Asian Pacific Journal of Tropical Biomedicine

278-283

Authors: Roopesh Poojary, Nayanatara Arun Kumar, Reshma Kumarchandra, NA Vinodini, K Bhagyalakshmi, Ganesh Sanjeev

Objective: To explore the effect of hydroalcoholic extract of Cynodon dactylon on the whole body radiation-induced oxidative status of the cerebellum and cognitive impairments in mice. Methods: Swiss albino mice were randomly divided into the control group, radiation control group, low dose and high dose Cynodon dactylon extract treated groups and pre-treated with Cynodon dactylon extract before irradiation. Cynodon dactylon extract was administered for 7 d daily in low dose (0.25 g/kg) and high dose (1 g/kg). On day 7, mice were irradiated with a sublethal dose of 5 Gy gamma rays. Motor coordination was assessed by elevated rotarod test and spatial memory was studied by water maze test. Subsequently, biochemical markers (glutathione, lipid peroxidation and nitric oxide levels) in the cerebellum were evaluated. Results: The gamma irradiated group showed significant impairment in motor coordination and spatial memory compared to normal mice. Mice treated by Cynodon dactylon extract prior to gamma radiation showed good improvement in both paradigms compared to the radiation control group. Moreover, glutathione level was increased, while lipid peroxidation and nitric oxide levels were significantly reduced in mice receiving low dose and high dose of Cynodon dactylon extract compared to the radiation control group. Conclusions: The present study suggests the neuroprotective role of Cynodon dactylon against radiation-induced cognitive impairment and oxidative stress on the cerebellum of mice.

291-298

Authors: Kedsara Junmarkho, Pintusorn Hansakul

Objective: To study the inhibitory effect of rice bran extracts of Thai black Kam Muang and red Hawm Dawk Mali Deang on oxidative stress factors including superoxide (O2•-), nitric oxide (NO•), and inducible nitric oxide synthase (iNOS). Methods: Bran extracts (40% ethanol) of Kam Muang and Hawm Dawk Mali Deang were obtained and evaluated for in vitro 2-2’-azino-di-(3-ethylbenzthiazoline sulfonate) (ABTS) and NO• scavenging activity. Their inhibitory effects on cellular O2•- and NO• were measured in phorbol 12-myristate 13-acetate-stimulated neutrophil-like HL-60 cells and lipopolysaccharide- stimulated RAW264.7 macrophages, respectively, and their viability was monitored using the MTT assay. The effect on iNOS expression was also assessed by the Western blotting assay. Total contents of phenolics, flavonoids, and subtypes were also determined. Results: Hawm Dawk Mali Deang exhibited about 3.5-fold greater cellular O2•- inhibitory activity than Kam Muang [EC50 values of (23.57±4.54) and (81.98±1.45) μg/mL, respectively] in phorbol 12-myristate 13-acetate-stimulated HL-60 cells. Hawm Dawk Mali Deang exhibited about 2-fold higher in vitro ABTS•+ and NO• scavenging activity than Kam Muang, but it exerted cellular NO• inhibitory activity of only about 26% (undetermined EC50 value) in lipopolysaccharide-stimulated RAW264.7 cells. Conversely, Kam Muang exerted potent cellular NO• inhibitory activity [EC50 value: (281.13±59.18) μg/mL] and dose-dependently decreased iNOS levels. No cytotoxicity of both extracts was detected in both cell types. As for corresponding contents, Hawm Dawk Mali Deang contained higher contents of phenolics and flavonoids than Kam Muang. Moreover, Kam Muang and Hawm Dawk Mali Deang had a high content of total anthocyanins [(14.73±0.52) mg C3GE/g of extract] and total proanthocyanidins [(115.13±1.47) mg CE/g of extract], respectively. Conclusions: Based on these data, bran extracts of Thai black Kam Muang and red rice Hawm Dawk Mali Deang can help lower oxidative stress and inflammation attributed partly to O2•- and NO•.

307-314

Authors: NI Mongalo, OS Soyingbe, TJ Makhafola

Objective: To evaluate the antimicrobial, antioxidant, cytotoxicity and anticancer activity of fractions from Jatropha zeyheri roots and to explore the phytochemical profile of the most biologically active fraction. Methods: Fractions from Jatropha zeyheri ethyl acetate extract were investigated for antimicrobial activity against a plethora of pathogenic microorganisms of different origins. The cytotoxicity studies of fractions were evaluated in vitro using tetrazolium-based calorimetric assay against human dermal fibroblast, colon adenocarcinoma (Caco-2), breast cancer (MCF-7) and lung cancer (A547) cell lines. The anti-oxidant activity of fractions was determined in vitro against 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis-(3-ethylbenzothiazoline- 6-sulfonic acid) diammonium salt (ABTS) and chelation of iron (Fe2+). Gas chromatography mass spectrometry analysis was performed to detect phytochemical constituents in fraction with potent biological activity. Results: Fraction 2 of Jatropha zeyheri roots exhibited the lowest minimum inhibitory concentration of 40 μg/mL against Klebsiella pneumoniae and 80 μg/mL against Candida albicans, Staphylococcus aureus and Mycoplasma hominis. The fractions revealed some varying degrees of cytotoxicity against human dermal fibroblasts yielding LC50 values ranging from 28.96 to 166.52 μg/mL. Fraction 3 exhibited the highest selectivity index value of 2.08 against Klebsiella pneumoniae. Moreover, fraction 2 selectively inhibited the growth of Caco-2 with LC50 of 8.83 μg/mL, compared to other cancerous cell lines. Fraction 2 of Jatropha zeyheri further exhibited IC50 of 19.66, 22.63 and 1.82 μg/mL against DPPH, ABTS and Fe2+, respectively. Gas chromatography mass spectrometry analysis revealed the presence of cyclotetracosane (10.08%), 9-hexacosene (9.40%), hexadecanoic acid (3.90%), (Z)-9-octadecenamide (3.63%), octacosane (2.27%), 11-n-decylheneicosane (2.23%), ethyl vallesiachotamate (2.17%), heneicosanoic acid (2.10%), and octadecanoic acid (2.08%) in fraction 2 of Jatropha zeyheri. Conclusions: These identified compounds, particularly cyclotetracosane (hydrocarbon), may well explain the biological activity of fraction 2 of Jatropha zeyheri, which possesses higher biological activity than other fractions. These compounds can be further investigated for use in treating various bacterial and fungal opportunistic infections associated with HIV-AIDS and related cancers.