herbal resources play a very important role in the management of the skin and
inflammatory diseases. Some studies suggest that psoriasis symptoms can be
relieved by change in
diet and lifestyle. Fasting, low energy diets and
vegetarian diets have improved psoriasis symptoms.
In some treatments supplementation with fish oil shows a beneficial effect due
to the presence of omega – 3 Fatty Acids and Vitamin E. Cannabis is also
suggested for treating psoriasis due to the anti-inflammatory properties of its
cannabinoids and their regulatory effect on immune system (Bhuchar et al., 2012,
Brown et al., 1998, Brown et al., 2004; Farber et al., 1986; Koo et al., 1998,
Mantle et al., 2001; Deng et al., 2013).
Some herbal alternatives for natural psoriasis treatment and the possible
rationale of their anti-psoriatic activity have been discussed below briefly on
the basis of reports of some researches.
Herbal Remedies for Treating Psoriasis
Capsicum frutescens It is commonly known as Cayenne, its chief component being
capsaicin. One hypothesis on the pathogenesis of psoriasis suggests a neurogenic
inflammatory etiology mediated through substance – P (SP). SP activates
inflammatory cells and ultimately perpetuates vasodilatation, angiogenesis and
keratinocyte hyperproliferation. In accordance, psoriatic lesions are known to
be more densely innervated with higher SP content than control or uninvolved
psoriatic skin. Capsaicin stimulates the release of SP by binding to the
vanilloid receptor on slow – conducting, unmyelinated type C neurons and
ultimately leads to its depletion (Joe et al., 1997, Bernstein et al., 1986,
IIis et al., 1993).
2. Aloe vera
Aloe vera is a popular plant used in cosmetic care
and first aid products in case of thermal injuries. Aloe containsanthroquinones,
steroids, saponins, mucopolysaccharides and salicylic acid. Syed and colleagues
(1996) conducted a double – blind, placebo – controlled study on 60 patients
with psoriasis with slight to moderateplaque type psoriasis
and an average 8.5 year duration
of their disease. Patients self – administered topical Aloe vera extract cream
or vehicle placebo three times a day without occlusion for 4 weeks to their
psoriatic plaques. The aloe group showed significantly higher rates of clearing
the psoriatic plaques in almost all patients. Anthraquinone and acemannan, the
main active compounds in Aloe vera, have antibacterial activity against
Staphylococcus and Streptococcus species and may provide a rationale for their
therapeutic efficacy in psoriasis. In addition, salicylic acid, a component of
Aloe vera, is a keratolytic and would contribute to its reported efficacy in the
desquamation of psoriatic plaques (Syed et al., 1996, Klein et al., 1988, Robson
et al., 1982, Choonhakarn et al., 2010, Paulsen et al., 2005, Dhanabal et al.,
3. Milk Thistle
Silybum marianum It is commonly known as Milk Thistle. This plant is very well
known for its hepatoprotective activity. Numerous changes have been detected in
the liver of patients with psoriasis, including steatosis, periportal
inflammation, fibrosis, necrosis and cirrhosis. A multifactorial etiology of
liver disease in patients with psoriasis includes changes due to alcohol use,
nutritional factors, anti – psoriatic medications and a direct effect of the
psoriasis itself. Abnormally high levels of cAMP and leukotrienes have been
observed in psoriatic patients and normalization of these levels may improve the
condition. The importance of silymarin in the treatment of psoriasis may be due
to its ability to improve endotoxin removal by the liver, inhibit cAMP
phosphodiesterase and inhibit leukotriene synthesis. (Sabir et al., 2014).
4. Dong quay
Angelica sinensis It
is commonly known as Dong quay. This
medicine extracts contain potent furocoumarin i.e. psoralen. Psoralens are
potent photosensitizers in the presence of UVA. Exposure to UVA, following
psoralen ingestion, causes epidermal DNA cross – linking and thus a decrease in
the rate of epidermal DNA synthesis. Patients are self-administering a form of
psoralen– UVA (PUVA) therapy by consuming dong quay
and then receiving ultraviolet light therapy or natural sunlight. Koo & Arain,
1998 studied patients with psoriasis, two-thirds patients got complete relief
from their disease after oral treatment with this plant extract. Another herb
used in treating psoriasis hogweed (Heracleum sphondylium ), also contains a
psoralen but the efficacy and side effects are not available (Bhuchar et al.,
2012, Koo et al., 1998).
Matricaria recutita It is commonly known as Chamomile. The chamomile flowers
have a long therapeutic tradition in treating gastrointestinal ailments. The
rationale for its use in psoriasis is that chamazulene, a by-product of the non –
volatile oil extract, matricin, known to have anti – inflammatory activity by
inhibition of lipoxygenase and as a result, leukotriene B4 (LTB4) formation.
There is evidence supporting the role of increased LTB4 formation in psoriatic
plaques; therefore, inhibition results in disease improvement. Chamomile oil has
antimicrobial activity against skin pathogens, Staphylococcus and
Candida. The flavonoids, quercetin and
apigenin, are also active compounds of the flower. Quercetin is reported to be a
potent inhibitor of lipoxygenase and to a lesser degree, cyclooxygenase.
Quercetin also shows good skin penetration property (Murti et al., 2012, Safayhi
et al., 1994).
6. Tea Tree Oil
Melaleuca alternifolia It
is traditionally known as Tea Tree Oil and is popular for its wound healing
property. The oil contains terpin – 4-ol, alpha – terpineol and alpha – pinene
which confer antimicrobial activity against Propionibacterium acnes and
Staphylococcus epidermidis. No
studies have investigated the use of tea tree oil in psoriasis; however, its
role in urticarial reactions and control of whale and flare has been reported.
Hence, study can be made to evaluate its anti – psoriatic efficacy. Although
there is reported efficacy in the treatment of acne, dandruff and cold sores,
tea tree oil can produce allergic dermatitis in individuals sensitized to the
sesquiterpenoid fractions. Oral ingestion can lead to the detrimental effects of
cognitive disorientation, systemic contact dermatitis and coma (Carson et al.,
2001, Carson et al., 1998, Koh et al., 2002, May et al., 2000).
Gaultheria procumbens It is commonly known as Wintergreen. Wintergreen is a
plant native to the Eastern United States and historically was used by Native
Americans as an analgesic. It contains 118 Singh and Tripathy / Journal of
Applied Pharmaceutical Science 4 (11); 2014: 114-121 methyl salicylate, which is
having anti – inflammatory properties. Although used topically for psoriasis,
wintergreen can cause systemic effects like tinnitus, vomiting, tachypnea and
acid – base disturbances. Patients using aspirin or a prescribed salicylic acid
compound in conjunction with a salicylate herbal (for example, wintergreen, aloe
vera, or red clover) are more susceptible for systemic toxicities. Additionally,
oil of wintergreen can increase prothrombin time and international normalized
ratio (INR) of clotting, creating problems for patients on warfarin. There are
no investigations on its effectiveness in psoriasis, but have potential anti –
inflammatory effect and needs further scientific investigations for its use in
psoriasis (Sahu et al., 2011).
8. Slippery elm
Ulmus rubra It is commonly known as Slippery elm, named so for its mucilage
component, derived from the inner bark of the elm. Historically, Native
Americans used this extract as a poultice for boils and wounds. It is currently
marketed as a treatment for irritable bowel syndrome, reflux and cystitis. Brown
and colleagues (2004) evaluated a study group of five patients with chronic
plaque-type psoriasis on a home based six month medical nutritional therapeutic
regimen. They assessed psoriasis symptoms and bowel permeability over the
experimentation period and reported an improvement in all studied parameters.
Psoriasis area and Severity Index averaged post test scores showed significant
improvement (Buchar et al., 2012, Brown et al., 2004).
Curcuma longa/ Curcuma domestica Turmeric has a long history of being used for
infections and kidney stones. The use in psoriasis is a relatively new adjunct.
The anti-inflammatory components are thought to be contained in the curcuminoids
and volatile oils which function through selective inhibition of phosphorylase
kinase (PhK). PhK is an enzyme found in the epidermis. Significantly higher
levels have been noted to correlate with clinical activity of psoriasis. It is
also reported decreased PhK activity in the curcumin and calcipotriol treated
groups corresponded to severity of parakeratosis, decreases in keratinocyte
transferrin receptor expression and density of epidermal CD8 + T cells. The
study did not report any adverse effects, although contact dermatitis is a
reported adverse effect (Joe et al., 1997).