Free Radical Scavenging Activity of Extracts from Thai Plants in Guttiferae and Schisandraceae Families

ABSTRACT

Five Thai plants from the Guttiferae (Hypericum hookerianum. Wight & Arn, Garcinia speciosa. Wall, Garcinia xanthochymus. Hook f. ex. T. Anderson, Cratoxylum formosum. ssp. pruniflorum. (Kurz) Gogel, and Calophyllum polyanthum. Wall ex Choisy) and one from the Schisandraceae (Schisandra verruculosa.) were extracted by methanol and chloroform. The extracts were screened for free radical scavenging activity using the DPPH assay. All extracts showed a dose-dependent antioxidant activity. The most potent with the lowest IC₅₀ values were observed in the methanol extracts from the wood of G. speciosa., which were 2.5- and 5.3-fold more potent than the two standard antioxidants, ascorbic acid and α.-tocopherol, respectively. Free radical scavenging activities ranging from moderate to high were observed in both methanol and chloroform extracts from H. hookerianum., C. formosum. ssp. pruniflorum., G. xanthochymus., S. verruculosa. and C. polyanthum.. The information from this study can explain the traditional use and the further development of these extracts into new pharmaceuticals.     

Isolation of the Lignan 6-Methoxypodophyllotoxin from Linum boissieri. and Biosynthesis of Lignans in this Species

Abstract

We were able to establish a suspension culture of Linum boissieri. that produces 6-methoxypodophyllotoxin (6MPT). As a first step to gain insight into the lignan biosynthesis in L. boissieri. cell cultures, we were able to measure phenylalanine ammonia-lyase (PAL) activity in raw protein extracts. PAL is a key enzyme in the early part of the general phenylpropanoid pathway, leading (beside others) to the precursors for lignan biosynthesis.     

Radical Scavenging Activity of Methanol Leaf Extracts of Orthosiphon stamineus.

Abstract

The antioxidant activity of methanol extracts of Orthosiphon stamineus. Benth (Lamiaceae), cultivated in different regions of Malaysia, was determined by measuring the scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and on superoxide anion. The results showed a variation in free-radical and superoxide-anion scavenging activities of the methanol extracts ranging from 62.82 to 92.34% and 53.29 to 75.88%, respectively. Methanol extract was active, and its antioxidative potency was comparable to that of pure quercetin and higher than that of the widely used synthetic antioxidant butylated hydroxylanisole (BHA). The UV and HPLC chromatographic fingerprints of the major phenolics were qualitatively similar for all the methanol leaf extracts of Orthosiphon stamineus. from various locations.     

The potential medicinal value of plants from Asteraceae family with antioxidant defense enzymes as biological targets

Abstract

Context: Plants and most of the plant-derived compounds have long been known for their potential pharmaceutical effects. They are well known to play an important role in the treatment of several diseases from diabetes to various types of cancers. Today most of the clinically effective pharmaceuticals are developed from plant-derived ancestors in the history of medicine.

Objective: The aim of this study was to evaluate the free radical scavenging activity and total phenolic and flavonoid contents of methanol, ethanol, and acetone extracts from flowers and leaves of Onopordum acanthium L., Carduus acanthoides L., Cirsium arvense (L.) Scop., and Centaurea solstitialis L., all from the Asteraceae family, for investigating their potential medicinal values of biological targets that are participating in the antioxidant defense system such as catalase (CAT), glutathione S-transferase (GST), and glutathione peroxidase (GPx).

Materials and methods: In this study, free radical scavenging activity and total phenolic and flavonoid contents of the plant samples were assayed by DPPH, Folin–Ciocalteu, and aluminum chloride colorimetric methods. Also, the effects of extracts on CAT, GST, and GPx enzyme activities were investigated.

Results and discussion: The highest phenolic and flavonoid contents were detected in the acetone extract of C. acanthoides flowers, with 90.305?mg GAE/L and 185.43?mg Q/L values, respectively. The highest DPPH radical scavenging was observed with the methanol leaf extracts of C. arvense with an IC₅₀ value of 366?ng/mL. The maximum GPx and GST enzyme inhibition activities were observed with acetone extracts from the flower of C. solstitialis with IC₅₀ values of 79 and 232?ng/mL, respectively.     

Constituents from <Emphasis Type="Italic">Senecio scandens</Emphasis> and their antioxidant bioactivity

Forty-one compounds including two new constituents, senecainin A (1) and 3-methoxyisonicotinic acid (2), were characterized from the methanol extracts of the whole plant of Senecio scandens. The structures of the new compounds were comprehensively established with the aid of 1D and 2D NMR spectroscopic and mass spectrometric analyses. The chemical structures of known compounds were identified by comparison of their spectroscopic and physical data with those reported in the literature. In addition, the antioxidant activity of some of the isolates was examined in the DPPH free radical scavenging assay. Among the tested compounds, (−)-monoepoxylignanolide, (−)-pinoresinol and (−)-epi-pinoresinol displayed significant antioxidant bioactivity.     

Antigenotoxic and Free Radical Scavenging Activities of Extracts from Moricandia arvensis

This study evaluates genotoxic and antigenotoxic effects of extracts from leaves of Moricandia arvensis, which are used in traditional cooking and medicines. Extracts showed no genotoxicity when tested with the SOS Chromotest using E. coli PQ37 and PQ35 strains, except for the total oligomers flavonoids enriched extract. Petroleum ether and methanol extracts are the most active in reducing nitrofurantoin genotoxicity, whereas methanol and total oligomers flavonoids enriched extracts showed the most important inhibitory effect of H₂O₂ genotoxicity. In addition, these two extracts showed important free radical scavenging activity toward the DPPH^· radical, whereas the chloroform extract exhibited the highest value of TEAC against ABTS^+· radical.     

Superoxide Radical Scavenging Properties of Extracts and Flavonoids Isolated from the Leaves of Blumea balsamifera

In view of the pharmacological interest in flavonoids, the superoxide radical scavenging capacity of pet-ether, chloroform, and methanol extracts and flavonoids of Blumea balsamifera DC leaves on nonenzymatically (phenazine methosulfate/NADH) generated superoxide radicals were evaluated. The methanol extract (93.91 ± 1.37%) exhibited higher radical scavenging activity than the chloroform extract (84.58 ± 1.51%). The pet-ether extract was inactive toward nonenzymatically generated superoxide radicals. The superoxide radical scavenging capacity of flavonoids (100 µM) as determined was decreased in the order quercetin &gt; luteolin &gt; 5,7,3′,5′-tetrahydroxyflavanone &gt; blumeatin &gt; rhamnetin &gt; tamarixetin &gt; luteolin-7-methyl ether &gt; dihydroquercetin-4′-methyl ether &gt; dihydroquercetin-4′,7-dimethyl ether. It was concluded that flavonoids with a free hydroxyl group were more active than methylated compounds, and the flavonoid content of extracts contributed to their superoxide radical scavenging activity.     

2种藏紫草体外抗氧化及抗菌活性比较

目的 比较长花滇紫草和团花滇紫草75%乙醇提取物的体外抗氧化及抗菌活性。方法 采用ABTS法、FRAP法、邻苯三酚自氧化法测定体外抗氧化能力，并采用肉汤连续稀释法初步考察了2种藏紫草体提取物体外对15种不同菌株的抗菌作用。结果 不同浓度藏紫草的75%乙醇提取物对ABTS自由基和超氧阴离子都有较强的清除能力，与BHT阳性药相当或略高于BHT；总还原力随取物浓度增加而增强；2种藏紫草的提取物对革兰阳性菌有一定的抗菌活性，但对肠杆菌科菌株及铜绿假单胞菌均未见抗菌作用。结论 2种来源的藏紫草均具有一定的体外抗氧化和抗菌作用。     

Evaluation of the antioxidant activity of Betula pendula leaves extract and its effects on model foods

Context: Betula pendula Roth (Betulaceae) exhibits many pharmacological activities in humans including anticancer, antibacterial, and antiviral effects. However, the antioxidant activity of BP towards lipid degradation has not been fully determined.

Objective: The BP ethanol and methanol extracts were evaluated to determine antioxidant activity by an in vitro method and lyophilized extract of BP was added to beef patties to study oxidative stability.

Materials and methods: Antioxidant activities of extracts of BP were determined by measuring scavenging radical activity against methoxy radical generated by Fenton reaction 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (TEAC) radical cation, the oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP) assays. The lipid deterioration in beef patties containing 0.1% and 0.3% (w/w) of lyophilized extract of BP stored in 80:20 (v/v) O₂:CO₂ modified atmosphere (MAP) at 4?°C for 10 days was determined using thiobarbituric acid reacting substances (TBARS), % metmyoglobin and colour value.

Results: The BP methanol extract revealed the presence of catechin, myricetin, quercetin, naringenin, and p-coumaric acid. The BP ethanol (50% w/w) extract showed scavenging activity in TEAC, ORAC and FRAP assays with values of 1.45, 2.81, 1.52?mmol Trolox equivalents (TE)/g DW, respectively. Reductions in lipid oxidation were found in samples treated with lyophilized BP extract (0.1% and 0.3% w/w) as manifested by the changes of colour and metmyoglobin concentration. A preliminary study film with BP showed retard degradation of lipid in muscle food.

Conclusion: The present results indicated that the BP extracts can be used as natural food antioxidants.     

Lignan Production by Cell Cultures of Linum setaceum. and Linum campanulatum.

Abstract

Callus and suspension cultures of Linum campanulatum. L. and Linum setaceum. Brot. (Linaceae) were established to study accumulation of lignans. Justicidin B proved to be the main constituent in the callus and suspension cultures of Linum campanulatum. L. Phytochemical analysis of cell cultures of Linum setaceum. Brot. has demonstrated that callus produces yatein, desoxypodophyllotoxin, and β.-peltatin, whereas the suspension cultures contain yatein, desoxypodophyllotoxin, β.-peltatin, and 6-methoxypodophyllotoxin.     

Optimization of podophyllotoxin extraction method from Linum album cell cultures

Context: Suspension cultures of Linum album Kotschy ex Boiss. (Linaceae) accumulate podophyllotoxin (an anticancer agent) and could therefore serve as an alternative source of this important aryltetralin lactone lignan.

Objective: The present work compared four podophyllotoxin extraction methods and optimization of the best one by using single factor experiments.

Materials and methods: Linum album cell cultures were established from in vitro plantlets and subcultured in MS medium with hormones every 7–8 days. Four podophyllotoxin extraction methods were assayed and the best one was optimized by single factor experiments, studying the effect of methanol concentration, extraction time, and sonication time.

Results: Cell cultures accumulated enough podophyllotoxin to be analyzed by HPLC. The methanol/dichloromethane and buffer extraction methods were found to be the best. Methanol alone and hot ethanol were not effective for extracting podophyllotoxin.

Discussion and conclusion: The optimized method based on methanol/dichloromethane extraction combined with HPLC quantification was able to determine small amounts of podophyllotoxin in Linum album cell cultures, showing that this system could constitute a possible alternative source of podophyllotoxin to Podophyllum (Berberidaceae).     

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.     

In vitro Antioxidant Potential of Different Parts of Oroxylum indicum: A Comparative Study

The present study evaluated the in vitro antioxidant potential of different parts of Oroxylum indicum. 2,2-diphelyl 1-picrylhydrazyl (DPPH), nitric oxide, superoxide anion and hydroxyl radical scavenging potential and reductive ability assay of methanol extract of different parts i.e. root, root bark, stem, stem bark, leaves and fruits were performed. Leaves and bark extracts exhibits highest free radical scavenging activity than bark, stem and fruit extract. Leaves extract showed maximum reductive ability and found to contain maximum amount of polyphenolic compounds. The highest free radical activity may be due to presence of polyphenolic compounds.     

Antioxidant and radical scavenging properties of <Emphasis Type="Italic">Iris germanica</Emphasis>

The antioxidant activity of aqueous and ethanol extracts of iris (Iris germanica L., family Iridaceae) has been evaluated in vitro using various antioxidant assays, including reducing power, free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, and metal chelating activities. Both aqueous and ethanol extracts exhibit strong total antioxidant activity, showing 95.9, 88.4, 79.9% and 90.5, 78.0, 65.3% inhibition on peroxidation of linoleic acid emulsion in concentrations of 10, 30, and 50 μg-ml, respectively. Both extracts also possess effective reducing power and exhibit free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, and metal chelating activities in concentrations of 20, 40, and 60 μg-ml. The antioxidant properties were compared to those of reference antioxidants (BHA, BHT, and α-tocopherol). In addition, the total content of phenolic compounds in both aqueous and ethanol iris extracts has been determined as gallic acid equivalent. The results indicate that iris has in vitro antioxidant properties, which can be the major factor responsible for the inhibition of lipid peroxidation. Published in Khimiko-Farmatsevticheskii Zhurnal, Vol. 41, No. 8, pp. 13–18, August, 2007.     

Medicinal cuisines: Diet and ethopharmacology

Abstract

The in vitro antioxidant potential of Triphala and its constituents was tested with the following systems: radical scavenging activity measured by DPPH reduction, and superoxide radical and peroxy radical scavenging properties measured by riboflavin/light/NBT reduction and linoleic acid peroxidation, respectively. Alcohol extracts of Triphala and its constituents were studied comparatively and found to be strong anti-oxidants. Triphala was also effective in preventing superoxide-induced haemolysis of red blood cells. The extracts also prevented lipid peroxidation induced by Fe³⁺/ADP/Ascorbate system in rat liver mitochondria. The major phenolic compounds of the alcohol extracts were confirmed as tannins.     

Wound Healing and Antioxidant Activity of Achyranthes aspera

Achyranthes aspera Linn (Amaranthaceae), commonly known as apamarga, is a commonly available plant in India. This plant has been used in the treatment of cuts by the people living in Tamil Nadu. The ethanol and aqueous extracts of leaves of Achyranthes aspera were prepared and its wound healing and antioxidant activity were evaluated. The wound healing activity was studied using two wound models, excision wound model and incision wound model. The free radical scavenging activity of the extracts was also assessed using two methods, DPPH radical scavenging activity, and superoxide scavenging activity. The extracts responded significantly in both the wound models tested. Also, the plant exhibited good antioxidant effect by preventing the formation of free radicals in the two models studied. Comparatively, the aqueous extract was found to be more effective. These findings could justify the inclusion of this plant in the management of cuts by the local people.     

Antioxidant Activities of Some Cameroonian Plants Extracts Used in the Treatment of Intestinal and Infectious Diseases

Antioxidant activity test using two different methods namely 2,2-diphenyl-1-picrylhydrazyl and 2,2''-azinobis(3-ethylbenzothialozinesulfonate) diammonium salt free radical scavenging test has been carried out on three Cameroonian plant extracts used in the treatment of intestinal and infectious diseases: Pittosporum mannii Hook f. (Pittosporaceae), Vepris heterophylla R. Letouzey (Rutaceae) and Ricinodendron heudelotii (Baill) Pierre ex Pax (Euphorbiaceae). Results of this study in the 2,2-diphenyl-1-picrylhydrazyl scavenging test show that the ethyl acetate extract of P. mannii and the methanol extract of V. heterophylla exhibit high free radical scavenging activities with IC₅₀ values of 177.74 and 204.69 μg/ml, respectively while the methanol/dichloromethane (1+1) extract of R. heudelotii showed weak free radical scavenging activities as compared to Trolox (939.19 μg/ml) used as standard. In the same manner, 2,2''-azinobis(3-ethylbenzothialozinesulfonate) diammonium salt radical scavenging test of these extracts was in accordance of the result of 2,2-diphenyl-1-picrylhydrazyl test. The antioxidant properties of these extracts probably explain partly, the use of these plants in traditional medicine for the treatment of infectious diseases and inflammations.     

Investigation of biological activity of polar extracts isolated from Phlomis crinita Cav ssp. mauritanica Munby

The lyophilized infusion, the methanol, the ethyl acetate, and the total oligomer flavonoid (TOF)-enriched extracts prepared from the dried leaves of Phlomis crinita Cav. ssp. mauritanica Munby were investigated for the contents of flavonoids, tannins, coumarines and steroids. Antibacterial activity was investigated toward five bacterial strains. An inhibitory effect was observed against Staphyllococcus aureus and Enterococcus feacalis, and the minimal inhibitory concentrations ranged from 2.5 to 5 mg/mL of extract. The tested extracts exhibit an important free radical scavenging activity toward the 1,1-diphenyl 2-picrylhydrazyl (DPPH) free radical; with IC₅₀ values of 30.5, 6, 32, and 31.5 μg/mL, respectively, in the presence of lyophilized infusion, the TOF, the methanol, and the ethyl acetate extracts. Genotoxic and antigenotoxic properties of the different extracts were studied by using the SOS chromotest with Escherichia coli PQ37. The lyophilized infusion and TOF extracts obtained from P. crinita ssp. mauritanica showed no genotoxicity, whereas methanol and ethyl acetate extracts are considered as marginally genotoxic. On the other hand, we showed that each extract inhibited the mutagenicity induced by aflatoxin B1 (AFB1) (10 μg/assay) and nifuroxazide (NF) (10 μg/assay). The ethyl acetate extract showed the strongest level of protection toward the genotoxicity induced by both directly and indirectly genotoxic NF and AFB1. These tests proved that the lyophilized infusion possesses an antiradical activity likewise, it showed no genotoxic effect; that is why we choose this extract to assess its antiulcerogenic activity by using an ethanol-induced ulcerogenesis model in the rat. This test demonstrates that 300 mg/kg of a P. crinita ssp. mauritanica lyophilized infusion was more effective than the reference compound, cimetidine.     

In vitro studies to assess the antidiabetic,antiperoxidative, and radical scavenging potential of Stereospermum colais

Context: Stereospermum colais (Buch.-Ham. ex Dillw.) Mabberley (Bignoniaceae), which has traditional medicinal properties, is distributed all over deciduous forests. In spite of its many uses, the antidiabetic, antiperoxidative and radical scavenging activities of this species have not been assessed, and its chemical composition is scarcely known.

Objective: Antidiabetic, antiperoxidation, xanthine oxidase (XO) inhibition, and radical scavenging activities of acetone and methanol extracts of Stereospermum colais roots were investigated. Protective effects of Stereospermum colais root extract in stabilizing sunflower oil was also examined.

Materials and methods: The protective effect of acetone (ASC) and methanol (MSC) extracts of Stereospermum colais root for the potential inhibition of α-glucosidase and α-amylase enzymes were studied by in vitro method. Glycation inhibitory activity was also studied to inhibit the production of glycated end products.

Results: Compared with acarbose, ASC showed a strong inhibitory activity against α-glucosidase (IC₅₀ 61.21 µg/mL) and a moderate inhibitory activity against α-amylase (IC₅₀ 681.08 µg/mL). Glycation inhibitory activity of Stereospermum colais root extracts by using an in vitro glucose-bovine serum albumin (BSA) assay was also done and compared with standard gallic acid. ASC also shows high XO inhibition potential, free radical scavenging activities, and low p-anisidine value indicates the high medicinal potency of Stereospermum colais root.

Discussion and conclusion: These results suggest that the extract of Stereospermum colais may be interesting for incorporation in pharmaceutical preparations for human health, since it can suppress hyperglycaemia, and or as food additives due to its antiradical efficiency.     

In vitro assessment of selected Korean plants for antioxidant and antiacetylcholinesterase activities

Context: Antiacetylcholinesterase (AChE) drugs have been a main therapeutic treatment for Alzheimer’s disease because increased AChE levels play a key role in reducing neurotransmission.

Objectives: Extracts from 35 Korean plants were selected and screened for antioxidant and anti-cholinesterase activity to explore new sources derived from Korean natural resources that could be used as AD therapeutic agents.

Materials and methods: The antioxidant effect of extracts from 35 selected Korean plants was determined using two most common free radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS). Additionally, the effect of extracts, identified as antioxidants, on acetylcholinesterase inhibition was assessed by an acetylcholinesterase assay kit.

Results: Out of 36 extracts of 35 plants tested, Oenothera biennis L. (9.09?μg/mL), Saururus chinensis (Lour.) Baill. (9.52?μg/mL) and Betula platyphylla var. japonica (9.85?μg/mL) showed strong DPPH scavenging activity. Twelve other extracts also exerted moderate free radical scavenging activities with IC₅₀ values ranging from 10 to 50?μg/mL. Antioxidant capacity detected by ABTS assay was only significant in O. biennis (23.40?μg/mL), while the other extracts were weak or unable to reduce the production of ABTS. Based on the antioxidant activities of these plant extracts, 19 extracts with IC₅₀ values less than 100?μg/mL in DPPH assay were selected for further AChE inhibition assay. Among the extracts tested, the IC₅₀ value for Prunella vulgaris var. lilacina NAKAI (18.83?μg/mL) in AChE inhibitory activity was the lowest, followed by O. biennis (20.09?μg/mL) and Pharbitis nil Chosy (22.79?μg/mL).

Conclusions: Considering complex multifactorial etiology of AD, the extracts of P. vulgaris var. lilacina (aerial part), O. biennis (seed) and P. nil (seed) may be safe and ideal candidates for future AD modifying therapies.