Anti-Inflammatory Activity of Dichloromethane Extract of Heterotheca inuloides in Vivo and in Vitro*

Abstract

The dichloromethane extract from the dried flowers of Heterotheca inuloides Cass. was investigated on several pharmacological models of inflammation in vivo and in vitro. It showed anti-inflammatory activity on the croton oil-induced oedema test in mouse ear, at 1 mg/ear. The compound isolated from this extract, 7-hydroxy-3,4-dihydrocadalin, showed anti-inflammatory effect on the same experimental model (ED50 of 0.9 mumol/ear), as well as on COX-1 and COX-2 catalysed prostaglandin biosynthesis assays, with IC50 values of 22 microM and 526 microM, respectively. No effect was observed on carrageenan-induced oedema and on fMLP/PAF-induced exocytosis of human neutrophils. The COX-1 inhibitory effect showed by 7-hydroxy-3,4-dihydrocadalin might be related to the anti-inflammatory activity on the topical oedema induced by croton oil.

Antineuropathic effect of 7-hydroxy-3,4-dihydrocadalin in streptozotocin-induced diabetic rodents

“…Antioxidant activity of 7-hydroxy-3,4-dihydrocadalin results of interest as pathogenesis of diabetic neuropathy is related with metabolic changes in several pathways that interact in a mutually facilitatory fashion to cause an imbalance in the mitochondrial redox state and an increment in the expression of pro-inflammatory genes producing neuronal hypersensitivity [3,5]. Remarkably, 7-hydroxy-3,4-dihydrocadalin has also demonstrated anti-inflammatory properties on the croton oil-induced edema test in mouse ear [22] and carrageenan-induced paw edema model [18]. Speculating, 7-hydroxy-3,4-dihydrocadalin could be useful to treat the diabetic neuropathy in a more integrative manner as it combines antineuropathic, antioxidant and possibly anti-inflammatory properties.…”

“…Recent evidence obtained in our laboratory points out that 7-hydroxy-3,4-dihydrocadalin seems to be one of the main sesquiterpenoid responsible of the antinociceptive effect of this plant in inflammatory conditions [18]. Notwithstanding, considering that 7-hydroxy-3,4-dihydrocadalin has antioxidant [19-21] and anti-inflammatory [18,22] properties, the most important therapeutic effect of 7-hydroxy-3,4-dihydrocadalin could be found it in the treatment of chronic pain, specially, in those painful conditions where there is an imbalance of oxidative stress and systemic inflammatory state as painful diabetic neuropathy.…”

Mexican Arnica Anti–Inflammatory Action: Plant Age is Correlated with the Concentration of Anti–Inflammatory Sesquiterpenes in the Medicinal Plant Heterotheca inuloides Cass. (Asteraceae)1

“…Besides anti-inflammatory activity (Gené et al 1998;Segura et al 2000;Delgado et al 2001), these compounds may be antibacterial, growth inhibiting (Kubo et al 1995), antioxidant, or cytotoxic (Kubo et al 1996).…”

“…Extraction and Quantification of the Antiinflammatory Compounds: We quantified the following anti-inflammatory terpenes contained by Mexican árnica: caryolan-1, 9β-diol, cadalen-15-oic acid, 7-hydroxycadalene, 4-hydroxy-2-isopropyl-4, 7-dimethyl-1(4H) naftalinone, 7-hydroxy-4αH-3, 4-dihydrocadalene (Segura et al 2000;Delgado et al 2001), β-caryophyllene and β-caryophyllene epoxide (Shimizu et al 1990). …”

“…Even though the active compounds of Mexican árnica and the anti-inflammatory and analgesic activities of certain secondary metabolites of this species are known (Gené et al 1998;Segura et al 2000;Delgado et al 2001), there is no information about the variation in concentration of the anti-inflammatory metabolites in this or other cultivated plants. Therefore, our goal was to quantify the variation of anti-inflammatory cadalenes and isocadalenes in Mexican árnica plants subjected to soil fertilization and harvesting regime (stem cutting events) that mimic contemporary cultivation practices in Mexico.…”