Antibacterial, Anti-HIV-1 Protease and Cytotoxic Activities of Aqueous Ethanolic Extracts from Combretum Adenogonium Steud. Ex A. Rich (Combretaceae).

\ud \ud Records have shown that Combretum adenogonium Steud. Ex A. Rich (Combretaceae) is used in traditional medicine systems of several tribes in Tanzania. This study focused on the investigation of antibacterial activity, anti-HIV-1 protease activity, toxicity properties and classes of phytochemicals in extracts from C. adenogonium Steud. Ex A. Rich (Combretaceae) to evaluate potential of these extracts for development as herbal remedies. Dried plant material were ground to fine powder and extracted using 80% aqueous ethanol to afford root, leaf and stem bark extracts. The extracts were assayed for anti-HIV-1 protease activities, antibacterial activities using microdilution methods and cytotoxicity using brine shrimps lethality assay. Screening for major phytochemical classes was carried out using standard chemical tests. All extracts exhibited antibacterial activity to at least one of the test bacteria with MIC-values ranging from 0.31-5.0 mg/ml. Two extracts, namely, root and stem bark exhibited anti-HIV-1 PR activity with IC50 values of 24.7 and 26.5 μg/ml, respectively. Stem bark and leaf extracts showed mild toxicity with LC50 values of 65.768 μg/ml and 76.965 μg/ml, respectively, whereas roots were relatively non-toxic (LC50 = 110.042 μg/ml). Phytochemical screening of the extracts indicated presence of flavonoids, terpenoids, alkaloids, tannins, glycosides and saponins. These results provide promising baseline information for the potential development of C. adenogonium extracts in treatment of bacterial and HIV/AIDS-related opportunistic infections

ANTIMYCOBACTERIAL, ANTIOXIDANT AND CYTOTOXIC ACTIVITIES OF ESSENTIAL OIL OF GALL OF PISTACIA ATLANTICA DESF. FROM ALGERIA

Background: The aim of this study was to assess the antimycobacterial, antioxidant and the cytotoxic activities of the essential oil from the gall part of Pistacia atlantica Desf from Algeria. Materials and Methods: The antimycobacterial activity was evaluated by the broth microdilution method against three species of mycobacteria: Mycobacterium smegmatis, Mycobacterium aurum and Mycobacterium fortuitum. Antioxidant activity was determined using free-radical scavenging assays. The safety of essential oil was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on C3A and Vero monkey kidney cells. Results: The minimal inhibitory concentration (MIC) values ranged from 0.16 to 2.5 mg/mL with minimal bactericidal concentration (MBC) values ranged from 0.62 to >2.5 mg/mL. The antioxidant activity showed IC50 values ranged between 417.61 - >2000µg/mL and 495.6 - >2000µg/mL for DPPH and ABTS assay respectively. The cytotoxicity assay showed LC50 ranged between 26.47 to 93.64 µg/mL against Vero cells and 74.29 to 225.40 µg/mL against C3A. The results of this study show that the essential oils from the gall of P. atlantica have low toxicity and moderate activity against fast growing M. smegmatis and M. aurum. Conclusion: These results substantiate their potential as used in the treatment of non-tuberculous mycobacterial infections. This finding is predictive of their activity against M. tuberculosis, therefore, further study might be considered to investigate the activity against pathogenic Mycobacterium strains

Conservation law enforcement : policing protected areas

This article examines how recent increases in commercial poaching of wildlife intensify the dictates that underpin conservation law and its enforcement; namely, the securing of space, punishing of transgressors, and protecting of nonhuman life. Drawing on ethnographic research with antipoaching personnel in Mozambique, I examine how rangers translate these legal and normative manifestations of conservation law enforcement on the ground and in their daily practices to police protected areas and the wildlife within them. This article makes two contributions. First, drawing on insights from the political geography and ecology of conservation with the political geography of policing, I demonstrate how territorial, sovereign, and biopolitical practices and logics coalesce to secure the spaces and the lives of the nonhuman from ostensible human threats. Second, it is rangers who are deployed as petty environmental sovereigns to achieve these objectives through often violent practices. Although many rangers might feel uncomfortable with the use of violence, their agency to commit or resist using violence is authorized, enabled, and constrained by the normative and legal structures of conservation law enforcement within which they operate. The social differentiation among rangers also means that some have more agency to navigate these structures than others. These insights help understand the actually existing operationalization of delegated and performative power over bodies, space, and the use of direct violence. I suggest that critiques of conservation violence, and the use of violence by those acting as petty sovereigns more broadly, should be primarily oriented at the broader structures within which they operate

Light Perception in Two Strictly Subterranean Rodents: Life in the Dark or Blue?

BACKGROUND: The African mole-rats (Bathyergidae, Rodentia) are strictly subterranean, congenitally microphthalmic rodents that are hardly ever exposed to environmental light. Because of the lack of an overt behavioural reaction to light, they have long been considered to be blind. However, recent anatomical studies have suggested retention of basic visual capabilities. In this study, we employed behavioural tests to find out if two mole-rat species are able to discriminate between light and dark, if they are able to discriminate colours and, finally, if the presence of light in burrows provokes plugging behaviour, which is assumed to have a primarily anti-predatory function. METHODOLOGY/PRINCIPAL FINDING: We used a binary choice test to show that the silvery mole-rat Heliophobius argenteocinereus and the giant mole-rat Fukomys mechowii exhibit a clear photoavoidance response to full-spectrum ("white"), blue and green-yellow light, but no significant reaction to ultraviolet or red light during nest building. The mole-rats thus retain dark/light discrimination capabilities and a capacity to perceive short to medium-wavelength light in the photopic range of intensities. These findings further suggest that the mole-rat S opsin has its absorption maximum in the violet/blue part of the spectrum. The assay did not yield conclusive evidence regarding colour discrimination. To test the putative role of vision in bathyergid anti-predatory behaviour, we examined the reaction of mole-rats to the incidence of light in an artificial burrow system. The presence of light in the burrow effectively induced plugging of the illuminated tunnel. CONCLUSION/SIGNIFICANCE: Our findings suggest that the photopic vision is conserved and that low acuity residual vision plays an important role in predator avoidance and tunnel maintenance in the African mole-rats

Cytotoxicity, nitric oxide and acetylcholinesterase inhibitory activity of three limonoids isolated from Trichilia welwitschii (Meliaceae)

BACKGROUND: Limonoids are highly oxygenated compounds with a prototypical structure. Their occurrence in the plant kingdom is mainly confined to plant families of Meliaceae and Rutaceae. Owing to their wide range of pharmacological and therapeutic properties, this study was aimed at investigating the potential nitric oxide (NO) and acetylcholinesterase (AChE) inhibitory activity and the cytotoxicity of three limonoids: trichilia lactone D5 (1), rohituka 3 (2) and dregeanin DM4 (3), isolated from Trichilia welwitschii C.DC RESULTS: Results indicated that the three limonoids had low cytotoxicity towards Vero cells with LC50 values ranging from 89.17 to 75.82 (μg/L. Compounds (2) and (3) had lower cytotoxicity compared to puromycin and doxorubicin used as reference cytotoxic compounds. Compound (1) (LC50 of 23.55 (μg/L) had good antiproliferative activity against RAW 264.7 cancer cells. At the lowest concentration tested (0.5 μg/mL), compound (2) and (3) released the lowest amount of nitric oxide (2.97 and 2.93 μM, respectively). The three limonoids had anti-AChE activity with IC50 values ranged of 19.13 (μg/L for (1), 34.15 (μg/L for (2) and 45.66 (μg/L for (3), compared to galantamine (IC50 of 8.22 ( g/mL) used as positive control CONCLUSION: The limonoid compounds studied in this work inhibited nitric oxide production in LPS-stimulated macrophages and had anti-AChE activity. Trichilia lactone D5 had potential antiproliferative activity against RAW 264.7 cancer cells. The limonoids had low cytotoxicity towards Vero cells lines. This study provided further examples of the importance of limonoids compounds as potential AChE inhibitors and anti-inflammatory agents targeting the inhibition of NO productio