In Vivo Antimalarial Activity of Leaf Latex of Aloe melanacantha against Plasmodium berghei Infected Mice.

BACKGROUND: Malaria is a major health concern in the world in general and developing countries in particular. Nowadays, the control of malaria has ended up steadily more complex due to the spread of drug-resistant parasites. Medicinal plants are the verifiable source of compelling antimalarial drugs. The present study was aimed to assess the in vivo antimalarial activity of leaf latex of A. melanacantha against Plasmodium berghei in mice. METHODS: Acute oral toxicity study of the leaf latex was assessed in mice up to a dose of 2,000 mg/kg. A four-day suppressive model was utilized to investigate the antimalarial activity of the plant. Three extract doses, 100, 200, and 400 mg/kg/day, doses of the plant leaf latex, chloroquine, 10 mg/kg (positive control) and distilled water, and 10 mL/kg (negative control) were administered to mice. Percent parasitemia suppression, packed cell volume, mean survival time, body weight, and rectal body temperature were used to determine antimalarial activity. RESULTS: Test groups treated with 100, 200, and 400 mg/kg of the latex showed a significant parasitemia suppression in dose dependent manner compared to the negative control with an IC50 of 22.63 mg/ml. Mice treated with 100, 200, and 400 mg/kg have shown parasitemia suppression of 14.86%, 29%, and 43.2%, respectively. The chemosuppression was significant (P < 0.05) at all doses compared to the negative control. Similarly, mice treated with 100 mg/kg, 200 mg/kg, and 400 mg/kg have shown a significant survival time compared to the negative control. At the same time, weight loss reduction was observed within the test groups treated with 100 mg/kg and 200 mg/kg of the latex while the test groups treated with 400 mg/kg had showed almost no weight loss reduction. The latex also reversed the PCV reduction significantly (P < 0.05) at 200 mg/kg and 400 mg/kg doses and prevented rectal temperature dropping significantly (P < 0.05) at all doses. CONCLUSION: The leaf latex of A. melanacantha has shown significant antimalarial activity against P. berghei in mice supporting the genuine traditional antimalarial usage of the plant.

Design, synthesis, and primary activity assays of baicalein derivatives as cyclin-dependent kinase 1 inhibitors.

Malignant tumor is a disease with high mortality. Traditional treatment methods have many disadvantages, such as side-effects, drug resistance. Because cyclin-dependent kinase 1 (CDK1) plays an indispensable role in cell cycle regulation, it became an attractive target in rational anti-cancer drug discovery. Herein, we reported a series of baicalein derivatives, which remarkably repressed the proliferation of MCF-7 tumor cells and the activity of CDK1/cyclin B kinase. Among them, compound 4a displayed better inhibition rate than flavopiridol against MCF-7 proliferation at the concentration of 50 µg/ml, comparable to compound CGP74514A, while compound 3o possessed the best activity against CDK1/cyclin B kinase (IC50  = 1.26 µM). The inhibitory activities toward the kinase well correlated with anti-proliferative activities. Molecular docking results suggested that compound 3o can interact with the key amino acid residues, E81, L83, and D146, of CDK1 through hydrogen bond just like flavopiridol does. And it can also form an extra hydrogen bond with D146 by its introduced 7-acrylate group, which flavopiridol does not have. These findings proved that baicalein derivatives can be used as CDK1 inhibitors fighting against cancer.

Antibacterial Potential of Aloe weloensis (Aloeacea) Leaf Latex against Gram-Positive and Gram-Negative Bacteria Strains.

OBJECTIVE: To evaluate the antibacterial effects of the leaf latex of Aloe weloensis against infectious bacterial strains. METHODS: The leaf latex of A. weloensis at different concentrations (400, 500, and 600 mg/ml) was evaluated for antibacterial activities using the disc diffusion method against some Gram-negative species such as Escherichia coli (ATCC 14700) and Pseudomonas aeruginosa (ATCC 35619) and Gram-positive such as Staphylococcus aureus (ATCC 50080) and Enterococcus fecalis (ATCC 4623). RESULTS: The tested concentrations of the latex ranging between 400 and 600 mg·mL-1 showed significant antibacterial activity against bacterial strain. The highest dose (600 mg/ml) of A. weloensis leaf latex revealed the maximum activity (25.93 ± 0.066 inhibition zone) followed by the dose 500 mg/ml against S. aureus. The lowest antibacterial activity was observed by the concentration 400 mg/ml (5.03 ± 0.03) against E. coli. CONCLUSION: The results of the present investigation suggest that the leaf latex of A. weloensis can be used as potential leads to discover new drugs to control some bacterial infections.