The Role of Botanical Medicine in Dermatology

Botanical Medicine Introduction

The use of herbal medicine to resolve medical conditions dates back to the 18^th century in ancient Greece.^[1] Hippocrates saw diseases of his time to be imbalances of body fluids, or four humors as he named them.^[1] His suggested treatments of the humoral imbalances comprised of botanical medicines, which were considered to be less invasive than the current standard of care of that time period.^[1] Although the philosophy surrounding humoral imbalances has fallen out of modern medicine ideologies, botanical medicine is being researched more frequently to validate the historical uses of plants as medicine.^[2]

 

How Botanical Medicine is Used

Formulating Botanical Medicines

Tincture

Since most tinctures contain alcohol, they have a much longer shelf life than some of the other herbal preparations. The strength of the alcohol used can range from 45%, 60%, 70% and 90%.^[4] Typically, the ratio used for a tincture is one-part herb to four or five parts alcohol.^[4] Once the ingredients are put into a jar, they should be sealed tightly and shaken daily for two weeks.^[4] After two weeks the solution can be strained and put into smaller containers with a dropper.^[4] Since they are much stronger than infusions or other preparations, a much smaller dose is required.^[4]

Essential Oils

Essential oils are extracted from plant material using steam distillation.^[11] For example, the essential oil glands of lavender are located in the flowers of the plant, so it is better to use the flowers over the leaves or stems.^[11] Essential oils can penetrate through the deep layers of the skin.^[12] This is due to their high concentration of terpenes along with their ability to change the structure of the stratum corneum by interacting with intracellular lipids.^[12] Essential oils have been implicated for the use as enhancers for transdermal delivery of hydrophilic and lipophilic drugs due to this ability.^[12-14] However, caution should be taken when applying essential oils directly onto the skin as they may result in contact allergy.^[15,16] Diluting them in a carrier oil may help reduce this risk.^[17]

Oil Infusion

The preparation for an oil infusion is similar to that of a tincture, however instead of using a solution of alcohol, a fixed vegetable oil is used. Typically, olive, sunflower, or almond oil is used.^[4] The chosen herb is cut and placed into a glass container along with the oil to sit for several weeks and shaken daily.^[4] Oil infusions applied on the skin are not able to penetrate as deep as essential oils do.^[18,19] A study found jojoba oil and avocado oil to only be detectable on the stratum corneum layer of the skin.^[18] These oils are thought to have a semi-occlusive effect in order to retain moisture on the skin while acting as a protective barrier as well.^[18,19] Plant oils contain triglycerides, free fatty acids, tocopherols, sterols, stanols, phospholipids, waxes, squalene, phenolic compounds that influence the skin physiology resulting in these effects.^[19]

Pharmaceutical Interactions with Botanical Medicine

Herbal medicines can have interactions with other pharmaceuticals as well as the enzymes that metabolize various xenobiotics.^[20-22] Listed are examples of herb-drug interactions.

St. John’s Wort

St. John’s Wort (Hypericum perforatum) commonly used herbal medicine for depression has been shown to induce CYP3A4, CYP2C9, and CYP2C19.^[20] Some interactions with St. John’s Wort and pharmaceutical drugs may result in reduced efficacy of oral contraception, reduced blood cyclosporine A concentrations, and reduced plasma concentrations of antiretroviral drugs.^[21]

Echinacea

Echinacea (E. purpurea, E. angustifolia, E. pallida) has been shown to stimulate the immune system, and if often taken to prevent or treat various viral infections.^[22] With few adverse effects, Echinacea is thought of to be safe, but it has been shown to inhibit in vivo CYP1A2 catalytic activity, which could interact with other pharmaceuticals metabolized by CYP1A2 such as cyclobenzaprine and tacrine.^[23] Echinacea is typically used short term in an acute manner and is not intended for long term use.

Warfarin

Warfarin is primarily metabolized by cytochrome P450s, with isoenzyme CYP2C9 accounting for the greatest proportion of metabolism.^[24] Herbs that also act on cytochrome P450s will alter the plasma concentration of warfarin.^[24] Since warfarin mainly binds to albumin, herbs that bind to albumin will affect plasma concentrations as well. Herbs that interfere with platelet aggregation, gut vitamin K synthesis, the vitamin K cycle, and the coagulation cascade may also impact the effects of warfarin.^[24] Cranberry, chamomile, cannabis, ginkgo biloba, garlic, grapefruit, and lyceum, have been found to have major potentiation effects when combined with warfarin.^[24] St. John’s wort and red clover have been found to have major inhibitory effects.^[24] Turmeric may increase risk of bleeding in patients taking warfarin.^[25,26]

Clinical Research of Botanical Medicine in Dermatology

Pediculus humanus capitis

Essential oils from wild bergamot, clove, lavender, tea tree, and Yunnan verbena were diluted in carrier oils and dropped onto living lice of subjects.^[7] The most efficacious herb were cloves either diluted in coco or sunflower oil, killing over 90% within two hours after lice were exposed to the clove essential oil for thirty minutes.^[7] The other essential oils were not as successful, and each varied in major chemical components.^[7] Eugenol was thought to be the main component of the clove oil.^[7]

Acne vulgaris

Green tea has been shown to target main pathological processes in acne^[27] by its sebosuppressive,^[28] antimicrobial against C. acnes and other microbes,^[29] and anti-inflammatory effects by inhibiting NF-κB and AP-1 pathways, and causes apoptosis of sebocytes and subsequently decreasing C. acnes levels.^[30] Topical 2% green tea lotion has been shown to be an efficacious and inexpensive treatment option for those with mild-to-moderate acne vulgaris.^[31] Tea tree oil can be used in the treatment of acne with its anti-inflammatory and antimicrobial effects.^[32] A constituent of tea tree oil, Terpinen-4-ol, has been shown to decrease inflammatory cytokines.^[33]

Botanical Medicine as a Viable Treatment Modality 

Botanical medicine, one of the oldest treatment modalities, has been drawing attention from the conventional medical and research communities as alternative or adjuvant treatments to conventional care.^[1] The different preparations of botanical medicine allow a wider therapeutic use for various conditions,^[3,6] and research has been showing promising results, especially within the dermatological sphere of medicine.^[7,31] More research is warranted to explore other possible drug-herb interactions and the safety of botanical medicines in each preparation.

Practical Tips

• For patient compliance, it may be better to recommend something less time consuming to take and prepare, like a tincture, tea, or topical since there are several companies out there that have these pre-prepared at affordable prices.

• Tinctures maintain a long shelf life due to the alcohol content.

• When considering an herbal product, it’s important to evaluate the company’s quality control measures.
• Anytime anyone is taking botanicals it is necessary to ask what medications they are on, especially if they are taking, or plan to take, St. John’s wort.
• Caution should be taken when applying essential oils directly to the skin as some individuals may experience an allergic reaction. Diluting in a carrier oil may help reduce this risk. Essential oils should never be taken internally.