Background: Moringa oleifera is one of the most famous plants used for medicinal purposes. Its leaf extracts have antimicrobial activity and antioxidant activities, and reduce swelling in ulcers. Objectives: The present article aimed to determine the metabolic profile of Moringa oleifera leaf extracts from two samples originating from India and to evaluate in vitro and ex vivo their biological activities. Methods: The antioxidant properties of Moringa oleifera leaf extracts (methanol, 50% ethanol, and 70% ethanol) were studied in vitro for antimicrobial, anti-inflammatory, and antioxidant activities. The ex vivo contractile effects of the extracts were determined by assaying circularly isolated smooth muscle (SM) strips from a rat’s stomach. Results: The obtained results indicated that one of the samples had amino acid and organic acid content approximately twice that of the second sample. In all the tests, the 50% ethanol extract of both samples showed better antioxidant activity (209 mM TE 100 g⁻¹ for the DPPH method). The 70% ethanolic extract of Sample 1 exhibited the strongest antimicrobial activity, inhibiting Gram-positive Bacillus cereus, Bacillus subtilis, and Staphylococcus aureus. The 50% ethanolic extract of both samples exhibited the highest anti-inflammatory activity, demonstrating a twice better effect than the reference drug diclofenac. Finally, the pre-incubation of SM preparations with both samples significantly enhanced the ACh-induced contractile response, increasing it by 134% and 111%, respectively. Conclusions: The findings suggested potential applications of Moringa oleifera as a suitable candidate for antimicrobial, antioxidant, anti-inflammatory, and antispasmodic supplementation for alternative pharmaceutical and nutraceutical products.

Introduction: Examination of the potential possibilities of 2-chloro-N-(1-(3,4-dimethoxyphenyl)propan-2-yl)-2-phenylacetamide (IQP) to affect bioelectrogenesis and the contractile activity of isolated smooth muscles (SM) from stomach. Aim: Having in mind the structural similarities between the molecules of papaverine and IQP, the aim of the present study was to examine such features of the newly synthesized molecule that may potentially affect the muscle tonus, spontaneous bioelectrical and contractile activities of smooth muscles isolated from the stomach, basing on specific mechanisms of papaverine. Materials and methods: The synthesis of IQP is based on the initially formed aziridine ring by principles of Gilbert’s reaction. Impact of IQP on the bioelectrogenesis and the contractile activity of isolated smooth muscles from male Wistar rats was measured by the single sucrose-gap method and isometrically recorded. Results: IQP (1×10-5 – 2.5×10-4 mol/l) causes muscle relaxation, producing changes in two processes that have influence on the mechanical activity of smooth muscles:1. Blocked Ca2+ influx through the potential-dependent membrane Ca2+ channels, followed in turn by lowering the Ca2+ intracellular levels. This effect is proved by the changes in the frequency and amplitude of spike-potentials in sucrose-bridge experiments when IQP is applied.2. Activation of a cAMP-dependent signal cascade. The relaxing effect of IQP was significantly reduced in the presence of KT5720(5×10-6 mol/l), an inhibitor of protein kinase A. Conclusion: We assume that there might be interconnections between these two IQP-dependent processes, because PKA-dependent phosphorylation of the L-type Ca2+ channels in smooth muscles provokes a reaction of inactivation.