Capsicum annuumis an annual herb (from
1–5 m in height), while the other species are
usually perennial woody shrubs, all native to
tropical America and now widely cultivated.
C. frutescensis readily distinguished from
C. annuumin that its stem is shrubby, its
flowers are borne in groups,^1 it grows up to
2 m in height, and it is a perennial (DE SMET;
ROSENGARTEN;TERRELL). All five species yield
pungent fruits commonly called red pepper or
simply capsicum. Mild fruits commonly
known as paprika, bell pepper, sweet pepper,
or green pepper are usually produced by vari-
eties ofC. annuum.
Capsicum oleoresin is obtained by extract-
ing red pepper with a suitable organic solvent;
extraction of sweet pepper (paprika) with
similar solvents yields paprika oleoresin,
which contains high concentrations of caro-
tenoids but little or no pungent principles,
depending on the process.
CHEMICAL COMPOSITION
Capsicum contains up to 1.5% (usually
0.1–1.0%) pungent principles, composed
mainly of capsaicin; other pungent alkaloid
principles (capsaicinoids) include dihydrocap-
saicin, nordihydrocapsaicin, homocapsaicin,
and homodihydrocapsaicin, with the last two
in minor concentrations.2–4Other constituents
present include carotenoids (capsanthin,
capsorubin, b-carotene, lutein, zeaxanthin,
etc.);5–10fats (9–17%), proteins (12–15%),
vitamins A, C, and others; and a small amount
of a volatile oil made up of more than 125
components of which 24 were identified, in-
cluding 4-methyl-1-pentyl-2-methyl butyrate,
3-methyl-1-pentyl-3-methyl butyrate, and
isohexyl isocaproate (JIANGSU;MARSH).^11
Mild peppers (e.g., paprika and bell pepper)
contain similar constituents as hot peppers
but with little or no pungent principles.^12
PHARMACOLOGY AND BIOLOGICAL
ACTIVITIES
While a single dose of capsaicin activates pain,
inflammation and hypersensitivity, repeated
(long-term) application in appropriately
formulated product forms leads to desensiti-
zation, analgesic, and anti-inflammatory activ-
ity. Capsiacin-induced analgesia and desensi-
tization has been explained on the basis of
neuropeptide release and depletion, selective
targeting of C fibers in the pain pathway, and
activation of the vanilloid receptor type 1.13,14
Extracts of five species of hot peppers
showedin vitroantimicrobial activity.^15 Lipid
peroxidation and bacterial counts were inhib-
ited by the addition of hot or sweet peppers to
beef patties.^16 Antioxidant activity of capsi-
cum is attributed to capsaicin.17,18In vitroin-
hibition of bacteria and platelet aggregation
by capsaicin has been associated within vitro
fluidization of lipid membranes.^19 Gerbils fed
a high-cholesterol diet containing capsicum
oleoresin showed reduced serum levels of
cholesterol and triglycerides.^20 High oral
doses of capsicum in rats lowered serum glu-
cose levels.^21 Administered intragastrically
to rats, capsaicin inhibited the formation of
hydrochloricacid-inducedulcers,^22 damageto
the gastric mucosa, myeloperoxidase activity,
lipid peroxidation, and hemorrhagic erosion.
Capsaicin also inhibits constitutive activation
of NF-kB in malignant melanoma cells and
when topically applied to the skin of mice.^17
Placebo-controlled studies of topical pre-
parations containing capsaicin have found
benefits in the treatment of lower back pain,^23
cluster headache, postmastectomy pain
syndrome, pruritis, psoriasis, fibromyalgia,
arthritis (FUGH-BERMAN;MCKENNA), and osteo-
arthritis.^24 Oral administration of red pepper
powder (providing 1.75 mg capsaicin and
hydrocapsaicin/day) in gelatin capsules was
reported to be more effective than placebo in
reducing the intensity of dyspepsia symp-
toms,^25 as was intranasal capsaicin spray in
decreasing idiopathic rhinitis^26 and intranasal
capsaicin in postsurgical recurrence of
nasal obstruction and nasal polyposis.^27 Other
clinical studies have shown benefits from
capsaicin in the treatment of neurogenic
incontinence (intravesically applied),28–30hy-
persensitive and overactive bladder,^31 diabetic
neuropathy,^32 and postherpetic neuralgia.^33Capsicum 133