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Journal Article
Three new α-glucosidase inhibitors from guggul, the oleogum resin of Commiphora wightii, El-Mekkawy, Sahar, Meselhy Meselhy R., Nkobole Nolitha, and Lall Namrita , Natural product research, Volume 27, Issue 2, p.146-154, (2013) Abstract
Three new α-glucosidase inhibitors from guggul, the oleogum resin of Commiphora wightii., El-Mekkawy, Sahar, Meselhy Meselhy R., Nkobole Nolitha, and Lall Namrita , Natural product research, 2013, Volume 27, Issue 2, p.146-54, (2013) Abstract

Three new compounds; epi-mukulin, (Z)-Δ(1,2) dehydroguggulsterone and Δ(6,7)dehydro-20-hydroxygugglsterone were isolated from the n-hexane-soluble fraction (HSF) of the methanol extract of guggul, the oleogum resin of Commiphora wightii together with six known compounds: diasesartemin, (+)-epi-magnolin, (+)-diayangambin, gugglsterol I, (E)-guggulsterone and (Z)-guggulsterone. Their structures were elucidated on the basis of different spectroscopic data. α-Glucosidase inhibitory effects of HSF and the isolated compounds were evaluated calorimetrically. The HSF showed significant α-glucosidase inhibitory effect [IC(50) value of 140 µg mL(-1) (p < 0.05)]. Under the assay conditions, diasesartemin (IC(50) = 60.6 ± 0.01 µM) was found to be more potent than the positive control, acarbose (IC(50) = 92.94 ± 0.01 µM); a known α-glucosidase inhibitor (p < 0.05). The IC(50) values of epi-mukulin and (Z)-guggulsterone were found to be 159.33 and 132.14 µM, respectively. Other compounds showed weak α-glucosidase inhibitory effects, <30% inhibition of the enzyme activity at 0.1 mg mL(-1).

TINCTRMINE, A NOVEL Ca2+ ANTAGONIST N-CONTAINING QUINOCHALCONE C-GLYCOSIDE FROM CARTHAMUS TINCTORIUS L., Meselhy, Meselhy R., KADOTA Shigetoshi, Momose Yasunori, Hattori Masao, and NAMBA Tsuneo , Chemical and pharmaceutical bulletin, Volume 40, Issue 12, p.3355-3357, (1992) Abstract
Transformation of shikonin by a cell-free extract of Eubacterium sp. A-44, a human intestinal bacterium, Meselhy, Meselhy R., Nishimoto Eri, Akao Teruaki, and Hattori Masao , (2001) Abstract
Two new quinochalcone yellow pigments from Carthamus tinctorius and Ca2+ antagonistic activity of tinctormine, Meselhy, Meselhy R., KADOTA Shigetoshi, Momose Yasunori, HATAKEYAMA Noboru, KUSAI Akihiko, Hattori Masao, and NAMBA Tsuneo , Chemical and pharmaceutical bulletin, Volume 41, Issue 10, p.1796-1802, (1993) Abstract
UPLC-Orbitrap HRMS metabolic profiling of Cymbopogon citratus cultivated in Egypt; neuroprotective effect against AlCl-induced neurotoxicity in rats., Madi, Yasmine F., Choucry Mouchira A., El-Marasy Salma A., Meselhy Meselhy R., and El-Kashoury El-Sayeda A. , Journal of ethnopharmacology, Volume 259, p.112930, (2020) Abstract

ETHNOPHARMACOLOGICAL RELEVANCE: Cymbopogon citratus (lemongrass) is commonly used in teas, soups and treat inflammatory-based ailments, vascular and nervous disorders.

AIM OF THE STUDY: The study aimed to evaluate the neuroprotective effect of Cymbopogon citratus leaves through scientific protocol. The effect of aqueous (AE) and ethanolic (EE) extracts was evaluated against AlCl-induced Alzheimer's disease (AD) in rats. Metabolic profiling of the plant, isolation of bioactive compounds and standardization of the active fraction were investigated.

MATERIALS AND METHODS: AE of Cymbopogon citratus leaves was prepared as per traditional method (infusion), EE was prepared by repeated maceration in 90% ethanol, bioactive fraction (BAEE) was obtained from EE and the active compounds thereof were obtained by column chromatography. Metabolic profiling of Cymbopogon citratus was performed by UPLC-Orbitrap HRMS and HPLC was used for standardization. AlCl-induced Alzheimer's rats were used to assess neuroprotective effect of the extracts. Neuroprotective mechanism(s) of Cymbopogon citratus extracts was clarified through histopathological examination of brain tissues, estimation of AD biochemical markers, oxidative stress and neuroinflammation in brain homogenates. In addition, antioxidant (using DPPH assay) and anticholinesterase (using modified Ellman's method) activities were investigated.

RESULTS: AlCl-treated rats (17 mg/kg/day) showed histopathological alteration in brain tissues together with elevated levels of Aβ, tau proteins, MDA, NF-kB and IL-6. However, treatment with AE and EE of Cymbopogon citratus leaves prevented the pathological changes and maintained the levels of oxidative stress and inflammatory markers. In addition, BAEE significantly inhibited acetylcholinesterase enzyme (2.11 ± 0.11 mg/ml) and exhibited a strong antioxidant activity (24.99 ± 0.00 μg/ml). UPLC-MS of Cymbopogon citratus leaves showed peaks for twenty-eight compounds, twenty-one of them were identified. Three flavonoids; isoorientin, isoschaftoside and luteolin-7-O-neohesperidoside were isolated from BAEE as major constituents. The powdered leaves of Cymbopogon citratus was found to contain remarkable amounts of caffeic acid (3.49 mg/g dry wt.) and isoorientin (7.37 mg/g dry wt.) as determined by HPLC.

CONCLUSION: Cymbopogon citratus ethanolic extract attenuates AlCl-induced neurotoxicity in rats through inhibition of oxidative stress and inflammatory markers. This effect could possibly attributed, in part to its high content of phenolic acids and flavonoids. Accordingly, we recommend Cymbopogon citratus leaves for protection against AD.

UPLC-PDA-ESI/MS metabolic profiling of dill shoots bioactive fraction; evidence of its antioxidant and hepatoprotective effects in vitro and in vivo., Rasheed, Dalia M., Emad Ayat M., Ali Sherifa F., Ali Sameh S., Farag Mohamed A., Meselhy Meselhy R., and Sattar Essam A. , Journal of food biochemistry, p.e13741, (2021) Abstract

Hydroxyl radical ( OH) scavenging capacity of aqueous dill (Anethum graveolens L.) shoot (ADSh) extract was assessed using electron paramagnetic resonance (EPR) spectroscopy. ADSh extract (at concentrations of 0.5 and 10 mg/ml) exerted high (OH) radical scavenging power. ADSh extract was further fractionated on Diaion HP-20 column to yield five fractions. EPR spin-trapping assay revealed fraction 4 (eluted with 75% aq. MeOH) to possess ( OH) radical scavenging capacity over a concentration range (0.01-10 mg/ml), whereas fraction 2 (eluted with 25% aq. MeOH) appeared to be pro-oxidant at concentration 0.01 mg/ml. UPLC-PDA-ESI-MS metabolite profiling of ADSh extract revealed 87 metabolites, of which 64 compounds were identified in fraction 4, the most active fraction. Furthermore, ADSh extract demonstrated a hepatoprotective effect against acetaminophen (APAP)-induced hepatotoxicity in rats. Pretreatment of rats with ADSh extract (200 mg/kg b.wt) markedly attenuated the increased in the serum hepatic enzyme levels. It also increased free glutathione level and total antioxidant capacity in the serum of treated rats. [Correction added on May 3, 2021, after first online publication: "rates" has been changed to "rats" in the previous sentence.] Additionally, levels of (TNF-α and IL-1β) were back to almost normal levels compared to the control group. The above findings suggest that ADSh extract has a protective effect against APAP-induced liver damage.

和漢医薬学雑誌= Journal of traditional medicines 20 (5), 201-207, 2003-10-20, Xiong, Xin, Zhai Suodi, Yao Zhongqiang, Tazawa Takako, Zhao Huai-qing, Li Yan, Meselhy Meselhy Ragab, Nakamura Norio, Akao Teruaki, and Hattori Masao , Prog. Neurobiol, Volume 56, p.211-235, (1998) Abstract