Phytochemical analysis, antioxidant and antimicrobial activities of leaves and flowers ethyl acetate and n-butanol fractions from an Algerian endemic plant Calycotome spinosa (L.) Link

Hypoglycemic and Hypotensive Effects of Calycotome villosa Subsp. intermedia Seeds in Meriones shawi Rats: In Vivo, Ex Vivo, and In Vitro Investigations

Calycotome villosa subsp. intermedia is used in traditional medicine for the prevention and self-treatment of a variety of illnesses, including diabetes mellitus, obesity, and hypertension. The present study aims to investigate the in vivo, ex vivo, and in vitro hypoglycemic and hypotensive effects of the lyophilized aqueous extract of Calycotome villosa subsp. intermedia seeds (CV) on Meriones shawi submitted to hypercaloric diet and physical inactivity (HCD/PI) for 12 weeks. This diet induces a type 2 diabetes/metabolic syndrome phenotype with hypertension. Furthermore, HCD/PI decreased aorta contraction due to noradrenaline, enhanced L-arginine, and depressed insulin-evoked relaxation, while the relaxing effects of the NO donor SNAP and of diazoxide were unchanged. In vivo experiments showed that the oral administration of the CV extract (50 mg/kg b.wt) for 3 consecutive weeks significantly attenuated the development of type 2 diabetes, obesity, dyslipidemia, and hypertension. These effects may involve the improvement of lipid metabolism, insulin sensitivity, systolic arterial pressure, and urine output. Additionally, ex vivo and in vitro investigations revealed that CV treatment improved vascular contraction to noradrenaline, induced a slight aorta relaxation in response to carbachol, increased the vasorelaxation effect evoked by insulin, and depressed the L-arginine evoked relaxation. However, CV did not change the endothelium-independent vasorelaxation response evoked by SNAP or diazoxide. Hence, the present study provides useful information and supports the traditional use of CV in the prevention and self-treatment of numerous ailments. Overall, it can be concluded that Calycotome villosa subsp. intermedia seed extracts might be useful in the management of type 2 diabetes and hypertension.

Cytotoxic effect of Myrtus communis, Aristolochia longa, and Calycotome spinosa on human erythrocyte cells

Introduction. Myrtus communis, Aristolochia longa, and Calycotome spinosa are medicinal plants frequently used in Algeria. Some plants can cause a fragility of the erythrocyte membrane and lead to hemolysis. Therefore, we aimed to study the cytotoxicity of aqueous extracts from the aerial part of these species against red blood cells. Study objects and methods. The hemolytic effect was determined spectrophotometrically by incubating an erythrocyte solution with different concentrations of the aqueous extracts (25, 50, 100, and 200 mg/mL) at 37°C during one hour. In addition, we performed phytochemical screening and measured the contents of polyphenols and flavonoids. Results and discussion. After one hour of incubation of human red blood cells with the aqueous extracts at different concentrations, the hemolysis percentage showed a significant leak of hemoglobin with A. longa (68.75 ± 6.11%; 200 mg/mL), the most toxic extract followed by C. spinosa (34.86 ± 5.06%; 200 mg/mL). In contrast, M. communis showed very low cytotoxicity (20.13 ± 3.11%; 200 mg/mL). Conclusion. These plants are sources of a wide range of bioactive compounds but their use in traditional medicine must be adapted to avoid any toxic effect.

New approach in the characterization of bioactive compounds isolated from Calycotome spinosa (L.) Link leaves by the use of negative electrospray ionization LITMSn, LC-ESI-MS/MS, as well as NMR analysis

Two novel compounds were isolated for the first time from Calycotome spinosa (L.) Link, an alkaloid 5-Hydroxy-1H-indole (4) and a cyclitol D-pinitol (5), together with the three well-known flavonoids; Chrysin-7-O-(β-D-glucopyranoside) (1), Chrysin-7-O-β-D-(6″-acetyl)glycopyranoside (2) and Apigenin-7-O-β-D-glycopyranoside (3). The chemical structures of the isolated compounds were elucidated by spectroscopic data and mass spectrometric analyses; including a fresh approach 1D-NMR, 2D-NMR with LC-ESI-MS/MS. In this study, the new compound (4) that has been obtained from the leaves MeOH extract presented the best radical scavenging activity (DPPH) (IC₅₀ < 10 µg/mL) compared to the standard butylated hydroxytoluene (BHT, IC₅₀ = 34.73 ± 0.23 μg/mL) and showed the highest total antioxidant capacity (TAC = 985.54 ± 0.13 mg AAE/g extract) in contrast to ascorbic acid (TAC = 905.95 ± 0.07 mg AAE/g extract). Furthermore, the strongest reducing power (EC₅₀ = 344.82 ± 0.02 µg/mL), as well as the remarkable scavenging potential by ABTS assay (IC₅₀ = 7.8 ± 0.43 µg/mL), were exhibited by the same composite (4). Followed by the methanol crude extract and the compound (3) that also showed a potent antioxidant (DPPH; IC₅₀ = 41.04 ± 0.15 and 47.36 ± 0.21 µg/mL, TAC; 671.02 ± 0.21 and 608.67 ± 0.34 mg AAE/g extract, FRAP; EC₅₀ = 763.73 ± 0.32 and 814.61 ± 0.31 µg/mL, ABTS; IC₅₀ = 19.18 ± 0.06 and 63.72 ± 0.64 µg/mL, respectively), but less than the previous samples. On the opposite side, compound (5) had the lowest activity, in which its values were less interesting to determine. Moreover, compound (4) has equally exerted an attractive antibacterial activity against Staphylococcus aureus (ATTC-25923), Pseudomonas aeruginosa (ATTC- 27853) and Salmonella abony (NCTC 6017), as measured by the disc diffusion assay, with inhibition zones of 16 ± 0.5, 9.83 ± 0.29 and 8 ± 0.28 mm, in that order. To the best of our knowledge, 5-Hydroxy-1H-indole was isolated from plants for the second time in our current work. Thus, the obtained results from this investigation propose that the leaves of C. spinosa are a rich natural source for value molecules as potential antioxidants and antimicrobial agents for best human health.