I really shouldn’t be writing this article, as Nutrition & Healing is privileged to include an article about botanicals nearly every month written by world-class botanical expert Kerry Bone [BSc (Hons), Dip Phyto, FNIMH, FNHAA, AHG, MCPP, FANTA], who knows much more about herbs than me!
But I first read about Centella asiatica in the 1970s and 1980s, when it was still known and sold as gotu kola. Several sources recounted the story of Taoist master herbalist Ching Yuen Li, who was said to have lived for over 200 years. The story passed down through generations is that his longevity was at least partially attributable to a group of botanicals he used regularly, one of which was Centella asiatica.
Like most of us, I was interested in healthy longevity, and Centella was – and still is – remarkably inexpensive. So it was added to two of my lists: supplements to take, and research of which to keep track.
Centella, previously commonly known as gotu kola, has many beneficial actions in the body, ranging from its ability to heal wounds and burns to improving skin conditions like psoriasis, scleroderma and even leprosy. In both animal and human studies,3 there is even evidence that it may help improve cognitive function.
In India, Centella is lauded as a spiritual herb, believed to assist with meditation. It’s reported that monks prepare a tonic of Centella tea with honey. Ayurvedic practitioners use it as a cooling herb to reduce fevers, asthma, bronchitis, and abdominal disorders. It’s commonly used as a brain tonic for many nerve-related disorders.
As is so often the case, modern research is simply confirming what our ancestors already knew about Centella and other herbs, and occasionally adding something new to our understanding such as their ‘molecular mechanisms of action’. I’ve collected – with help – some of the modern research findings on Centella here.
Stimulate collagen production
Centella’s active ingredients include several compounds (for the scientifically inclined, pentacyclic triterpene compounds) that have been shown to help increase the proliferation of fibroblasts (cells which produce collagen) and the production of collagen itself. More than 25 per cent of the protein in our bodies is type I collagen, an important structural protein found in highest amounts in connective tissue. Connective tissue makes up tendons, ligaments, and the skin, and is found in the cornea, blood vessels, between the vertebrae, the dentin of the teeth, and the gastrointestinal tract and cartilage. We’ve all seen a few older people described as ‘gaunt’ and ‘faded’; some of that tissue loss is collagen.
Soothe sun-damage, reverse wrinkles, and more
Centella is well known in China and Southeast Asia for its wound-healing properties. Modern research has now confirmed what’s been known for generations: Centella can be useful for the treatment of sun-damaged skin and wrinkles as well as burns and other tissue damage.
Centelloids is the name given to the group of molecules in Centella which have been identified as being the most helpful for healing. The centelloids include asiaticoside, asiatic acid, madecassoside, and madecassic acid. Research has identified that these compounds support the repair and healing of wounds as well as increase the strength of skin, connective tissues, nails and hair. In addition these same compounds stimulate the production of hyaluronic acid, best known for its presence in joint fluid where it helps to maintain skin thickness and texture. And type I collagen formation improves scar maturation and reduces inflammation.
Proven anti-ageing benefits in appearance
Because it increases type I collagen, which decreases as we age, Centella can be a powerful herbal aid in the treatment of sun-damaged skin. In a double-blind, randomised clinical study, 20 women aged 45-60 with photoaged skin were asked to apply a topical extract consisting of 0.1 per cent madecassoside, and 5 per cent vitamin C for six months. At the end of the trial, their skin was assessed for elasticity, firmness and hydration and improvement was confirmed in two-thirds of participants.
Researchers noted improvement in all of the parameters being evaluated, including improvement in the appearance of wrinkles, both deep and superficial. Skin remodelling was determined to be occurring at both a structural and functional level. The combination of vitamin C and one active constituent of Centella, madecassoside, appear to act synergistically, providing greater benefit when used together than when used separately.10
Banish burns and help heal wounds
According to recent studies, the active ingredients of Centella that are most responsible for its burn-healing abilities are madecassoside and asiaticoside. Of these, madecassoside is better at promoting burn-wound healing than asiaticoside.11 The way Centella heals burns is similar to the way it improves sun-damaged skin, by stimulating the production of fibroblasts which in turn increase the synthesis of type I collagen.12,13 Its impact on collagen makes it an ideal herb to use because it improves wound healing while at the same time reducing excess collagen build-up that can contribute to the formation of scars and keloids.
In animal studies, extracts of Centella applied topically three times daily to wounds over a 24-day period led to increases in collagen synthesis and strength. The wounds treated with the Centella extract healed more rapidly than controls that were left untreated. Healing was seen when it was applied as a cream, ointment and gel, but the gel showed the greatest healing response.
In another study of 112 rats, Centella’s ability to heal surgical incisions and burn wounds was examined. Four different preparations of the herb were tested and each increased the speed of healing in both the incisions and burn wounds.
Centella’s healing benefits extend to the field of gynaecology, where it has been used to treat women following episiotomy, an incision made during childbirth to reduce tearing of the vulva. One study reported more rapid healing in women treated with Centella when compared with those who didn’t receive it.
Reduce the appearance of stretch marks
A cream made up of Centella, alpha-tocopherol (a fraction of vitamin E) and enzymatically digested collagen and elastin (for the technically inclined, collagen and elastin hydrolysates) has been successfully used to reduce stretch marks in pregnant women. A study involving 100 women who had previously had stretch marks during pregnancy showed a reduction in their appearance in a subsequent pregnancy using the Centella cream, when compared to a group of women not using it.
In a study of the effects of Centella on rabbit corneal epithelial cells (the surface cells over the centre of the eye), low concentrations of a Centella extract promoted healing better than higher concentrations. The concentration that appeared to be the most effective was 62.5 parts per million of an aqueous extract of Centella.
Herb improves psoriasis and scleroderma
Psoriasis is an autoimmune skin condition in which skin cells (keratinocytes) multiply too rapidly leading to itchy red scaly patches. Instead of taking the typical 28-30 days for cells to be replaced, they turn over in three to five days.19 Psoriasis can be very difficult to treat and conventional medicine often uses cytotoxic (poisonous, but not fatal) topical treatments such as psoralens.
Unfortunately, these harsh approaches often don’t provide much benefit. Extracts of Centella on the other hand have been found to inhibit the production of keratinocytes making it a promising potential treatment for psoriasis.
Scleroderma – an auto-immune skin condition that leads to gradual thickening and hardening of skin and internal lining surfaces of the body – responds to Centella as well. One study examined the effects of madecassol (one of the many ingredients found in Centella) on focal and systemic scleroderma. The six-month study followed 54 participants between the ages of 15 and 70 who had scleroderma for periods of time ranging from three months to 15 years.
A combination of madecassol in tablets, ointment or powder was given to participants. All volunteers received tablets twice a day for six months. Twelve had general improvement in their symptoms as well as improvement in their skin conditions. Another 10 participants reported improvement in how they felt and didn’t show any progression of symptoms. No improvement was observed in participants with progressive disease. The greatest improvement occurred in those participants with systemic scleroderma who were applying the ointment topically to finger ulcers.
‘Short circuit’ cellulite
Centella has been reported as a remedy for cellulite, a lumpy-appearing form of fat often occurring on the abdomen and thighs. In one study, 20 healthy participants took an oral preparation containing 60 mg of Centella for 90 days and another group took a placebo. In the Centella-treated group, the diameter of the lumpy fat cells decreased significantly.
Conquer circulation issues
Some studies have examined Centella’s potential for improving venous insufficiency. Its ability to improve connective tissue and increase vascular integrity make it a potential therapy for varicose veins and other circulatory disorders and, as is so often written in sceptical modern research, it merits further study.
Reduce your ulcer risk
In an animal study, researchers examined Centella’s ability to prevent stomach ulcers after alcohol (specifically, ethanol) is administered. They concluded that Centella may exert anti-ulcer influence by improving the gastric mucosa and decreasing the damage caused by free radicals. In another animal study, Centella improved healing of acetic acid induced ulcers in rats.
Effectively boost brain power
Despite having few modern human studies to back the practice, Centella has been used to support healthy cognitive function for many years. In 1992, one of the earliest animal studies of cognitive function involved rats that were given an oral herbal extract of Centella prior to a learning experiment. Rats were given the Centella for 14 days and then tested to see if they retained certain behaviours. Researchers found that the Centella-treated rats retained memories up to 60 times more effectively than untreated animals.
In other animal studies, a Centella water extract was shown to have neuroprotective benefits. Amyloid beta is a protein that accumulates to toxic excess in the neurons of those with Alzheimer’s disease. When rats that were genetically altered to have high amounts of amyloid beta in their brain neurons were treated with Centella, they showed improvements in memory and learning. The researchers also identified specific compounds (this time, dicaffeoylquinic acids for the technically inclined) in Centella that appear to be able to protect against cell death.
In a randomised, placebo-controlled, double-blind study, 28 healthy human participants took Centella in 250, 500, or 750mg doses, twice a day for two months. At the end of the study, researchers noted improvement in both memory and mood.
Improve strength and stamina
Centella may be able to play a role in reducing some of the effects of ageing through its antioxidant actions, counteracting the effects of oxidative stress, and increasing stamina and vigour. In a three-month study of the benefits of Centella on strength, especially that of the lower extremity, researchers noted improvement in seniors who were given Centella.
Study participants were given 250, 500, and 750mg doses once daily during the three-month study. After two months, improvement in strength, as assessed by performance with a 30-second chair stand test, was seen in those taking 500 and 750mg doses. Study results show that Centella used as a supplement or functional food may be able to improve strength in elders.
Nix anxiety naturally
Centella has a long history as a useful remedy for anxiety and other nervous conditions. Modern research has backed up those success stories by identifying molecules, called saponin glycosides, which are believed to be responsible for some of these effects.31 These components of Centella are mildly sedating in high doses and shouldn’t be taken with other sedating products.
A leg up on leprosy
Although it was a scourge in Biblical times, leprosy hasn’t been much of a problem in the UK or US. However, the devastating disease does still exist in some areas of the world even today, and Centella may be able to help.
Studies of Centella’s major constituent, asiaticoside, show that it may be an effective treatment for leprosy. Asiaticoside works by interfering with the covering of the Bacillus leprae organism, making it easier to kill.
Centella asiatica has few side effects and no known toxicity. It can be given as a dry herb, capsule, tincture, or tablet. Typical capsule doses range from 300 to 600mg. It can also be used as a tea by adding hot water to one to two teaspoons of the dry herb and steeping for up to 15 minutes. Remember, Centella has one other virtue: compared to other supplements, it’s cheap!
Wishing you the best of health,
Dr. Jonathan V. Wright
Nutrition & Healing
Vol. 9, Issue 4 • April 2015
Full references and citations for this article are available in the downloadable PDF version of the monthly Nutrition and Healing issue in which this article appears.