In vitro antibacterial and antioxidant activity of flavonoids from the roots of Tephrosia vogelii: a combined experimental and computational study.

Tephrosia vogelii is a traditional medicinal plant used to treat hypertension, diarrhea and urinary disorders. Silica gel chromatographic separation of CH2Cl2/MeOH (1:1) roots extract of T. vogelii afforded seven compounds namely; ß-sitosterol (1a), stigmasterol (1b), 6a, 12a-dehydro-deguelin (2), tephrosin (3), maackiain (4), obovatin (5) and 6-oxo, 6a, 12a-dehydro-deguelin (6). GC-MS analysis of essential oils from the root of T. vogelii displayed a total of 17 compounds of which cis-nerolidol (41.7 %) and cadinol (19.7 %) were the major constituents. CH2Cl2/MeOH (1:1) extract, MeOH extract, maackiain (4) and obovatin (5) showed moderate inhibitory activity against Pseudomonas aeruginosa with MIC value of 0.5, 0.66, 0.83 and 0.83 mg/mL, respectively, compared to ciprofloxacin (MIC of 0.078 µg/mL). 6a, 12a-dihydro-deguelin (2), and 6-oxo, 6a, 12a-dehydro-deguelin (6) displayed significant activity against S. epidermis with MIC values of 0.66 mg/mL. Tephrosin (3) and maackiain (4) also showed moderate antibacterial activity against Staphylococcus aureus and Proteus mirabilis with MIC values of 0.83 and 0.5 mg/mL, respectively, compared to ciprofloxacin (0.312 µg/mL). The radical scavenging activity results indicated that tephrosin (3), obovatin (5) and 6-oxo, 6a, 12a-dehydro-deguelin (6) showed potent DPPH scavenging activity with IC50 values of 10.97, 10.43 and 10.73 µg/mL, respectively, compared to ascorbic acid (IC50 of 5.83 µg/mL). The docking prediction results revealed that 6a, 12a-dehydro-deguelin (2) displayed the best binding energy of -8.1 kcal/mol towards pyruvate kinase of S. aureus (PDB ID: 3T07) and -7.9 kcal/mol towards P. mirabilis urease (PDB ID: 1E9Y) and DNA gyrase B of Escherichia coli (PDB: 4F86) receptors compared to ciprofloxacin (-7.2 to -8.0 kcal/mol). Maackiain (4) and obovatin (5) displayed the minimum binding energy of -7.9 and -8.2 kcal/mol towards the LasR protein of P. aeruginosa (PDB: ID 2UV) and S. epidermidis FtsZ (PDB: ID 4M8I), respectively. The SwissADME drug-likeness and Pro Tox II toxicity prediction results indicated that compounds (2-6) obeyed Lipinski's rule of five with 0 violations and none of them were found to be hepatotoxic, mutagenic, and cytotoxic, respectively. The in vitro assessment results supported by the in silico analysis revealed that crude extracts and isolated compounds showed promising antibacterial and antioxidant activity, which proves the therapeutic potential of the roots of T. vogelii.

Antidiarrheal Activities of the Methanol Leaf Extracts of Olinia rochetiana (Oliniaceae) Against Castor Oil-Induced Diarrhea in Mice.

Background: Olinia rochetiana has been used traditionally to cure diarrheal disease. Therefore, this study aimed to investigate the acute toxicity and antidiarrheal effect of O. rochetiana leaf extracts. Methods: Cold maceration was used to extract plant leaf powder with 80% methanol. The extract's antidiarrheal action was tested against a castor oil-induced diarrheal model, a charcoal meal test, and enteropooling tests at doses of 100, 200, and 400 mg/kg. Negative controls received the vehicle at 10 mL/kg, while positive controls received loperamide at 3 mg/kg. Results: From the study, no apparent toxicity was observed when a single dose of 2000 mg/kg was administered. In the castor oil-induced model, the extract delayed the onset of diarrhea, reduced stool frequency, and decreased wet feces weight and number in a dose-dependent manner at 200 mg/kg (p < 0.05) and 400 mg/kg (p < 0.01). The percent reduction in moist feces at 100, 200, and 400 mg/kg was 54.2, 23.97, and 18.26%, respectively, indicating a significant dose-dependent decrease. In a charcoal meal test, the extracts at 200 and 400 mg/kg revealed a peristaltic index of 65 and 46%, respectively, with considerable inhibition of charcoal transport at 23 and 39%. The weight and volume of intestinal contents dropped significantly at a dose of 400 mg/kg (p < 0.01), which is 0.43 mg/kg, in the enteropooling test when compared with the tested dose. The computed in vivo antidiarrheal index revealed diarrheal inhibition values of 46.06 and 71.06% at 200 and 400 mg/kg, respectively. Conclusion: In the current investigation, O. rochetiana showed significant antidiarrheal activity with no symptoms of toxicity in mice.

Evaluation of Antihyperglycemic Effect of Extract of Moringa stenopetala (Baker f.) Aqueous Leaves on Alloxan-Induced Diabetic Rats.

BACKGROUND: Diabetes is a serious metabolic disorder with complications that result in significant morbidity and mortality. Current drugs used for diabetes therapy are not free from side effects and do not restore normal glucose homeostasis. Therefore, the purpose of this study is to evaluate the antidiabetic effect of Moringa stenopetala (Baker f.) aqueous leaves extract. METHODS: Thirty rats of weight 90-150 gram were distributed to five groups (n= 6). Then labelled as diabetic control (DC), normal control (NC), extract treated (MS 250 and 500mg/kg), and glibenclamide treated (GL 5mg/kg). The experimental rats were induced by intra-peritoneal injection of Alloxan monohydrate at a dose of 180 mg/kg after dissolving in normal saline. Clinical biochemistry such as AST, ALT, ALP, urea, creatinine, and cholesterol, blood glucose level, histopathological and preliminary phytochemical screening were evaluated. RESULTS: Phytochemical tests revealed the presence of different secondary metabolites. Alkaloid, flavonoid, tannin, saponin, phytosteroids, phenols and terpenoids. Moringa stenopetala (Baker f.) leaves aqueous extract (250 and 500mg/kg) improved the body weight of rats, showed remarkable reduction in blood glucose concentration (P<0.05), and significantly decreased serum urea, creatinine, ALT, AST and ALP (P < 0.05). Levels of serum cholesterol remained unaltered in the experimental groups when compared with diabetic control. Histopathology of non-treated rats showed deterioration of insulin producing pancreas cells; nevertheless, ß-cells restoration was observed due to administration of Moringa stenopetala (Baker f.) aqueous leaves extract. CONCLUSION: It is possible to conclude that oral administration of Moringa stenopetala (Baker f.) aqueous leaf extracts (250mg/kg and 500mg/kg) for 28 days showed beneficial effects on antihyperglycemia, improved body weight and Alloxan damaged pancreatic ß-cells, and restored biochemical changes.

Development, Characterization, and Evaluation of Novel Broad-Spectrum Antimicrobial Topical Formulations from Cymbopogon martini (Roxb.) W. Watson Essential Oil.

BACKGROUND: Skin infections were the most frequently encountered of all infections and the 4th leading cause of nonfatal disease burden. Topical drugs have been used for the management of skin infections. The growing concern of drug resistance to the topical agents has warned the need for continuous development of novel drug. Essential oils are the best candidate for new drug with different mode of action and target as they are rich in chemical constituents. OBJECTIVE: To evaluate and develop safe and effective topical antimicrobial formulations from essential oil of Cymbopogon martini. Method. Essential oil was extracted using hydrodistillation aerial part C. martini and topical formulations were prepared in five different semisolid bases. In vitro antimicrobial investigations were performed on essential oil and topical formulations. Skin sensitizations of the formulations were evaluated using guinea pig maximization. RESULTS: The essential oil of C. martini has shown broad-spectrum antimicrobial potency against all tested organisms with MIC value ranging from 0.65 to 10 µg/ml. Absolute inhibitions of growth of fungi were observed against Trichophyton mentagrophytes and Trichophyton rubrum at concentrations above 1% of oil and against Microsporum canis and Trichophyton verrucosum at a concentration of 4% oil. Among topical formulations, the highest antimicrobial activity was recorded in hydrophilic ointment followed by macrogol blend ointment. The antimicrobial activity of oil was higher in fungal pathogen compared to bacteria. Gram positive bacteria were more sensitive than gram negative bacteria. Hydrophilic and macrogol blend ointment containing 5% oil did not produce any skin sensitization on guinea pigs. CONCLUSION: In conclusion, topical formulations of C. martini essential oil can be alternative topical agents with safe broad-spectrum activity for the treatment of skin disorder. Further studies should focus on shelf life study and clinical study of the product.