Research & Education

Calendula – The Magic of Marigolds

 

With the onset of summer pharmacies and doctors’ offices usually start to fill up with people experiencing achy muscles and joints that come from sudden overexertion after the long winter and the up and down weather of spring. Whether it’s weekend warriors going a little too hard and fast in their athletic pursuits or the muscle and joint pains that often come after hours of gardening yardwork and other physical chores people seek relief from the painful reminder that they’re “not as young as they used to be.” As we know many of the most common go-to pain relievers such as NSAIDs come with some very harmful side-effects. As patients become more aware of the potentially dangerous pitfalls of using these drugs long-term they may be looking for safer more natural alternatives. And they wouldn’t have to go much further than their own garden to find one.

Calendula—more commonly known as marigold—contains anti-inflammatory compounds that may help relieve the discomfort associated with strained overworked muscles and joints. These seemingly ubiquitous perennial flowers get their yellow orange and gold colors from the carotenoids lutein zeaxanthin and beta-carotene but even though those are important dietary antioxidants they aren’t the active compounds responsible for the inflammation-reducing properties of calendula extract.

Active components in calendula extract have been demonstrated effective whether taken orally or applied topically such as in a pain-soothing cream or ointment. Orally administered calendula extract inhibited chemically induced paw edema in a mouse model of chronic inflammation. Additionally calendula extract significantly inhibited elevations in pro-inflammatory cytokines IL- 1β IL-6 TNF-α and IFN-γ as well as C- reactive protein in mice injected with lipopolysaccharide. Researchers hypothesize that the mechanism of action involves inhibition of COX-2 and reduced subsequent production of pro-inflammatory prostaglandins. 

Topical calendula extract is known to be beneficial for wound healing particularly for burns. This may be of benefit during summertime beyond muscle strains and joint pain as it may be helpful for reducing ultraviolet light-induced skin damage. Many natural sunscreen products contain calendula for this reason. Human skin cells exposed to hydrogen peroxide were protected against oxidative damage when pre-incubated with calendula extract suggesting that calendula is beneficial for general skin protection but particularly when skin is exposed to a UV or oxidative challenge. 

In a rat model of thermal burns rats receiving 200mg/kg of orally administered calendula extract showed significant improvements in healing parameters compared to untreated rats. Compared to the untreated rats the calendula group showed increased amounts of collagen-hydroxyproline suggesting accelerated wound healing. They also showed lower amounts of haptoglobin and orosomucoid—acute phase proteins that are elevated in response to burn injury. Antioxidant defenses were increased and lipid peroxidation was decreased in the treated group compared to the untreated and markers for tissue damage including alkaline phosphatase and alanine and aspartate transaminases were significantly lowered in the calendula groups in a dose-dependent manner. Aside from calendula’s anti-inflammatory properties the high carotenoid content may be at work here with the antioxidants scavenging free radicals in the damaged tissue.

Calendula extract has been shown to be safe across a variety of parameters including skin irritation sensitization and phototoxicity. “Acute toxicity studies in rats and mice indicate that the extract is relatively nontoxic” and an Ames test determined that saponins isolated from the plant are non-mutagenic. Calendula’s excellent safety profile may be why it’s been used throughout history for a variety of traditional medicinal purposes including as an antipyretic antimicrobial and for issues as diverse as hemorrhoids jaundice and varicose veins. Considering the modern body of supportive literature it’s not surprising that it has also been used for reducing the pain and swelling associated with musculoskeletal injuries.

And hey for individuals who don’t have any of the issues for which calendula extract may be helpful marigolds are nice to have around simply because they’re pretty and bright and that’s as good a reason as any!