Phytolatex synthesized gold nanoparticles as novel agent to enhance sun protection factor of commercial sunscreens.

OBJECTIVE: To study the potential of phytolatex (latex of Jatropha gossypifolia) fabricated gold nanoparticles as promising candidate in sunscreen formulations for enhancement in sun protection factor. METHODS: In this study, plant latex was used as reducing and capping agent to synthesize gold nanoparticles. Latex fabricated gold nanoparticles were characterized by different analytical techniques such as UV-Vis spectroscopy, Fourier transforms infrared spectroscopy, dynamic light scattering, zeta potential, transmission electron microscopy and X-ray diffraction. Potential of sunscreen preparations containing gold nanoparticles to protect skin from UV radiation was investigated by in vitro sun protection factor analysis. Transmission electron microscopy and UV-Vis spectroscopy techniques were used to get insight into mechanism by which AuNPs enhance sun protection factor of sunscreen. RESULTS: Monodisperse gold nanoparticles were synthesized using plant latex without need of hazardous chemical reducing and capping agents. Gold nanoparticles showed surface plasmon resonance peak at 550 nm in UV-Vis spectroscopic study. Gold nanoparticles were spherical and triangular in shape with size range of 30-50 nm. The zeta potential of gold nanoparticles was found to be -9.39 ± 0.19 mV. XRD analysis confirmed face-centred cubic (fcc) structure of gold nanoparticles. Incorporation of latex synthesized gold nanoparticles (2 and 4 [% w/w]) into commercial sunscreens increased the sun protection factor from 2.43 ± 0.74 to 24.11 ± 0.46% than sunscreen devoid of gold nanoparticles. From UV-Vis absorption spectroscopy and TEM analysis, it was observed that gold nanoparticles enhance the sun protection factor of commercial sunscreens due to reflection and scattering of UV radiation. CONCLUSION: Phytolatex synthesized gold nanoparticle is novel agent to enhance sun protection factor of commercial sunscreens. Gold nanoparticles aggregation in commercial sunscreen was the main factor behind SPF enhancement. This study showed that gold nanoparticles are potent alternative to traditionally used hazardous titanium dioxide and zinc oxide nanoparticles in sunscreen.

Studies on amendment of different biopolymers in sandy loam and their effect on germination, seedling growth of Gossypium herbaceum L.

Different biopolymers, agar, cellulose, alginate, psyllium gaur gum, and bacterial exopolysaccharide (EPS) powders were amended to check their efficacy in enhancing maximum water holding capacity (MWHC), permanent wilting point (PWP), and germination and seedling growth of the Gossypium herbaceum in a laboratory scale. The efficacy of all biopolymers for enhancement of MWHC, PWP, and growth was also analyzed by measuring organic carbon, organic matter, total nitrogen, respiration rate, and microflora in amended and control sandy loams. The range of concentrations (0.2-2%) of all biopolymers was incorporated in sandy loam containing pots. The soil without polymer was considered as control. The psyllium (0.6%) and bacterial EPS (1%) amended soil has 242 and 233% increase in MWHC and thus delaying in the permanent wilting point by 108 and 84 h at 37 °C, respectively, as compared to control. All biopolymers found to increase more or less MWHC, organic matter, total nitrogen, microflora, and PWP as compared to control. The psyllium and bacterial EPS show the highest increase organic matter, biomass, and microflora. The highest reduction in MWHC after 12 weeks were observed in cellulose, gaur gum, and alginate; besides, psyllium, bacterial EPS, and agar showed comparatively less reduction MWHC, i.e., 24% and 14.5%, respectively. The toxicity studies of biopolymer were carried out on earthworm (Eisenia foetida). It revealed their nontoxic nature. The biopolymer amendment in sandy loam can be an effective strategy to improved soil texture, fertility, and thereby crop yield.

Larvicidal activities of six plants extracts against two mosquito species, Aedes aegypti and Anopheles stephensi.

Larvicidal activity of crude chloroform, dichloromethane and methanol extracts of the leaves and roots of six Indian plants, Aegle marmelos L., Balanites aegyptica L., Calotropis gigantica L., Murraya koenigii L., Nyctanthes arbor-tristis L. and Plumbago zeylanica L., were tested against the early fourth instar larvae of Aedes aegypti L. and Anopheles stephensi. The larval mortality was observed after 24 h of exposure. All extracts showed moderate larvicidal effects. However, the highest larval mortality was found in methanol extracts of P. zeylanica roots and B. aegyptica roots against Ae.aegypti (LC50 169.61 mg/lit, 289.59 mg/lit) and An.stephensi (LC50 222.34 mg/lit, 102.29 mg/lit), respectively. The methanol extracts of plants were more effective than the other extracts. This is an ideal eco-friendly approach aid for the control of mosquito species, Ae. aegypti, and An.stephensi.