Antidiabetic,antilipidemic, and antioxidant activities of Gouania longipetala methanol leaf extract in alloxan-induced diabetic rats

Abstract

Context: Gouania longipetala Hemsl. (Rhamnaceae) is used in folkloric medicine for treating diabetes mellitus and its associated symptoms.

Objective: This study evaluated the antidiabetic antilipidemic and antioxidant activities of the plant methanol leaf extract.

Materials and methods: Diabetes was induced in rats by intraperitoneal injection of alloxan monohydrate (160?mg/kg). Three test doses (50, 100, and 150?mg/kg) of G. longipetala extract (GLE) were administered orally and the effects were compared with glibenclamide (2?mg/kg). The effect of GLE on hyperglycemia and sub-acute study for 21?d were carried out using its effect on fasting blood sugar (FBS) level. Serum biochemistry and antioxidant activity were evaluated. Histopathological evaluation of the pancreas was also done.

Results: The LD₅₀ of G. longipetala was found to be >4000?mg/kg. The extract significantly (p?<?0.0001) decreased the FBS levels of treated rats from 16.2?±?2.03 to 6.5?±?1.52?mM/L at 150?mg/kg within 24?h. The extract decreased FBS levels of rats by 62.0, 74.8, and 75.0% on day 21 at 50, 100, and 150?mg/kg, respectively. GLE reduced the level of malondiadehyde from 23.0?±?1.34?to 10.3?±?0.43?mg/dL, increased superoxide dismutase activities from 2.97?±?0.34 to 5.80?±?0.53?IU/L at 150?mg/kg, and improved the serum lipid profile of treated rats. GLE also caused restoration of the altered histopathological changes of the pancreas.

Discussion and conclusion: Gouania longipetala demonstrated significant antidiabetic, antilipidemic, and antioxidant activities that may be due to its multiple effects involving both pancreatic and extra-pancreatic mechanisms.     

Antidiabetic and antioxidant potency evaluation of different fractions obtained from Cucumis prophetarum fruit

Abstract

Context: Cucumis prophetarum Linn. (Cucurbitaceae) fruit is used for inflammatory-related problems and is proved to be possessing anticancer and hepatoprotective effects.

Objective: The present investigation was to study the effect of different fractions of C. prophetarum on antidiabetic and antioxidant activity.

Materials and methods: Aqueous crude extract (CE) of C. prophetarum fruits was fractionated into water soluble fraction 1 (F1), chloroform fraction 2 (F2), basic fraction 3 (F3), and neutral fraction 4 (F4) by acid–base extraction. CE and its fractions at different doses (0.02–0.1?mg/mL) were subjected to antidiabetic (α-amylase and α-glucosidase inhibition assays) and antioxidant (DPPH, superoxide radical scavenging (SO) and metal chelation) evaluation.

Results: F1 exhibited effective antidiabetic activity (p?<?0.05) with an IC₅₀ value of 20.6 and 59.9?µg/mL. The activity decreased in the order of CE?>?F4?>F3?>?F2, according to α-amylase assay, which were the same, with the exception of the rank order of F4 and CE, as the α-glucosidase assay. Furthermore, F1 (IC₅₀?=?73?µg/mL) showed better reducing ability than CE?>F4?>F2?>?F3 (IC₅₀?=?78–272?µg/mL), according to the DPPH assay. In SO and metal chelation assays, F1 showed the highest activity (IC₅₀?=?101 and 147?µg/mL), respectively; the activity decreased in the order of CE?>F4?>F3?>?F2 (IC₅₀?=?126–469?µg/mL) for SO and 194–944?µg/mL for metal chelation assay.

Conclusion: The results indicate that F1 possesses potent in vitro antidiabetic and antioxidant activities.     

Antihyperglycemic and antihyperlipidemic effects of Salvadora persica in streptozotocin-induced diabetic rats

Context: Many synthetic antidiabetic components show toxic and/or mutagenic effects. Hence, attention has been given to naturally occurring antidiabetic components. Identification of effective antidiabetic components from plants origin is an ideal strategy for new drug development. The fresh root, bark, and leaves of Salvadora persica L. (Salvadoraceae) have been used in folk medicine for the treatment of a wide range of medical problems such as cough, asthma, scurvy, piles, rheumatism, leprosy, and gonorrhea disorders.

Objective: The S. persica root extract was investigated for the reduction of the risk of diabetes in diabetic rats.

Material and methods: The hydro-alcoholic root extract, 200 and 400?mg/kg, was fed to streptozotocin-induced diabetic rats for 21?d. Blood serum glucose, lipid profile, body weight, and food intake were monitored at 0, 7, 14, and 21?d after induction of diabetes.

Results: S. persica hydro-alcoholic root extract was not toxic at doses up to 1200?mg/kg. Significant reduction of blood glucose and lipid profile in diabetic rats treated with 400?mg/kg hydro-alcoholic root extract after 21?d versus diabetic control and glibenclamide-treated rats. The glibenclamide and root extract-treated group’s peak values of blood glucose significantly decreased from 281.50 to 106?mg/dL and 285.50 to 150.25?mg/dL, respectively. Hence, in this study, observations showed that root hydro-alcoholic reduced the blood glucose level in diabetic rats but values did not return to normal controls.

Conclusion: The research suggests that the root extract was significantly effective when compared with control and standard in the treatment of hyperlipidemia and hyperglycemia in diabetic rats. Therefore, it may be beneficial to diabetic patients.     

Phytochemical analysis and antioxidant activity of Lycium barbarum (Goji) cultivated in Greece

Context: The fruit of Lycium barbarum L. (Solanaceae), known as goji berry, has been exploited for a long time in traditional Chinese medicine. In recent decades, it has received much attention as one of the trendiest functional foods with a wide array of pharmacological activities in Western diets.

Objective: In this study the phenolic profile and potential antioxidant capacity of Lycium barbarum cultivated in Crete (Greece) were investigated.

Materials and methods: The berries were defatted with hexane and then extracted with dichloromethane and methanol using a Soxhlet apparatus. Furthermore, the methanol extract was fractionated with ethyl acetate and butanol. All fractions/extracts were tested for their antioxidant activity (DPPH, FRAP, chemiluminescence). Folin–Ciocalteu and LC-DAD-MS analyses were utilized for the identification of the phenolic compounds.

Results: The total phenolic content ranged from 14.13?±?0.40 (water fraction) to 109.72?±?4.09 (ethyl acetate fraction) mg gallic acid equivalent/g dry extract. Ethyl acetate extract exhibited the highest scavenging activities determined as EC₅₀ (4.73?±?0.20?mg/mL) and IC₅₀ (0.47?±?0.001?mg/mL) using DPPH and chemiluminescence assays. Seventeen phenolic compounds, including cinnamoylquinic acids and derivatives, hydrocinnamic acids and flavonoid derivatives, were tentatively identified. To the best of our knowledge, quercetin 3-O-hexose coumaric ester and quercetin 3-O-hexose-O-hexose-O-rhamnose are reported for the first time in goji berry fruits.

Discussion and conclusion: The results of this study suggest that consumption of goji berry fruits could serve as a potential source of natural antioxidant compounds and that goji berry phenolic extracts could be exploited for nutritional pharmaceutical purposes.     

Cytotoxic,antioxidant and antimicrobial effects of nine species of woundwort (Stachys) plants

Context: Woundwort (Stachys) plants from the Lamiaceae family have been used in folk medicine for various purposes.

Objective: This study was designed to analyze cytotoxic, antioxidant and antimicrobial activities of Stachys plants, because these fields have extensively benefited of drug discovery from natural sources.

Materials and methods: Nine Stachys plants were collected from different regions of Iran. Cytotoxic activities of methanol, 80% methanol and dichloromethane (DCM) extracts of these plants were assessed on three human cancer cell lines (HL-60, K562 and MCF-7 cells) with the MTT assay, while antioxidant and antimicrobial activities were determined on methanol extracts by DPPH and nutrient broth micro-dilution assays, respectively.

Results: DCM extract of St. pilifera Benth. had the lowest IC₅₀ in three cancer cell lines ranging from 33.1 to 48.2?µg/ml, followed by the 80% methanol extract of St. persica S.G.Gmel. ex C.A.Mey. (IC₅₀ range: 62.1–104.1?µg/ml) and DCM extract of St. byzantina C. Koch (IC₅₀ range: 62.7–131.0?µg/ml). St. byzantina. St. lavandulifolia Vahl., St. acerosa Boiss., St. obtusicrena Boiss. and St. persica showed lowest IC₅₀ values in the DPPH scavenging assay (135.1, 162.6, 164.7, 169.4 and 172.4?µg/ml, respectively), while their total phenolic contents were 23.9, 18.2, 18.6, 20.4, 27.8?mg equivalent of gallic acid in 1?g dry plant, respectively. The methanol extracts of St. byzantina and St. persica inhibited all six tested Gram-negative and Gram-positive bacterial strains.

Conclusion: Various Stachys species (especially St. byzantina and St. persica) are valuable sources of natural compounds with important biological properties.     

Amelioration of hyperglycaemia and modulation of antioxidant status by Alcea rosea seeds in alloxan-induced diabetic rats

Context: Alcea rosea L. (Malvaceae) has various medicinal uses including anticancer, anti-inflammatory and analgesic properties. However, there is no report on its antidiabetic activity.

Objective: Alcea rosea seed extracts were evaluated for antihyperglycaemic and antioxidative potential in diabetic rats.

Materials and methods: Single intra-peritoneal injection of alloxan (130?mg/kg b.w.) was used for induction of diabetes in Albino Wistar rats. Antihyperglycaemic and antioxidant activities of methanol and aqueous extracts of Alcea rosea seed (100 and 300?mg/kg b.w.), administered orally on daily basis for 15 days, were assessed in vivo for fasting blood glucose level and antioxidant status of liver and pancreas. Metformin was used as a positive control.

Results: Aqueous and methanol extracts (300?mg/kg b.w.) decreased blood glucose level in diabetic rats by 24% and 46%, respectively. Administration of aqueous and methanol extracts at 300?mg/kg b.w. significantly (p?2O₂ decomposed/min/mg of protein), respectively. Similar results were observed for pancreas.

Discussion and conclusions: Antihyperglycaemic and antioxidative potentials of Alcea rosea seeds suggest its usefulness in management of diabetes and its complications. This is the first report on antidiabetic activity of this plant.     

Antihyperglycemic,antilipid peroxidation,and insulin secretory activities of Otostegia persica shoot extract in streptozotocin-induced diabetic rats and in vitro C187 pancreatic β-cells

Context: Otostegia persica Boiss (Lamiaceae) contains antioxidant agents and is used in traditional medicine for treatment of diabetes mellitus complications.

Objectives: The acute antihyperglycemic, antilipid peroxidation, and insulin secretory activities of methanol extract of O. persica aerial parts were investigated.

Materials and methods: The extract [200, 300, 400?mg/kg body weight (b.w.)] was given orally to rats and glucose (2?g/kg b.w. orally) was administered 30?min later. Glucose and insulin serum levels were measured before and 30, 60, 120, and 240?min after administration of the test samples in normal and diabetic rats. The in vitro insulin secretory activity of extract was evaluated in C187 pancreatic β-cells and its antilipid peroxidation effect was determined by measuring malondialdehyde (MDA) and glutathione (GSH) levels in rat livers after 240?min. The identification of the major phytoconstituents of the extract was carried out using gas chromatography-mass spectrometry.

Results: The extract (300?mg/kg b.w.) significantly decreased the serum glucose level in diabetic rats at 1 h (494?±?13.4 vs. 426?±?12.9), 2 h (472.8?±?17.8 vs. 396?±?22), and 4?h (438.8?±?25 vs. 346?±?19) after treatment. Accordingly, the serum insulin level increased at the same times. The extract significantly increased glucose-induced insulin secretion in C187 β-cells. Moreover, the extract significantly decreased MDA and increased GSH levels in the liver of diabetic rats. Phytochemical analysis revealed thymol as the major phytoconstituent in the extract.

Discussion and conclusion: O. persica shoot extract has antihyperglycemic, antilipid peroxidation, and insulin secretory properties.     

Antidiabetic,antihyperlipidaemic, and antioxidant activity of Syzygium densiflorum fruits in streptozotocin and nicotinamide-induced diabetic rats

Context Syzygium densiflorum Wall. ex Wight & Arn (Myrtaceae) has been traditionally used by local tribes of the Nilgiris, Tamil Nadu, India, for the treatment of diabetes, however, no definitive experimental studies are available.

Objective This study investigates the antidiabetic, antihyperlipidaemic and antioxidant activities of ethanol extract of S. densiflorum (EFSD) fruits in streptozotocin (STZ) and nicotinamide (NA)-induced diabetic rats.

Materials and methods Acute oral toxicity and oral glucose tolerance were assessed in normal rats. The antidiabetic, antihyperlipidaemic and antioxidant activities were investigated in STZ???NA-induced diabetic rats. Diabetic rats were orally administered with glibenclamide (10?mg/kg b.wt), EFSD (200, 400 and 800?mg/kg b.wt) for 28 d. Further, changes in the blood glucose level (BGL), biochemical parameters, antioxidants were observed and histology of pancreas was performed.

Results No toxicity and lethality were observed. Results of the following parameters are represented by treated versus disease control (STZ?+?NA) groups. BGL (161.33?±?22.8 versus 476.17?±?56.58?mg/dl), glycosylated haemoglobin (5.285?±?0.19 versus 8.05?±?0.55%), urea (40.32?±?1.96 versus 75.37?±?2.91?mg/dl), uric acid (1.2?±?0.07 versus 2.16?±?0.05?mg/dl), total cholesterol (89.3?±?5.14 versus 139.7?±?5.95?mg/dl) and triglycerides (79.65?±?2.52 versus 108.9?±?3.61?mg/dl) were significantly decreased, whereas haemoglobin (11.75?±?0.73 versus 7.95?±?0.42?g/dl), high‐density lipoprotein cholesterol (14.2?±?1.11 versus 6.97?±?0.84?mg/dl), total protein (45%) and liver glycogen (87%) were significantly increased in EFSD-treated diabetic group. Significant changes were observed in the enzymatic and non-enzymatic antioxidants in EFSD-treated groups (p?<?0.001). Histopathological examination showed the regeneration of β-cells in Islets of Langerhans.

Conclusion This study confirms the antidiabetic, antihyperlipidaemic and antioxidant activities of S. densiflorum fruits.     

Antidiabetic,antioxidant, and antilipid peroxidative activities of Dracocephalum polychaetum shoot extract in streptozotocin-induced diabetic rats: In vivo and in vitro studies

Context: Dracocephalum polychaetum Bornm. (Lamiaceae) is used in folk medicine and contains antioxidant agents.

Objectives: The objective of this study is to investigate the antidiabetic, antioxidant, and antilipid peroxidative properties of methanol extract of D. polychaetum aerial parts.

Materials and methods: The effect of extract (200, 300, and 400?mg/kg, b.w.) on oral glucose tolerance test (OGTT) was investigated. Also, extract (300?mg/kg) administered orally in diabetic rats for 14?d then, serum levels of some biochemical factors were evaluated. Pancreas samples were used for the determination of malondealdehyde (MDA) level, glutathione (GSH) content, superoxide dismutase, and catalase enzyme activities. Red blood cells (RBCs) and plasma were used for MDA estimation. Pancreatic α-amylase inhibition, DPPH (1,1-diphenyl-2-picrylhydrazyl), and FRAP (ferric reducing antioxidant power) assays were done. The total flavonoid content of the extract was determined by spectrophotometry.

Results: Extract (300?mg/kg) decreased serum glucose level (27.1%) significantly at 120?min in OGTT. Serum levels of creatinine, triglycerides, cholesterol, alanine amino transferase and MDA levels in plasma, RBCs, and pancreas significantly decreased in treated (300?mg/kg) diabetic rats, while pancreatic GSH content, superoxide dismutase, and catalase enzymatic activities increased (p?<?0.05). The IC₅₀ values for the extract and butyl hydroxyanisole were 5.6 and 1.15?mg/mL in DPPH and 0.155 and 0.062?mg/mL in the FRAP methods, respectively. The extract had no inhibitory effect on α-amylase activity. The total amount of flavonoids of the extract was estimated to be 1.8% (g/g) on the basis of quercetin content.

Conclusion: Dracocephalum polychaetum shoot extract has antioxidant, antihyperlipidemic, and antilipid peroxidative properties.     

Antidiabetic,antioxidant, and TNF-α lowering properties of extract of the traditionally used plant Ixeris gracilis in alloxan-induced diabetic mice

Abstract

Context: Ixeris gracilis DC. Stebbins (Asteraceae) is a plant considered to be medicinal by local communities of Meghalaya, India.

Objective: To evaluate the antidiabetic potential, antioxidant activity, and effect of the 80% methanolic extract of the leaves of Ixeris gracilis on tumor necrosis factor-α (TNF-α) expression.

Materials and methods: Varying doses (250–1000?mg/kg body weight) were administered intraperitoneally to normoglycemic mice and their hypoglycemic properties noted for 24?h; the optimum dose observed was used to evaluate its antihyperglycemic activity and effect on glucose tolerance. In vitro antioxidant activity was analyzed by assessing the DPPH radicals scavenging ability of the extract and the total polyphenols, flavonoid, carbohydrate, and protein contents were determined. Diabetic mice were then subjected to daily intraperitoneal injections of the extract for 12 days after which the antioxidant enzyme activities in the tissues were assayed and serum TNF-α was evaluated by ELISA.

Results: The extract displayed varying hypoglycemic activity. The dose of 250?mg/kg body weight exhibited potent antihyperglycemic activity and improved glucose tolerance. The extract was able to scavenge free radicals (IC₅₀ 57.544?µg/ml) and contained polyphenol (76.269?±?0.204?mg GAE/g dry wt), flavonoid (70.070?±?0.626?mg rutin equivalent/g dry wt), protein (4.368?±?8.916?mg/g dry wt), and carbohydrate (558.189?±?0.002?mg/g dry wt). TNF-α level and overall activity of glutathione peroxidase and superoxide dismutase in the liver, kidney, and brain of extract-treated diabetic mice were improved.

Conclusion: The study supports the inclusion of Ixeris gracilis in the list of plants with antidiabetic potential.     

HPTLC analysis,antioxidant, anti-inflammatory and antiproliferative activities of Arisaema tortuosum tuber extract

Context: Oxidative stress and inflammation are related to several chronic diseases including cancer and atherosclerosis. Arisaema tortuosum (Wall.) Schott (Araceae) is an Indian folk medicinal herb traditionally used for treatment of various diseases related to inflammation and stress.

Objective: This study was carried out for HPTLC analysis and evaluation of antioxidant, anti-inflammatory and antiproliferative activities of a methanol extract of A. tortuosum tuber.

Materials and methods: The antioxidant activities of methanol extract of A. tortuosum tuber (1?mg/mL) were evaluated by DPPH, ABTS and FRAP assays and anti-inflammatory effects by diene-conjugate and β-glucuronidase assays, with in vitro tumor growth inhibition on HeLa cancer cells. The results for antioxidant and anti-inflammatory effects were compared using Trolox and salicylic acid as reference compounds, respectively.

Results: The TLC and HPTLC analysis showed the presence of quercetin, rutin, luteolin and lectin (R_f values 0.97, 0.53, 0.59 and 1.58, respectively). The methanol fraction of tuber exhibit higher activity in each antioxidant system with a special attention for DPPH (IC₅₀?=?852?μg/mL), ABTS (IC₅₀?=?532?μg/mL), and FRAP (IC₅₀?=?458?μg/mL), as compared with Trolox as standard, with a remarkable amount of phenolics (86.2?mg/100?g) and flavonoids (175.5?mg/100?g), along with potent anti-inflammatory activity indicated by diene-conjugate (86.20%) and β-glucuronidase (92.92%) inhibition, as compared with salicylic acid as reference compound. The antiproliferative activity at 100?mg/mL was 88% inhibition with HeLa cells. The inhibition of HeLa cell proliferation was greatest (p?A. tortuosum tuber extract treatments and least with the 25?mg/mL dose.

Discussion and conclusion: Our results suggested that A. tortuosum tuber might be used as a promising and potent antioxidant, anti-inflammatory, and antiproliferative agent and might be used for standardization of potential drug after successful isolation and characterization of bioactive compounds.     

Antidiabetic and antioxidant activity of Swietenia mahagoni in streptozotocin-induced diabetic rats

Context: Swietenia mahagoni L. Jacq. (Meliaceae) is a medium to large evergreen tree native to Southern Florida, Cuba, The Bahamas, Hispaniola, and Jamaica.

Objective: To evaluate the antidiabetic and antioxidant potential of S. mahagoni bark.

Materials and methods: In the present study, the antidiabetic activity of the methanol extract of S. mahagoni (MESM) bark in streptozotocin (STZ; 65?mg/kg body weight)-induced diabetic rats was evaluated. Glibenclamide (0.5?mg/kg; orally) was taken as the reference drug. The blood glucose levels and body weights were measured every 5th day over a period of 15 days. Antioxidant effects were assayed in diabetic rats by estimating thiobarbituric acid reactive substances (TBARS), glutathione (GSH), and catalase (CAT) levels.

Results and discussion: Oral administration of MESM at the doses of 25 and 50?mg/kg b.w. resulted in a significant (p?<?0.001) reduction in blood glucose levels in diabetic rats. Body weights were significantly (p?<?0.001) reduced in STZ-induced diabetic rats when compared to normal rats, while the extract significantly restored body weight. The present study was further undertaken to evaluate the antioxidant activity of MESM in STZ-induced diabetic rats. Decreased levels of TBARS and increased levels of GSH and CAT activity indicated a reduction in free radical formation in tissues such as the liver and kidney of diabetic rats.

Conclusion: These findings showed the significant hypoglycemic and antioxidant activity of the extract (MESM) in diabetic rats.     

Antioxidant,anticholinesterase and tyrosinase inhibition activities,and fatty acids of Crocus mathewii – A forgotten endemic angiosperm of Turkey

Context We report the first ever chemical/biochemical study on Crocus mathewii Kerndorff (Iridaceae) – a Turkish endemic angiosperm. This plant has never been explored for its phytochemistry and bioactivities.

Objective This study explores C. mathewii corm and aerial parts for the chemical and biological properties of hexane, ethyl acetate, methanol and water fractions of the extracts.

Material and methods Plant material (20 g) was extracted by methanol (250?mL?×?5, 3 days each) and fractioned into hexane, ethyl acetate, methanol and water. All fractions were subjected to β-carotene–linoleic acid, DPPH^·, ABTS^·+, CUPRAC, metal chelating and tyrosinase inhibition activities. Hexane fractions were submitted to GC–MS analysis.

Results Ethyl acetate fractions showed excellent IC₅₀ values in DPPH^· (aerial 36.21?±?0.76 and corm 33.87?±?0.02?mg/L) and ABTS^·+ (aerial 33.01?±?0.79 and bulb 27.87?±?0.33?mg/L); higher than the IC₅₀ of the standard α-tocopherol (DPPH 116.25?±?1.97; ABTS 52.64?±?0.37?mg/L), higher than BHA in DPPH (57.31?±?0.25?mg/L), but slightly lower in ABTS (19.86?±?2.73?mg/L). Methanol extract of aerial parts also showed higher activity than α-tocopherol in DPPH (85.56?±?11.51?mg/L) but slightly less (72.90?±?3.66?mg/L) than both the standards in ABTS. Linoleic (aerial 53.9%, corm 43.9%) and palmitic (aerial 22.2%, corm 18%) were found as the major fatty acids.

Discussion and conclusion Some fractions of C. mathewii showed higher antioxidant activities than the standards. There is a need to explore more about this plant.     

In vitro antioxidant and cytotoxic properties of ethanol extract of Alpinia oxyphylla fruits

Abstract

Context. Alpinia oxyphylla Miquel (Zingiberaceae) is a traditional Chinese herbal medicine widely used for the treatment of intestinal disorders, urosis and diuresis. However, information about antioxidant and cytotoxic properties of its fruits remains to be elucidated.

Objective: The ethanol crude extract (CE) and its fractions [petroleum ether fraction (PF), ethyl acetate fraction (EF), n-butanol fraction (BF) and water fraction (WF) extracted by petroleum ether, ethyl acetate, n-butanol and water, respectively] of A. oxyphylla fruits were investigated for their antioxidant activity and cytotoxicity.

Materials and methods: The total phenolic content (TPC) and antioxidant activity of the extracts were determined by Folin–Ciocalteu reagent, 1,1-diphenyl-2-picrylhydrazyl (DPPH^?), Trolox equivalent antioxidant capacity and reducing power assay. Cytotoxicity of the extracts (0–200?μg/mL) was tested on six human cancer cell lines (breast cancer cell line, cervix carcinoma cell line, lung adenocarcinoma cell line, liver carcinoma cell line, gastric cancer cell line and colon cancer cell line) using the sulforhodamine B assay.

Results: The TPC of extracts varied from 8.2 to 20.3?mg gallic acid equivalents/g dry weight. DPPH radical scavenging effect of extracts decreased in the order of EF?>?BF?>?CE?>?PF?>?WF, with IC₅₀ values ranging from 74.7 to 680.8?μg/mL. 2,2-azo-bis(3-Ethylbenzothiazoline-6-sulfoic acid) diammonium salt scavenging activity ranged from 0.118 to 0.236?mmol Trolox equivalence/mg extract. The extracts exhibited concentration-dependent reducing power, and EF showed the highest reducing ability. A satisfactory correlation (R²?>?0.826) between TPC and antioxidant activity was observed. In addition, EF, PF and CE exhibited potent anticancer effects on six cancer cell lines with IC₅₀ values ranging from 40.1 to 166.3?μg/mL.

Discussion and conclusion: The ethanol extract of A. oxyphylla fruit, especially the EF, was found to possess potent antioxidant and anticancer activities, and thus a great potential for the application in food and drug products.     

Evaluation of antiurolithiatic and antioxidant potential of Lepidagathis prostrata: A Pashanbhed plant

Context: Oxidative stress acts as an essential mediator in the pathophysiology of urolithiasis. Lepidagathis prostrata Dalz. (Acanthaceae) is a Pashanbhed plant that is recommended for the management of urolithiasis; however, no scientific validation has been reported.

Objectives: To evaluate the antiurolithiatic and antioxidant potential of L. prostrata.

Materials and methods: Methanol extract (LPM) and fractions; petroleum ether (LPPE), ethyl acetate (LPEA), n-butanol (LPBU) and aqueous (LPAQ) were prepared. In vitro antiurolithiatic activity was evaluated by the capacity to inhibit calcium oxalate (CaOx) nucleation and aggregation at different concentrations of extract/fractions (0.04–3?mg/mL) for 30?min. Total phenol and flavonoid content and antioxidant potential were determined. A validated HPTLC method was performed to quantify lupeol and β-sitosterol.

Results: LPEA exhibited the highest dose-dependent inhibition of CaOx nucleation (IC₅₀: 336.23?±?30.79?µg/mL) and aggregation (IC₅₀: 149.63?±?10.31?µg/mL), which was significantly (p?<?0.05) better than standard Cystone®. The polar LPBU fraction was enriched with phenols (47.34?±?0.19?mg GAE/g) and flavonoids (20.38?±?0.05?mg QE/g), which correlates with its highest antioxidant potential in DPPH, ABTS, nitric oxide scavenging and iron chelating activities (IC₅₀: 1.18–87.34?µg/mL). To our knowledge, this is the first study reporting the presence of lupeol and β-sitosterol in L. prostrata.

Conclusion: The antiurolithiatic activity of L. prostrata is probably mediated through the inhibition of CaOx crystallization. In addition to its free radical scavenging and antioxidant activities, it would act as an excellent agent for the prevention of urolithiasis.     

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.     

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.     

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.     

Antidiabetic components of Cassia alata leaves: Identification through α-glucosidase inhibition studies

Context: Cassia alata Linn. [syn. Senna alata (L.) Roxb.] (Caesalpiniaceae) is used for treating various disease conditions including diabetes but its mechanism(s) of action and active principles remain to be elucidated.

Objective: The antidiabetic principles were identified using an in vitro α-glucosidase inhibition study.

Materials and methods: The methanol extract of leaves of C. alata, which showed potent α-glucosidase inhibitory activity (IC₅₀, 63.75?±?12.81 µg/ml), was fractionated. Active fractions were taken for further analysis by a variety of techniques including HPLC and Combiflash chromatography. The identity of the isolated compounds was established by spectroscopic analysis while their potential antidiabetic activity was assessed by in vitro enzyme inhibition studies.

Results: The α-glucosidase inhibitory effect of the crude extract was far better than the standard clinically used drug, acarbose (IC₅₀, 107.31?±?12.31 µg/ml). A subsequent fractionation of the crude extract was made using solvents of ascending polarity (petroleum ether, chloroform, ethyl acetate, n-butanol and water). The ethyl acetate (IC₅₀, 2.95?±?0.47 µg/ml) and n-butanol (IC₅₀, 25.80?±?2.01 µg/ml) fractions which contained predominantly kaempferol (56.7?±?7.7 µM) and kaempferol 3-O-gentiobioside (50.0?±?8.5 µM), respectively, displayed the highest carbohydrate enzyme inhibitory effect.

Discussion: One of the possible antidiabetic mechanisms of action of C. alata is by inhibiting carbohydrate digestion. This is the first report on α-glucosidase activity of kaempferol 3-O-gentiobioside.

Conclusion: Considering the activity profile of the crude extract and isolated bioactive compounds, further in vivo and clinical studies on C. alata extracts and compounds are well merited.     

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.