Beneficial effect of Citrus limon peel aqueous methanol extract on experimentally induced urolithic rats

Figures & data

Figure 1. Chemical structures of the compounds identified in GC–MS.

Table 1. Major compounds obtained from GC–MS analyses of the LP extract.

Compound number	Compound name	Retention time	Molecular formula	Molecular weight	Peak area (%)
1	6-Amino-7-methyl-2H-benzo[b][1,4]oxazin-3(4H)-one	13.8	C9H10N2O2	178.19	28.51
2	2-(Hydroxymethyl)-6-methoxytetrahydro-2H-pyran-3,4,5-triol	14.3	C7H14O6	194.18	10.21
3	6-(Hydroxymethyl)-5-(2,3,4-trihydroxy-5-(hydroxymethyl) cyclohexyloxy)tetrahydro-2H-pyran-2,3,4-triol	15.6	C12H22O11	340.32	6.40
4	6,10-Dimethoxy-3-3-dimethyl-1-methylsulfanyl-2-aza-spiro [4.5]deca-1,6,9-trien-8-one	16.9	C14H19NO3S	281.37	11.73
5	1,2,3,4,5,6-Hexhydro-1,1,5,5-tetramethyl-2,4a-methanonapthalen-7 (4aH)-one	18.4	C15H22O	204.31	4.03
6	2,5-Di-tert-pentylcyclohexa-2,5-diene-1,4-dione	21.6	C16H24O2	248.36	32.00
7	6-[(Z)-4-((E)-2-(5-Hydroxy-2-methylenecyclohexylidene)ethylidene]- 7a-methylocatahydro-1H-inden-1yl)-2-methylheptane-2,3-diol	22.1	C27H44O3	416.6	7.12

Table 2. Serum parameters of LP extract supplemented and control rats.

Serum parameters	Control	Lemon peel extract (5000 mg/kg bodyweight)
Glucose^1	98.6 ± 9	92.5 ± 1.4^NS
Urea^1	26.93 ± 1.5	22.04 ± 4.6^NS
Creatinine^1	1.1 ± 0.1	0.94 ± 0.2^NS
Total cholesetrol^1	48.19 ± 4.2	46.47 ± 1.9^NS
Triglyerides^1	76.65 ± 6.6	84.2 ± 5.33^NS
Calcium^1	10.9 ± 1.4	9.99 ± 0.2^NS
Albumin^2	4.57 ± 0.2	4.73 ± 0.5^NS
Protein^2	9.98 ± 1.3	10.78 ± 0.1^NS
Alanine transaminase^3	26.62 ± 3.5	27.93 ± 4.9^NS
Aspartate transaminase^3	47.52 ± 3.6	48.82 ± 1.3^NS
Alkaline phosphatase^3	48.89 ± 16.3	47.39 ± 7.1^NS

The study was carried out according to the OECD guidelines. 1 – mg/dL; 2 – g/dL; 3 – U/L. The values are expressed as mean ± SD (n=3). The results were statistically analysed by non-parametric Student’s t-test. The comparisons were made as ‘control versus LP extract supplemented rats’. NS, not significant.

Table 3. Haematological parameters of LP extract supplemented and control rats.

Haematological parameters	Control	Lemon peel extract (5000 mg/kg bodyweight)
RBC^1	6.39 ± 0.1	6.52 ± 0.04^NS
WBC^2	4.1 ± 0.2	3.8 ± 0.1^NS
Platelet^3	560 ± 8.5	239 ± 11.1***
Hemoglobin^4	12.5 ± 0.3	12.9 ± 0.1^NS
Hematocrit^5	37.5 ± 0.3	38.4 ± 0.2^NS
Mean corpuscular volume^6	58.7 ± 0.1	59 ± 0.2^NS
Mean platelet volume^6	8.4 ± 0.4	7.8 ± 0.2^NS
Mean corpuscular hemoglobin^7	19.5 ± 0.2	19.7 ± 0.1^NS
Mean corpuscular hemoglobin concentration^4	33.3 ± 0.1	33.5 ± 0.2^NS

The study was carried out according to the OECD guidelines. 1 – ×10¹²/μl; 2 – ×10³/μl; 3 – ×10⁹/μl; 4 – g/dL; 5 – %; 6 – femtolitre (fL); 7 – picogram (pg). The values are expressed as mean±SD (n=3). The results were statistically analysed by unpaired Student’s t-test. The comparisons were made as ‘control versus LP extract supplemented rats’. ***p < 0.001. NS, not significant.

Table 4. Effect of LP extract on urinary parameters of control and experimental groups.

Biochemical parameters	Group 1	Group 2	Group 3	Group 4
Calcium^1	3.11 ± 0.27	4.47 ± 0.44^a***	3.49 ± 0.37^b**	3.49 ± 0.29^c**
Oxalate^1	2.65 ± 0.38	18.86 ± 0.55^a**	4.24 ± 0.4^b*	7.07 ± 0.11^c*
Citrate^1	2.46 ± 0.17	1.67 ± 0.13^a***	3.26 ± 0.34^b*	2.52 ± 0.19^c*
Phosphorus^1	5.36 ± 0.41	7.77 ± 0.32^a***	5.6 ± 0.31^b***	5.7 ± 0.4^c**
Urea^2	11.53 ± 0.26	3.1 ± 0.44^a***	9.01 ± 0.51^b*	9.26 ± 0.25^c*
Creatinine^1	3.23 ± 0.18	0.91 ± 0.07^a***	3.01 ± 0.15^b**	2.95 ± 0.1^c**
Protein^1	2.14 ± 0.11	4.18 ± 0.1^a***	2.03 ± 0.02^b***	2.13 ± 0.16^c**

1 – mg/24 h; 2 – g/L. The values are expressed as mean±SD and the results were statistically analysed by one-way ANOVA with Dunnett’s multiple comparison post-test (n=6). The comparisons were made as ‘a’ – Group 1 versus Group 2; ‘b’ – Group 2 versus Groups 3; ‘c’ – Group 2 versus Groups 4. ***p < 0.001, **p < 0.01, *p < 0.05.

Table 5. Effect of LP extract on serum parameters of control and experimental groups.

Biochemical parameters	Group 1	Group 2	Group 3	Group 4
Calcium	10.1 ± 0.9	8.87 ± 0.93^a***	9.9 ± 0.84^b*	9.42 ± 0.58^c*
Phosphorus	8.04 ± 0.44	6.2 ± 0.38^a***	7.82 ± 0.19^b**	7.66 ± 0.46^c*
Protein	1.16 ± 0.06	1.58 ± 0.06^a***	1.19 ± 0.05^b***	1.17 ± 0.06^c*
Creatinine	1.41 ± 0.28	3.45 ± 0.04^a***	1.92 ± 0.27^b***	1.52 ± 0.22^c**
Urea	91.9 ± 3.2	248.1 ± 4.2^a***	84 ± 8.5^b***	96.1 ± 3.6^c**

All the parameters were expressed as mg/dL. The values are expressed as mean ± SD. The results were statistically analyzed by one-way ANOVA with Dunnett’s multiple comparison post-test (n=6). The comparisons were made as ‘a’ – Group 1 versus Group 2; ‘b’ – Group 2 versus Groups 3; ‘c’ – Group 2 versus Groups 4. ***p < 0.001, **p < 0.01, *p < 0.05.

Figure 2. Effects of LP extract on tissue antioxidant enzymes. (a) Superoxide dismutase (SOD); (b) catalase, and (c) lipid peroxidation. The values are expressed as mean ± SD. The results were statistically analyzed by one-way ANOVA with Bonferroni’s multiple comparison post test (n = 6). The comparisons were made as ‘a’ – Group 1 versus Group 2; ‘b’ – Group 2 versus Groups 3; ‘c’ – Group 2 versus Groups 4. ***p < 0.001, **p < 0.01, *p < 0.05.

Figure 3. Figure shows kidney sections of control and various experimental groups stained with haematoxylin and eosin and Von Kossa (×400).

Figure 4. Figure shows immunohistochemical expression of NF-κB and THP in control and various experimental groups (×400).