In vitro and in silico assessment of antidiabetic and antioxidant potencies of secondary metabolites from Gymnema sylvestre.

This study investigated the chemical constituents, antioxidant potential, and in vitro and in silico antidiabetic activity of Gymnema sylvestre. Column chromatography and spectroscopic techniques identified twelve compounds from the methanol extract, including 4 sterols (1-4), 5 triterpenoids (5-9), and 3 flavonoids (10-12). The chemophenetic significance of all compounds was also investigated. The antioxidant capacity of the extract and compounds (1-4) was evaluated using FRAP and DPPH assays. The extract exhibited strong free radical scavenging activity (IC50 = 48.34 µg/mL), while compounds (1-4) displayed varying degrees of efficacy (IC50 = 98.30-286.13 µg/mL). The FRAP assay indicated significant reducing power for both extract and compounds (58.54, 47.61, 56.61, and 49.11 mg Eq.VitC/g for extract and compounds 1 & 2, 3, and 4, respectively). The antidiabetic potential was assessed through α-amylase and α-glucosidase enzyme inhibition assays. The crude extract demonstrated the most potent inhibition (IC50 = 218.46 and 57.42 µg/mL for α-glucosidase and α-amylase respectively) suggesting its potential for managing postprandial hyperglycaemia. In silico studies employed molecular docking and dynamics simulations to elucidate the interactions between identified compounds and α-amylase/α-glucosidase enzymes. The results revealed promising binding affinities between the compounds and target enzymes, with compound 6 demonstrating the highest predicted inhibitory activity with -10 kcal/mol and -9.1 kcal/mol for α-amylase and α-glucosidase, respectively. This study highlights the presence of diverse bioactive compounds in Gymnema sylvestre. The extract exhibits antioxidant properties and inhibits carbohydrate-digesting enzymes, suggesting its potential as a complementary therapeutic approach for managing hyperglycaemia associated with type 2 diabetes.

Antileishmanial and Antiplasmodial Activities of Secondary Metabolites from the Root of Antrocaryon klaineanum Pierre (Anacardiaceae).

Antrocaryon klaineanum is traditionally used for the treatment of back pain, malaria, female sterility, chlamydiae infections, liver diseases, wounds, and hemorrhoid. This work aimed at investigating the bioactive compounds with antileishmanial and antiplasmodial activities from A. klaineanum. An unreported glucocerebroside antroklaicerebroside (1) together with five known compounds (2-6) were isolated from the root barks of Antrocaryon klaineanum using chromatographic techniques. The NMR, MS, and IR spectroscopic data in association with previous literature were used for the characterization of all the isolated compounds. Compounds 1-4 are reported for the first time from A. klaineanum. The methanol crude extract (AK-MeOH), the n-hexane fraction (AK-Hex), the dichloromethane fraction (AK-DCM), the ethyl acetate fraction (AK-EtOAc), and compounds 1-6 were all evaluated for their antiparasitic effects against Plasmodium falciparum strains susceptible to chloroquine (3D7), resistant to chloroquine (Dd2), and promastigotes of Leishmania donovani (MHOM/SD/62/1S). The AK-Hex, AK-EtOAc, AK-MeOH, and compound 2 were strongly active against Dd2 strain with IC50 ranging from 2.78 ± 0.06 to 9.30 ± 0.29 µg/mL. Particularly, AK-MeOH was the most active-more than the reference drugs used-with an IC50 of 2.78 ± 0.06 µg/mL. The AK-EtOAc as well as all the tested compounds showed strong antileishmanial activities with IC50 ranging from 4.80 ± 0.13 to 9.14 ± 0.96 µg/mL.

Antioxidant content and activity of stem and leaf extracts of Gouania longipetala Hemsl. (Rhamnaceae).

Background: Gouania longipetala Hemsl. is a scandent shrub used in traditional medicine for the management of different ailments such as gout, female infertility, heart diseases, diabetes, and malaria. Pathophysiology of the diseases is generally associated with oxidative stress. Antioxidant properties of G. longipetala have not yet been well elucidated. Aims: This study aimed to evaluate the antioxidant content and antioxidant activity of methanol extracts from the plant's stems and leaves. Materials and methods: Methanol extracts from the plant stems and leaves were screened for phytochemical components with antioxidant properties (Vitamin C, total phenolics, and flavonoids). The antioxidant reducing power of the extracts as well as its effects on lipid peroxidation and catalase were also evaluated in vitro using biochemical assays. Results: Leaf extract was richer than stem extract in different antioxidants such as Vitamin C, phenolics, and flavonoids. Both leaf and stem extracts showed similar inhibitory effect on lipid peroxidation and stimulatory effect on catalase activity, while leaf extract had higher ferric antioxidant effect than stem extract. Conclusion: Both extracts from G. Longipetala possessed antioxidant content, though activities with leaf extract displayed higher antioxidant properties than stem extract.

Antiproliferative activity of semisynthetic xylopic acid derivatives.

Two ent-kaurene diterpenoids, ent-15-ß-acetyloxy-kaur-16-en-19-oic acid (xylopic acid) 1 and ent-7-oxo-kaur-16-en-19-oic acid 2 were isolated from the fruits of Xylopia aethiopica. Chemical manipulation of xylopic acid yielded ent-kaurane derivatives 3, 4, 5, and 6. Their structures were elucidated by spectroscopic analysis, including 1 D- and 2 D-NMR spectroscopies. The antiproliferative activities of compounds 1, 2, 3, 4, and 6 were tested on breast MCF7 and SkBr3, endometrial Ishikawa, ovarian BG-1, mesothelioma IST-MES1 and hepatocellular HepG2 human tumor cells, and on mammalian MRC-10 fibroblast cells. Ketone 2 showed significant antiproliferative activity against MFC7 human breast cancer cells (IC50 = 3 ± 1 µM) and A549 pulmonary adenocarcinoma (8 ± 1 µM), that was higher than the well-known anti-cancer agent cisplatin (IC50 = 19 ± 3 and 15 ± 4 µM, respectively).[Formula: see text].