Anti-Inflammatory Investigations of Extracts of Zanthoxylum rhetsa

Abstract

Zanthoxylum rhetsa has been consumed in the diet in northern Thailand and also used as a medicament in ancient scripture for arthropathies. Thus, this study aimed to evaluate the activity of various extracts from differential parts of Z. rhetsa via inhibition of inflammatory mediators (NO, TNF-α, and PGE2) in RAW264.7 macrophages. The chemical composition in active extracts was also analyzed by GC/MS. The parts of this plant studied were whole fruits (F), pericarp (P), and seed (O). The methods of extraction included maceration in hexane, 95% ethanol and 50% ethanol, boiling in water, and water distillation. The results demonstrated that the hexane and 95% ethanolic extract from pericarp (PH and P95) and seed essential oil (SO) were the most active extracts. PH and P95 gave the highest inhibition of NO production with IC50 as 11.99 ± 1.66 μg/ml and 15.33 ± 1.05 μg/ml, respectively, and they also showed the highest anti-inflammatory effect on TNF-α with IC50 as 36.08 ± 0.55 μg/ml and 34.90 ± 2.58 μg/ml, respectively. PH and P95 also showed the highest inhibitory effect on PGE2 but less than SO with IC50 as 13.72 ± 0.81 μg/ml, 12.26 ± 0.71 μg/ml, and 8.61 ± 2.23 μg/ml, respectively. 2,3-Pinanediol was the major anti-inflammatory compound analyzed in PH (11.28%) and P95 (19.82%) while terpinen-4-ol constituted a major anti-inflammatory compound in SO at 35.13%. These findings are the first supportive data for ethnomedical use for analgesic and anti-inflammatory activity in acute (SO) and chronic (PH and P95) inflammation.

Anti-Arthritic and Anti-Inflammatory Effects of Andaliman Extract and Nanoandaliman in Inflammatory Arthritic Mice

“…A study by Su et al on various metabolites secreted from different organs of the Acanthopanax senticosus plant, showed that of 130 metabolites, 39 metabolites were expressed in roots, 51 metabolites were expressed in seeds, and 40 metabolites were expressed in leaves [ 24 ]. A similar study by Imphat et al reported on the investigation of Z. rhetsa for anti-inflammatory effects; it showed that the extraction of Z. rhetsa pericarp resulted in a higher total yield of extract than the fruit and seed parts, from four different type of extraction, including hexane, ethanol (50% and 90%), decoction, and water extraction [ 15 ].…”

“…Other than the plant part, the usage of solvent also determines the total extraction yield. Several studies showed that ethanol extraction offered the highest total yield for Zanthoxylum plant maceration [ 15 , 22 ]. Essential oil is known as a non-polar compound that consists of ether, keton, aldehyde, and terpenoid.…”

“…Non-polar solvents, such as hexane and ethanol bind easily with the essential oil of andaliman, while polar solvents such as water and acetone bind easily with the water-soluble compound from andaliman. By comparing the other study results for Z. rhetza extraction, it was shown that hexane gave less total yield than that of the ethanol extraction from Z. rhetza pericarp [ 15 ]. Our findings indicate that andaliman extract was rich in monoterpenoid compounds, such as limonene, citronellal, geranyl acetate, and geraniol, which are widely known as anti-inflammatory compounds.…”

“…This result is in line with previous reports [ 25 , 26 ]. In addition, various plants from the Zanthoxylum genus have also been reported for their medical uses, particularly their anti-inflammatory activities, such as Z. acanthopodium , Z. rhetza , Z. piperitum, Z. armatum, and Z. nitidium [ 14 , 15 , 26 ]. Most of these plants have major monoterpenoid compounds in particular essential oils, which might be responsible for their anti-inflammatory efficacy.…”

“…Unfortunately, up until now, there are only a few in vivo studies on andaliman as an alternative natural medicine for arthritis. The latest research showed that Z. rhetza , a spice similar to andaliman, exerted anti-inflammatory activity for treating rheumatoid arthritis and osteoarthritis by inhibiting the gene expression of TNF-α and prostaglandin E2 (PGE2), which are related to in vitro inflammation [ 15 ]. Research on herbal medicine has focused on determining its efficacy as well as finding a better way to deliver it.…”