Antibacterial activity of diosquinone and plumbagin from the root of Diospyros mespiliformis (Hostch) (Ebenaceae)

Abstract

Diosquinone and plumbagin isolated from the root of Diospyros rnespiliforrnis (Hostch), a common ingredient in several folk medicines and foods, have been shown to have antibacterial activity against a wide range of organisms. The minimum inhibitory concentrations (MICs) of diosquinone against Staphylococcus aureus NCTC 6571 and S. aureus E3T ranged from 3 to 30 pglmL, while those against Escherichia coli KL16 and Pseudomoms aeruginosa NCTC 6750 ranged from 15 to 16pglmL. MICs were found to increase with the concentration of cells used in the inaculum. Bacterial studies showed that S. aureus NCTC 6571 exhibited a paradoxical biphasic response to dioquinone in nutrient broth, whereas bacterial activity against E . coli KL16 increased with concentration up to the highest concentration of dioquinone tested. Activity against E . coli KL16 was more pronounced in phosphate-buffered saline than in nutrient broth.The other active compound isolated, the naphthoquinone plumbagin, gave MIC values between 400 and 600 pg/mL.

Synergistic Effect of Combined Antibiotic and Methanol Extract of Eucalyptus camaldulensis leaf Against Staphylococcus aureus and Pseudomonas aeruginosa

“…The minimum inhibitory concentration (MIC) of the methanol leaf extract of E. camaldulensis, ceftriaxone and gentamycin were carried out using the agar dilution method described by Lajubutu et al, (1995). Different concentrations were prepared to give a final 50 to 0.048 mg /ml, 2500 to19.5 µg/ml, 2000 to1.95 µg/ml of the plant extracts, ceftriaxone (CRO), gentamycin (CN), respectively.…”

In vitro cytotoxicity activity of diosquinone, a naphthoquinone epoxide

“…Tested Compound: Diosquinone[1], a naphthoquinone epoxide which we have previously isolated from the root sample of D. mespiliformis (collected from Olokemeji forest reserve in Ogun state of Nigeria during the onset of raining season) (Lajubutu et al, 1995) and the root of D. tricolor (collected from coastal area of Lagos State) (Lajubutu, 1994) was used in this assay.…”

“…This is the first known report of the cytotoxicity potential of diosquinone. This compound which has been reportedly isolated and identified from two Nigerian Diospyros species (Lajubutu 1994, Lajubutu et al, 1995 has only been documented for its antibacterial activities.…”

“…The decoction of D. tricolor has been used in treatment of leprosy, dysentery and diarrhoea (Hegnauer, 1966). Diosquinone and plumbagin were isolated with α-amyrin, β-sitosterol, betulin and betulinic acid from D. mespiliformis (Lajubutu et al, 1995). The minimum inhibitory concentration (MICs) of Diosquinone from the root of D. mespiliformis against some Grampositive bacteria ranged from 3 -30 µg while those against Gram-negative bacterial range from 15 -60 µg.…”

Inhibitory effect of isolated Lupeol from stem bark of <i>Diospyros mespiliformis </i>Horsch (Ebenaceae) against some microbial pathogens

“…Studies have shown that the leaf extracts of D. mespiliformis are effective against Plasmodium falciparum in vitro (Etkin, 1997), Plasmodium berghei invivo (Adzu and Salawu, 2009) and relieved pains and fever in rodent models (Adzu et al, 2002). Tannins, alkaloids, diosquinone and plumbagin were isolated from D. mespiliformis and demonstrated activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa thus providing the basis for the plant usage in herbal medicine (Adeniyi et al, 2006;Lajubutu et al, 2006). Root extract of D. mespiliformis have shown toxicity potential using subchronic administration in mice (Ali et al, 2012).…”