- estrogen
- androgens
- glucocorticoids
Female Contraceptives
Progesterone (main component) & estrogen for oral contraceptives .
Progesterone prevents the estrogen surge which blocks the release of gonadotropin releasing hormone (GnRH) from the hypothalamus which inhibits the mid cycle gonadotropin surge of FSH (follicular stimulating hormone) and LH (lutenizing horomone) produced by the pituitary gland.
-cervical mucus becomes thick and viscid
-endometrial changes make it more difficult for implantation
Progestin/progestogen & estrogen Contraceptives
- started when menstruation is over
- taken for 21 days, followed by 7 days off
- reduce risk of ovarian cancer
- reduce risk of breast cancer when taken for less than 10 years
Male Contraceptive:
Gossypium spp. (cotton)
Common Name: cotton Geography: China Plant part Used:oil from fruit Ethnomedical Uses: birth control on males Active compound: gossypol
Gossypol mechanism of action
inhibits sperm formation
Hevea brasiliensis (para rubber)
Geography: S. America, rainforest
Plant part used: bark latex
Ethnomedical use: utensils
Mech of action: mechanical protection
Benign Prostatic Hypertrophy
-Elevated levels of dihydrotestosterone (DHT) in prostate
-
Dihydrotestosterone (DHT)
- potent form of testosterone that stimulates the enlargement of the prostate cells
- testosterone is converted to more potent DHT by 5-alpha- reductase
5-alpha-reductase (5AR)
converts testosterone into DHT.
activity increases with age and its main action is on the prostate
Serenoa repens
Common Name: Saw palmetto
Geography: Native to Florida
Ethnomedical Use: fruits used by Native Americans to treat benign prostatic hypertrophy, is an aphrodisiac
Saw Palmetto Mechanism
Inhibits 5-alpha reductase and in turn production of DHT in the prostate
Vitex agnus-castus (Chasteberry)
Common Name: chasteberry
Geography: S. Europe
Ethnomedical Use: reduces sexual desire and premenstrual stress syndrome.
Chasteberry Mechanism
stimulation of gondadotropin releasing horomone in hypothalamus –>
increases release of LH
increases progesterone level
decreases estrogen
Oenothera biennis
Common Name: Evening primrose
Geography: Europe
Ethnomedical Use: oil from ripe seeds & aerial parts used to treat premenstrual syndrome, menopausal hot flashes
Cimicifuga (actaea) racemosa
Common Name: black cohosh
Geography: Eastern North America
Ethnomedical Use: roots and rhizomes used for PMS, and menopausal hot flashes.
Ginseng Panax ginseng & P. quinquefolius
Common Name: ginseng
Geography: Panax- Koreas, NE China
P. quinquefolius- E. North America
Ethnomedical Use: tonic to enhance mood, physical performance, intellectual performance, improve metabolic functions, aphrodisiac
Galactogogues
enhance flow of breast milk
Tigonella foenum-graecum (fenugreek)
Common Name: fenugreek
Geography:Europe
Ethnomedical Use: galactogogue, used in tea, Eurasian condiment
Saponaria officinalis
Common Name: soapwort
Geography:Europe
Ethnomedical Use: galactogogue
