Analysis of the Potential Topical Anti-Inflammatory Activity ofAverrhoa carambolaL. in Mice

Abstract

Inflammatory skin disorders, such as psoriasis and atopic dermatitis, are very common in the population; however, the treatments currently available are not well tolerated and are often ineffective. Averrhoa carambola L. (Oxalidaceae) is an Asian tree that has been used in traditional folk medicine in the treatment of several skin disorders. The present study evaluates the topical anti-inflammatory effects of the crude ethanolic extract of A. carambola leaves, its hexane, ethyl acetate, and butanol fractions and two isolated flavonoids on skin inflammation. Anti-inflammatory activity was measured using a croton oil-induced ear edema model of inflammation in mice. Topically applied ethanolic extract reduced edema in a dose-dependent manner, resulting in a maximum inhibition of 73 ± 3% and an ID50 value of 0.05 (range: 0.02–0.13) mg/ear. Myeloperoxidase (MPO) activity was also inhibited by the extract, resulting in a maximum inhibition of 60 ± 6% (0.6 mg/ear). All of the fractions tested caused inhibition of edema formation and of MPO activity. Treatment with the ethyl acetate fraction was the most effective, resulting in inhibition levels of 75 ± 5 and 54 ± 8% for edema formation and MPO activity, respectively. However, treatment of mice with isolated compounds [apigenin-6-C-β-l-fucopyranoside and apigenin-6-C-(2″-O-α-l-rhamnopyranosyl)-β-l-fucopyranoside] did not yield successful results. Apigenin-6-C-(2″-O-α-l-rhamnopyranosyl)-β-l-fucopyranoside caused only a mild reduction in edema formation (28 ± 11%). Taken together, these preliminary results support the popular use of A. carambola as an anti-inflammatory agent and open up new possibilities for its use in skin disorders.

Chemical constituents and evaluation of the toxic and antioxidant activities of Averrhoa carambola leaves

“…The species A. carambola presents hypoglycemic (Chau et al, 2004a;Ferreira et al, 2008), hypocholesterolemic (Chau et al, 2004b), antimicrobial (Hsu et al, 2007), antioxidant (Shui & Leong, 2006), and anti-infl ammatory (Cabrini et al, 2011) effects. An alcoholic extract of the stems of A. carambola has been shown to exhibit selective activity against brain tumor cells while that of the leaves was effective against liver carcinoma cells (Tadros & Sleem, 2004).…”

A Comprehensive Review of An Important Medicinal Plant – Averrhoa carambola L.

“…As previously shown, A. carambola is rich in flavonoids and tannins [16] and particularly with flavones. [28] Although the flavonoids evaluated in this study were ineffective, it would be interesting to determine the potential activity of the other compounds from the plant in order to elucidate the mechanism by which the plant influences the inflammatory process. [28] It is also possible that these high flavonoid contents may act in a synergistic manner with other A. carambola components to achieve these bioactivities.…”

“…[28] Although the flavonoids evaluated in this study were ineffective, it would be interesting to determine the potential activity of the other compounds from the plant in order to elucidate the mechanism by which the plant influences the inflammatory process. [28] It is also possible that these high flavonoid contents may act in a synergistic manner with other A. carambola components to achieve these bioactivities. Ferreira et al [25] reported that the reduction of fasting glycemia promoted by the treatment with hydroalcoholic extracts of the leaves was not mediated by an inhibition of hepatic gluconeogenesis and/or an increased glucose uptake by muscles.…”

“…Cabrini et al [28] reported that ethanolic extracts from A. carambola L. leaf and its butanol, ethyl acetate and hexane fractions are effective in reducing croton oil-induced ear edema and cellular migration in mice. These results support the popular use of this plant for skin inflammatory disorders.…”

Physicochemical and sensory characteristics of reduced sugar starfruit juice

“…Starfruit is rich in vitamins, minerals, sugars, and fibers (Moreschi et al, 2007). It is usually used to treat headaches, vomiting, coughing, and hangover, as an appetite stimulant, diuretic, antidiarrheal and febrifugal agent (Cabrini et al, 2011). Starfruit is usually consumed fresh.…”