Sabira Naqvi

A study on antioxidant, free radical scavenging, anti-inflammatory and hepatoprotective actions of Aegiceras corniculatum (stem) extracts

AIM OF THE STUDY The present study was conducted to evaluate the antioxidant, anti-inflammatory and hepatoprotective potential of Aegiceras corniculatum Linn. Blanco (Aegicerataceae). METHODS AND RESULTS The n-hexane, ethyl acetate and methanol extracts, derived from Aegiceras corniculatum stems, scavenged superoxide anions (O2*) and hydroxyl radicals (*OH) in nitro blue tetrazolium reduction and deoxyribose degradation assays, respectively. All the extracts inhibited the process of lipid peroxidation at its initiation step. Additionally, in rat liver microsomes n-hexane and ethyl acetate extracts also caused termination of radical chain reaction supporting their scavenging action towards lipid peroxy radicals (LOO*). Moreover, increased production of O2* in human neutrophils, stimulated by phorbol-12-myristate-13-acetate (PMA) and/or opsonized zymosan were also suppressed (IC50 approximately 3-20 microg/mL). Thereby, revealing the ability of plant extracts to antagonize the oxidative stress via interference with NADPH oxidase metabolic pathway. These in vitro results coincide with the reduction in the glucose oxidase-induced paw edema in mice in the presence of ethyl acetate and methanol extracts (10, 50, and 100mg/kg, i.p.). Plant extracts (250, 500 and 1000 mg/kg, p.o.) also significantly protected the carbon tetrachloride (CCl4)-induced oxidative tissue injury in rat liver. This was reflected by a approximately 60% decline in the levels of serum aminotransferase enzymes. CONCLUSION Aegiceras corniculatum extracts found to possess pronounced antioxidant effect that may be at least in part related to its anti-inflammatory and hepatoprotective activities. This study provides a scientific basis for the ethnomedical claims that Aegiceras corniculatum is effective against inflammation and liver injury.

Potential antidepressant activity of Areca catechu nut via elevation of serotonin and noradrenaline in the hippocampus of rats.

The current study was aimed at investigating the potential antidepressant activity of Areca catechu nut ethanol extract and its various fractions using behavioral (acute and sub‐chronic forced swim tests) and biochemical (monoamines and their metabolite levels using high performance liquid chromatography) tests. The areca nut ethanol extract and its aqueous fraction exhibited antidepressant activity in both acute and sub‐chronic forced swim tests (IC50 ~ 50 and 20 mg/kg, respectively), which was further confirmed by unaltered locomotor (horizontal and vertical) activities of rats in the activity cage. Phytochemical analysis revealed that saponins of areca nut may be the active component in its antidepressant action. The rats treated sub‐chronically with areca nut extract displayed toxic effects, whereas its active aqueous fraction was non‐toxic, indicating the presence of different constituents for antidepressant and toxic effects. In the hippocampus of rats, the areca nut extract (50 mg/kg) and aqueous fraction (20 mg/kg) caused a significant elevation of serotonin (around 35%) and noradrenaline (around 30%) compared with the control (261 ± 25 and 512 ± 29 ng/g, respectively). In conclusion, the areca nut possesses potential antidepressant effect via the elevation of serotonin and noradrenaline. Copyright

Evaluation of antinociceptive effect of Aegiceras corniculatum stems extracts and its possible mechanism of action in rodents.

ETHNOPHARMACOLOGICAL RELEVANCE Aegiceras corniculatum (Linn.) Blanco is used in various traditional medicinal system(s) for the treatment of rheumatism, painful arthritis and inflammation. Therefore, the pharmacological studies of its antinociceptive effect was undertaken to validate its traditional use. MATERIALS AND METHODS n-Hexane, ethyl acetate and methanol extract(s) derived from Aegiceras corniculatum (stems) were studied using various nociceptive model(s) induced chemically or thermally in mice including acetic acid-induced writhing, formalin-induced paw licking and hot plate test. RESULTS In acetic acid-induced writhing test, plant extracts dose dependently decreased the writhing numbers. The methanolic extract (1-10mg/kg, i.p. in mice) of the plant was more potent than acetaminophen and acetyl salicylic acid, with an IC(50) of 4.2 ± 0.99 mg/kg. Moreover, the time of nociceptive behaviors induced by intraplantar formalin injection was also suppressed during 1st and 2nd phases in the presence of ethyl acetate extract whereas, n-hexane and methanolic extracts inhibited the paw licking in mice during the 1st (IC(50) 12 ± 0.76 mg/kg) and 2nd phases (IC(50) 3.8 ± 0.55 mg/kg). Naloxone, β-funaltrexamine, and naltrindole antagonized the n-hexane extract-induced antinociception in the first phase of formalin test indicating its non-selective analgesic response via opioid receptor(s). However, ethyl acetate extract was devoid of any opioid action. Additionally, these extracts significantly inhibited the pain stimulation in hot plate test. Withdrawal syndrome of morphine dependence was also diminished in the presence of plant extracts via potentiation of GABAergic system. CONCLUSION These results suggested that Aegiceras corniculatum extract(s) possesses analgesic properties and acts on the central nervous system, thereby suppressing the inflammatory pain justifying its folklore use.

Aegiceras corniculatum extract suppresses initial and late phases of inflammation in rat paw and attenuates the production of eicosanoids in rat neutrophils and human platelets

AIM OF THE STUDY The present study is designed to explore the anti-inflammatory potential of Aegiceras corniculatum Linn. Blanco stems extracts and their mechanism of action against various pro-inflammatory mediators and to validate its traditional use against inflammatory diseases. MATERIALS AND METHODS Rat paw edema and peritonitis models were employed for in vivo studies. For in vitro studies human platelets and rat neutrophils were stimulated with Ca(2+)-ionophore A23187 leading to the production of various pro-inflammatory metabolites, i.e., 12-HTT, 12-HETE and LTB(4) and 5-HETE which were quantified by HPLC. RESULTS The highly polar methanol extract (100mg/kg) caused approximately 90% reduction in the carrageenan- and prostaglandin E2-induced paw edema in rats. It also caused the inhibition of cycloxygenase-1 metabolite, 12-HHT (IC(50) 41.1+/-1.5microg/ml) with a concomitant rise in 12-lipoxygenase metabolite, 12-HETE in A23187 stimulated human platelets. Conversely, the non-polar hexane extract attenuated (IC(50) 0.36+/-0.12microg/ml) 12-HETE formation with a parallel rise in 12-HHT, thereby displaying a selectivity towards 12-lipoxygenase. Non-polar hexane extract also antagonized the production of 5-lipoxygenase metabolites, i.e., leukotriene B(4) and 5-HETE in the rat neutrophils. Furthermore, ethyl acetate extract inhibited both COX and 5-LOX with a marked decline in the production of 12-HHT (IC(50) 0.08+/-0.002microg/ml) and LTB(4) (IC(50) 0.86+/-0.03microg/ml), respectively. The anti-inflammatory effect of hexane and ethyl acetate extracts was also reflected by the diminution of carrageenan-induced cell infiltration in rat peritoneum. Additionally, plant extracts caused approximately 60% suppression in dextran-induced paw edema implying that they also ameliorate histamine and serotonin release. CONCLUSION Hexane, ethyl acetate and methanol extracts derived from Aegiceras corniculatum possess significant anti-inflammatory activity via multiple mechanisms and validate their traditional use against inflammation-related diseases.

Bioassay-guided isolation of antioxidant agents with analgesic properties from flowers of Tagetes patula

Context: Tagetes patula L. is one of the French marigold group of the Asteraceae family. It is recognized in folklore for its medicinal and pesticidal properties. Objective: In search of more effective, but non-toxic compounds with antioxidative potential led to the bioassay guided isolation studies on the extracts of T. patula. Materials and methods: The bioassay on Tagetes patula flowers were carried out guided by in vitro antioxidant activity using DPPH assay. A minor but proven plant constituent methyl protocatechuate (1) was isolated by column chromatography, while patuletin (2) and patulitrin (3) obtained in bulk by employing solvent partition of methanol extract. Derivatization of patuletin into benzoyl, cinnamoyl and methyl was conducted to establish the structure activity relationship (SAR). Analgesic activity of compound 2 was evaluated using acetic acid-induced writhing test and hot-plate test in mice. The toxicity of methanol extract and compound 2 were also determined. Results: Polar extracts, fractions and phases demonstrated better antioxidant activity. The synthetic methyl protocatechuate (1) showed IC50 value of 2.8 ± 0.2 μg/mL, whereas patuletin (2) (IC50 = 4.3 ± 0.25 µg/mL) was comparable to quercetin and rutin but significantly better than patulitrin (3) (IC50 = 10.17 ± 1.16 µg/mL). Toxicity test for the methanol extract and compound 2 did not elicit any behavioral changes or cause mortality in mice. Compound 2 also demonstrated mild analgesic property. Discussion and conclusion: These findings demonstrate that the plant polar extracts and fractions possess significant antioxidant property with non-toxic effect. Compound 1 is a genuine plant constituent of T. patula.

Forced swimming stress does not affect monoamine levels and neurodegeneration in rats

ObjectiveThe current study was aimed to investigate the correlations between immobility time in the forced swimming test (FST, a behavioral indicator of stress level) and hippocampal monoamine levels (markers of depression), plasma adrenalin level (a peripheral marker of stress) as well as fluoro-jade C staining (a marker of neurodegeneration).MethodsMale Sprague-Dawley rats were subjected to acute, sub-chronic (7 d) or chronic (14 d) FSTs and immobility time was recorded. Levels of noradrenalin, serotonin and dopamine in the hippocampus, and adrenalin level in the plasma were quantified by high-performance liquid chromatography with electrochemical detection. Brain sections from rats after chronic forced swimming or rotenone treatment (3 mg/kg subcutaneously for 4 d) were stained with fluoro-jade C.ResultsThe rats subjected to swimming stress (acute, sub-chronic and chronic) showed long immobility times [(214 ± 5), (220 ± 4) and (231 ± 7) s, respectively], indicating that the animals were under stress. However, the rats did not exhibit significant declines in hippocampal monoamine levels, and the plasma adrenalin level was not significantly increased compared to that in unstressed rats. The rats that underwent chronic swimming stress did not manifest fluoro-jade C staining in brain sections, while degenerating neurons were evident after rotenone treatment.ConclusionThe immobility time in the FST does not correlate with markers of depression (monoamine levels) and internal stress (adrenalin levels and neurodegeneration), hence this parameter may not be a true indicator of stress level.摘要目的本文旨在研究强迫性游泳试验中的不动时间(压力的行为性指示)与海马中单胺水平(抑郁指标)、 血浆中肾上腺素水平(循环系统中的压力指标)以及神经退行性变化(fluoro-jade C染色法检测)的关系。方法给予雄性Sprague-Dawley大鼠急性、 亚慢性(7天)或慢性(14天)强迫游泳的压力, 并在强迫游泳试验中记录大鼠的不动时间。 试验结束后, 用高效液相色谱电化学检测法测定大鼠海马中去甲肾上腺素、 5-羟色胺和多巴胺以及血浆中肾上腺素的水平, 并对大鼠脑片进行fluoro-jade C染色。结果急性、 亚慢性和慢性压力的大鼠均显示出较长的不动时间, 分别为(214 ± 5) s, (220 ± 4) s和 (231 ± 7) s, 表明这些大鼠都处在压力状态下。 然而, 与非压力状态下的对照组大鼠相比, 急性和亚慢性压力下的大鼠海马中单胺类分子的水平并没有显著降低, 并且血浆中肾上腺素的水平也没有显著升高。 此外, 慢性压力大鼠的脑片呈现出fluoro-jade C染色阴性。结论强迫性游泳试验中的不动时间与抑郁和压力并不相关, 提示此法可能不能准确地指示压力水平。

Primary structure of hemoglobin from cobraNaja naja naja

Cobra snakeNaja naja naja hemoglobin shows four bands on Triton electrophoresis. We present the primary structure of oneα and oneβ chain. The separation of polypeptide chains was achieved by ion exchange chromatography on carboxymethyl cellulose column. The amino acid sequence was established by automatic Edman degradation of the native chains and tryptic and hydrolytic peptides in a gas-phase sequencer. The structural data are compared with those of human and other reptile hemoglobins and reveal not only large variations from human but within reptiles. The amino acid exchanges involve several subunit contacts and heme binding sites. This is the first study on the hemoglobin of a land snake. There are only two amino acid sequences of sea snake hemoglobin (Microcephalophis gracilis gracilis andLiophis miliaris) reported in the literature.

Bioassay-guided studies on Bombax ceiba leaf extract: isolation of shamimoside, a new antioxidant xanthone C-glucoside

Bioassay-guided isolation studies on the methanolic extract of the leaves of Bombax ceiba employing DPPH antioxidant assay led to the isolation of a new xanthone C-glucoside, shamimoside (2), along with three known constituents, mangiferin (1), stigma-5-en-3-O-β-glucoside, and β-amyrin. The structure of shamimoside has been elucidated through extensive spectroscopic methods, including 1D and 2D NMR experiments, as 4-C-β-D-glucopyranosyl-1,3,6,8-tetrahydroxy-7-O-(p-hydroxybenzoyl)-9H-xanthen-9-one (2). It is the first naturally occurring xanthone containing a benzoate moiety directly attached to an aromatic ring. Polar extracts and fractions demonstrated better antioxidant activity, and 1 was found to be more potent than 2 in this assay.

Cytotoxic and antioxidant properties of phenolic compounds from Tagetes patula flower

Abstract Context: Tagetes patula Linn. (Asteraceae) (French Marigold) flowers are used by local practitioners for cancer treatment; however, it lacks scientific justification. Objective: Identification of bioactive compounds in T. patula flower for cytotoxic and growth inhibition in human cancer cell lines along with its antioxidant properties using chemical and cell based systems. Materials and methods: The T. patula flower methanol extract, its seven fractions, and three phenolic compounds including methyl protocatechuate (1), patuletin (2), and patulitrin (3) were evaluated using sulforhodamine-B assay against HeLa, HT-144, NCI-H460, MCF-7, PC-3, and SF-268 human cancer cell lines. In parallel, antioxidant activity was evaluated using chemical (DPPH·, deoxyribose, and lipid peroxidation assays) and cell-based chemiluminescence systems (human neutrophils and mice macrophages). Results: The methanol extract and ethyl acetate insoluble fraction exhibited cytotoxic and growth inhibitory effects against HeLa in which 2 exhibited highest cell growth inhibition (GI50: 0.6 ± 0.1 µg/ml) and cytotoxicity (LC50: 2.5 ± 0.1 µg/ml). It also scavenged LOO· (IC50: 6.5 ± 0.7 µg/ml) and (IC50: 27.5 ± 1.3 μg/ml) in chemical systems and human neutrophils, respectively. However, 1 preferably scavenged H2O2–Cl− (IC50: 0.5 ± 0.01 μg/ml) in mice macrophages. Discussion and conclusion: Compound 2 from T. patula flower exhibited both growth inhibitory and cytotoxic properties while 1 and 3 were only growth inhibitory against HeLa. 1–3 also displayed antioxidant properties implying its probable role in growth inhibition/cytotoxic action. The present study provides scientific evidence for the use of T. patula flower in cancer treatment by traditional healer.

Partial sequence of hemoglobin from cobra (Naja naja naja)

Hemoglobin from the cobra snake, Naja naja naja, was isolated and its chains separated on a CM-cellulose column. The separation profile revealed an α and two β chains having the molar proportions of [α]2,[β1]1,[β2]1. The N-terminal amino acid sequence of the intact chains and of the CNBr peptides were carried out. Theβ2 chain was found to be heterogeneous comprising a minor component amounting to 11%. This later showed changes at two positions 9 and 14 in the first 30 residues sequenced.