Anti-acetylcholinesterase activity and antioxidant properties of extracts and fractions of Carpolobia lutea

Context: There is an unmet need to discover new treatments for Alzheimer’s disease. This study determined the anti-acetylcholinesterase (AChE) activity, DPPH free radical scavenging and antioxidant properties of Carpolobia lutea G. Don (Polygalaceae).

Objective: The objective of this study is to quantify C. lutea anti-AChE, DPPH free radical scavenging, and antioxidant activities and cell cytotoxicity.

Materials and methods: Plant stem, leaves and roots were subjected to sequential solvent extractions, and screened for anti-AChE activity across a concentration range of 0.02–200?μg/mL. Plant DPPH radical scavenging activity, reducing power, and total phenolic and flavonoid contents were determined, and cytotoxicity evaluated using human hepatocytes.

Results: Carpolobia lutea exhibited concentration-dependent anti-AChE activity. The most potent inhibitory activity for the stem was the crude ethanol extract and hexane stem fraction oil (IC₅₀?=?140?μg/mL); for the leaves, the chloroform leaf fraction (IC₅₀?=?60?μg/mL); and for roots, the methanol, ethyl acetate and aqueous root fractions (IC₅₀?=?0.3–3?μg/mL). Dose-dependent free radical scavenging activity and reducing power were observed with increasing stem, leaf or root concentration. Total phenolic contents were the highest in the stem: ～632?mg gallic acid equivalents/g for a hexane stem fraction oil. Total flavonoid content was the highest in the leaves: ～297?mg quercetin equivalents/g for a chloroform leaf fraction. At 1?μg/mL, only the crude ethanol extract oil was significantly cytotoxic to hepatocytes.

Discussion and conclusions: Carpolobia lutea possesses anti-AChE activity and beneficial antioxidant capacity indicative of its potential development as a treatment of Alzheimer’s and other diseases characterized by a cholinergic deficit.     

Anti-nociceptive effects of <Emphasis Type="Italic">Carpolobia lutea</Emphasis> G. Don (Polygalaceae) leaf fractions in animal models

Leaves from Carpolobia lutea (Polygalaceae) were screened to establish the antiulcer ethnomedicinal claim and to quantitatively isolate, elucidate the active compounds by semi-preparative HPLC. The anti-nociceptive effects of Carpolobia lutea (CL) G. Don (Polygalaceae) organic leaf extracts were tested in experimental models in mice. The anti-nociceptive mechanism was determined using tail-flick test, acetic acid-induced abdominal constrictions, formalin-induced hind paw licking and the hot plate test. The fractions (ethanol, ethyl acetate, chloroform, n-hexane) and crude ethyl acetate extract of CL (770 mg/kg, i.p.) produced significant inhibitions of both phases of the formalin-induced pain in mice, a reduction in acetic acid-induced writhing as well as and an elevation of the pain threshold in the hot plate test in mice. The inhibitions were greater to those produced by indomethacin (5 mg/kg, i.p.). Ethyl acetate fraction revealed cinnamic and coumaric acids derivatives, which are described for the first time in literature. These cinnamalglucosides polyphenols characterised from CL may in part account for the pharmacological activities. These findings confirm its ethnomedical use in anti-inflammatory pain and in pains from gastric ulcer-associated symptoms.     

Evaluation of the antidiarrheal and antioxidant properties of Justicia hypocrateriformis

Content: Justicia hypocrateriformis Vahl (Acanthaceae) is used as an herbal remedy for diarrhea in Cameroon folk medicine.

Objective: This study evaluates the antidiarrheal and antioxidant properties of the aqueous extract of J. hypocrateriformis (JH).

Materials and methods: Preliminary phytochemical screening and an acute toxicity testing of the extract were carried out. The antidiarrheal activity of JH extract (100, 250, and 500?mg/kg) was assessed at curative and preventive levels in castor oil-induced diarrhea in mice. The antioxidant activity was measured by ferric reducing antioxidant power (FRAP), total phenolic content, and radical scavenging activity.

Results: A high lethal dose (LD₅₀) of 14.35?g/kg obtained in acute toxicity implies the extract is not toxic. Phytochemical screening revealed the presence of phenols, tannins, flavonoids, saponins, anthraquinones, and anthocyanins. JH showed a significant protection against castor oil-induced diarrhea as evidenced by a decrease in the number of defecation and wet stool. JH (100–500?mg/kg, p.o.) produced a non-significant dose-dependent decrease in castor oil-induced intestinal transit in the preventive study. In the curative and in healthy mice study, the decrease was only significant at 500?mg/kg. JH possessed a radical scavenging activity with an IC₅₀ of 9.93?mg/ml compared to 4.90?mg/ml for catechin. JH FRAP of 2703.77?±?0?mg/g (catechin equiv) and phenolic concentration of 14?169.99?±?612.39?mg/g (catechin equiv) were also obtained.

Conclusion: Justicia hypocrateriformis extract possesses antidiarrheal activity supported by its antioxidant potential and phytochemical constituents.     

Effective antidiabetic and antioxidant fractions of Otostegia persica extract and their constituents

Context: Otostegia persica (Burm.) Boiss. (Lamiaceae), “Goldar” in Persian, is widely used in the folk medicine of south Iran for control of diabetes mellitus.

Objective: In the present study, hypoglycemic and antioxidant effects of different fractions of the O. persica extract were investigated and constituents of effective fractions were elucidated.

Materials and method: Different concentrations (100–400?mg/kg) of aqueous infusion (AI) of flowering aerial parts of the plant (traditional preparation) and all fractions of the O. persica extract (i.p. injection) were tested for antidiabetic activity in streptozocin-induced diabetic NMRI mice. Blood glucose level was measured at time 0 and intervals of 1, 2, 4, and 6?h later. Antioxidant activities of different fractions of the plant extract and pure compounds (0.1, 0.5, and 1?mg/ml) were determined with the DPPH method. Four compounds were isolated and identified from potent fractions.

Results and discussion: Antidiabetic activity demonstrated that the effect of the methanol fraction at a dose of 300?mg/kg was equivalent with glibenclamide, and at a dose of 400?mg/kg was comparable with glibenclamide and insulin (p?>?0.05). The EC₅₀ of the methanol fraction was 307.12?mg. Methanol and ethyl acetate fractions showed antioxidant activities (both IC₅₀ equal to 0.49?mg/ml), so these fractions were selected for the purification of compounds. Chrysoeriol from ethyl acetate and three apigenin derivatives (6-methylapigenin, apigenin-7-O-glucoside, and echinaticin) from the methanol fraction were isolated and identified (new for the species). Chrysoeriol exhibited potent antioxidant activity comparable with vitamin E and BHT (p?>?0.05).

Conclusion: The present study confirmed the folklore usage of O. persica for antidiabetic properties.     

Assessment of the antidiarrhoeal properties of the aqueous extract and its soluble fractions of Chebulae Fructus (Terminalia chebula fruits)

Context Chebulae Fructus is used as an herbal remedy for diarrhoea in traditional Chinese medicine. However, there is no scientific evidence to support its antidiarrhoeal activity.

Objective This study evaluates the antidiarrhoeal properties of Chebulae Fructus aqueous extract (CFAE) and determines the active fraction.

Materials and methods The antidiarrhoeal effect of CFAE (200–800?mg/kg) was investigated by determining the wet dropping, intestinal transit in BALB/c mice and enteropooling in Wister rats. The protective effects of the CFAE on the intestinal and liver were tested by histopathological analyses. The antidiarrhoeal fraction was determined by castor oil-induced diarrhoea and its main constituents were identified by HPLC-ESI-MS.

Results The extract at doses of 200, 400 and 800?mg/kg reduced the diarrhoea by 9.1, 40.0 and 58.2% and inhibited intestinal transit by 18.3, 24.1 and 35.7%, respectively. Additionally, the CFAE (200, 400 and 800?mg/kg) decreased the volume of enteropooling by 47.1, 58.8 and 64.7%, respectively. Mice treated with castor oil presented morphological alterations in the small intestine and the liver. However, the lesions of mice treated with CFAE were alleviated. Moreover, the ethyl acetate fraction was the active fraction of CFAE, the fraction (41.7, 83.4 and 166.8?mg/kg) reduced the diarrhoea by 9.1, 38.2 and 54.5%, respectively. The major components of the ethyl acetate fraction were tannins, including gallic acid, 3, 4, 6-tri-O-galloyl-β-d-Glc, corilagin and ellagic acid according to the HPLC-ESI-MS analysis.

Conclusion The CFAE possessed antidiarrhoeal property and the ethyl acetate fraction was its main active fraction.     

Antioxidant and antidiarrheal activities of ethanol extract of Ardisia elliptica fruits

Context: Ardisia elliptica Thunb Lam. (Myrsinaceae) is widely used traditionally in the treatment of diarrhea related health disorders in Bangladesh.

Objective: The crude ethanol extract of Ardisia elliptica fruits (EFA) was evaluated for its antioxidant and antidiarrhoeal activities.

Materials and methods: DPPH radical scavenging, nitric oxide scavenging, reducing power and Fe⁺⁺ ion chelating ability were used for determining antioxidant activities and animal models were used for antidiarrheal activities such as the castor oil and magnesium sulfate-induced diarrhea, enteropooling induced by the administration of castor oil and magnesium sulfate at the doses of 250 and 500?mg/kg.

Results: The extract possessed a significant DPPH free radical scavenging activity with an IC₅₀ value of 30.75?μg/ml compared to ascorbic acid (IC₅₀: 7.89?μg/ml). The IC₅₀ values of the extract and ascorbic acid were 51.72 and 38.68?μg/ml, respectively, in nitric oxide scavenging assay. The IC₅₀ value of the extract for Fe⁺⁺ ion chelating ability (41.30?μg/ml) was also found to be significant compared to the IC₅₀ value of EDTA (22.57?μg/ml). The EFA also showed a significant protection (p?Conclusion: Therefore, the obtained results confirm the antioxidant and antidiarrheal activity of EFA and thus support the traditional uses of this plant as a modality for antioxidant and antidiarrheal activity.     

Antimalarial,antiplasmodial and analgesic activities of root extract of Alchornea laxiflora

Context: Alchornea laxiflora (Benth.) Pax. &; Hoffman (Euphorbiaceae) root decoctions are traditionally used in the treatment of malaria and pain in Nigeria.

Objective: To assess the antimalarial, antiplasmodial and analgesic potentials of root extract and fractions against malarial infections and chemically-induced pains.

Material and methods: The root extract and fractions of Alchornea laxiflora were investigated for antimalarial activity against Plasmodium berghei infection in mice, antiplasmodial activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of Plasmodium falciparum using SYBR green assay method and analgesic activity against experimentally-induced pain models. Acute toxicity study of the extract, cytotoxic activity against HeLa cells and GCMS analysis of the active fraction were carried out.

Results: The root extract (75–225?mg/kg, p.o.) with LD₅₀ of 748.33?mg/kg exerted significant (p?P. berghei infection in suppressive, prophylactive and curative tests. The root extract and fractions also exerted moderate activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of P. falciparum with the ethyl acetate fraction exerting the highest activity with IC₅₀ value of 38.44?±?0.89?μg/mL (Pf 3D7) and 40.17?±?0.78?μg/mL (Pf INDO). The crude extract was not cytotoxic to HeLa cells with LC₅₀ value >100?μg/mL. The crude extract and ethyl acetate fraction exerted significant (p?Discussion and conclusions: These results suggest that the root extract/fractions of A. laxiflora possess antimalarial, antiplasmodial and analgesic potentials and these justify its use in ethnomedicine to treat malaria and pain.     

Phytochemical analysis,antiproliferative and antioxidant activities of Chrozophora tinctoria: a natural dye plant

Context: Chrozophora tinctoria (L.) A. Juss. (Euphorbiaceae) is known as ‘dyer’s-croton’ and used to obtain dye substances. Recently, natural antioxidants and colorants have been of interest because of their safety and therapeutic effects.

Objective: This study investigates the antiproliferative and antioxidant activities of the various extracts and fractions from C. tinctoria and analyzes their phytochemical contents.

Materials and methods: The aerial parts of C. tinctoria were extracted with water, ethyl acetate, n-butanol, and methanol/chloroform. Phenolic compounds and other constituents of the extracts were analyzed by HPLC/TOF-MS. The ethyl acetate extract (EA) was fractionated by flash chromatography. The extracts, fractions, and major phenolic compounds were investigated for their antiproliferative activities on human cervical adenocarcinoma (HeLa) cell line at the concentrations of 5–100?μg/mL by using BrdU ELISA assay during 24?h of incubation. DPPH radical scavenging activities (5–150?μg/mL) and total phenolic contents of the samples were also evaluated.

Results: 4-Hydroxybenzoic acid (268.20?mg/kg), apigenin-7-glucoside (133.34?mg/kg), and gallic acid (68.92?mg/kg) were the major components of EA. CT/E-F6 (IC₅₀?=?64.59?±?0.01?μg/mL) exhibited the highest antiproliferative activity. CT/E-F2 (IC₅₀=?14.0?±?0.0?μg/mL) and some fractions displayed higher radical scavenging activity compared to synthetic antioxidant BHT (IC_50?=_?23.1?±?0.0?μg/mL). Among the main phenolics, gallic acid exhibited the highest antiproliferative and radical scavenging abilities (IC_50?<_?5?μg/mL).

Conclusion: In this study, we have determined the biologically active fractions and their high effects may be attributed to the presence of gallic acid.     

Antidiarrheal potential of standardized extract of Rhododendron arboreum Smith flowers in experimental animals

Objective:

To investigate standardized ethyl acetate fraction of Rhododendron arboreum (EFRA) flowers for antidiarrheal activity in experimental animals.

Materials and Methods:

A simple sensitive high performance thin layer chromatography (HPTLC) method was used for the determination of hyperin in EFRA. The standardized fraction was investigated for castor oil, magnesium sulfate-induced diarrhea, measurement of gastrointestinal transit using charcoal and castor oil-induced enteropooling.

Results:

The concentration of hyperin in flowers of R. arboreum was found to be 0.148% by HPTLC. Oral administration of EFRA at 100, 200 and 400 mg/kg exhibited dose-dependent and significant (P<0.05-0.001) antidiarrheal potential in castor oil and magnesium sulfate-induced diarrhea. EFRA at doses of 100, 200 and 400 mg/kg also produced significant (P<0.05-0.001) dose-dependent reduction in propulsive movement in castor oil-induced gastrointestinal transit using charcoal meal in rats. EFRA was found to possess an antienteropooling in castor oil-induced experimental animals by reducing both weight and volume of intestinal content significantly.

Conclusion:

These findings demonstrate that standardized ethyl acetate fraction of R. arboreum flowers has potent antidiarrheal activity thus justifying its traditional use in diarrhea and have great potential as a source for natural health products.KEY WORDS: Antidiarrheal, enteropooling, gastrointestinal motility, high performance thin layer chromatography, Rhododendron arboreum     

Antidiarrheal activity of extracts and compound from Trilepisium madagascariense stem bark

Objective:

The present study was performed to evaluate the preventive and curative antidiarrheal effects of the methanol extract, fractions and compound from the stem bark of Trilepisium madagascariense in rats.

Materials and Methods:

The methanol extract from the stem bark of T. madagascariense, its fractions (n-hexane, ethyl acetate, n-butanol and aqueous residue) and compound (obtained from further column chromatography of the ethyl acetate fraction) were evaluated for the antidiarrheal activity in rats. These test samples (at 100, 200 and 400 mg/kg for the extract and fractions and 2.5 mg/kg for compound) were assayed on the latent periods, purging indices and fecal frequencies in castor oil-induced diarrhea. Gastrointestinal transit and castor oil-induced enteropooling assays were conducted. Shigella-induced diarrhea was assayed. Blood chemistry and fecal Shigella load were examined.

Results:

The fractionation of the ethyl acetate fraction from the methanol extract of T. madagascariense afforded a known compound [isoliquiritigenin (1)]. Compound 1 increased the latent period of diarrhea induction (179.40 min) compared to the saline control (60.80 min). The purging indices, fecal frequencies and intestinal enteropooling decreased with an increase in the dose of test samples. The blood cell counts, sera creatinine and fecal Shigella load decreased significantly (P ≤ 0.05) in the plant extract-treated rats compared to the saline control.

Conclusion:

The results of our study, being reported for the first time, provide clear evidence that the methanol extract, fractions and isoliquiritigenin from T. madagascariense stem bark possess antidiarrheal activities.     

Evaluation of antinociceptive and antidiarrhoeal properties of Manilkara zapota leaves in Swiss albino mice

Context Manilkara zapota (L.). P. Royen. (Sapotaceae) has been used in folk medicine to treat pain, diarrhoea, inflammation, arthralgia, and other disorders.

Objective Screening of Manilkara zapota leaves ethanol extract and its different solvent soluble fractions for possible antinociceptive and antidiarrhoeal activities in Swiss albino mice.

Materials and methods The extract and various fractions (200 and 400?mg/kg body weight; p.o.) were tested for peripheral and central antinociceptive activity by acetic acid-induced writhing and radiant heat tail-flick method, respectively; castor oil-induced diarrhoeal model was used to evaluate antidiarrhoeal activity at both doses. All the samples were administered once in a day and the duration of study was approximately 5?h.

Results Ethanol extract (400?mg/kg), petroleum ether fraction (400?mg/kg), and ethyl acetate fraction (400?mg/kg) showed significant peripheral antinociceptive activity having 59.89, 58.24, and 46.7% (p?<?0.001) of writhing inhibition, respectively, which is comparable with that of standard diclofenac (59.34% inhibition). The ethanol extract (400?mg/kg) and petroleum ether fraction (400?mg/kg) also showed promising central analgesic activity having 74.15 and 82.15% (p?<?0.001) elongation of reaction time, respectively, at 90?min after administration of sample which is also similar to that obtained by morphine (85.84% elongation). In antidiarrhoeal activity screening, ethanol extract (200 and 400?mg/kg) showed significant inhibition of defecation by 53.57 and 60.71%, respectively (p?<?0.001) compared with that of loperamide (71.42%).

Discussion and conclusion The findings of the studies demonstrated antinociceptive and antidiarrhoeal activities of M. zapota leaves which could be the therapeutic option against pain and diarrhoeal disease.     

The application of 1,8-cineole,a terpenoid oxide present in medicinal plants,inhibits castor oil-induced diarrhea in rats

Abstract

Context: 1,8-Cineole, a terpene, characterized as a major constituent occurring in the essential oils of several aromatic plants. It is widely used in pharmaceutical industry, as a food additive and for culinary purposes.

Objective: This study investigates the inhibitory effect of 1,8-cineole on transit time and diarrhea in animal models.

Materials and methods: Acute toxicity and lethality of 1-8-cineole was determined by Lork’s guidelines. The antidiarrheal effect of 1,8-cineole was investigated by determining the intestinal transit and enterpooling in rats. In all experiments, different doses of 1,8-cineole (20–120?mg/kg), atropine, and loperamide were administered orally.

Results: The LD₅₀ of 1,8-cineole for oral administration was estimated to be 1280?mg/kg. 1,8-Cineole (20–120?mg/kg) did not show a significant decrease in small intestine transit (p?>?0.05); however, the highest dose displayed a significant decrease in comparison with atropine (p?<?0.05). This substance decreased the peristaltic index value to 68?±?0.36% at a dose of 120?mg/kg compared with the control group (85.22?±?4.31%) in the castor oil transit test. 1,8-Cineole significantly delayed the onset of diarrhea to ?142.33?±?6.08?min at 120?mg/kg, while the time was 103.66?±?20.73?min for the control and >240?min for the loperamide. Moreover, 1,8-cineole significantly decreased intestinal fluid accumulation (p?<?0.05).

Conclusions: This study demonstrated antispasmodic and antisecretory activities of 1,8-cineole and rationalized the traditional use of the plant containing various levels of this terpene in the treatment of gastrointestinal complains such as diarrhea.     

Landolphia owariensis leaf extracts reduce parasitemia in Plasmodium berghei-infected mice

Context Landolphia owariensis P. Beauv. (Apocyanaceae) leaf is used in southeast Nigeria to treat malaria.

Objective This study evaluated the antiplasmodial activity of L. owariensis leaf extract and fractions, also the phytoconstituents were standardized and analyzed.

Methods The effects of daily, oral administrations of 200, 400 and 800?mg/kg of L. owariensis leaf extract (LOE), its hexane (LOHF), ethyl acetate (LOEF) and methanol (LOMF) fractions on early, established and residual infections in Plasmodium berghei-infected albino mice were evaluated in vivo. The extract and fractions were subjected to phytochemical analysis and HPLC fingerprinting, and the acute toxicity of LOE was evaluated.

Results The extract and fractions elicited 29–86, 18–95 and 75–96% significant (p?<?0.001) suppression of parasitemia in early, established and residual infections, respectively. The ED₅₀ values for suppressive activity of LOE, LOHF, LOEF and LOMF were 266.56, 514.93, 392.95 and 165.70?mg/kg, respectively. The post-day 30-survival index was 16.7–50, 16.7, 16.7–66.7 and 50–83.3% for LOE, LOHF, LOEF, and LOMF, respectively. Extract-treated mice significantly (p?<?0.001) gained weight and had reduced mortality compared with negative control (untreated) mice. An oral LD₅₀ value >5000?mg/kg in mice was established for LOE. The LOMF showed the greatest antiplasmodial activity in all the models, suggesting that the antimalarial activity of the plant may be attributed to alkaloids, flavonoids, saponins and tannins present in the fraction.

Conclusion Results demonstrate the antiplasmodial activity of L. owariensis leaf, and provide a pharmacological rationale for its ethnomedicinal use as an antimalarial agent.     

Evaluation of the analgesic and anti-inflammatory activities of <Emphasis Type="Italic">Curcuma mangga</Emphasis> Val and Zijp rhizomes

The effects of Curcuma mangga ethanolic extract (CME) and its fractions, e.g., aqueous, chloroform, ethyl acetate, and hexane fractions, from C. mangga rhizome were investigated on nociceptive responses using writhing, hot plate, and formalin tests in mice and inflammatory models using carrageenan-induced rat paw edema and croton oil-induced mouse ear edema. The results showed that CME and all fractions (200 mg/kg, p.o.) significantly reduced the number of writhings. Oral administration (p.o.) of CME, chloroform, and hexane fractions (200 mg/kg) significantly prolonged the latency time, whereas aqueous and ethyl acetate fractions were inactive. The activities of CME, chloroform, and hexane fractions were abolished by naloxone (2 mg/kg, intraperitoneal (i.p.)). CME and all fractions at the dose of 200 mg/kg significantly produced antinociception in both early and late phases of the formalin test. CME, chloroform, and hexane fractions were more prominent in licking inhibition than those of the aqueous and ethyl acetate fractions. CME and all fractions (150 mg/kg, p.o.) showed significant reduction of rat paw edema. The order of activity on inhibition of paw edema at 4 h was chloroform fraction > hexane fraction > ethyl acetate fraction > CME > aqueous fraction. When topically applied at 0.5 mg/ear, CME and all fractions suppressed ear edema induced by croton oil. CME and chloroform fraction showed a greater inhibition by 53.97 and 50.29%, respectively. These results suggested that CME and its fractions, especially chloroform and hexane fractions from C. mangga rhizome, possessed centrally acting analgesic as well as anti-inflammatory activities.     

Photoprotective effects of cranberry juice and its various fractions against blue light-induced impairment in human retinal pigment epithelial cells

Context: Cranberry has numerous biological activities, including antioxidation, anticancer, cardioprotection, as well as treatment of urinary tract infection (UTI), attributed to abundant phenolic contents.

Objective: The current study focused on the effect of cranberry juice (CJ) on blue light exposed human retinal pigment epithelial (ARPE-19) cells which mimic age-related macular degeneration (AMD).

Materials and methods: Preliminary phytochemical and HPLC analysis, as well as total antioxidant capacity and scavenging activity of cranberry ethyl acetate extract and different CJ fractions (condensed tannins containing fraction), were evaluated. In cell line model, ARPE-19 were irradiated with blue light at 450?nm wavelength for 10?h (mimic AMD) and treated with different fractions of CJ extract at different doses (5–50?μg/mL) by assessing the cell viability or proliferation rate using MTT assay (repairing efficacy).

Results: Phytochemical and HPLC analysis reveals the presence of several phenolic compounds (flavonoids, proanthocyanidin, quercetin) in ethyl acetate extract and different fractions of CJ. However, the condensed tannin containing fraction of ethyl acetate extract of CJ displayed the greater (p?p?p?Discussion and conclusion: In conclusion, this study distinctly proved that condensed tannin containing fraction of CJ probably exhibits better free radicals scavenging activity and thereby effectively protected the ARPE-19 cells and thus, hampers the progress of AMD.     

Effects of Aphloia theiformis on key enzymes related to diabetes mellitus

Context: Aphloia theiformis (Vahl.) Benn. (Flacourtiaceae) (AT) is traditionally used for the management of diabetes mellitus (DM), but there is no scientific data regarding activity against enzymes linked to this condition.

Objective: To evaluate the kinetics of AT on key enzymes inhibition related to DM, and establish the antioxidant profile of AT.

Materials and methods: Dried powdered AT leaves were used to prepare crude methanol extract (70% v/v) (CME). Kinetics of CME (5000 to 156.25?μg/mL) on α-amylase, α-glucosidase, and lipase inhibition were studied. CME was partitioned using solvents of increasing polarity and kinetics of enzyme inhibition of each fraction (1000–31.25?μg/mL) was evaluated. Potent fractions were combined to assess any synergistic effect. Total phenol, flavonoid, tannin, anthocyanin contents, and antioxidant capacity of AT was evaluated using standard spectrophotometric methods.

Results: CME, ethyl acetate, and n-butanol fractions showed potent inhibitory activities against the enzymes with IC₅₀ ranging from 22.94–939.97?μg/mL. Significant (p?50 (15.72 and 157.03?μg/mL against α-amylase and lipase, respectively) was observed when ethyl acetate and n-butanol fractions were combined; showing synergism. The extracts showed noncompetitive inhibition against α-amylase and α-glucosidase. Ethyl acetate, n-butanol fractions, and CME showed highest antioxidant capacities (0.44–1.41?μg GAE/mg sample), and phenol content (211.74-675.53?μg GAE/mg sample).

Conclusion: This study supports the use of AT in the management of DM and provides the rationale for bioactivity guided isolation and characterization of compounds from the ethyl acetate and n-butanol fractions.     

Antidiarrheal,antisecretory, and bronchodilatory activities of Hypericum perforatum

This study describes the antidiarrheal, antisecretory, and bronchodilatory activities of Hypericum perforatum Linn. (Hypericaceae), commonly known as St. John’s wort, to justify its traditional use in the hyperactivity of the gastrointestinal and respiratory systems. The crude extract of Hypericum perforatum (Hp.Cr) at a dose of 500?mg/kg caused 20% protection against castor oil-induced diarrhea in mice and 60% at 1000?mg/kg (p?<?0.05 vs. saline). Hp.Cr at 300 and 1000?mg/kg reduced the castor oil-induced fluid accumulation in mice to 107.0?±?3.3?g (p?<?0.01) and 84.0?±?4.2?g (p?<?0.001) respectively, whereas in the castor oil-treated group, it was 126.9?±?3.9?g. When tested against carbachol (CCh)-mediated bronchoconstriction in rats under anesthesia, Hp.Cr dose-dependently (3–?30?mg/kg) suppressed the CCh (1?μmol/kg)-induced increase in the inspiratory pressure. Thus this study rationalizes the Hypericum perforatum usefulness in overactive gut and airways disorders, such as diarrhea and asthma.     

Antimalarial and antiplasmodial activity of husk extract and fractions of Zea mays

Context: Zea mays L. (Poacae) husk decoctions are traditionally used in the treatment of malaria by various tribes in Nigeria.

Objective: To assess the antimalarial and antiplasmodial potentials of the husk extract and fractions on malaria parasites using in vivo and in vitro models.

Materials and methods: The ethanol husk extract and fractions (187–748?mg/kg, p.o.) of Zea mays were investigated for antimalarial activity against Plasmodium berghei using rodent (mice) malaria models and in vitro activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of Plasmodium falciparum using the SRBR green assay method. Median lethal dose and cytotoxic activities against HeLa and HEKS cells were also carried out. The GCMS analysis of the most active fraction was carried out.

Results: The husk extract (187–748?mg/kg, p.o.) with LD₅₀ of 1874.83?mg/kg was found to exert significant (p?P. berghei infection in suppressive, prophylactive and curative tests. The crude extract and fractions also exerted prominent activity against both chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of P. falciparum with the ethyl acetate fraction exerting the highest activity with IC₅₀ values of 9.31?±?0.46?μg/mL (Pf 3D7) and 3.69?±?0.66?μg/mL (Pf INDO). The crude extract and fractions were not cytotoxic to the two cell lines tested with IC₅₀ values of?>100?μg/mL against both HeLa and HEKS cell lines.

Discussion and conclusion: These results suggest that the husk extract/fractions of Zea mays possesses antimalarial and antiplasmodial activities and these justify its use in ethnomedicine to treat malaria infections.     

Kinetics of α-glucosidase inhibition by different fractions of three species of Labiatae extracts: a new diabetes treatment model

Context: Glucosidases are a group of enzymes playing crucial roles in digestion of carbohydrates. Glucosidase inhibitors can reduce carbohydrate digestion rate and have the potential to prevent development of type 2 diabetes. The Labiatae is one of the largest plant families grown globally and many studies that have isolated new pharmaceutical compounds. In folk medicine, some of Labiatae plants such as Zataria multiflora Boiss, Salvia mirzayanii Rech. F. &; Esfand, and Otostegia persica Boiss are consumed for the treatment of diabetes.

Objectives: This study investigates the inhibitory effects of different fractions of three mentioned species extracts on α-glucosidase.

Materials and methods: Ethanol extracts of these plants leaves were fractionated using petroleum ether, chloroform, ethyl acetate, and n-butanol solutions. The duration of this study was 12?months. To measure enzyme inhibition, 5?μL of the enzyme, 20?μL of substrate and samples were used and for evaluation mode of inhibition, constant amounts of α-glucosidase were incubated with rising concentrations of substrate (PNPG).

Results: The results revealed that the ethyl acetate fraction of Zataria multiflora (IC₅₀ =?0.35?±?0.01?mg/mL) and petroleum ether fraction of Salvia mirzayanii (IC₅₀ =?0.4?±?0.11?mg/mL) were the most potent inhibitors of α-glucosidase in comparison with the other samples and acarbose as the standard (IC₅₀ =?7?±?0.19?mg/mL). All of the samples exhibited noncompetitive-uncompetitive inhibition.

Discussion and conclusion: It can be inferred from this study that α-glucosidase inhibitory potential of the studied extracts may be a marker of antidiabetic potential of these extracts.     

Sedative effects of Iranian Artemisia annua in mice: Possible benzodiazepine receptors involvement

Context: Artemisia annua L. (Asteraceae), commonly known as sweet wormwood or Qinghao, is an annual herb/shrub native of Asia. The plant grows broadly in Caspian Sea shores in North of Iran. In China, the aerial parts of this plant are source of artemisinin, which is an antimalarial compound.

Objective: This study aimed to establish the scientific basis of reported ethnomedicinal use of A. annua as sedative agent.

Material and methods: The plants were gathered from Gilan Province in Iran. Plant aerial parts were extracted with methanol and concentrated in vacuum. Methanol extract was partitioned into chloroform, petroleum ether, and ethyl acetate. Each fraction was administered intraperitoneally (i.p.) in male mice with different concentrations (50, 100, and 200?mg/kg), and for evaluation of sedative activity, immobility time was determined. In effort to clarify the mechanism of action, flumazenil (3?mg/kg, i.p.) as a benzodiazepine (BZD) receptor antagonist was injected 15?min before chloroform fraction (200?mg/kg, i.p.).

Results: Compared with control group (saline-treated mice), the chloroform fraction significantly increased immobility time in a dose-dependent manner. Flumazenil decreased immobility time induced by chloroform fraction significantly.

Discussion and conclusion: The results of the present study suggest that A. annua growing in Iran has sedative effects, which are probably mediated via BZD receptors pathways.