Pequi fruit (Caryocar brasiliense Camb.) pulp oil reduces exercise-induced inflammatory markers and blood pressure of male and female runners

Abstract

The objective of this study was to investigate the anti-inflammatory properties of pequi (Caryocar brasiliense) fruit oil and its effects on the postprandial lipidemia and arterial blood pressure of male and female athletes. These athletes were evaluated after races in the same environment and under the same type, intensity, and length of weekly training conditions, both before and after ingestion of 400 mg pequi oil capsules for 14 days. Pequi fruit contains several antioxidants, and its oil has been associated with anti-inflammatory properties in other pequi species. Because the oil of pequi is mostly composed of oleic and palmitic fatty acids, the oil may alter the ratio of triglyceride to cholesterol in postprandial lipidemia. Epidemiologic studies suggest that an increased intake of monounsaturated fatty acids (such as oleic acid) is inversely related to blood pressure. Thus, we hypothesize that pequi oil could reduce exercise-induced inflammation and blood pressure, and modulate postprandial lipidemia in runners. To test this hypothesis, arterial blood pressures were checked before races; blood samples were taken after the races and submitted for analysis of leukocytes and platelets analysis, high-sensitivity C-reactive protein values, and postprandial lipids. Pequi oil resulted in anti-inflammatory effects and reduced the total cholesterol and low-density lipoprotein in the age group older than 45 years, mainly for men. The results showed a general trend for reduced arterial pressure, suggesting that pequi oil may have a hypotensive effect. However, this finding needs additional investigation. Thus, pequi oil, besides possessing many nutritional properties, may be a good candidate supplement for athletes.

Introduction

Reactive oxygen species (ROS) are constantly formed in the human body, mainly as a result of normal oxidative metabolism in the mitochondria, and neutralized by an elaborate antioxidant defense system [1]. Because exercise increases oxygen consumption, it also enhances ROS generation, which at relatively low cellular levels may influence metabolism in physiologic conditions [2]. A weak production of ROS is necessary for normal contractile activity of skeletal muscles [2], and physical training is known to induce antioxidant enzymes [3], [4], [5]. The generation of ROS by myocytes is potentially important because it seems to play a significant role in signaling molecules, modulating some regulatory systems involved in the skeletal muscle performance [2]. They also have effects on the immune system that are considered positive [4].

However, intensive or prolonged exercise, above habitual intensity of effort or training with very elevated frequency, overloads the endogenous antioxidant system's capacity, resulting in oxidative stress [3], [4], [5], [6]. Thus, it results in increased levels of malondialdehyde (MDA) in the blood, which serve as indirect indicators of lipid peroxidation and can be measured by thiobarbituric acid reactive substances (TBARs) assay [5], [7], [8]. Moreover, it can initiate reactions that resemble the acute phase of the immune response to infection, inducing changes in the immune cell count and release of acute phase proteins, such as high-sensitivity C-reactive protein (hs-CRP) [6], [9], [10]. In this context, dietary antioxidant intake can help to prevent oxidative stress and injuries [1], [4].

Many studies have investigated the impact of the antioxidant status in the exercise-induced damages [1], [4], [7], [11]; and with this purpose, most dietary interventions have focused on nutritive factors such as vitamin antioxidants or drugs that mediate exercise-induced oxidative stress [12]. Nutritional supplements have been widely studied, among which vitamin E, vitamin C, creatine, and glutamine supplementation is included [4], [7]. However, no study has examined individually the antioxidant roles of carotenoids or carotenoid-rich dietary food or supplements; only β-carotene (30 mg) has been tested in a mixture with vitamins C (1000 mg) and E (592 mg) [1], [4], [7]. Thus far, evaluation of the effectiveness of dietary antioxidant intervention in oxidative stress and exercise-induced damages remains incomplete because it can depend not only on the nature of the antioxidant in use, but also on the exercise type and the partial pressure of oxygen in the tissues.

Biological antioxidants, such as those found in plant-based foods, contain bioactive phytochemicals [12] and may play a vital role in protecting the cell from exercise-induced oxidative stress [11]. Pequi (Caryocar brasiliense Camb.) is a typical tree found in the Brazilian Cerrado. Pequi fruit pulp oil contains natural antioxidants, such as different carotenoids [13], [14], [15], [16]. These substances are effective chain-breaking antioxidants at low partial pressure of oxygen [17], [18] and can prevent oxidative injuries in those endurance athletes who overload their endogenous antioxidant system capacity through elevated training frequency or intense and prolonged exercise. In addition, the fatty acid composition of the oil is mainly composed of oleic acid (51.37% to 55.87%) and palmitic acid (35.17% to 46.79%) [14], [19], which are involved in the modulation of the ratio of triglyceride (TG) to cholesterol in postprandial triglyceride-rich lipoprotein (TRL) [20].

In a previous study, pequi oil was efficient in reducing DNA damages and tissue injuries evaluated for aspartate aminotransferase and alanine aminotransferase [21]. In addition, according to ethnobotanical studies, the oils of the fruit pulp from C coriaceum (another species of pequi) possess significant anti-inflammatory effects [22], [23]. Because these oils are similar to those of C brasiliense, where oleic and palmitic acids are also the major components [24], we hypothesized that pequi oil could efficiently reduce exercise-induced inflammation and modulate postprandial lipidemia of runners. Because some epidemiologic studies have suggested that an increased intake of monounsaturated fatty acids (MUFA, such as oleic acid) is inversely related to blood pressure [25], we also hypothesized that pequi oil intake could influence arterial pressure. Thus, the objective of this study was to investigate the anti-inflammatory properties of pequi (C brasiliense) fruit oil and its effects on the postprandial lipidemia and arterial blood pressure of runners after races run in the same environment and under the same conditions, intensity, and length of weekly training conditions (before and after taking the pequi oil supplement). This research is important to further understand the benefits of carotenoid supplements in the prevention of exercise-induced damage, mainly for those athletes who exercise strenuously and surpass their endogenous antioxidant defenses.