Aqueous extract from Ipomoea asarifolia (Convolvulaceae) leaves and its phenolic compounds have anti-inflammatory activity in murine models of edema, peritonitis and air-pouch inflammation.
ETHNOPHARMACOLOGICAL RELEVANCE
Ipomoea asarifolia (Desr.) Roem. and Schult.(Convolvulaceae), popularly known as salsa or salsa-brava, is a plant of which the decoction of leaves is used in folk medicine to treat various inflammatory disorders such of dermatitis, scabies, symptoms of syphilis, skin ulcers and external wounds. However, little is known about possible compounds and mechanisms of action of the plant to support the activities reported by popular use.


AIM OF THE STUDY
The study aimed to identify bioactive molecules present in the crude extract of I. asarifolia leaves and investigate the anti-inflammatory potential of this extract in different experimental in vivo models to improve the understanding on that activity.


MATERIAL AND METHODS
Aqueous extract of I. asarifolia leaves was prepared by decoction (1:10 m/v) and its chromatographic profile was obtained by high performance liquid chromatography coupled with diode array detector (HPLC-DAD) and liquid chromatography diode array detector coupled with mass spectrometry (LC-DAD-MS). The potential anti-inflammatory activity of the extract was assessed using the following in vivo models: xylene-induced ear edema (20, 30 and 40mg/kg), evaluating the degree of edema formation; carrageenan-induced peritonitis (10, 20 and 30mg/kg), evaluating leukocyte migration and cytokine levels (IL-1β, IL-6, IL-12 and TNF-α) at 4h; zymosan-induced air pouch inflammation (20, 30 and 40mg/kg), evaluating the kinetics of leukocyte migration by total and differential counts at 6, 24 and 48h. The same tests were conducted using pure compounds identified in the aqueous extract from I. asarifolia leaves in different doses for each experimental model.


RESULTS
The compounds identified in the aqueous extract of I. asarifolia leaves by HPLC-DAD and LC-DAD-MS were rutin, chlorogenic acid and caffeic acid. The extract significantly reduced ear edema induced by xylene (81%, 85% and 86% for doses of 20, 30 and 40mg/kg, respectively, p<0.001), as well as cell migration in experimental models of peritonitis (70%, 78% and 83% for doses of 10, 20 and 30mg/kg, respectively, p<0.001) and air pouch inflammation (58%, 67% and 53% for doses of 20, 30 and 40mg/kg, respectively, p<0.001). In addition, the extract demonstrated the ability to significantly inhibit the production of cytokines IL-1β, IL-6, IL-12 and TNF-α (p<0.001). The secondary metabolites tested (rutin, chlorogenic acid and caffeic acid) also showed the ability to significantly (p<0.001) decrease the parameters analyzed above.


CONCLUSION
This is the first study to identify and confirm these phenolic compounds in I. asarifolia leaves extract and to suggest that these compounds contribute to the anti-inflammatory activity in vivo, as reported by ethnomedicinal use of this plant. Through the different experimental models performed, we can conclude that the results obtained with the aqueous extract from I. asarifolia leaves support its popular use for the treatment of inflammatory disorders.
['Furtado|Allanny A|AA|', 'Torres-Rêgo|Manoela|M|', 'Lima|Maíra C J S|MCJS|', 'Bitencourt|Mariana A O|MAO|', 'Estrela|Andréia Bergamo|AB|', 'Souza da Silva|Nayara|N|', 'da Silva Siqueira|Emerson Michell|EM|', 'Tomaz|José Carlos|JC|', 'Lopes|Norberto Peporine|NP|', 'Silva-Júnior|Arnóbio Antônio|AA|', 'Zucolotto|Silvana M|SM|', 'Fernandes-Pedrosa|Matheus F|MF|']
D000818:Animals D000893:Anti-Inflammatory Agents D002351:Carrageenan D002634:Chemotaxis, Leukocyte D002851:Chromatography, High Pressure Liquid D002855:Chromatography, Thin Layer D016207:Cytokines D004195:Disease Models, Animal D004305:Dose-Response Relationship, Drug D004487:Edema D005260:Female D007249:Inflammation D018836:Inflammation Mediators D027741:Ipomoea D007958:Leukocyte Count D007962:Leukocytes D008297:Male D013058:Mass Spectrometry D008807:Mice, Inbred BALB C D010538:Peritonitis D010636:Phenols D008517:Phytotherapy D010936:Plant Extracts D018515:Plant Leaves D010946:Plants, Medicinal D013997:Time Factors D014992:Xylenes D015054:Zymosan
Ipomoea asarifolia Convolvulaceae Anti-inflammatory In vivo models