Abiotic stressors modulate phytochemical characteristics of Cissampelos Pareira L. extracts

Abstract

Cissampelos pareira L. is commonly known in South America as ka’apeva, ka’ápeva, ysypómorotí, caápebá, zarza, pareirabrava, or mil hombres. Ethnopharmacological uses of decoctions containing leaves and roots has been widely reported in Asia, Central and South America. Ethanolic extract of this plant is particularly rich in polyphenolic compounds which have been associated to different bioactive properties1 . Natural products isolation and recovery from plant materials consumes numerous resources to yield minimal results. In order to enhance the recovery ratio from raw materials different abiotic stressors, such as UV-C treatment or physical treatments could be applied to magnify the extraction of bioactive compounds. However, standardization of these procedures is required to obtain the desired phytochemical profile. The objective of this work was to evaluate the effect of different pre-extraction treatments (air dry, cutting and UV-C radiation) on the phenolic profile of C. pareira ethanolic extracts (CPEt). Aerial parts of C. pareira were collected in Corrientes Argentina, the material was divided and different procedures were performed: control (C), cutting (Cu), UV-C exposure with two dose 419 mJ/cm2(UV1) or 1558 mJ/cm2 (UV2), or a combination of cutting plus UV1 (T1) or plus UV2 (T2), following the aforementioned treatments the material was air dried for 48 h at 25°C, also a group without drying was evaluated (F). All the extracts were prepared with ethanol at ratio 1 : 6 followed by maceration for 48 h and further vacuum-concentrated. Total phenolic and flavonoid content were evaluated spectrophotometrically. HPLC-DAD analysis was performed to evaluate phenolic profile in the different extracts evaluating absorbance at 280 and 320 nm. Human red blood cell stabilization test (HRBCS) was used as screening of anti-inflammatory potential 2 . Total phenolic compounds content was significantly increased in C, UV1, UV2 and T2 treated samples, being T2the treatment that achieved the maximum value (142.26 ± 10.32 mg gallic acid/ g extract). Similarly, flavonoid content was increased by UV1 and UV2, reaching the highest value in T2 samples (260.75 ± 30.67 mg catechin / g extract). Extraction of fresh material (F) had the lowest values for both determinations. The stabilization of red blood cell membranes test indicated that T2 and Cu had haemolytic inhibitory ratios of 1.7 and 2.1 when compared to control (diclofenac sodium). The HPLC-DAD profile of F sample had 7 major retention time peaks. The 16.15 and 16.54 min peaks were compatible with flavonoid structures in accordance with the maximum absorbance between 270 and 334 nm in UV-spectra. Qualitative and quantitative variations in C and Cu samples were noticed, i.e., an increment in 15.04 min RT peak with λmax at 270 nm. Moreover, these peaks were significantly reduced in UV1, UV2 and T1 which might partially explain the changes in the HRBCS test. The extract prepared after T2 exhibited a phenolic profile similar to C, however the relative abundance of these compounds was increased. Our results highlight the importance of selecting appropriate pre-extraction treatments to obtain extracts with desirable phytochemical composition, which might translate into appropriate bioactive effects.