Current Bioactive Compounds - Volume 17, Issue 5, 2021

Background: Aloe barbadensis (Miller) is one of the most used medicinal herbs in the world since antiquity due to its valuable pharmacological properties. The species of A. vera are widely distributed and cultivated throughout the world. Objective: This review article aims to present an account of information on the phytochemistry and pharmacological properties of bioactive compounds from A. vera, highlighting their mechanism of action and function as food supplement to improve human health. The development of A. vera based phytomedicines and its future trends were also evaluated. Methods: A bibliographic search of scientific literature published till March 2020 was carried out from the scientific databases and different search engines such as PubMed, ScienceDirect, Cochrane library, and Scopus. The keywords used in several combinations included: Aloe vera, phytochemistry, pharmacological activity, treatment, prevention, disease, health, in vitro, in vivo and clinical studies. From eligible articles, the data were independently extracted by the standard data extraction method. Results: A. vera is a good source of bioactive compounds. A. vera has been reported for its numerous therapeutic applications. Besides, several valuable therapeutic potentials, the plant has also been used as crop and food preservation as well as a functional food supplement due to the presence of high content of carbohydrates, vitamins and several antioxidant molecules. Its oral ingestion has been related to diarrhea, electrolyte imbalance, kidney dysfunction, drug interactions, dermatitis, erythema, and phototoxicity. Conclusion: Although there are several A. vera-based products available, the knowledge on the relationship between biological and therapeutic properties should be clearly defined to ascertain the exact action mechanism(s) to develop new drugs.

Background: Globally, multidrug resistance has increased in both the society and health care systems related to bacterial infections which is impaired due to massive antimicrobial treatments. Therefore, we need efficient, non-toxic compounds from plant-based alternatives. The aim of the present study is to investigate the antimicrobial efficacy of leaf extracts with various solvents of Aegle marmelos, Plumbago zeylanica and Rhinacanthus nasutus against human pathogenic organisms. Methods: Antimicrobial properties of various extracts of A. marmelos, P. zeylanica and R. nasutus were investigated against human pathogenic organisms such as Acinetobacter baumannii, Salmonella enteriditis, Bacillus cereus, Streptococcus pneumonia, Mycobacterium tuberculosis and Aspergillus fumigatous by agar well diffusion method. Minimum Inhibitory Concentration (MIC), Minimum Bactericidal / Fungicidal Concentration (MBC/MFC) values were also evaluated by the microdilution method and the phytochemicals and functional groups using HPLC, GC-MS and FTIR analysis were identified. Results: Ethyl acetate leaf extract of P. zeylanica showed better antimicrobial activity against the tested pathogens, especially for S. pneumoniae (40 mm) followed by ethyl acetate extract of R. nasutus (36 mm) against S. pneumoniae. While the least inhibition zone was observed for the aqueous extract of P. zeylanica against S. enteritis (10 mm). The MIC value ranged from 3.75 μg/ml to 60 μg/ml and MBC/MFC 7.5 μg/ml to 60 μg/ml. Phytochemical analysis exhibited the presence of alkaloids, steroids, saponins, flavonoids, tannins, terpenes, phenolics and cardiac glycoside in all samples of selected plant extracts. Tannins, phenolics and glycoside were found only in the ethyl acetate extract of P. zeylanica. HPLC and GC-MS analysis of ethyl acetate leaf extract of P. zeylanica produced ten major peaks thus exhibiting eleven compounds respectively. The chemical nature of the leaf extract was analyzed by the FT-IR spectrum. Conclusion: Ethyl acetate leaf extract of P. zeylanica showed better antimicrobial activity than other extracts and even standard drugs. Therefore, this plant could be further considered for advanced research to identify active biomolecules in developing antimicrobial drugs.

Background: Stems of Nicotiana tabacum have secondary metabolites with antimicrobial and antioxidant properties. The purpose of the present study was to investigate the therapeutic properties of synthesized silver nanoparticles (Protein-AgNPs) in an isolated protein mixture from stems. Methodology: A N. tabacum protein mixture was used for the formation of silver nanoparticles by the bioreduction method. Characterization of Protein – AgNPs was completed using UV-Vis spectroscopy, Dynamic Light Scattering (DLS), Atomic Force Microscope (AFM) and Scanning Electron Microscope (SEM). Therapeutic properties of Protein-AgNPs were evident with antimicrobial and antioxidant activities. The antimicrobial activity of Protein-AgNPs was determined by the agar well diffusion and broth diffusion methods. The mode of action of Protein-AgNPs was determined by the cellular membrane leakage assay. Antioxidant activities of Protein-AgNPs were quantified by Superoxide Dismutase activity (SOD), Catalase activity (Cat), Glutathione S Transferase activity (GST), Glutathione Content (GSH) and lipid peroxidation. Results: The synthesized Protein-AgNPs were less than 100nm as characterized by UV-Vis spectroscopy, DLS, AFM and SEM. Antimicrobial activity was observed against both Gram positive and Gram negative bacteria, revealing maximum antimicrobial activity against Staphylococcus aureus and Acinetobacter baumannii (p value ≤ 0.05) as determined by the agar well diffusion method and the broth dilution method. The mode of action is likely to be cellular membrane damage, because protein and nucleic acid leakage was significant in treated cells. The antioxidant activities of Protein-AgNPs were higher than purified proteins as determined by Superoxide Dismutase activity (SOD), Catalase activity (Cat), Glutathione Stransferase activity (GST), Glutathione content (GSH) and lipid peroxidation. Conclusion: Synthesized silver nanoparticles from a tobacco stem protein mixture can be utilized as a herbal remedy or as a nano-drug delivery system against diseases such microbial pathogens.

Background: Eucalyptus camaldulensis Dehnh is abundantly found in Erbil, Iraq and commonly used as an antispasmodic and antipyretic remedy for treating respiratory tract diseases. The present study aimed to evaluate the effectiveness of E. camaldulensis in achieving glucose homeostasis through the inhibition of α-glucosidase enzyme using in-vitro model and also determine the chemical composition of essential oil by gas chromatography mass spectroscopy (GC/MS). Methods: The chemical composition of E. camaldulensis essential oil by was determined by GC/MS and its antidiabetic activity was assessed through inhibition of α-glucosidase enzyme in in- -vitro models. Results: The essential oil yielded 40 chemical constituents amounting to 98.55%. The major constituents of essential oil of E. camaldulensis leaf were 1,8-cineole (28.4%), isocaryophyllene oxide (8.4%), β-ocimene (7.9%), α-farnesene (7.9%), globulol (7.3%), terpinen-4-ol (7.6%), isophytol (3.6%), viridiflorol (3.2%), p-cymen-3-ol (3.1%) and α-bisabolol (1.2%). The essential oil of E. camaldulensis showed concentration-dependent inhibition of α-glucosidase enzyme and the inhibition ranged from 75.38±2.09 to 6.08±1.89% for concentration 100 to 3.125 μg/mL. The α-glucosidase inhibition of E. camaldulensis (IC50 value 16.7±2.61 μg/mL) was found almost comparable with standard drug acarbose (IC50 value 12.04±3.17 μg/mL). Conclusion: The result of this study concluded E. camaldulensis essential oil as having 1,8-cineole, isocaryophyllene oxide and β-ocimene as major constituents; the study findings also confirm the traditional claim of its use in the treatment of diabetes mellitus.

Aim: To investigate neuroprotective potential of Forskolin (FSK) in combination with Solanesol (SNL) along with clinically proven drugs (riluzole, baclofen, and citalopram) on behavioral, molecular and neurochemical alterations in methyl mercury-induced Amyotrophic Lateral Sclerosis (ALS) rats. Background: ALS is a motor neuron disease in which oxidative stress is the principal mechanism of neuronal death which can be mimicked by the dominant mutations in an antioxidant enzyme SOD-1. Due to MeHg neurotoxicity, behavioral and neurochemical alterations occur in rats. During ALS, mitochondrial CoQ10 dysfunctioning and downregulation of adenyl cyclase/CREB are major pathological hallmark for neurodegeneration in ALS. Clinically proven drug therapy comes with limited therapeutic involvement and is used as approachable therapy in ALS patients. Objective: Therefore, current research explores the up-regulation of adenyl cyclase/cAMP/CREB by FSK 30, 60 mg/kg in combination with mitochondrial ETC-coenzyme-Q10 precursor SNL 15, 30 mg/kg can be a preventive therapeutic approach to overcome the ALS like symptoms. Methods: MeHg (5 mg/kg) is a neurotoxic compound that leads to ALS like behavioral & neurochemical alterations. Results: Chronic treatment with the combination of FSK 30,60 mg/kg and SNL 15,30 mg/kg alone and along with standard drugs citalopram (5 mg/kg), riluzole (5 mg/kg) and baclofen (3 mg/kg) increased the adenyl cyclase and mitochondrial CoQ10 and ETC-complexes enzyme levels and shows the neuroprotective potential by significantly improving the cognitive deficitslocomotion, grip strength, and restoration of neurochemicals alterations along with reducing the level of inflammatory mediators and oxidative stress in ALS rats. Conclusion: Thus, we concluded that FSK in combination with SNL along with standard drugs can be a possible therapeutic approach for the treatment of ALS.

Background: In view of the need of discovering new antifungal agents, the synthesis of compounds comprising new structural scaffolds is an important approach, since they may act by new mechanisms of action and overcome resistance issues. Objective: Synthesis of new 1,2-benzisoxazolin-3-ones inspired in eugenol and ebselen as new antifungal agents against Candida spp. Methods: A series of 1,2-benzisoxazolin-3-ones, based on eugenol and analogs, was synthesized by the cyclization of the respective hydroxamic acids under Mitsunobu conditions. IR, NMR, and MS spectroscopies characterized the synthesized compounds. The final products were screened for their antifungal activity against five Candida spp., using microdilution assays and cytotoxicity against peripheral blood mononuclear cells by the MTT method. Results: The products were obtained in good yields and the results showed that most of the synthesized compounds were better antifungal agents than eugenol against the Candida species evaluated and that the derivative IVd (IC50 53 μmol L-1) showed activity comparable to fluconazole against C. glabrata. Moreover, IVd showed the best selectivity profile among the synthesized new compounds. Conclusion: A new 1,2-benzisoxazolin-3-one (IVd) was obtained as a promising candidate for the development of new antifungal agents based on a new chemical scaffold.

Background: Hypercholesterolemia is considered as one of the major risk factors for atherosclerosis. The study aimed to evaluate the effect of Ocimum basilieum L. against hypercholesterolemia in rats. Methods: Isolation and identification of flavonoid compounds from the methanolic extract of Ocimum basilicum L. leaves were performed by UV, ¹H, ¹³C-NMR and1D/2D NMR, HMBC and HMQC techniques. The biochemical evaluation was performed through measuring Total Cholesterol (TC), High Density Lipoprotein-Cholesterol (HDL-C), Low Density Lipoprotein-Cholesterol (LDL-C), Triglycerides (TG), Malondialdehyde (MDA), Glutathione (GSH), Total Antioxidant Capacity (TAC), aspartate and Alanine Aminotransferases (AST & ALT), Alkaline Phosphatase (ALP), urea, creatinine and albumin levels as well as DNA fragmentation pattern of kidneys. The histopathological features of liver and kidney were also examined. Results: The phytochemical study revealed the presence of seven flavonoid compounds (apigenin- 8-C-(α-L-rhamnopyranosyl-(1→2)-β-O –glucopyranoside (1), apigenin 6, 8-di-C-β-glucopyranoside (vicenin 2) (2), apigenin 7-O-(6”-O-trans-p-coumaryl)-β–glucopyranoside (3), apigenin 7-O- β-glucopyranoside (4), apigenin 8-C-β-glucopyranoside (vitexin) (5), apigenin -6-C-β-glucopyranoside (isovitexin) (6), apigenin (7)) and one phenolic compound; rosmarinic acid (8). Treatment with leaves extract at a dose of 250 mg/kg body weight for nine weeks simultaneously with oral cholesterol administration (30 mg/0.3 ml 0.7% tween/ animal) to rats fed with high fat diet restored all the biochemical parameters and the architectures of liver and kidney. Conclusion: Methanolic extract of Ocimum basilieum L. leaves succeeded to act as a hypolipidemic, antioxidant and hepato-renal therapeutic agent due to its rich biologically active phenolic and flavonoids compounds.