In vivo antibacterial activity of Garcinia mangostana pericarp extract against methicillin-resistant Staphylococcus aureus in a mouse superficial skin infection model

Figures & data

Figure 1. HPLC chromatogram. (A) Ethanol solvent (blank), (B) α-mangostin standard solution (10 μg/mL) with retention time (t_R) 6.016 min, (C) γ-mangostin standard solution (10 μg/mL) with retention time (t_R) 3.207 min, (D) GM-EtOH, the ethanolic G. mangostana extract with the peak of α- and γ-mangostin and (E) GM-MeOH, the methanolic G. mangostana extract with the peak of α- and γ-mangostin.

Table 1. Contents of chemical markers in the G. mangostana crude extract.

Chemical markers	GM-EtOH	GM-MeOH
Phenolic contents (mg/g) equivalent to gallic acid	62.88 ± 3.68	69.42 ± 5.10
Flavonoid contents (mg/g) equivalent to quercetin	36.95 ± 0.03	33.18 ± 3.83
Anthocyanin (mg/g) equivalent to  cyanidin-3-glucoside	98.20 ± 22.04	11.70 ± 0.69
Percentage of tannin contribution (%)	64.56 ± 1.08	71.49 ± 1.57
α-Mangostin (% of dry weight)	13.20 ± 0.49	9.83 ± 0.30
γ-Mangostin (% of dry weight)	2.34 ± 1.01	2.96 ± 0.28

GM-EtOH: the ethanolic G. mangotana crude extract; GM-MeOH: the methanolic G. mangostana crude extract.

Table 2. Inhibition zone, MIC and MBC values of the G. mangostana crude extract against MSSA and MRSA.

	Inhibition zone (mm)		MIC (μg/mL)		MBC (μg/mL)
	MSSA	MRSA	MSSA	MRSA	MSSA	MRSA
GM-EtOH	12.75 ± 1.04	13.17 ± 1.15	14	17	25	30
GM-MeOH	13.25 ± 0.65	12.50 ± 0.00	17	20	25	35
α-Mangostin	11.17 ± 0.29	10.00 ± 0.00	6.25	6.25	100	100
Gentamicin	16.50 ± 2.29	0.00 ± 0.00	1.56	>10,000	25	>10,000
Erythromycin	22.83 ± 0.29	0.00 ± 0.00	0.78	>10,000	>25	>10:000

MIC: minimum inhibitory concentration; MBC: minimum bactericidal concentration; MSSA: methicillin-sensitive S. aureus ATCC 23235; MRSA: methicillin-resistant S. aureus DMST 20651; GM-EtOH: the ethanolic G. mangotana crude extract; GM-MeOH: the methanolic G. mangostana crude extract.

Figure 2. Effects of GM-EtOH on TEWL in the tape stripping model in mice. TEWL was measured on the back of the mice as described in the method (n = 9–10). Control, non-infected mice with the tape stripping induced wound; NT, MRSA-infected wound in mice with no treatment; Base, MRSA-infected wound in mice treated with 100 μL of a 10% ethanol in propylene glycol solution; GM-EtOH, MRSA-infected wound in mice treated with 100 μL of a 10% GM-EtOH in a 10% ethanol in propylene glycol solution; Erythromycin, MRSA-infected wound in mice treated with 100 μL of a 4% commercial erythromycin gel; Gentamicin, MRSA-infected wound in mice treated with 100 μL of a 0.1% commercial gentamicin cream. *p < 0.001 versus control on the same day using one-way ANOVA followed by LSD post hoc test.

Figure 3. Effects of GM-EtOH and α-mangostin on TEWL in the tape stripping model in mice. TEWL was measured on the back of the mice as described in the method (n = 7–10). Control, non-infected mice with the tape stripping induced wound; NT, MRSA-infected wound in mice with no treatment; GM-EtOH, MRSA-infected wound in mice treated with 100 μL of a 10% GM-EtOH in a 10% ethanol in propylene glycol solution; Alpha-MGS, MRSA-infected wound in mice treated with 100 μL of a 1.32% α-mangostin in a 10% ethanol in propylene glycol solution; Erythromycin, MRSA-infected wound in mice treated with 100 μL of a 1.32% erythromycin in a 10% ethanol in propylene glycol solution. *p < 0.001 versus control on the same day using one-way ANOVA followed by LSD post hoc test.

Figure 4. The effect of GM-EtOH on** the number of S. aureus colonies. MRSA was swabbed from the wound of the mouse back to culture on the MSA plate and number of colonies were counted at 24 h after the incubation (n = 9-10). Control, non-infected mice with the tape stripping induced wound; NT, MRSA-infected wound in mice with no treatment; Base, MRSA-infected wound in mice treated with 100 μL of a 10% ethanol in propylene glycol solution; GM-EtOH, MRSA-infected wound in mice treated with 100 μL of a 10% GM-EtOH in a 10% ethanol in propylene glycol solution; Erythromycin, MRSA-infected wound in mice treated with 100 μL of a 4% commercial erythromycin gel; Gentamicin, MRSA-infected wound in mice treated with 100 μL of a 0.1% commercial gentamicin cream. *p < 0.001 versus control and ^#p < 0.001 versus GM-EtOH on the same day using one-way ANOVA followed by LSD post hoc test.

Figure 5. The effect of GM-EtOH and α-mangostin in the number of MRSA colonies. MRSA was swabbed from the wound of the mouse back and diluted to 2 mL of NSS before culturing on the MSA containing oxacillin (6 μg/mL) plate. The number of colonies was counted at 24 h after the incubation (n = 7–10). Control, non-infected mice with the tape stripping induced wound; NT, MRSA-infected wound in mice with no treatment; GM-EtOH, MRSA-infected wound in mice treated with 100 μL of a 10% GM-EtOH in a 10% ethanol in propylene glycol solution; Alpha-MGS, MRSA-infected wound in mice treated with 100 μL of a 1.32% α-mangostin in a 10% ethanol in propylene glycol solution; Erythromycin, MRSA-infected wound in mice treated with 100 μL of a 1.32% erythromycin in a 10% ethanol in propylene glycol solution. *p < 0.05 versus control and #p < 0.05 versus GM-EtOH on the same day using one-way ANOVA followed by LSD post hoc test.

Figure 6. The effect of GM-EtOH on the wound-appearance. The photograph of the wound was recorded daily (n = 9–10) after the treatments. The figure showed the wound-appearance on the last day of observation (the ninth day). Control, non-infected mice with the tape stripping induced wound; NT, MRSA-infected wound in mice with no treatment; Base, MRSA-infected wound in mice treated with 100 μL of a 10% ethanol in propylene glycol solution; GM-EtOH, MRSA-infected wound in mice treated with 100 μL of a 10% GM-EtOH in a 10% ethanol in propylene glycol solution; Erythromycin, MRSA-infected wound in mice treated with 100 μL of a 4% commercial erythromycin gel; Gentamicin, MRSA-infected wound in mice treated with 100 μL of a 0.1% commercial gentamicin cream.

Figure 7. The effect of GM-EtOH and α-mangostin on the wound-appearance. The photograph of the wound was recorded daily (n = 7–10) after the treatments. The figure showed the wound-appearance on the last day of observation (the ninth day). Control, non-infected mice with the tape stripping induced wound; NT, MRSA-infected wound in mice with no treatment; GM-EtOH, MRSA-infected wound in mice treated with 100 μL of a 10% GM-EtOH in a 10% ethanol in propylene glycol solution; Alpha-MGS, MRSA-infected wound in mice treated with 100 μL of a 1.32% α-mangostin in a 10% ethanol in propylene glycol solution; Erythromycin, MRSA-infected wound in mice treated with 100 μL of a 1.32% erythromycin in a 10% ethanol in propylene glycol solution.