Aqueous Kernel Extract Research Articles

Fabrication, characterization, anti-inflammatory, and anti-diabetic activity of silver nanoparticles synthesized from Azadirachta indica kernel aqueous extract

The Azadirachta indica is an excellent and pharmaceutically valuable phytochemicals enriched traditional medicinal plant. The purpose of the research was to assess the ability of A. indica aqueous kernel extract to synthesize silver nanoparticles as well as their anti-inflammatory and anti-diabetic activity in vitro. The obtained results state that the aqueous kernel extract of A. indica can fabricate the silver nanoparticles and be confirmed by standard analytical techniques. Under UV–visible spectrophotometer analysis, the absorbance peak was found at 430 nm was related to the surface plasmon resonance of silver nanoparticles. The FTIR (Fourier-transform infrared spectroscopy) analysis revealed that numbers of functional groups belong to the pharmaceutically valuable phytochemicals, which act as reducing, capping, and stabilizing agent on silver nanoparticles synthesis. The size and shape of the silver nanoparticles were examined as 19.27–22.15 nm and spherical in shape. Interestingly, this kernel fabricated silver nanoparticles possess a reasonable anti-inflammatory (69.77%) and anti-diabetic (73.5%) activity at 100 μg mL−1 and these were partially comparable with standards (anti-inflammatory: 81.15%; anti-diabetic: 87.9%). Thus, the aqueous kernel extract fabricated silver nanoparticles can be considered for further in-vivo study to assess the practical possibility to promote as a pharmaceutical agent.

Steroid glycosides as potential analytes for Cu‐doping on TiO2 for photocatalytic water treatment

The kernel of Thevetia peruviana, a toxic ornamental shrub, is rich in cardiac glycosides and, its concentration could be as high as 4.8%. This work aimed for the functionalization of a photocatalyst support, TiO2 by Cu‐doping using a facile bio‐mediated green methodology. Herein, the mechanism of Cu‐doping on TiO2 mediated by cardiac glycosides present in the bioextract is proposed. Cu(II) was first immobilized on TiO2 and, then the aqueous kernel extract of T. peruviana was used to dope Cu(II) on TiO2 at room temperature. The loading of Cu doped on TiO2 was found to be about 99% of the initial amount of Cu(II) taken in the immobilization stage. With the increase in Cu loading, there was a gradual redshift in the optical absorbance but the optimal dopant concentration was found to be 1.5% (true loading). The polydispersity index was increased by 1.8‐folds due to the transformation of the rutile phase to the anatase phase (maximum 8.48%) and increase in the crystallite size (17.7–24.5 nm). Cu‐doped TiO2 exhibited as high as 75% trypan blue dye degradation in 120 min at the optimal dopant concentration under the visible light irradiation by the combined effect of photocatalysis and photosensitization which was originated in the presence of trypan blue dye. However, the photosensitization effect due to the adsorption of pigments present in the bioextract was also insignificant as evidenced from the decomposition of a colorless pharmaceutical compound. The electron spin resonance spectra confirmed that radicals primarily caused the dye decomposition. © 2018 American Institute of Chemical Engineers Environ Prog, 37: 1901–1907, 2018

Immuno-suppressive effects of aqueous extract of soapnut Sapindus emarginatus on the larvae and pupae of vector mosquito, Aedes aegypti

We recently reported the presence of potent anti-mosquito activity in aqueous kernel extract of the soapnut, Sapindus emarginatus, and demonstrated its impact on marker enzymes in larvae and pupae of the vector mosquito, Aedes aegypti. As a sequel to these findings, the present study elucidates immunotoxicity of this extract with respect to hemocyte-mediated cellular immune responses in fourth instar larvae and pupae as well as cuticular melanization reaction in the larvae of A. aegypti. The exposure of these two developmental stages of the mosquito to the soapnut extract at a lethal threshold concentration neither affected hemocyte viability tested up to 3h in vitro nor did it influence the hemocyte count. By contrast, exposure of the mosquito larvae and pupae to this extract significantly reduced the ability of their hemocytes to bind yeast cells, an important early event in the process of non-self recognition by immune cells. Consequently, the phagocytic activity of these hemocytes against yeast cells was also found to be adversely affected upon exposure of larvae and pupae to the extract. Besides, a perceptible initial delay in melanization reaction at the injured site of the cuticle in the extract-exposed larvae was observed. All these findings demonstrate, for the first time, the immuno-suppressive potential of a botanical biocide in the vector mosquito.

Effects of extract of soapnut Sapindus emarginatus on esterases and phosphatases of the vector mosquito, Aedes aegypti (Diptera: Culicidae)

Our earlier investigations with kernels from the soapnut Sapindus emarginatus revealed it as a new source of botanical biocide with potent antimosquito activity, as evident from the proven unique ability of the aqueous kernel extract to kill all the developmental stages of three important vector mosquito species, Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. This extract was also found to be safe for two non-target aquatic insects. As a sequel to these findings, we have further examined quantitative and qualitative changes in total proteins, esterases, and phosphatases in whole body homogenates of fourth instar larvae and pupae of A. aegypti exposed to this extract at an appropriate threshold time for its lethal effect to gain insights into the impact of the botanical biocide on biochemical characteristics of the target vector mosquito at two distinct developmental stages. The profiles of proteins, esterases (acetylcholinesterse, α- and β-carboxylesterases), and phosphatases (acid and alkaline) exhibited distinct patterns of variation during normal development of fourth instar larvae and pupae, indicating intrinsic difference in biochemical features between these two developmental stages of A. aegypti. Upon exposure of the larvae to the extract, significant reduction in the activities of acetylcholinesterse, β-carboxylesterase, and acid phosphatases were recorded, whereas the total proteins, α-carboxylesterase and alkaline phosphatase activities were unaffected. By contrast, only alkaline phosphatase activity was significantly affected in pupae exposed to the extract. Analysis of these enzymes in native PAGE revealed that they exist in isoforms in both the larvae and pupae. The alterations in the levels of enzymatic activities observed from the quantitative assays of various enzymes were reflected by the respective zymograms with perceptible differences in the intensity and the number of bands detected especially with β-carboxylesterase, acid and alkaline phosphatase activity between the control and exposed test organisms. Despite the fact that the soapnut kernel extract causes mortality of both the larvae and pupae of A. aegypti, the findings of this study demonstrate that the impact of this extract is most pronounced in various enzyme profiles of the larvae rather than the pupae. Such discrepancy implicates the presence of unique biochemical mechanisms in the pupae of mosquito for detoxification of botanical biocides.

Antimosquito activity of aqueous kernel extract of soapnut Sapindus emarginatus: impact on various developmental stages of three vector mosquito species and nontarget aquatic insects

Aqueous (physiological saline) extracts of seed kernel from seven indigenous plants were initially screened for their antimosquito activity against eggs, larvae of all instars, and pupae of Aedes aegypti. Among various seed kernels tested, the soapnut Sapindus emarginatus (Sapindaceae) extract was found to exhibit, for the first time, a strong antimosquito activity as evident from its ability to inflict 100% mortality of all the developmental stages of A. aegypti. Furthermore, the kernel extract of S. emarginatus also exerted ovicidal, larvicidal, and pupicidal activity against two other important vector mosquitoes, namely, Anopheles stephensi and Culex quinquefasciatus. Differential susceptibility of the various developmental stages of the three mosquito species exposed to soapnut extract was also noticed. The kernel extract was found to be safe for two nontarget aquatic insects tested: the larvae of Chironomus costatus and the nymphs of Diplonychus rusticus. Lethal concentration values of soapnut extract to these nontarget insects were always threefold or fivefold higher than those that produced 100% mortality of the larvae of the three mosquito species examined. The findings of this study clearly demonstrate that the aqueous kernel extract of S. emarginatus has potent antimosquito activity detectable against all the developmental stages of three important vector mosquito species as well as it is safe for nontarget aquatic organisms, and thus this new botanical resource could be used as an eco-friendly alternative biocidal agent in control of mosquitoes.