Dildar Ahmed

Dr. Dildar Ahmed

Forman Christian College, Lahore, Punjab, Pakistan
orcid

Research Focus & Metrics

Academic Career Length

39Years (1988-Present)

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

Representative Publications

View All Publications
4 June 2015 in Antioxidants
Verified
Journal Article
Open access
PDF file
Dildar AhmedDildar Ahmed
Dildar Ahmed
MKMehboob Khan
Mehboob Khan
RSRamsha Saeed
Ramsha Saeed
In the quest for new medicines, the methanolic, hexanic, and aqueous extracts of Adiantum caudatum leaves, obtained by Soxhlet extraction, were analyzed for phenolic and flavonoid contents, and antioxidant and antimicrobial potential. TPCs (total phenolic content) of the methanolic, aqueous and hexanic extracts were 27.7, 21.1, and 16.7 μg of gallic acid equivalents per mL, respectively, while TFCs (total flavonoid content) were 13.2, 11.6, and 10.0 μg of rutin equivalents per mL, respectively. Antioxidant activities of the extracts in reducing power, FRAP (ferric reducing antioxidant power), phosphomolybdate and ABTS assays follow the same order of methanolic ˃ aqueous ˃ hexanic. In the DPPH assay, however, the aqueous extract exhibited a slightly higher antioxidant activity than the methanolic one. Methanol is therefore a better solvent to extract most of the antioxidant components from A. caudatum leaves. In lipid peroxidation inhibitory assay, the extracts showed almost similar behavior and their activity decreased gradually with time. The aqueous extract was the strongest inhibitor after two days, but the hexanic became the most potent after about three days. The antibacterial potential of the extracts was determined against Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. Towards all the microbes, the aqueous extract was the most potent and the hexanic the least. P. aeruginosa was the most susceptible strain, while the aqueous and methanolic extracts exhibited a slightly higher efficacy against this pathogen than the drug amoxicillin. In conclusion, A. caudatum can potentially provide a remedy against disorders caused by oxidative stress and infections.

30 June 2012 in Pakistan Journal of Chemistry
Verified
Journal Article
Closed access
SKS. Khair-Ul-Bariyah
S. Khair-Ul-Bariyah
Dildar AhmedDildar Ahmed
Dildar Ahmed
MIM. Ikram
M. Ikram

4 December 2019 in Biology
Verified
Journal Article
Open access
PDF file
ZNZoy-I- Noor
Zoy-I- Noor
Dildar AhmedDildar Ahmed
Dildar Ahmed
DRDr Hafiz Muzzammel Rehman
Dr Hafiz Muzzammel Rehman
Muhammad Tahir ul QamarMuhammad Tahir ul Qamar
Muhammad Tahir ul Qamar
MFMatheus Froeyen
Matheus Froeyen
MUHAMMAD Usman MIRZAMUHAMMAD Usman MIRZA
MUHAMMAD Usman MIRZA
The present study explored phytochemicals, porcine pancreatic α-amylase (PPA) and lipase (PPL) inhibitory activities and antioxidant potential of polar and nonpolar extracts of the leaves and flowers of Ocimum basilicum and the in-silico mode of interaction between these enzymes and the major chemical constituents of the herb. The hexane extract (HE) and hydro-ethanolic extract (EE) obtained sequentially were used to estimate PPA and PPL inhibitory and antioxidant activities, total phenolic content (TPC) and total flavonoid content (TFC). Chemical constituents of the essential oils and HE were determined by GC-MS (Gas Chromatography-Mass Spectrometry). For PPA inhibition, IC50 (µg/mL) of the extracts were 0.27–0.37, which were close to 0.24 of acarbose, while for PPL inhibition, IC50 (µg/mL) of the extracts were 278.40–399.65, and that of Orlistat 145.72. The flowers EE was most potent antioxidant followed by leaves EE. The leaves EE had highest TPC and TFC followed of flowers EE. The essential oil of flowers had higher estragole (55%) than linalool (37%), while the essential oil of the leaves had higher linalool (42%) than estragole (38%). The HE of the flowers contained higher estragole (42%) than linalool (23%), while of the HE of the leaves too had higher estragole (65%) than linalool (18%). The in-silico molecular docking study showed linalool and estragole to have considerable PPA and PPL binding potential, which were further investigated through molecular dynamics simulations and binding free energy calculations. The PPA and PPL inhibitory activities of O. basilicum extracts and their notable antioxidant potential propose the herb as a multi-target complimentary medicine for diabetes, obesity and oxidative stress.

1 March 2017 in Asian Pacific Journal of Tropical Medicine
Verified
Journal Article
Open access
MMMaria Maqsood
Maria Maqsood
Dildar AhmedDildar Ahmed
Dildar Ahmed
IAIqra Atique
Iqra Atique
WMWajeeha Malik
Wajeeha Malik
To explore pancreatic lipase inhibitory activity under different extraction conditions in order to track the most potent extract. The methanolic extract and its fractions in solvents of increasing polarity, ether, chloroform, ethyl acetate, n-butanol and water, were made through cold maceration. Extracts in ethanol, ethyl acetate, acetone and chloroform were similarly prepared. Aqueous extract was prepared through hot decoction method. A reported method was used to determine lipase inhibitory activity of extracts and fractions over wide ranges of concentrations. The extracts and fractions exhibited concentration dependent activity. The IC50 (μg/mL) values of methanolic, ethanolic, chloroform, ethyl acetate, acetone, ethyl acetate (after washing with water) and aqueous decoction were 293.40, 266.47, 157.59, 182.12, 352.34, 257.00, and 190.00, respectively. The activity of chloroform, ethyl acetate and aqueous extracts were close to that of the drug orlistat (IC50 146 μg/mL). Out of the fractions of the methanolic extract, the chloroform fraction was most active (IC50 189.6 μg/mL). The order of inhibitory activity of the fractions was as follows: chloroform>ether>n-butanolic>aqueous>ethyl acetate. The GC/MS analysis of the most active chloroform faction showed the presence of hexadecanoic acid, methyl hexadecanoate, isopropyl palmitate, methyl 9,12-octadecadienate, and methyl 9,12,15-octadecatrienoate. The study suggests that Lagenaria siceraria has potential to inhibit pancreatic lipase activity, suppressing lipid digestion and thereby diminishing entry of lipids into the body. Regular intake of aqueous decoction of the fruit may therefore be recommended for control of obesity. Fatty acids and their esters may play role as inhibitors of lipase.

26 November 2016 in Environmental Monitoring and Assessment
Verified
Journal Article
Closed access
PDF file
NRNazia Rafique
Nazia Rafique
STSaadia R. Tariq
Saadia R. Tariq
Dildar AhmedDildar Ahmed
Dildar Ahmed

20 October 2014 in Antioxidants
Verified
Journal Article
Open access
PDF file
Dildar AhmedDildar Ahmed
Dildar Ahmed
KFKhaizran Fatima
Khaizran Fatima
RSRamsha Saeed
Ramsha Saeed
The objective of the present work was to investigate the anti-oxidative potential of methanolic extract of Carissa opaca roots and its fractions in solvents of different polarities. Total phenolic (TPC) and flavonoid (TFC) contents of methanolic extract were 211.95 ± 0.78 μg/mL gallic acid equivalents (GAE) and 8.35 ± 0.21 μg/mL rutin equivalents (RE), respectively. Ethyl acetate contained the highest amounts of both (TFC, 11.8 ± 0.28 RE; TPC, 342.80 ± 0.42 GAE) followed by chloroform fraction (TFC, 7.50 ± 0.14 RE; TPC, 275.85 ± 0.50 GAE). Extract and fractions displayed remarkable DPPH radical scavenging activity. EC50 values of methanolic extract was 0.88 mg/mL, while that of hexane, chloroform, ethyl acetate, n-butanolic and aqueous fractions were 0.58, 0.38, 0.29, 0.36 and 5.83 mg/mL, respectively, ethyl acetate fraction being most potent. The ethyl acetate fraction also showed the highest activity in terms of reducing power, phosphomolybdate and ABTS assays. All the fractions showed fairly good lipid peroxidation inhibitory activity, which remained almost constant over three days. Based on the results it can be concluded that roots of Carissa opaca contains phytochemicals with exploitable antioxidant, free radical scavenging, and lipid peroxidation inhibitory potential.