Mohamed A. Al-Kahtani’s research while affiliated with King Khalid University and other places

Sunbirds, as specialized nectarivores, have developed multiple lingual and oropharyngeal peculiarities imposed by this dietary specialization that particularly extract floral nectar. We have described the functional morphology of the tongues and palates of the shining sunbird, Cinnyris habessinicus, using gross anatomical, histological, and scanning electron microscopic methods. The tongue was bifurcated with fringed lamella and extended posteriorly, forming a broad trough at the lingual body and terminating in two fleshy, alae linguae. The lingual apex and body are nonpapillate and nonglandular, and its root had a muscular pad followed by a conspicuous laryngeal mound bordered by three prominent rows of conical papillae. The lingual root had clusters of mucoid glands with rich acidic mucins, and the laryngeal region had complex papillary distribution at the back margins. Both the lingual body and root had well-developed skeletal elements, musculature, and connective tissues. Furthermore, the palate was membranous and made up of four main ridges with a central choanal slit guarded by choanal papillae. Overall, the presented results showed structural and anatomical features that are the results of the nectarivory dietary niche.

Regarding applicative, facile, green chemical research, a bio-inspired approach is being reported for the sonochemical synthesis of Ag nanoparticles by gelatin as a natural reducing/stabilizing and solid support agent without using any toxic and harmful reagent. The biosynthesized Ag [email protected] bionanocomposite were characterized by advanced physicochemical techniques like ultraviolet-visible (UV-Vis), Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron Microscopy (HR-TEM), Energy Dispersive X-ray spectroscopy (EDX), and X-ray Diffraction (XRD) study. It has been established that gelatin-stabilized silver nanoparticles have a spherical shape with a mean diameter from ∼5-10 nm. To survey the antioxidant potentials of Ag [email protected], one of the common antioxidant techniques i.e., DPPH was used. The results of DPPH test proved excellent antioxidant properties of Ag [email protected] in comparison to the positive control used i.e., butylated hydroxytoluene. The IC50 of Ag [email protected] was 250 µg/mL in the antioxidant test. Determination of anti-liver cancer effects of Ag [email protected] was carried out by the MTT assay and against pleomorphic hepatocellular carcinoma (SNU-387), morris hepatoma (McA-RH7777), and novikoff hepatoma (N1-S1 Fudr) cell lines. The results of MTT assay confirmed removing SNU-387, McA-RH7777, and N1-S1 Fudr cell lines after treating with low concentrations of Ag [email protected] The IC50 of the Ag [email protected] was 192, 144, and 228 µg/mL against SNU-387, McA-RH7777, and N1-S1 Fudr cell lines, respectively. The best result of anti-human liver cancer effects of Ag [email protected] against the above cell lines was seen in the case of the N1-S1 Fudr cell line. According to the above results, significant anti-liver cancer effects of Ag [email protected] is confirmed.

We characterized the morphological and anatomical adaptations of the lingual microstructures of the Eurasian collared dove and discussed their implications for its dietary niche. We analyzed tongues of nine S. decaocto using histological, histochemical, stereomicroscopic, and scanning electron microscopic techniques. Our findings showed that the tongue is relatively short with a tapered apex that carries a terminal lingual nail. However, the lingual body has median scales and is bordered laterally by filiform papillae. Further, the tongue body bears a distinctive papillary crest. The tongue root is nonpapillate and infiltered with orifices of the posterior salivary glands. The bulky laryngeal mound has a circular glottic fissure, carrying a single row of papillae at the rear edge. Concurrently, our histological and histochemical findings demonstrate that the tongue has taste buds, anterior and posterior salivary glands, along with an elongated entoglossum that extends from lingual apex to root. Besides, ovoid and globular mucous glands displayed intense alcianophilic reactions. More substantially, the palate is made up of three palatine ridges with a caudal choanal cleft that was bounded by two rows of palatine papillae. Our data indicate multiple and novel structural variations for the lingual and palatal sculptures coopted for their feeding style.

The prevalence of the infectious diseases caused by Candida species and other human pathogenic microbes has led to the discovery of some natural agents against multidrug resistant microbes. Therefore, this research was designated to determine the capability of synthesized nanoparticles (NPs) from aqueous extract of leaves and fruits of Casuarina equisetifolia as anticandidal and antibacterial against some microbes. Silver NPs (AgNPs) were successfully gained from aqueous leaves and fruit extracts of C. equisetifolia which is defined on the basis of UV-visible spectroscopy, X-ray diffraction analysis and scanning electron microscope. The results showed that leaves and fruits extracts of C. equisetifolia acts as an excellent capping agent. XRD based on the FWHM analysis showed that AgCl and Ag had an average NPs size of 90.97 nm and 71.28 nm, respectively for fruits and 15.33 nm and 14.01 nm, respectively for leaves. UV-visible spectroscopy showed a maximum absorbance at 442 nm for fruits and 433 nm for leaves. SEM showed that the size of NPs from leaves lied in between of (30 to180 nm) and for fruits (70 to 250 nm). Candida albicans was severely affected by NPs of leaves with inhibition zone (3.03± 1.61 cm) and NPs of fruits had (1.37± 0.15 cm) inhibition zone. Nanoparticles from leaves exhibited maximum activity against P. mirabilis (3.52± 0.13 cm) and low activities against M. luteus (1.50±0.18 cm) inhibition zones. In conclusion, these eco-friendly synthesized AgNPs from leaves and fruits of C. equisetifolia could be used as competitive alternative natural drugs than conventional synthetic chemicals.

Our study was conducted to characterize the retinal structure of the Egyptian fruit bat, Rousettus aegyptiacus to determine the distribution of photoreceptors and melanosomal populations in various retinal zones. Also, we paid attention to the specific structural and functional adaptations related to their nocturnal habits. We analyzed the retinae of 12 adult male Egyptian fruit bats using morphometrical, histological, ultrastructural, and immunoblotting standard techniques. Histological findings revealed that the retinal cells have variations in geometrical architecture and different retinal thickness together with their corresponding layers bearing specific choroidal papillae projecting towards the inner retina. Immunoblotting and ultrastructure results showed that the microstructure of the retina conforms to that pattern found in mammalian species. The retinal photoreceptors are rod-dominant; alternatively, possess two spectral types of cones: SWS and LW/MWS cones as evidence for the basis for dichromatic vision. In addition, the outer retina showed densely-distributed melanin granules with a significant increase in the number of pigment epithelium cells in the eccentric retina. Furthermore, the asymmetric distribution among the retinal quadrants for the visual pigments of both rods and cones coinciding with neuronal cells such as bipolar and ganglion cells confers instructive information about their visual perception and orientation. In conclusion, our findings indicate that R. aegyptiacus efficiently discriminates colors with complex visual adaptations to mediate increased visual acuity coopted for the nocturnal niches.

We describe the morphological adaptations of the tongue and gastrointestinal tract of the striped sand snake Psammophis sibilans and discuss their functional importance. Using standard histological, histochemical, and scanning electron microscopy techniques, we analyzed 11 adult snakes of both sexes. Our findings showed that the bifurcated non-papillate tongue exhibited chemoreceptive adaptions to squamate foraging behavior. The lingual apex tapered terminally with sensory spines, and the body of the tongue possesses a characteristic central odor–receptor chamber that might serve to trap and retain scent molecules. Furthermore, the intrinsic musculature showed interwoven and well-developed transverse, vertical and longitudinal muscle fibers that control contraction and retraction during probing and flicking. The esophagus displayed highly folded mucosa lined with columnar epithelium with goblet cells. In contrast, the stomach mucosa formed finger-like gastric rugae, encompassing tubular glands with dorsal gastric pits. The intestine is distinct from other vertebrates in lacking the crypts of Lieberkühn in the tunica mucosa and submucosa. The intestine mucosa is mostly arranged in interdigitating villi oriented perpendicular to the luminal surface. We extrapolated subtle variations for both acid and neutral mucopolysaccharides and glycoproteins localization as well as collagen fibers using histochemical analyses. The elaborate histo-morphological and functional adaptation of the tongue and digestive tract plays a pivotal role in foraging and feeding behavior.

This study investigated the effect of Ellagic acid (EA) on SKOV‐3 cell growth and invasiveness and tested if the underlying mechanism involves modulating autophagy. Cells were treated with EA in the presence or absence of chloroquine (CQ), an autophagy inhibitor, compound C (CC), an AMPK inhibitor, or an insulin‐like growth factor‐1 (IGF‐1), a PI3K/Akt activator. EA, at an IC50 of 36.6 µM, inhibited cell proliferation, migration, and invasion and induced cell apoptosis in SKOV‐3 cells. These events were prevented by CQ. Also, EA increased levels of Beclin‐1, ATG‐5, LC3I/II, Bax, cleaved caspase‐3/8 and reduced those of p62 and Bcl‐2 in these cancer cells. Mechanistically, EA decreased levels of p‐S6K1 (Thr389) and 4EBP‐1 (Thr37/46), two downstream targets of mTORC1, and p‐Akt (Thr308) but increased levels of AMPK (Thr172) and p‐raptor (Ser792), a natural inhibitor of mTORC1. CC or IGF‐1 alone partially prevented the effect of EA on cell survival, cell invasions, and levels of LDH, Beclin‐1, and cleaved caspase‐3. In conclusion, EA can inhibit SKOV‐3 growth, migration, and invasion by activating cytotoxic autophagy mediated by inhibition of mTORC1 and Akt and activation of AMPK.

The wide distribution of infections-related pathogenic microbes is almost related to the contamination of food and/or drinking water. The current applied treatments face some limitations. In the current study, k-carrageenan polymer was used as supporting material for the proper/unreleased silver nanoparticles that showed strong antimicrobial activity against six pathogenic bacteria and yeast. The bio-extract of the pupa of green bottle fly was used as the main agent for the synthesis of silver nanoparticles. The qualitative investigation of biologically synthesized silver nanoparticles was determined using UV-Vis spectrophotometric analysis; however, the size of nanoparticles was in range of 30–100 nm, as confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and particle size analyzer. The proper integration of silver nanoparticles into the polymeric substrate was also characterized through fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), SEM, and tensile strength. The antimicrobial activity of k-carrageenan/silver nanoparticles against Gram positive, Gram negative, and yeast pathogens was highly effective. These results indicate the probable exploitation of the polymeric/nanoparticles composite as an extra stage in water purification systems in homes or even at water treatment plants.

Natural products, especially secondary metabolites produced by plants under stressed conditions, are shown to have different pharmacological impacts from one to another. Aeluropus lagopoides is one of the common halophyte plants that survive under stressed conditions, and has been used for healing wounds and as a painkiller. The bioactivity and the chemical composition of this plant have been poorly investigated. Consequently, the chemical components of A. lagopoides leaves were extracted using hexane (nonpolar), ethyl acetate (semi-polar), and n-butanol (polar) to extract the most extensive variety of metabolites. The cytotoxicity and anticancer impact of extracted secondary metabolites were evaluated against breast (MCF-7), colon (HCT-116), and liver (HepG2) cancer cell lines using a SulphoRhodamine-B (SRB) test. Their mechanisms of action were verified by observing the appearance of apoptotic bodies using the fluorescent microscope, while their antiproliferative impacts were evaluated using a flow cytometer. Results revealed that secondary metabolites extracted using hexane and ethyl acetate had the highest cytotoxicity and thus the greatest anticancer activity effect on HepG2 with IC50 (24.29 ± 0.85 and 11.22 ± 0.679 µg/mL, respectively). On the other hand, flow cytometer results showed that secondary metabolites could inhibit the cell cycle in the G0/G1 phase. To ascertain the chemical composition–function relationship, the extracts were analyzed using LC-MS/MS. Accordingly, A. lagopoides hexane and ethyl acetate extracts may contain agents with anticancer potential.