Primary investigating chemical constituents of bioactive extract from Centrostachys aquatica (R.Br.) Wall. ex Moq.-Tand.

This study is aimed to screen the biological activities and chemical composition to find evidences for potential medicinal applications of Centrostachys aquatica in the Mekong Delta. Crude methanol extract and subextracts in n-hexane, ethyl acetate, and acetone from Centrostachys aquatica were tested bioactivities. The methanol extract, n-hexane and ethyl acetate subextracts exhibited antimicrobial activity with corresponding MIC values of 200, 100 and 200 µg/mL, respectively. The ethyl acetate subextract was inhibited cytotoxicity against cancer cell line LU-1 with IC50 of 27.66 µg/mL. None of the extracts showed antioxidant ability. Three known secondary metabolites including oleanolic acid (1), 20(E)-hydroxy-b-ecdysone (2), and b-spinasterol (3) were isolated for the first time from the bioactive (ethyl acetate) subextract of Centrostachys aquatica. Their structures were elucidated by modern spectra as MS, NMR and comparison with published data.

Identification of Polyphenolics from Loranthus globosus as Potential Inhibitors of Cholinesterase and Oxidative Stress for Alzheimer’s Disease Treatment

Mistletoes are considered to be the potential medicinal herbs due to their rich traditional uses. Loranthus globosus is a Bangladeshi mango mistletoe that has been reported as folk medicine for various ailments and diseases. In an attempt to explore its effectiveness in Alzheimer’s disease (AD), we investigated the antioxidant and acetylcholinesterase inhibitory activity of L. globosus. We report that the crude methanol extract (CME) of the plant contains a good amount of polyphenolics and possesses antioxidant and cholinesterase inhibitory activity. Fractionation of CME with solvents of varying polarity revealed the highest activity and polyphenolic content in the ethylacetate fraction (EAF). Correlation analysis revealed a significant ( P < 0.05 ) association of polyphenolics with the antioxidant and cholinesterase inhibitory properties. Using column chromatography with diaion resin, the polyphenolics (EAF-PP) were isolated from the EAF that displayed the potent antioxidant and cholinesterase inhibitory activities. Kinetic analysis showed that EAF-PP exhibited a competitive type of inhibition. A total of thirty-six compounds including catechin and its different derivatives were identified in the EAF-PP by LC/MS analysis. Bioactivity-guided separation approach afforded the isolation of the two major active compounds catechin and catechin dimer from the EAF-PP. Hence, EAF-PP represents a potential source of antioxidants and cholinesterase inhibitors, which can be used in the management of AD.

Phytochemical and safety evaluations of Diospyros mespiliformis, and in silico evaluations of drug-likeness, pharmacokinetics and acute toxicity of its bioactive compound (Diospyrin)

Diospyros mespiliformis is among the popular multipurpose tropical fruit trees, commonly used as herbal medicines. However, due to the lack of adequate scientific data on the safety of this plant, the present study was conducted to determine the phytochemical compositions and acute toxicity profile of the crude methanol extract of D. mespiliformis. In addition, diospyrin, a bioactive compound from the plant was evaluated for in silico drug-likeness, pharmacokinetics (PKs) and acute toxicity. The phytochemical contents of the plant were quantified using standardized protocols while the 50% lethal dose (LD50) was evaluated using Lorke’s methods. Results revealed that flavonoids (265.46±0.32 mg/g) are the most abundant phytochemical in methanol leaf extract of D. mespiliformis, followed by alkaloids (224.56±0.19 mg/g) and phenols (191.82±0.04 mg/g) while saponins (7.90±0.32 mg/g) was the least abundant phytochemical. The plant extract has LD50 of > 5000 mg/kg in rats. No death was recorded throughout the study period. Similarly, no behavioural changes were observed in animals dosed with the crude extract at 10 -2900 mg/kg BW. Animals administered 5000 mg/kg BW were hyperactive, restless, and displayed profused breathing which lasted only for 30 minutes after administrations. Diospyrin a bioactive compound from D. mespiliformis demonstrated good druglike candidates and exhibited a high safety profile as revealed by in silico study. In conclusion, the crude methanol extract of D. mespiliformis and its bioactive compound is well-tolerated and non-toxic to rats, and thus could be considered a safe medicinal plant for acute oral remedies

Prenylated Flavonoids and C-15 Isoprenoid Analogues with Antibacterial Properties from the Whole Plant of Imperata cylindrica (L.) Raeusch (Gramineae)

The local botanical Imperata cylindrica in Cameroon was investigated for its antibacterial potency. The methanol extract afforded a total of seven compounds, including five hitherto unreported compounds comprising three flavonoids (1–3) and two C-15 isoprenoid analogues (4 and 5) together with known derivatives (6 and 7). The novelty of the flavonoids was related to the presence of both methyl and prenyl groups. The potential origin of the methyl in the flavonoids is discussed, as well as the chemophenetic significance of our findings. Isolation was performed over repeated silica gel and Sephadex LH-20 column chromatography and the structures were elucidated by (NMR and MS). The crude methanol extract and isolated compounds showed considerable antibacterial potency against a panel of multi-drug resistant (MDR) bacterial strains. The best MIC values were obtained with compound (2) against S. aureus ATCC 25923 (32 µg/mL) and MRSA1 (16 µg/mL).

Phytochemical Composition, Antioxidant Activity, and Enzyme Inhibitory Activities (α-Glucosidase, Xanthine Oxidase, and Acetylcholinesterase) of Musella lasiocarpa

In this study, we aimed to investigate the chemical components and biological activities of Musella lasiocarpa, a special flower that is edible and has functional properties. The crude methanol extract and its four fractions (petroleum ether, ethyl acetate, n-butanol, and aqueous fractions) were tested for their total antioxidant capacity, followed by their α-glucosidase, acetylcholinesterase, and xanthine oxidase inhibitory activities. Among the samples, the highest total phenolic and total flavonoid contents were found in the ethyl acetate (EtOAc) fraction (224.99 mg GAE/g DE) and crude methanol extract (187.81 mg QE/g DE), respectively. The EtOAc fraction of Musella lasiocarpa exhibited the strongest DPPH· scavenging ability, ABTS·+ scavenging ability, and α-glucosidase inhibitory activity with the IC50 values of 22.17, 12.10, and 125.66 μg/mL, respectively. The EtOAc fraction also showed the strongest ferric reducing antioxidant power (1513.89 mg FeSO4/g DE) and oxygen radical absorbance capacity ability (524.11 mg Trolox/g DE), which were higher than those of the control BHT. In contrast, the aqueous fraction demonstrated the highest acetylcholinesterase inhibitory activity (IC50 = 10.11 μg/mL), and the best xanthine oxidase inhibitory ability (IC50 = 5.23 μg/mL) was observed from the crude methanol extract as compared with allopurinol (24.85 μg/mL). The HPLC-MS/MS and GC-MS analyses further revealed an impressive arsenal of compounds, including phenolic acids, fatty acids, esters, terpenoids, and flavonoids, in the most biologically active EtOAc fraction. Taken together, this is the first report indicating the potential of Musella lasiocarpa as an excellent natural source of antioxidants with possible therapeutic, nutraceutical, and functional food applications.

In vitro and In vivo Investigations Provide New Insights into Bioactivities of Blumea clarkei Hook.f. Leaves

As there is a resurgence of interest in plants as promising sources of new active pharmaceutical constituents, the present study has been designed to establish the preliminary biological activities of Blumea clarkei Hook.f. leaves. Here, the crude methanol extract of the leaves along with its organic and aqueous soluble fractions were subjected to different in vitro and in vivo assays. The ethyl acetate soluble fraction exhibited the highest total phenolic content (71.59 mg of GAE/gm of extract) and DPPH free radical scavenging (IC50 value 19.25 μg/ml) whereas another polar fraction; the aqueous soluble extractive showed the maximum cytotoxicity (LC50 value of 18.60 μg/ml) in the brine shrimp lethality assay. In membrane stabilizing activity evaluation, the inhibition of hypotonic solution and heat induced hemolysis were revealed maximum by the DCM (30.64%) and aqueous soluble fraction (39.15%), respectively while the crude methanol extract exhibited the highest thrombolytic potential (30.47% clot lysis). The central analgesic activity of the crude extract significantly increased the latent response time in tail-immersion method (p<0.001) at doses 200 and 400 mg/kg of body weight after 90 minutes of administration when compared to the control group. In acetic acid-induced writhing method, the plant extract showed prominent peripheral analgesia (p<0.001) with 47.54% and 65.57% inhibition at 200- and 400-mg/kg of body weight, respectively. In addition, a dose dependent hypoglycemic and antidiarrheal activities were also observed by the crude extract. Bangladesh Pharmaceutical Journal 24(2): 149-158, 2021

Phytochemical Analysis, Antioxidant and Cytotoxic Activities of Mucuna pruriens Leaves

Mucuna pruriens is a tropical legume native to Africa, India and Bangladesh and is widely cultivated in tropical countries. In this study, a crude methanolic extract of the leaves of M. pruriens was investigated for its chemical constituents and to explore the phenolic and flavonoid content, antioxidant, cytotoxic and antimicrobial activities using established protocols. From the ethyl acetate soluble fraction of the crude methanol extract, three known compounds namely ferulic acid (1), 2-(5-methoxy-1-benzofuran-3-yl)-N-ethylethanamine (2) and stizolamine (3) were isolated and their structures were elucidated by the analysis of NMR spectral data. The crude extract was found to possess phenolic content of 216.16 μg/g whereas the concentration of flavonoid was found to 214.8 μg/g expressed in quercetin standard. Free radicals generated through DPPH were neutralized by crude methanolic extract and the IC50 value was obtained as 19.63 μg/ml. Regression analysis during brine shrimp lethality test enumerated LC50 value of crude methanolic extract at 10.72 μg/ml and was significant compared to the positive standard. The crude methanolic extract of leaf of M. pruriens did not show any significant antimicrobial activity against the organisms used in our test. Dhaka Univ. J. Pharm. Sci. 20(1): 103-109, 2021 (June)

DECIPHERING THE PHARMACOLOGICAL INSIGHTS OF FRACTIONATED ELATOSTEMA PAPILLOSUM WED. AND HOLIGARNA LONGIFOLIA ROXB. THROUGH IN VITRO AND IN VIVO STUDIES

The present research intended to explore the biological activities, namely acute toxicity test and hypoglycemic as well as in vitro anti-arthritic along with the antibacterial activity of crude methanol extracts with its different soluble fractions like petroleum ether (PESF), carbon tetrachloride (CTCSF), chloroform (CSF) and aqueous soluble fraction (AQSF) of Holigarna longifolia and Elatostema papillosum. Phytochemical screening was performed by established protocols. Acute toxicity and hypoglycemic effects were performed in experimental and alloxan-induced diabetic rats. In vitro anti-arthritic and antibacterial activity were conducted by protein denaturation inhibitory and disc diffusion methods. It was observed that no rats exhibit any lethality types, which reveal the safety of plant fractionates. It was also seen that both plants' fractionates showed significant (p < 0.01) activity on hyperglycemia compared to standard. Upon investigation, it was observed that crude methanol and its CS fraction of E. papillosum and only CS fraction of H. longifolia significantly (p < 0.05) inhibited denaturation of bovine serum albumin protein compared to standard diclofenac sodium. Moreover, it was observed that crude methanol extract and its CS fraction of E. papillosum showed significant inhibitory action on all Gram-positive bacteria's growth. In contrast, the PES fraction highlighted an inhibitory zone of 26.7 and 24.7 mm, respectively, towards B. subtilis and S. aureus. This study provides some support to explain the traditional uses of H. longifolia and E. papillosum.

Bioactive chemical constituents, acute toxicity and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity of Polyalthia longifolia root

Polyalthia longifolia (masquerade tree) is a plant which is believed to possess varied pharmacological and therapeutic values among different populations. The present report investigated the phytochemical composition, proximate, acute toxicity and antioxidant potential of P. longfolia root. All analyses were carried out using established methods; the antioxidant activity of the crude methanol extract and its fractions (n-hexane and ethyl acetate) were examined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay while the total phenolic and flavonoid contents were assessed using the Folin-Ciocalteu and the aluminum chloride calibration methods respectively. The phytochemical analysis revealed the presence of alkaloids, carbohydrate, reducing sugars, tannins, saponins, flavonoids, phenolic compounds and protein in aqueous extract. The proximate analysis showed moisture content, total ash, alcohol extractive value, water extractive value, acid insoluble ash and water soluble ash at 8.80, 9.35, 3.28, 3.29, 2.27 and 7.29% respectively. The ethyl acetate fraction showed the highest antioxidant property compared to the n-hexane fraction and crude methanol extract in all assays conducted. Also, the methanol fraction was found to have the highest flavonoids and phenolic content among the extract and fractions. Oral administration of crude methanol extract of P. longifolia to Swiss mice was relatively non-toxic at a maximum dose of 5000 mg/kg. The root extract and fractions of P. longifolia indicated moderately high level of some phytochemicals with outstanding radical scavenging activity, and therefore substantiate its use as a conventional and comparatively non-toxic plant antioxidant.