Ahmed Ibrahim Al-Asmari

Dr. Ahmed Ibrahim Al-Asmari

Special Toxicological Analysis Unit, King Faisal Specialist Hospital & Research Centre, Riyadh, Ar Riyāḑ, Saudi Arabia
orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 October 2022 in Annals of Medicine
Verified
Journal Article
Open access
NJNasimudeen R. Jabir
Nasimudeen R. Jabir
CFChelapram K. Firoz
Chelapram K. Firoz
TZTorki A. Zughaibi
Torki A. Zughaibi
MAMohammed Alsaadi
Mohammed Alsaadi
AAAdel M. Abuzenadah
Adel M. Abuzenadah
STShams Tabrez
Shams Tabrez
Introduction: Phytochemicals have garnered much attention because they are useful in managing several human diseases. Yohimbine is one such phytochemical with significant pharmacological potential and could be exploited for research by medicinal chemists. It is an indole alkaloid obtained from various natural/synthetic sources. Aims and Results: The research on yohimbine started early, and its use as a stimulant and aphrodisiac by humans has been reported for a long time. The pharmacological activity of yohimbine is mediated by the combined action of the central and peripheral nervous systems. It selectively blocks the pre and postsynaptic α2-adrenergic receptors and has a moderate affinity for α1 and α2 subtypes. Yohimbine also binds to other behaviourally relevant monoaminergic receptors in the following order: α-2 NE > 5HT-1A>, 5HT-1B > 1-D > D3 > D2 receptors. Conclusion: The current review highlights some significant findings that contribute to developing yohimbine-based drugs. It also highlights the therapeutic potential of yohimbine against selected human diseases. However, further research is recommended on the pharmacokinetics, molecular mechanisms, and drug safety requirements using well-designed randomized clinical trials to produce yohimbine as a pharmaceutical agent for human use.

1 September 2007 in Journal of Analytical Toxicology
Verified
Journal Article
Open access
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Ahmed Ibrahim Al-AsmariAhmed Ibrahim Al-Asmari
Ahmed Ibrahim Al-Asmari
RARobert A. Anderson
Robert A. Anderson
A method using liquid chromatography-electrospray ionization-tandem mass spectrometry was developed and validated for the determination of morphine, codeine, hydromorphone, dihydrocodeine, oxycodone, buprenorphine, and naloxone with their metabolites morphine-3-glucuronide, morphine-6-glucuronide, normorphine, 6-acetylmorphine, 6-acetylcodeine, codeine-6-glucuronide, norcodeine, hydromorphine-3-glucuronide, dihydrocodeine-6-glucuronide, dihydromorphine, dibydromorphine-3-glucuronide, dibydromorphine-6-glucuronide, oxymorphone, norbuprenorphine, buprenorphine-3-glucuronide, norbuprenorphine-3-glucuronide, and naloxone-3-glucuronide in human whole blood. Polar metabolites (glucuronides) and other analytes were extracted by SPE using Bond Elut C18. Chromatographic separation was performed on a Phenomenex Synergi reversed-phase column with gradient elution based on a mobile phase consisting of 10mM ammonium formate adjusted to pH 3 and acetonitrile. Intraday and interday precision for all analytes were between 0.6% and 13.8%, and recoveries were between 80.3% and 101.4%. Calibration curves were linear for all analytes over the concentration range 5–400 ng/mL, and correlation coefficients (R2) were better than 0.999. Limits of detection and quantitation were 0.16–1.2 ng/mL and 0.5–4.09 ng/mL, respectively. The method described consolidates previous work on opioids and their metabolites published in the literature and is the first to include the detection of naloxone-3-glucuronide. The method has been applied in routine postmortem cases after opiate overdose with the threefold purpose of providing interpretive information on the cause and type of death (rapid, sub-acute, or delayed death) and to distinguish heroin, morphine, and codeine users.

13 October 2021 in Saudi Journal of Biological Sciences
Verified
Journal Article
Open access
MAMaaged Akiel
Maaged Akiel
OAOhoud Y. Alshehri
Ohoud Y. Alshehri
SAShokran A. Aljihani
Shokran A. Aljihani
AAAmani Almuaysib
Amani Almuaysib
Ammar BaderAmmar Bader
Ammar Bader
Majed HalwaniMajed Halwani
Majed Halwani
All active natural molecules are not fully exploited as therapeutic agents, causing delays in the advancement of anticancer drug discovery. Viridiflorol is a natural volatile element that may work as anti-cancer compound. We tested the anticancer properties of viridiflorol at different concentrations ranging from 0.03 to 300 μM in vitro on three cancer cells including breast (MCF-7), lung (A549) and brain (Daoy). The cancer cells responses were documented after treatment using MTT and Annexin V assays. Viridiflorol showed cytotoxic effects against all tested cell lines, reducing cell viability in a concentration-dependent manner with variable IC50 values. Daoy and A549 cell lines were more sensitive to viridiflorol when compared with temozolomide and doxorubicin, respectively. Viridiflorol demonstrated the highest anticancer activity against the Daoy cells with an estimated IC50 of 0.1 µM followed by MCF-7 at 10 µM, and A549 at 30 µM. In addition, upon exposure to concentrations ranging from 30 µM to 300 µM of viridiflorol, early and late apoptotic cell death was induced in a concentration dependent manner in Daoy (55.8%-72.1%), MCF-7 (36.2%-72.7%) and A459 (35%-98.9%) cell lines, respectively. In conclusion, viridiflorol demonstrates cytotoxic and apoptotic ability in three different cancer cell lines (brain, breast and lung).


10 January 2023 in Frontiers in Public Health
Verified
Journal Article
Open access
BSBhupendra Pratap Singh
Bhupendra Pratap Singh
TZTorki A. Zughaibi
Torki A. Zughaibi
SASaif A. Alharthy
Saif A. Alharthy
Ahmed Ibrahim Al-AsmariAhmed Ibrahim Al-Asmari
Ahmed Ibrahim Al-Asmari
SRShakilur Rahman
Shakilur Rahman
Introduction: The concentrations of particulate and gaseous Polycyclic Hydrocarbons Carbon (PAHs) were determined in the urban atmosphere of Delhi in different seasons (winter, summer, and monsoon).Methodology: The samples were collected using instrument air metric (particulate phase) and charcoal tube (gaseous phase) and analyzed through Gas chromatography. The principal component and correlation were used to identify the sources of particulate and gaseous PAHs during different seasons.Results and discussion: The mean concentration of the sum of total PAHs (TPAHs) for particulate and gaseous phases at all the sites were found to be higher in the winter season (165.14 ± 50.44 ng/m3 and 65.73 ± 16.84 ng/m3) than in the summer season (134.08 ± 35.0 ng/m3 and 43.43 ± 9.59 ng/m3), whereas in the monsoon season the concentration was least (68.15 ± 18.25 ng/m3 and 37.63 1 13.62 ng/m3). The principal component analysis (PCA) results revealed that seasonal variations of PAHs accounted for over 86.9%, 84.5%, and 94.5% for the summer, monsoon, and winter seasons, respectively. The strong and positive correlation coefficients were observed between B(ghi)P and DahA (0.922), B(a)P and IcdP (0.857), and B(a)P and DahA (0.821), which indicated the common source emissions of PAHs. In addition to this, the correlation between Nap and Flu, Flu and Flt, B(a)P, and IcdP showed moderate to high correlation ranging from 0.68 to 0.75 for the particulate phase PAHs. The carcinogenic health risk values for gaseous and particulate phase PAHs at all sites were calculated to be 4.53 × 10−6, 2.36 × 10-5 for children, and 1.22 × 10−5, 6.35 × 10−5 for adults, respectively. The carcinogenic health risk for current results was found to be relatively higher than the prescribed standard of the Central Pollution Control Board, India (1.0 × 10−6).

17 October 2019 in Journal of Analytical Toxicology
Verified
Journal Article
Closed access
Ahmed Ibrahim Al-AsmariAhmed Ibrahim Al-Asmari
Ahmed Ibrahim Al-Asmari
A specific, sensitive, fast and simple method for analysis of Δ9-tetrahydrocannabinol (THC), 11-hydroxy-Δ9-THC (THC-OH) and 11-nor-Δ9-THC-9-carboxylic acid (THC-COOH) in routine postmortem cases using LC–MS–MS was developed and validated. Prior to solid phase extraction, urine, stomach contents and bile were pretreated using alkaline hydrolysis, while blood and vitreous humor were pretreated with protein precipitation. The distribution of THC, THC-OH and THC-COOH were investigated in 31 postmortem cases that tested positive for cannabinoids. This revealed new information regarding the distribution of THC in stomach contents and vitreous humor. Alkaline hydrolysis was sufficient for the deglucuronidation of THC-COOH-glucuronide to its free form, THC-COOH, in urine, bile and stomach contents. However, the THC-OH concentration in bile reported in this study is considerably high compared to that of previous studies. In conclusion, including THC and its metabolites (THC-OH and THC-COOH) is crucial for any forensic toxicology detection method to most accurately determine the role of cannabinoids in deaths.