Ziziphus spina-christi L. (ZSC-L) is a tree with thorny branches, belongs to the family Rhamnaceae and grows in the sub-tropics. The purpose of this research is to isolate and partially purify bioactive components from the crude ethanol extract of the stem bark of ZSC-L. Besides, bioassay-guided fractionation of ZSC-L stem bark was conducted using different solvents. The solvents were reutilized to minimize the production cost and environmental harm. In addition, the antimicrobial activities of the fractions were analyzed, followed by metabolic profiling using LC-HRMS. The n-butanol fraction showed the highest antimicrobial efficacy, so it was subjected to further purification. For the first time, two major compounds were isolated from the stem bark of ZSC-L and identified as lupane-type pentacyclic triterpenoids betulinic acid and betulin. Both compounds were used as antibacterial and anticancer agents and considered as a green product as the extraction procedure reduced the use of hazardous chemicals. Metabolic characterization of ZSC-L and its bioactive fractions were performed using LC-HR-ESI-MS and the results revealed the dereplication of 36 compounds belonging to different chemical classes. Flavonoids and triterpenes were the most prominent metabolite classes in the different fractions. The molecular docking results were obtained by studying the interaction of betulin and betulinic acid with antimicrobial receptors (4UYM, 1IYL, 1AJ2, 6J7L, 1AD4, 2VEG) to support the in vitro results. Our study highlights that Ziziphus spina-christi and its phytoconstituents, especially triterpenoids, act as a promising antimicrobial candidate in pharmaceutical and clinical applications.

Background: Pergularia tomentosa is a member of the Apocynaceae family found in a wide geographical region including the Gulf region, North Africa and the Middle East. It is known as Fattaka, Ghalqa or Am Lebina in Saudi Arabia, It is used as a remedy for the treatment of skin sores, asthma, and bronchitis. Objective: This study aims to investigate the cytotoxic effects of methanolic extract and Latex (milky secretion) extract. Methods: The stem of Pergularia tomentosa was cut, air dried and soaked for 72 h with methanol repeatedly three times. The crude latex (milk extract) was collected from healthy stem parts of P. tomentosa L by cutting the petiole of leaves, and left to flow where a thick white liquid (Milky) were secreted, collected in amber glass tube and extracted with methanol. Further, the methanolic extract was fractionated by subsequent extraction with various solvents, viz. n-hexane, ethyl acetate and methanol. The cytotoxic effects of Pergularia tomentosa L were evaluated using three cancer cell lines of colon carcinoma (HCT-116), hepatocellular carcinoma (HepG2) and breast carcinoma (MCF-7). The cytotoxic effects of Pergularia tomentosa L extracts against HCT-116, HepG2, and MCF-7 were determined by crystal violet staining method. Results: The potency of plant extract to decrease the cell viability of human cancer cells was arranged in descending order as follows: Methanol extract (IC50 = 10.2 μg/ml, 13.6 μg/ml and 29.5μg/ml, respectively). > Milky secretion extract (IC50 = 52.6 μg/ml, 58.6 μg/ml and 120 µg/ml, respectively). Methanolic extract was strong cytotoxic activity against HCT-116 and HepG2 (IC50= 10.2, 13.6 µg/ml, respectively) and moderately activity against MCF-7 (IC50= 29.5 µg/ml). The Milky extract exhibited moderate activity against HCT-116 and HepG2 (IC50= 52.6-58.6 µg/ ml, respectively) and weak activity against MCF-7 (120.0 µg/ml). Conclusion: The methanol extract of Pergularia tomentosa L showed higher cytotoxic effect as compared to the Latex (Milky secretion) extract. These extracts can be used as natural antitumor. In Future modern chromatographic separations are needed to get more quantity of metabolites. Further detailed investigation of the isolated metabolites is required to identify the phytoconstituents responsible for antioxidant and cytotoxic effects.

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Zizyphus spina-christi (L.) (Rhamnaceae family) is a subtropical plant known as 'Nabq' or 'Sidr' which is used for various medicinal purposes. It has used in folk medicine in pain related ailments throughout these regions. Aim of our work is to phytochemically investigate the plant's bark in our laboratory with Chromatographic approach. The crude ethanol extract of dried bark of Z. spina-christi (L.) was fractionated by diethyl ether, chloroform, ethyl acetate and finally with n-butanol. Finally the fractions were investigated for the chemical constituents by using gas chromatography-mass spectrometry. Thirty six compounds from the four fractions of the stem bark of Z. spina-christi (L.) have been identified and recognized, especially betulin, quercetin, stigmasterol, sitosterol, ethyl oleate and phytol by means of GC-MS analyses.