Optimization for ultrasonic-microwave synergetic extraction of total iridoid glycosides and screening of analgesic and anti-inflammatory active fractions from patrinia scabra Bunge (Valerianaceae)

Abstract

Background Patrinia scabra Bunge is a well-known herbal medicine for its favorable treatment on inflammatory diseases owing to its effective ingredients, in which iridoid glycoside plays an extremely significant role. This article aimed to improve the content of total iridoid glycosides in crude extract through a series optimization of extraction procedure. Moreover, considering that both pain and inflammation are two correlated responses triggered in response to injury, irritants or pathogen, the article investigated the anti-inflammatory and analgesic activities of P. scabra to screen out the active fraction. Method P. scabra was extracted by ultrasonic-microwave synergistic extraction (UMSE) to obtain total iridoid glycosides (PSI), during which a series of conditions were investigated based on single-factor experiments. The extraction process was further optimized by a reliable statistical method of response surface methodology (RSM). The elution fractions of P. scabra extract were prepared by macroporous resin column chromatography. Through the various animal experiment including acetic acid-induced writhing test, formalin induced licking and flinching, carrageenan-induced mice paw oedema test and xylene-induced ear edema in mice, the active fractions with favorable analgesic and anti-inflammatory effect were reasonably screen out. Results The content of PSI could reach up to 81.42 ± 0.31 mg/g under the optimum conditions as follows: ethanol concentration of 52%, material-to-liquid ratio of 1:18 g/mL, microwave power at 610 W and extraction time of 45 min. After gradient elution by the macroporous resin, the content of PSI increased significantly. Compared with other concentrations of elution liquid, the content of PSI in 30 and 50% ethanol eluate was increased to reach 497.65 and 506.90 mg/g, respectively. Owing to the pharmacology experiment, it was reasonably revealed that 30 and 50% ethanol elution fractions of P. scabra could relieve pain centrally and peripherally, exhibiting good analgesic and anti-inflammatory activities. Conclusion Patrinia scabra possessed rich iridoids and exhibited significant analgesic and anti-inflammatory activities.

P2X7‐Receptor Pathway Involvement in the Anti‐Inflammatory Activity of Medicinal Plants

“…For Scrophularia species, roots and aerial parts were considered separately. The hydro‐alcoholic [23] extracts were submitted to LC/MS analysis and the corresponding matrix between m/z value and peak area was created in format.csv. Then, the matrix was analyzed to correlate statistically the chemical composition of extracts with the corresponding biological activity.…”

“…On the other hand, common chemotaxonomic biomarkers of Scrophularia, Plantago and Gentiana extracts 17-31 were able to inhibit activation of the P2X7 receptor under the same conditions, with the exception of S. umbrosa extracts (15)(16). As a matter of fact, a focus on the metabolic profiles of Scrophularia extracts 15-22 obtained from LC/MS analysis revealed a clear difference between active (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31) and inactive (15)(16) extracts. Observation of the UPLC/MS chromatogram confirmed an intense peak at 3.57 min is present only in the active extracts whereas minority compounds vary between these two groups (Figure S1, Supporting Information).…”

A Transcriptomic and Metabolomic Study on the Biosynthesis of Iridoids in Phlomoides rotata from the Qinghai–Tibet Plateau

“…They are mostly in the form of glycosides and combine with glucose at the C-1 hydroxyl group. These metabolites, which are found in natural and traditional Chinese medicine, have been shown to have anti-inflammatory [ 2 , 3 ], hepatoprotective [ 4 ], liver protective [ 5 , 6 ], neuroprotective [ 7 ], and antioxidant activities [ 8 ]. The biosynthetic pathway for iridoid compounds can be divided into three stages: precursor formation, terpenoid skeleton biosynthesis, and subsequent chemical modification [ 9 , 10 , 11 , 12 ].…”