A review on the bioactive compounds of Rhus chinensis Mill. native to the Sikkim Himalayas

BackgroundRanunculus arvensis L. (R. arvensis) has long been used to treat a variety of medical conditions such as arthritis, asthma, hay fever, rheumatism, psoriasis, gut diseases and rheumatic pain. Here, we screened R. arvensis for antioxidant activity, phytochemical and high performance liquid chromatography (HPLC) analyses.MethodsThe chloroform, chloroform:methanol, methanol, methanol:acetone, acetone, methanol:water and water extracts of R. arvensis were examined for DPPH (1, 1-diphenyl-2-picrylhydrazyl) free radical scavenging assay, hydrogen peroxide scavenging assay, phosphomolybdenum assay, reducing power assay, flavonoid content, phenolic content and high performance liquid chromatography analysis.ResultsSignificant antioxidant activity was displayed by methanol extract (IC50 34.71 ± 0.02) in DPPH free radical scavenging assay. Total flavonoids and phenolics ranged 0.96–6.0 mg/g of extract calculated as rutin equivalent and 0.48–1.43 mg/g of extract calculated as gallic acid equivalent respectively. Significant value of rutin and caffeic acid was observed via high performance liquid chromatography.ConclusionsThese results showed that extracts of R. arvensis exhibited significant antioxidant activities. Moreover, R. arvensis is a rich source of rutin, flavonoids and phenolics.

Antioxidant activities of enzymatic extracts from brown seaweeds

Canarium odontophyllum, known locally as “Kembayau” or “Dabai”, is a highly seasonal fruit which is popular among local people in Borneo Island. This study was conducted to determine the antioxidant activity, phytochemicals (total phenolic, total flavonoid, total anthocyanin and total carotenoid contents) and acetylcholinesterase inhibitor potential of extracts of the flesh and seed of this fruit. C. odontophyllum was collected in Beaufort, Sabah, Malaysian Borneo and subsequently freeze-dried and extracted using 80% methanol and distilled water. Antioxidant activities were analyzed using DPPH free radical scavenging, ABTS decolourization and FRAP (Ferric reducing / antioxidant power) assays. Anti-Alzheimer’s potential was determined using acetylcholinesterase enzyme inhibition assay. The results showed that the total phenolic and flavonoid contents were higher in the flesh of C. odontophyllum with the values of 11.96 ± 0.05 mg gallic acid equivalent (GAE)/g and 10.11 ± 1.54 mg rutin equivalent (RU)/g, respectively. Total anthocyanin and carotenoid content were also higher in the flesh of the fruit with the values of 12.75 ± 0.28 mg/100g and 2.84 ± 0.11 mg/100g. The flesh of the fruit also showed higher antioxidant activity as assessed using DPPH, ABTS and FRAP assays. However, anti-cholinesterase activity was higher in the seed of C. odontophyllum which showed that possible other phytochemical content (besides phenolic and flavonoid) which might responsible to the observed effects. The same trend of phytochemicals, antioxidant and anti-cholinesterase activity were also observed in the distilled water extract. These findings suggested that C. odontophyllum is not only nutritious but also displayed potential pharmacological properties.

In the present study different extracts of Acacia nilotica leaves were tested for total phenolic and flavonoid content, antioxidant activities. Extracts were also subjected to phytochemical analysis using GC-MS analytical techniques. Antioxidant potential was determined using DPPH free radical scavenging assay, hydrogen peroxide scavenging assay, metal chelating assay and β-carotene-linoleic acid assay. Methanol extract exhibited maximum antioxidant activity (94.3 %) followed by the ethyl acetate extract (90.7 %). Total phenolic content was highest in the methanol extract and total flavonoid content in ethyl acetate extract. Positive correlation was observed between the total phenolic content, total flavonoid content and antioxidant activities. Principle component analysis revealed correlation between different parameters. D-pinitol, catechol, N-2,4-dnp-L-arginine, squalene, R-limonene, 9-octadecen-12-ynoic acid, methyl ester, androst-5-en, 2(1-H)-quinolinone, heptacosane, 2-pentadecanone, 6,10,14-trimethyl, linoleic acid, γ-linoleic acid, palmitic acid, stearic acid were the main compounds present in different extracts of Acacia nilotica leaves and could serve as a possible source of natural antioxidants in food and pharmaceutical industry.

BackgroundThe use of plants and their derived substances increases day by day for the discovery of therapeutic agents owing to their versatile applications. Current research is directed towards finding naturally-occurring antioxidants having anticancer properties from plant origin since oxidants play a crucial role in developing various human diseases. The present study was designed to investigate the antioxidant and anticancer properties of Sygygium fruticosum (Roxb.) (abbreviated as SF).MethodsThe dried coarse powder of seeds of SF was exhaustively extracted with methanol and the resulting crude methanolic extract (CME) was successively fractionated with petroleum ether, chloroform and ethyl acetate to get petroleum ether (PEF), chloroform (CHF), ethyl acetate (EAF) and lastly aqueous (AQF) fraction. The antioxidant activities were determined by several assays: total antioxidant capacity assay, DPPH free radical scavenging assay, hydroxyl radical scavenging assay, ferrous reducing antioxidant capacity and lipid peroxidation inhibition assay. The in vivo anticancer activity of SF was determined on Ehrlich’s Ascite cell (EAC) induced Swiss albino mice.ResultsAll the extractives showed strong antioxidant activities related to the standard. The total antioxidant capacity (TAC) of the fractions was in the following order: EAF>AQF>CME>PEF>CHF. The TAC of EAF at 320 μg/mL was 2.60±0.005 which was significantly higher (p < 0.01) than that of standard catechin (1.37 ± 0.005). The ferrous reducing antioxidant capacity of the extracts was in the following order: EAF>AQF>CME>AA>CHF>PEF. In DPPH free radical scavenging assay, the IC50 value of EAF was 4.85 μg/mL, whereas that of BHT was 9.85 μg/mL. In hydroxyl radical scavenging assay and lipid peroxidation inhibition assay, the EAF showed the most potent inhibitory activity with IC50 of 43.3 and 68.11 μg/mL, respectively. The lipid peroxidation inhibition assay was positively correlated (p < 0 .001) with both DPPH free radical scavenging and hydroxyl radical scavenging assay. The total phenolic contents of SF were also positively correlated (p < 0 .001) with DPPH free radical scavenging, hydroxyl radical scavenging and lipid peroxidation inhibition assay. Based on antioxidant activity, EAF was selected for cytotoxic assay and it was found that EAF inhibited 67.36% (p < 0.01) cell growth at a dose of 50 mg/kg (ip) on day six of EAC cell incubation.ConclusionsOur results suggest that EAF of seeds of SF possess significant antioxidant and moderate anticancer properties. Seeds of SF may therefore be a good source for natural antioxidants and a possible pharmaceutical supplement.

Background: Ethnobotanical survey in the rural villages in Nepal revealed that the fruits of Rhus chinensis Mill. have been using for the treatment of diarrhea and dysentery. Objective: To evaluate antimicrobial and antioxidant effects, and identification of chemical constituents in the fruits of R. chinensis. Materials and Methods: Phytochemical screening was performed on the hexane and 70% methanolic extracts of the sample followed by gas chromatographymass spectrometry (GC-MS). Total phenolic content (TPC) was estimated using Folin-Ciocalteu method. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical and hydrogen peroxide scavenging assays were used to evaluate the antioxidant capacity. Antibacterial effect was estabilished by the Agar well diffusion assay. Results: A total of 30 compounds belonging to phenolics, anhydrides, aldehydes, fatty acids and hydrocarbons were identified in the extracts. The TPC value of 123.52±1.29 mg GAE/g dry extract was estimated. IC50 value of 135.54±0.82 μg/mL was calculated in DPPH free radical scavenging assay. Scavenging of 42.69±0.1% DPPH free radical and 63.20±1.48% hydrogen peroxide at 100 μg/mL concentration of 70% methanolic extract were estimated. The maximum zone of inhibition (ZOI) observed was 23.00±0.57 mm against Escherichia coli at loading dose of 5 mg of the extract. Conclusion: All together 30 compounds were identified in the fruits. The extracts efficiently inhibited the growth of E. coli and Shigella dysenteriae verifying the rural knowledge. At the same time, the extracts displayed efficient antioxidant activity. The phytochemicals identified were responsible for these activities.

The present research work was carried out to evaluate the antioxidant potential and antiradical property of methanolic extract of Uncaria gambir. Antioxidant and radical scavenging activity were determined by using different in vitro assays including reducing power assay, superoxide anion scavenging activity assay, hydroxyl radical scavenging activity assay, nitric oxide scavenging activity assay, DPPH free radical scavenging assay and hydrogen peroxide method. Preliminary phytochemical screening revealed that the extract of U. gambir possesses flavonoids, alkaloids and phenolic materials. In the present investigation, quantitative estimation of flavonoids content and phenolic content was also carried out by colorimetric methods, using aluminium chloride and Folin–Ciocalteu reagent method, respectively, to establish relationship between antioxidant activity and total phenolics and flavonoid contents. The total phenolic and flavonoid contents were found to be 18.37±2.79 mg gallic acid equivalents (GAE)/g dry weight and 5.82±2.23 mg rutin equivalents (RE)/g dry weight, respectively. The extract showed significant antioxidant activity in a dose-dependent manner in all the assays. The IC50 values of all parameters were determined. Ascorbic acid was used as standard. The results obtained in the present study indicated that U. gambir extract could be a potential source of natural antioxidant. Key words: Antioxidant, ascorbic acid, DPPH, hydroxyl radical, Uncaria gambir

BACKGROUND: The ancient medicinal herb known as croton joufra, which originated in northeastern India, is still used today in folk medicine to treat a wide range of illnesses. Phytochemicals are naturally occurring active compounds found in plants that provide various biological activities in humans and animals. METHODS: Soxhlet extraction was used to prepare extracts of three different solvents (chloroform, methanol, and 50% ethanol). Total alkaloid and total tannin were calculated using the simple titrimetric method. Folin and Ciocalteu’s colorimetric method was used to estimate the total phenol content. In vitro antioxidant activity was evaluated using three different methods: DPPH free radical scavenging assay, hydrogen peroxide scavenging assay, and ABTS radical scavenging assay. Heat-induced bovine serum albumin (BSA) denaturation assay was used for evaluating in vitro anti-inflammatory activity. In vitro antidiabetic activity was determined by alpha-amylase inhibition assay. RESULTS: Among these three solvent extracts, a high amount of yield was found in the hydroalcoholic extract. Based on the qualitative and quantitative tests of plant extracts, it was shown that hydroalcoholic extracts contained a higher amount of alkaloids (162.33 ± 0.96 mg/g of dry extract), phenols (205.30 ± 0.95 mg/g of dry extract of gallic acid equivalent), and tannins (214.50 ± 0.95mg/g of dry extract) compared to chloroform and methanolic extract. Among these three extracts, the hydroalcoholic extract and methanolic extract have better antioxidant, anti-inflammatory, and antidiabetic activities than standard drugs such as ascorbic acid, aspirin, and metformin. CONCLUSION: From the results of the experiment, it was concluded that among these three solvent extracts, the hydroalcoholic (50% ethanol) extract contains substantial amounts of secondary metabolites such as alkaloids, phenols, and tannins. The hydroalcoholic extract also has promising pharmacological properties. So the hydroalcoholic extract of Croton joufra leaves may be used as a raw material for drug development.

BackgroundMerremia umbellata subsp. orientalis (Hallier f.), commonly known as Sapussunda in Bengali, is used in folk medicine for the treatment of different diseases such as helminthiasis, rheumatism, fever, wounds, burns, sores, management of pain due to cut etc. The present study was carried out to evaluate the antioxidant, analgesic and anthelmintic activities of ethanolic extract of stems of Merremia umbellate (ESMU).MethodsPhytochemical investigation was carried by using standard chemical test as described in literatures. In vitro free radical scavenging activity of ethanolic extract was quantitatively estimated using DPPH (2,2-diphenyl-1-picrylhydrazyl) free radicals scavenging assay. Total phenolic and tannin content were spectrophotometrically determined by Folin Ciocalteu reagent whereas the flavonoid was determined by aluminum chloride colorimetric assay. Acetic acid induced writhing method and hot plate method, using Swiss albino mice, were used to investigate the analgesic effect of ESMU whereas in-vitro anthelmintic activity was evaluated against Haemonchus contortus (Nematode) of cattle.ResultsPhytochemical screening revealed that the ESMU contain reducing sugar, alkaloids, flavonoids, tannins, gums, steroid, xanthoproteins, glycosides and acidic compound. In DPPH free radical scavenging assay, the extract showed scavenging potential with IC50 value of 161.81 μg/mL. Total phenolics, tannin and flavonoid content of crude extract were found to be 87.4 mg GAE/gm, 68.2 mg GAE /gm and 64.27 mg QE/gm respectively. Significant (P < 0.001) analgesic effect was observed in acetic acid induced writhing method at both doses 250 and 500 mg/kg. Similar effect was found in hot plate method that measures antinociceptive effect in response to heat stimuli. The ESMU also exhibited significant (P < 0.001) anthelmintic activity in a concentration dependent manner. The paralysis time and time for death were recorded as 9.30, 8.62 and 7.65 min and 19.58, 18.82, and 16.43 min respectively at a concentration of 25, 50 and 100 mg/mL respectively.ConclusionBased on the results obtained in this study clearly strengthen the traditional uses of M. umbellate stems as antioxidant, antinociceptive and anthelmintic. Therefore, this result suggested that the stems of Merremia umbellata might be a potential source of useful bioactive compounds.

Ethnobotanical survey in the Magar villages in Nawalpur district, Gandaki province, Nepal revealed that root of Phanera vahlii (Wight &amp; Arn.) Benth, bark of Rhododendron arboreum Sm. and flower of Woodfordia fruticosa (L.) Kurz, have been in use for diarrhea and dysentery. Root of Thalictrum foliolosum DC. has been used for the treatment of rheumatic pain. The study aimed to evaluate antimicrobial and antioxidant effects as well as total phenol content in Phanera vahlii, Rhododendron arboreum, Woodfordia fruticosa and Thalictrum foliolosum. Total phenol content (TPC) was estimated using Folin-Ciocalteu method. 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) free radical and hydrogen peroxide scavenging assays were used to evaluate the antioxidant capacity. Antibacterial effect was established by the Agar well diffusion assay. The minimum TPC value of 65.78±3.44 mg GAE/g dry extract was estimated in 70% methanolic extract of Thalictrum foliolosum and maximum TPC value of 258.40±6.26 mg GAE/g dry extract was estimated in 70% methanolic extract of Woodfordia fruticosa. IC50 value range 21.59±0.26 µg/ml in Rhododendron arboreum to 1124.79±3.69 µg/ml in Thalictrum foliolosum was calculated in DPPH free radical scavenging assay. Scavenging of DPPH free radical range from 12.40% to 94% at 100 µg/mL concentration of 70% methanolic extracts were estimated and scavenging of hydrogen peroxide range from 36% to 73%. The maximum zone of inhibition (ZOI) against Escherichia coli at loading dose of 5 mg of the extract observed was 18±0.73 mm by 70% methanolic extract of Woodfordia fruticosa and its minimum inhibition concentration (MIC) was &lt;1.56 µg /ml.The extracts efficiently inhibited the growth of Escherichia coli verifying the rural knowledge. At the same time, the extracts displayed efficient antioxidant activity.

A series of ortho-hydroxypyridine-4-ones were prepared in high yields and evaluated for antioxidant and iron chelating activities. N1-H hydroxypyridinones Va, Vb, and Ve were the best radical scavengers in DPPH free radical scavenging assay. Compound Vb was proved to be the most potent compound in hydrogen peroxide scavenging assay. All of the synthesized compounds had very close chelating ability, compounds containing N1-CH3 hydroxypyridinone ring were stronger chelating agents.

The aim of present study was to focus on the impact of spatial and different climatic conditions on phytochemical diversity and antioxidant potential of aqueous leaf extracts of Aloe vera collected from different climatic zones of India. Crude aqueous extracts of Aloe vera from different states varied in climatic conditions of India were screened for phytochemical diversity analysis and in vitro antioxidant activity. Phytochemical analysis was performed with the help of Fourier Transform Infrared (FTIR) Spectroscopy. DPPH free radical scavenging assay, metal chelating assay, hydrogen peroxide scavenging assay, reducing power assay and β carotene-linoleic assay were used to assess the antioxidant potential of Aloe vera aqueous leaf extracts. FTIR analysis in present study showed presence of various phytoconstituents from different Aloe vera samples. All antioxidant assays revealed that Highland and Semi-arid zone samples possessed higher antioxidant activity whereas Tropical zone samples possessed minimum. It could be concluded that different agro-climatic conditions have effects on phytochemical diversity and antioxidant potential of Aloe vera plant. This study demonstrated that antioxidant activity was higher in Aloe vera plants grown in Northern India in comparison to Southern India. Study also concluded that more phytochemicals are produced in plants under cold stress conditions. Aloe vera can be a potential source of novel natural antioxidant compounds.

Chalcones and aurones are found to possess high antioxidant activity. They are known to inhibit tyrosinase enzyme involved in synthesis of melanin. A series of substituted chalcones and aurones have been synthesized and tested for their antioxidant activity. Postulated structures of the newly synthesized compounds are in agreement with their IR, 1H NMR and MS. The docking study of this series of compounds was performed on crystal structure of tyrosinase from Bacillus megaterium using VlifeMDS 3.0 software. Antioxidant activity data obtained from four methods, i.e., DPPH free radical scavenging assay, iron chelating assay, reducing power assay and hydrogen peroxide scavenging assay, indicate that the activity increased with dimethylamino group on position 4/4′ of ring B as evident from the significant activities of SB7 and SB8 in case of chalcones and aurones, respectively. The poor activities of SB4 and SB5 in DPPH scavenging ability and reducing power assays could be because of presence of chloro group on B-ring. Furthermore, the activity is facilitated with the presence of hydroxyl group on A-ring (preferably on position 5/5′) in both chalcones and aurones.

BackgroundThe aim of the present study was to analyse the effect of climate change on phytochemicals, total phenolic content (TPC) and antioxidant potential of methanolic extracts of Aloe vera collected from different climatic zones of the India.MethodsCrude methanolic extracts of A. vera from the different states of India were screened for presence of various phytochemicals, total phenolic content and in vitro antioxidant activity. Total phenolic content was tested by Folin–Ciocalteau reagent based assay whilst DPPH free radical scavenging assay, metal chelating assay, hydrogen peroxide scavenging assay, reducing power assay and β carotene-linoleic assay were used to assess the antioxidant potential of A. vera methanolic leaf extracts.ResultsAlkaloids, phenols, flavonoids, saponins, and terpenes were the main phytochemicals presents in all accessions. A significant positive correlation was found between TPC and antioxidant activity of different accessions. Extracts of highland and semi-arid zones possessed maximum antioxidant potential. Accessions from tropical zones showed the least antioxidant activity in all assays.ConclusionsIt could be concluded that different agro-climatic conditions have effects on the phytochemicals, total phenolic content (TPC) and antioxidant potential of the A. vera plant. The results reveal that A. vera can be a potential source of novel natural antioxidant compounds.

Green Tea (Camellia sinensis L.) is renowned for its therapeutic properties due to its phenolic compounds. Extracts from plants with high polyphenol content possess antioxidant properties that neutralize free radicals involved in the oxidation of various molecules. This study investigated the total phenolic and flavonoid content, 1,1-diphenylpicrylhydrazyl (DPPH) radical scavenging activity (RSA), and ferric reducing antioxidant power (FRAP) of commercially available green tea leaves for potential use in the green synthesis of silica nanoparticles. The antioxidant activity of green tea leaves demonstrates its reducing power, which is crucial for utilizing its extract in nanoparticle synthesis. Gallic acid and quercetin served as standards in the Folin–Ciocalteu and aluminum chloride methods, respectively, to measure total phenolic and flavonoid concentrations. To determine antioxidant content ascorbic acid and gallic acid were standards for the DPPH free radical scavenging and FRAP assays. Fourier Transform Infrared (FT-IR) spectra was performed to evaluate the green tea extract. The results revealed green tea leaves exhibited high phenolic, flavonoid content and significant antioxidant activity. The presence of few notable vibrational bands in FT-IR graph also confirmed the existence of chemical substances that are associated with antioxidant qualities (polyphenols, flavonoids). Indicating that the green tea leaf extract can act as an effective reducing and capping agent in the synthesis of silica nanoparticles.