1.1 Background of the Study

Renal health plays a vital role in maintaining homeostasis by regulating blood pressure, filtering waste products, and balancing electrolyte levels. However, the increasing prevalence of renal impairments, largely due to dietary and environmental factors, has necessitated the exploration of natural remedies with potential nephroprotective effects. The kidneys are especially susceptible to dietary influences, including high-fat consumption, which has been linked to oxidative stress and compromised renal function. High-fat diets, such as those rich in coconut oil, although beneficial in moderate consumption, may lead to metabolic disturbances and kidney burden when consumed in excess (Fan et al., 2024). Solanum melongena, commonly known as garden egg or eggplant, is a tropical vegetable widely consumed across Africa and Asia. It is valued not only for its culinary versatility but also for its rich phytochemical and antioxidant properties. Recent studies have shown that garden egg fruit extracts can ameliorate biochemical and histological alterations in organs subjected to toxic insults (Adelakun et al., 2020). Specifically, the aqueous extract of Solanum melongena has demonstrated protective effects against mercury chloride-induced testicular toxicity by improving antioxidant status and restoring tissue integrity in rats (Adelakun et al., 2020). This finding suggests the potential systemic protective effects of garden egg, extending possibly to renal functions.

In the context of kidney health, the combination of dietary stressors and toxic agents has been simulated in animal models to assess the protective efficacy of various plant-based remedies. For instance, the combined extracts of Solanum melongena, Solanum lycopersicum (tomato), and Daucus carota (carrot), significantly improved renal biomarkers and restored electrolyte balance in rats exposed to lead toxicity (Ekpe et al., 2020). Similarly, protective effects were observed when garden egg and other vegetables were used as supplements to mitigate cadmium-induced renal dysfunction (Clement et al., 2018). These studies affirm the therapeutic potential of garden egg in supporting renal function under toxic and dietary stress. Additionally, the high antioxidant content in eggplant species, including Solanum aethiopicum, contributes to their renoprotective effects by reducing lipid peroxidation and enhancing endogenous antioxidant enzymes (Choi & Choi, 2024; Iheagwam & Chinedu, 2024). This bioactivity is crucial in mitigating the oxidative damage commonly associated with high-fat diets and nephrotoxic agents. Moreover, the anti-inflammatory properties of various herbal extracts, including garden egg, further strengthen their role in maintaining renal integrity and function (Akinloye et al., 2020). Despite the promising evidence supporting the protective potential of Solanum melongena, limited studies have specifically addressed its biochemical impact on renal biomarkers in the presence of a high-coconut diet—a dietary pattern becoming increasingly common in some regions due to its energy-dense nature. As such, this study seeks to fill this gap by investigating the biochemical effects of garden egg fruit extract on renal biomarkers in albino rats fed a high-coconut diet, thereby contributing to the growing body of knowledge on functional foods and natural nephroprotective agents.

1.2 Statement of the Problem

Kidney dysfunction is an escalating health concern globally, often triggered or worsened by prolonged exposure to certain dietary patterns, particularly those high in saturated fats like coconut oil. Diets rich in such fats have been shown to induce oxidative stress and compromise renal function, leading to unfavorable alterations in key biochemical markers (Fan et al., 2024). In many low-resource communities, the rising burden of renal complications is made worse by limited access to affordable and effective nephroprotective treatments, necessitating the exploration of plant-based alternatives that are both safe and accessible. Synthetic pharmacological interventions, though commonly used, frequently come with side effects that restrict long-term use. This has driven scientific interest toward natural remedies with antioxidant and anti-inflammatory properties. Garden egg (Solanum melongena), widely consumed in many African and Asian communities, has demonstrated promising pharmacological effects, including antioxidant and organ-protective activities (Choi & Choi, 2024). However, much of the existing literature centers on its effects on the liver, blood, and reproductive organs (Adelakun et al., 2020), with minimal focus on its role in renal function under high-fat dietary conditions. While some studies have shown that garden egg can mitigate kidney damage caused by toxic exposures such as heavy metals (Ekpe et al., 2020), its potential benefits against kidney impairment resulting from common dietary practices like high-coconut consumption remain underexplored. This presents a significant gap in nutritional science and toxicology, especially in contexts where coconut-based diets are part of regular consumption habits. Thus, this study seeks to investigate the biochemical effects of garden egg fruit extract on renal biomarkers in albino rats fed a high-coconut diet, to assess its possible application in dietary-based kidney protection strategies.

1.3 Aim of the Study

The aim of this study is to investigate the biochemical effects of garden egg (Solanum melongena), fruit extract on renal biomarkers in albino rats fed a high-coconut diet.

1.3.1 Objectives of the Study

1. To determine the impact of a high-coconut diet on kidney function in albino rats.
2. To assess the effects of garden egg fruit extract on renal biomarkers in albino rats.
3. To compare the kidney function of rats fed a high-coconut diet alone with those also given garden egg extract.
4. To evaluate whether garden egg fruit extract can reduce kidney damage caused by a high-fat (coconut-based), diet.

1.4 Significance of the Study

This study is important because it explores the potential of a commonly consumed vegetable—garden egg (Solanum melongena)—to protect the kidneys from damage caused by a high-coconut diet. Coconut-rich diets, though nutritionally beneficial in some ways, are also high in saturated fats, which may increase oxidative stress and impair kidney function over time (Fan et al., 2024). In areas where coconut forms a major part of the diet, understanding how to reduce its potential harm to vital organs is crucial for improving public health. Natural remedies like garden egg have shown promise due to their antioxidant and anti-inflammatory properties, which can protect organs such as the liver and kidneys from chemical and dietary toxicity (Adelakun et al., 2020). Despite this, very few studies have examined its effect on renal function specifically in the context of fat-rich diets. By addressing this gap, the current study provides evidence that could support the inclusion of garden egg as a nephroprotective food in local diets. Moreover, plant-based interventions are particularly relevant in low- and middle-income settings where access to modern healthcare may be limited and expensive drugs may not be sustainable for long-term use (Ekpe et al., 2020). This study, therefore, contributes to the growing body of research advocating for safe, affordable, and culturally acceptable dietary interventions for disease prevention and health promotion. This study is important because it investigates how a natural, locally available vegetable—garden egg (Solanum melongena)—can support kidney health in the face of dietary challenges like high saturated fat intake from coconut-based meals. Coconut is a staple in many regions and, while it offers nutritional benefits, excessive intake may elevate lipid levels and contribute to renal stress or dysfunction (Fan et al., 2024). As dietary patterns shift toward higher fat consumption, especially in urban and peri-urban communities, there is a growing concern about the burden of chronic diseases, including kidney-related disorders.

Garden egg is rich in polyphenols, flavonoids, and antioxidants that have shown the capacity to neutralize oxidative damage and improve biochemical parameters (Amaechi et al., 2021). Studies have demonstrated its hepatoprotective and nephroprotective potential in toxic models, including those induced by heavy metals and chemical agents (Adelakun et al., 2020). However, its role in counteracting fat-induced renal damage remains underexplored, making this research both timely and necessary. The findings from this work may inform dietary guidelines and public health recommendations, particularly in regions where both coconut and garden egg are widely consumed. It also aligns with the global movement toward exploring plant-based treatments for chronic diseases, reducing reliance on synthetic drugs that may have adverse effects or be inaccessible in low-resource settings (Khafaga et al., 2019).

Furthermore, the study contributes to academic knowledge by deepening the scientific understanding of the biochemical interactions between diet and organ function. This may stimulate further research into other indigenous vegetables and their possible protective effects on different body systems. Ultimately, the study supports the development of low-cost, food-based strategies for disease prevention, which is crucial for sustainable healthcare, especially in developing countries.