Anti-inflammatory activity of cinnamon (C. zeylanicum and C. cassia) extracts – identification of E-cinnamaldehyde and o-methoxy cinnamaldehyde as the most potent bioactive compounds

Abstract

Chronic inflammation is a contributing factor in many age-related diseases. In a previous study, we have shown that Sri Lankan cinnamon (C. zeylanicum) was one of the most potent anti-inflammatory foods out of 115 foods tested. However, knowledge about the exact nature of the anti-inflammatory compounds and their distribution in the two major cinnamon species used for human consumption is limited. The aim of this investigation was to determine the anti-inflammatory activity of C. zeylanicum and C. cassia and elucidate their main phytochemical compounds. When extracts were tested in LPS and IFN-γ activated RAW 264.7 macrophages, most of the anti-inflammatory activity, measured by down-regulation of nitric oxide and TNF-α production, was observed in the organic extracts. The most abundant compounds in these extracts were E-cinnamaldehyde and o-methoxycinnamaldehyde. The highest concentration of E-cinnamaldehyde was found in the DCM extract of C. zeylanicum or C. cassia (31 and 34 mg g(-1) of cinnamon, respectively). When these and other constituents were tested for their anti-inflammatory activity in RAW 264.7 and J774A.1 macrophages, the most potent compounds were E-cinnamaldehyde and o-methoxycinnamaldehyde, which exhibited IC₅₀ values for NO with RAW 264.7 cells of 55 ± 9 μM (7.3 ± 1.2 μg mL(-1)) and 35 ± 9 μM (5.7 ± 1.5 μg mL(-1)), respectively; and IC₅₀ values for TNF-α of 63 ± 9 μM (8.3 ± 1.2 μg mL(-1)) and 78 ± 16 μM (12.6 ± 2.6 μg mL(-1)), respectively. If therapeutic concentrations can be achieved in target tissues, cinnamon and its components may be useful in the treatment of age-related inflammatory conditions.

Flavonoid glycosides from Rubus chingii Hu fruits display anti-inflammatory activity through suppressing MAPKs activation in macrophages

“…RAW 264.7 cells were plated at 2.5 × 10 5 cells/mL in 24 well-plates and then incubated with or without LPS (1 µg/mL) in the absence or presence of various concentrations of samples for 24 h. One hundred microlitres of cell culture medium were mixed with 100 µL of Griess reagent (equal volumes of 1% sulphanilamide in 5% phosphoric acid and 0.1% N-1-naphtylethylenediamine dihydrochloride in distilled water), incubated at room temperature for 10 min, and then the absorbance at 540 nm was measured in a microplate reader. Nitrite concentrations in the supernatants were determined by comparison with a sodium nitrite standard curve (Gunawardena et al, 2015;Hooshmand et al, 2015). Fresh culture medium was used as the blank in all experiments.…”

Medicinal Plants of the Australian Aboriginal Dharawal People Exhibiting Anti‐Inflammatory Activity

“…NSAIDs in particular can cause severe side effects, most importantly gastric ulcers. NSAIDs are specifically designed as inhibitors of cyclooxygenase (COX) enzymes and, in contrast to CSAIDs, do not influence the production of proinflammatory cytokines such as TNF- α or free radicals such as nitric oxide [28]. CSAIDs specifically target p38 MAPK and NF- κ B signalling pathways to inhibit cytokine-mediated events with demonstrated efficacy in a range of animal models [29, 30].…”

“…Therefore, pharmacological compounds with the ability to attenuate the production of these inflammatory molecules may have potential for the treatment of many inflammatory diseases including AD [21, 22, 28, 34, 35]. …”

“…In recent years, the search for novel anti-inflammatory drugs from a wide range of medicinal plant resources has been intensified, and a variety of plant secondary metabolites including apigenin, curcumin, cinnamaldehyde, and resveratrol have already been found to suppress inflammatory responses [21, 22, 28]. …”

Āyurveda's Contributions to Vegetarian Nutrition in Medicine

“…It has been observed that cinnamon has lipid-lowering activity [37] and may also reduce insulin resistance [38]. It also has anti-inflammatory properties [39]. …”