Extraction and Fractionation of Prokinetic Phytochemicals from Chrozophora tinctoria and Their Bioactivities

Abstract

Chrozophora tinctoria is an annual plant of the family Euphorbiaceae, traditionally used as a laxative, a cathartic and an emetic. A methanolic extract of Chrozophora tinctoria (MEC) whole plant and an n-butanol fraction of Chrozophora tinctoria (NBFC) were analyzed by gas chromatography-mass spectrometry (GC-MS) to detect the phytochemicals. MEC and NBFC were tested for in vitro anti acetylcholinesterase (AChE) potential. The effect of both samples on intestinal propulsive movement and spasmolytic activity in the gastrointestinal tract (GIT) was also studied. About twelve compounds in MEC and three compounds in NBFC were tentatively identified through GC-MS. Some of them are compounds with known therapeutic activity, such as toluene; imipramine; undecane; 14-methyl-pentadecanoic acid methyl ester; and hexadecanoic acid. Both NBFC and MEC samples were checked for acute toxicity and were found to be highly toxic in a dose-dependent manner, causing diarrhea and emesis at 1 g/kg concentration in pigeons, with the highest lethargy and mortality above 3 g/kg. Both the samples of Chrozophora tinctoria revealed significant (p ≤ 0.01) laxative activity against metronidazole (7 mg/kg) and loperamide hydrochloride (4 mg/kg)-induced constipation. NBFC (81.18 ± 2.5%) and MEC (68.28 ± 2.4%) significantly increased charcoal meal intestinal transit compared to distal water (41.15 ± 4.3%). NBFC exhibited a significant relaxant effect (EC₅₀ = 3.40 ± 0.20 mg/mL) in spontaneous rabbit jejunum as compared to MEC (EC₅₀ = 4.34 ± 0.68 mg/kg). Similarly, the impact of NBFC on KCl-induced contraction was more significant than that of MEC (EC₅₀ values of 7.22 ± 0.06 mg/mL and 7.47 ± 0.57 mg/mL, respectively). The present study scientifically validates the folk use of Chrozophora tinctoria in the management of gastrointestinal diseases such as constipation. Further work is needed to isolate the phytochemicals that act as diarrheal agents in Chrozophora tinctoria.

Keywords: Chrozophora tinctoria; acetylcholinesterase inhibitor; acute toxicity; laxative; spasmolytic.

Figure 1

Chrozophora tinctoria plant growing in the natural environment (a) and dried form (b).

Figure 2

GC-MS chromatogram of methanolic extract of Chrozophora tinctoria (MEC). The numbers in the chromatogram are the retention times of the compounds.

Figure 3

GC-MS chromatogram of the n-butanol fraction of Chrozophora tinctoria (NBFC). The numbers inside the chromatogram are the retention times of the compounds.

Figure 4

The effect of MEC on spontaneous and KCl-induced (80 mM) contraction of rabbit jejunum. Rabbit jejunum muscle was relaxed in a dose-dependent manner. EC₅₀ values were calculated from curve fitting in GraphPad Prism 6.01. Each point represents the mean ± SEM of grouped data.

Figure 5

The effect of NBFC on spontaneous and KCl-induced (80 mM) contraction of rabbit jejunum. Rabbit jejunum muscle was relaxed in a dose-dependent manner. EC₅₀ values were calculated from curve fitting in GraphPad Prism 6.01. Each point represents the mean ± SEM of grouped data.