Adulticidal Activity of Hyptis suaveolens, Chenopodium ambrosioides and Lippia adoensis Leaf Extracts and Essential Oils against Anopheles gambiae (Diptera: Culicidae)

The study was undertaken to evaluate the adulticidal efficacy of the methanolic leaf extracts and essential oils of Chenopodium ambrosioides, Hyptis suaveolens and Lippia adoensis against adults of Anopheles gambiae. A chemical profile of each plant extracts (qualitative phytochemical screening) and essential oil (GC/MS analysis) was also determined. Doses of 125, 250, 500 and 1000 mg/bottle of plant extracts and 25, 50, 100 and 200 mg/bottle of essential oils were prepared and tested using CDC bottles. In each plant extract, alkaloids, flavonoids, saponins, tannins, phenolic groups, terpenoids, fats and oils were presents. Major chemical constituents of essential oils were thymol (27.09%), sabinene (18.93%) and 4-carene (52.88%) in L. adoensis, H. suaveolens and C. ambrosioides, respectively. L. adoensis extract (at 1000 mg/bottle) and essential oil of H. suaveolens (at 200 mg/bottle) were the most potent causing 100% mortality of An. gambiae adults, 24 h post-exposure. Methanolic extract of L. adoensis (LC50= 20.20 mg/bottle) was the most effective compared to other extracts. Similarly, essential oil of H. suaveolens (LC50= 5.27 mg/bottle) was revealed as the most toxic on An. gambiae adults compared to other oils. Therefore, the extracts of L. adoensis and essential oil of H. suaveolens showed a high activity and should be recommended to be promoting as natural bioinsecticides to control mosquito adults.

Synthesis of Zinc Oxide Nanoparticles Using Leaf Extract of Lippia adoensis (Koseret) and Evaluation of Its Antibacterial Activity

The synthesis of metal oxide nanoparticles with the use of medicinal plant extract is a promising alternative to the conventional chemical method. This work aimed to synthesize zinc oxide nanoparticles using a green approach from indigenous “Koseret” Lippia adoensis leaf extract which is an endemic medicinal plant and cultivated in home gardens of different regions of Ethiopia. The biosynthesized zinc oxide nanoparticles were characterized using thermogravimetric analysis, X-ray diffraction, scanning electron microscopy-energy dispersive spectroscopy, transmission electron microscopy, ultraviolet-visible spectroscopy, and Fourier transform infrared spectroscopy. Furthermore, this study also evaluated the antibacterial activity of the synthesized ZnO nanoparticles against clinical and standard strains of Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, and Enterococcus faecalis by the disc diffusion method. According to the result of this study, ZnO nanoparticles synthesized using Lippia adoensis leaf extract showed promising result against both Gram-positive and Gram-negative bacterial strains with a maximum inhibition zone of 14 mm and 12 mm, respectively, using uncalcinated form of the synthesized ZnO nanoparticles.

Economic Valuation of Lippia adoensis, implication for Access and Benefit Sharing agreement in Sidama and WestArsi Zones, SNNPR and Oromia Regions, Ethiopia

Biodiversity has major economic value. Most of these values are often not captured by the market. Hence, the potential of biodiversity is often underestimated. Such an underestimation is considered as one of the factors for rapid depletion of biodiversity and loss of habitats and species. Valuation of bio-resources would facilitate in identifying the real value of genetic resources and obtaining a reasonably better share of the overall benefits of genetic materials to the local communities, who are involved in its management. Accordingly, the Economic Valuation of Lippia adoensis was conducted implication for ABS. The result of this study identified the direct and indirect use values of Lippia adoensis. Majority of the respondents (98.33%) were willing to pay for use values of Lippia adoensis. Moreover, (80.8%) of the respondents were willingness to pay for Conservation of Lippia adoensis. Furthermore, 95(79.2%) of the respondents were willingness to pay for non-use value of Lippia adoensis in the study areas. The cumulative estimates of willingness to pay for use of values Lippia adoensis were 30,437.50 birr with an average annual willingness to pay of 253.64±275.63 birr for Lippia adoensis. The maximum willingness to pay was 1000 birr while the minimum WTP was 125 birr with range 875 birr. The value of R2 for linear function (model) was 0.541, semi log R2=0.452 and double log R2=0.291.From the given result the linear regression function (R2=0.541) the one with the best performance. The R2=0.541or 54.1%, this means that the dependent variable can be explained by the independent variable. In this study, household size (Sig.0.000), income level (Sig.0.000), number of Lippia adoensis (Sig.0.044) and distance of the market (Sig. 0.051) of the respondents made a unique and statistically significant, contribution to the prediction of willingness to pay for Lippia adoensis. Of the nine variables, household size of the responders makes the largest unique contribution (beta=0.490), followed by income level of the respondents (beta -0.396). Therefore, because of its prospect for the production of many preservative, spices, aromatherapy, medicine and pharmaceuticals industry, bio prospecting companies require to access the genetic resources following the Ethiopian legislation of Access and Benefit Sharing.

Essential oil optimizes the susceptibility of Callosobruchus maculatus and enhances the nutritional qualities of stored cowpea Vigna unguiculata

The intensive use of synthetic pesticides in cowpea storage has led to the development of resistance by Callosobruchus maculatus and subsequent degradation of grain quality. In an attempt to circumvent these constraints, the susceptibility of C. maculatus to 2,2-dichlorovinyldimethyl phosphate (DDVP) and Lippia adoensis essential oil (EO) was investigated and variations in the proportions of nutritional values of treated grains 150 days after storage were assessed. The survival rate was recorded after five generations. The resistance index and biochemical parameters of grains were determined. The results from this study revealed that the survival rate and resistance index significantly increased proportionally with damage in DDVP treatments ( r = 0.889; p = 0.018) while in EO treatments, those values remained low without significant variations ( p = 0.0764) throughout the generations. DDVP stored grains yielded higher crude protein values, but lower carbohydrates, tannins, phenolics and minerals compared to EO. Eighteen amino acids were detected in EO treated grains and 14 in DDVP which was devoid of albumin and prolamin. Lippia adoensis EO could therefore represent a safe alternative bio-pesticide to cope with insect resistance and enhance the nutritional qualities of stored cowpea seeds.