PDR for Herbal Medicines

166 /CAYENNE PDR FOR HERBAL MEDICINES

EFFECTS

Pain Modulation

The most important active ingredient in the herb is the

capsaicin, which exerts hyperemic effects. Cutaneous noci-

ceptors are also known as peripheral sensory neurons of

primary sensory neurons activated by noxious stimuli (Biro,

1997; Nakamura, 1999). Peripheral fibers produce a local

response consisting of edema, redness and vasodilation,

while afferent fibers relay nocioceptive information to the

central nervous system resulting in the perception of pain

and burning. Long-term desensitization of the fibers occurs

after repeated exposure to capsaicin, and results in a

subsequent loss of pain sensation (Appendino, 1997).

Capsaicin binds to the C-type vanilloid receptor (VR1) and

opens a cationic channel allowing the influx of calcium. The

calcium influx is an excitatory response, which initiates

release of neuropeptides (substance P). The neuropeptides

are responsible for chemogenic pain, thermoregulation and

neurogenic inflammation. By blocking the calcium channel,

there will be a depletion of substance P in the sensory nerves

and loss of pain (Appendino, 1997; Biro, 1997; Jung, 1999).

Antimicrobial

Capsaicin and dihydrocapsaicin have antimicrobial effects

against Bacillus cereus, Bacillus subtilis, Clostridium sporo-

genes, Clostridium tetani, and Streptococcus pyogenes

(Cichewicz, 1996). Capsaicin has shown bactericidal activity

against H. pylori and therefore, could have a protective effect

against H. pylori-associated gastroduodenal disease (Jones,

1997). A recent study using capsaicin from jalapeno peppers

did not support the role for jalapenos in the treatment of H.

pylori infection (Graham, 1999).

Antineoplastic

Capsaicin, once thought to be carcinogenic, has been shown

to not cause any significant increase in papilloma formation,

abnormal hyperplasia or inflammatory lesions. The drug

does not induce the epidermal ornithine decarboxylase

activity, suggesting that it lacks tumor-promotional activity

(Park, 1997; Park, 1998). Chemoprotective effects of capsai-

cin and dihydrocapsaicin include the inhibition of microsom-

al monooxygenases involved in carcinogen activation (Surh,

1995).

Detoxification/Gastroprotective/Thrombolytic Effects

Capsaicin and dihydrocapsaicin have detoxification activity
with pharmacologically active substances by interacting
irreversibly with hepatic drug metabolizing enzymes (Surh,
1995). Capsaicin has a gastroprotective effect against gastric
mucosal injury caused by aspirin (Yeoh, 1995). Capsicum
has been found to induce increased fibrinolytic activity and
simultaneously cause hypocoagulability of blood (Visudhi-
phan, 1982).

Many documented trials are based on observations of various

extracts of the drug. The initial local effect is pain, then

warmth, then hypersensitivity; reversible or irreversible

peripheral nerve damage is possible.

CLINICAL TRIALS

Pain Modulation

The efficacy of topical capsaicin was determined in 22

patients with chronic severe painful diabetic neuropathy over

an 8-week study period. The randomized, placebo-controlled

study demonstrated a significant improvement with capsaicin

0.75% applied 4 times daily for the overall clinical improve-

ment of pain status, as measured by physician's global

evaluation and by a categorical pain severity scale. The

capsaicin treatment group had a 16% decrease in mean pain

intensity by a visual analogue scale (VAS) versus 4.1%

decrease with the placebo group. The capsaicin treatment

group had a 44.6% decrease in mean pain relief on VAS

versus 23.2% decrease with the placebo group. Approxi-

mately 50% of subjects reported improved pain control or

were cured in a follow-up, open-label study, and 25% were

unchanged or worse (Tandan, 1992).

Gastroprotective Effects

The efficacy of capsaicin as a gastroprotective agent was

determined in 18 healthy volunteers with normal index

endoscopies. The volunteers underwent two studies four

weeks apart to evaluate the effect of capsaicin against

aspirin-induced gastric mucosal injury. Each volunteer took

20 g chili orally with 200 ml water in one study and 200 ml

water in another study. After 30 minutes, each case was

followed with 600 mg aspirin with 200 ml water. Endoscopy

was repeated 6 hours later, and the gastroduodenal mucosal

damage was assessed by a previously validated scoring

system. The median gastric injury score in the chili group

was significantly less, demonstrating a gastroprotective

effect of chili in human subjects (Yeoh, 1995).

INDICATIONS AND USAGE

Approved by Commission E:

• Muscular tensions


• Rheumatism

Unproven Uses: Cayenne is used for painful muscle spasms

in areas of shoulder, arm and spine. In folk medicine the herb

is used for frostbite, chronic lumbago and as a gargle for

hoarseness, sore throats and infected throats. The drug is also

used internally for gastrointestinal disorders, seasickness and

as prophylactic therapy for arteriosclerosis, stroke and heart

disease.

The herb is used in cream form for circulation and as a

female orgasm stimulant. Use should be limited to 2 days,