The biosynthesis of silver nanoparticles (AgNPs) from Diospyros villosa leaves and stem bark extracts is described. The stem bark AgNPs of D. villosa synthesized at 80 °C (S80) showed good scavenging activity with a lower IC50 value of 8.75 µg·mL−1 compared to ascorbic acid (9.58 µg·mL−1). The total phenol content of the S80 AgNPs was measured and found to be 10.22 ± 0.14 mg.g−1 gallic acid equivalence (GAE). Bacterial growth inhibition (% GI) and violacein inhibition (% VI) of 10.08% and 58.83%, respectively, was observed against C.subtsugae CV017 with leaf AgNPs synthesized at 80 °C (L80) at 80 μg·mL−1. Stem bark AgNPs synthesized at room temperature (SRT) also indicated % GI of 13.83% and % VI of 65.97% against C. subtsugae CV017 at 160 μg·mL−1. Leaf AgNPs of D. villosa synthesized at room temperature (LRT), showed % GI of 29.07% and % VI of 56.53%, respectively, against C. violaceum ATCC 12472 at 320 μg·mL−1. The L80 and SRT at 160 μg·mL−1 and LRT at 320 μg·mL−1 may be considered as potential QS inhibitors following their activity against C. subtsugae CV017 and C. violaceum ATCC 12472, respectively. Therefore, D. villosa represents a potential source of antioxidants as well as an anti-quorum sensing therapeutic candidate for the control of Gram-negative bacterial infections.

The Cnidoscolous acontifolius hydroalcholic leaf extract (CAHLE) has been described as exhibiting biological activity in the central nervous system assays. The objectives of this study were to investigate the anxiolytic and antinociceptive effects of CAHLE in mice. Swiss albino mice (18 to 22 g) were randomly allotted to thirteen groups (n = 5 each). Groups 1 to 5 and 9 to 13 were treated with graded doses of CAHLE (100, 200, 400, 800 and 1600 mg/kg), Groups 6 and 7 received normal saline (10 ml/kg) and diazepam (1 mg/kg), respectively, while group 8 received 5 mg/kg of pentazocine hydrochloride (HCl). All drugs and test compounds were administered via intraperitoneal route except for pentazocine which was given subcutaneously. Data analysis was by one factor analysis of variance (ANOVA) followed by post hoc analysis using Student Newman Kuels multiple comparison tests. CAHLE treated mice showed increase open arm entries and open arm exploration time compared to control group in the elevated plus maze test. CAHLE treated mice also exhibited a time-dependent and a dosedependent increase in tail flick latency. CAHLE treated mice also exhibited longer lasting protection from pain compared to standard. The study concluded that CAHLE possesses mild anxiolytic and analgesic properties to warrant its use in treatment of anxiety and relief of pain.

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This study aimed to evaluate the phytochemical components, antioxidant capacity, and antimicrobial effects of Diospyros villosa (L.) De Winter leaves and stem bark. The extracts were obtained using different media (methanol, chloroform, and hexane). The DPPH and FRAP methods were used to assess the antioxidant activity and the Folin–Ciocalteu method was used to determine the total phenolic contents of the crude extracts. The antimicrobial effects of the extracts against five pathogenic bacteria were determined using the MIC, MBC, and agar-well diffusion methods. Flavonoids, alkaloids, and phenols were identified in the D. villosa extracts. The mean concentrations of the methanolic leaf and stem-bark extracts against DPPH providing 50% inhibition were 9.53 ± 0.25 μg·mL−1 and 9.52 ± 0.30 μg·mL−1, respectively. In addition, the total phenolic content within the test range of concentrations was found to be 28.45 ± 0.50 mg of gallic acid equivalent per g of sample extract [mg·g−1 (GAE)] (methanolic leaf extract) and 4.88 ± 0.36 mg·g−1 (GAE) (methanolic stem-bark extract). The methanolic leaf extracts further showed promising antimicrobial activity against Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus with inhibition zones of 18.0 ± 0.58, 23.5 ± 0.58, 20.0 ± 0.88, and 17.0 ± 2.0 mm, respectively which were comparable to the control (gentamicin and streptomycin). The results suggest that bioactive compounds are abundant in D. villosa leaves and stem bark and could serve as a potential source of natural antioxidants as well as an antibacterial agent for the treatment of pathogenic bacterial infections.

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