Potential of Red Okra Extract (Abelmoschus esculentus L. Moench) to Restore Kidney Damage due to Sodium Nitrite

Sodium nitrite (NaNO2) found in vegetables, drinking water, and cured meats, can damage tissue because it is an oxidant. Plant phytochemicals such as quercetin are antioxidants. This study aimed to determine the potential of red okra pods ethanol extract (ROE) to repair kidney damage in mice (Mus musculus) induced by NaNO2. The red okra pods were extracted three times with saturated ethanol. The experiment used 36 male BALB/c mice aged 6-8 weeks and body weight of about 28 g. There are six research groups, namely, normal control, negative control (exposure to NaNO2 50 mg/kg BW), treatment of exposure to NaNO2 and administration of ROE at doses of 25, 50, 75, and 100 mg/kg BW. Sodium nitrite and ROE were given daily for 23 days by gavage. On day 24, the serum was isolated. Blood urea nitrogen (BUN) and creatinine (Cre) levels are measured to assess kidney function, as well as measuring the oxidant malondialdehyde (MDA) and the antioxidant enzyme of superoxide dismutase (SOD). The kidneys were made histological preparations and analyzed on the proximal convoluted tubule (PCT).  All data were statistically analyzed (α=0.05). This study indicated that the administration of ROE at a 100 mg/kg BW dose is the most optimal in repairing damage to the PCT with increased normal cells and reduced necrosis. Besides, it degraded BUN, Cre, and MDA levels in the serum of mice exposed to NaNO2 compared to the other treatments. All doses of ROE promoted the SOD level. ROE restore kidney tissue, especially on PCT to normal. Kidney damage due to exposure to NaNO2 preservatives can be reduced by administering ROE. ROE prevents kidney damage through an increase in antioxidant enzymes. ROE can be used as a food ingredient as a source of antioxidants, thereby reducing the impact of oxidant compounds.

Antioxidant and Nephroprotective Effects of Okra Pods Extract (Abelmoschus esculentus L.) against Lead Acetate-Induced Toxicity in Mice

In this study, we determine the curative effects of okra pods (Abelmoschus esculentus L.) extract against lead acetate toxicity in mice kidney. n-Hexane, ethyl acetate, and methanol solvent were used for extracting okra pods. The role of the extract as an antioxidant was tested by DPPH and FRAP methods. The methanol extract was used for experiments in animals. A total of 30 male BALB/c mice were randomly divided into six equal groups: normal control, negative control (lead-induced), and treatment groups (lead-induced for 28 days and administration of methanol extract at doses of 50, 100, 200, and 400 mg/kg BW for the 28 days). The following were analyzed in all groups: activity of the antioxidant enzymes, namely, superoxide dismutase (SOD) and catalase (CAT); oxidant level, namely, malondialdehyde (MDA) and nitric oxide (NO); and markers of kidney injury, namely, blood urea nitrogen (BUN) and creatinine (Cre). Kidney histopathology was also evaluated. This study showed that the methanol extract showed the highest antioxidant activity (IC₅₀ is 35.21 µg/mL, and FRAP is 57.58 µM Fe^2+/g). The CAT and SOD activities increased significantly in okra-treated groups (P < 0.05). The okra administration groups experienced a significant decrease in MDA, NO, BUN, and Cre levels (P < 0.05). Thickness of the epithelial proximal tubule, diameter of the proximal tubule, and percentage of necrotic cells in proximal tubule decreased, but the diameter ratio of glomerular Bowman's capsule in mice treated with okra was optimally improved and repaired like normal control (P < 0.05). The results of this study reveal that methanol extract has a very strong antioxidant effect and can reduce the influence of toxicity induced by lead acetate in mice kidney.