Renoprotective Role of Natural Honey in the prevention of High Blood Pressure in Animal Model

Introduction

Honey is a natural product produced from the nectar and exudation of plants by the honeybees, Apis mellifera (Alvarez-Suarez et al., 2010). The natural honey has been reported to contain about 200 substances, which consist of not only highly concentrated solution of sugars, but also the complex mixture of other saccharides, amino acids, peptides, enzymes, proteins, organic acids, polyphenols, carotenoidlike substances, vitamins, and minerals (Gheldof etal., 2002; Sato & Miyata, 2000; White, 1975).

Sugars are the main constituents of honey, comprising about 95% of its dry weight (Alvarez-Suarez et al., 2010). While glucose and fructose are the dominant constituents, about 25 different sugars have been detected (Doner, 1977; Siddiqui, 1970). The view by White (1975) has demonstrated that proteins in honey are mainly enzymes. Honey contains roughly 0.5% proteins (Alvarez-Suarez et al., 2010) and the protein contents in some honeys can be over 1 000 µg/g (Azeredo et al., 2003). Main enzymes include diastase, invertase, glucose oxidase and catalase. Although the content of amino acids in honey is relatively small, it has been found that almost all of physiologically essential amino acids are present in honey (Cotte et al., 2004; Hermosín et al., 2003). The primary amino acid is proline, contributing 50-85% of the total amino acids (Hermosín et al., 2003). The level of organic acids in honey is relatively low and about 18 organic acids have been detected (Nanda et al., 2003). Most of the acidity present in honey is added by honeybees (Echigo & Takenaka, 1974). Gluconic acid, the predominant honey organic acid, is the product of glucose oxidation, presenting at 50-fold higher levels than other acids (Cherchi et al., 1994). Investigations have shown that a wide range of trace elements are present in honey, including Al, Ba, Bi, Co, Cr, Mo, Ni, Pb, Sn, Ti, as well as minerals (Ca, Cu, Fe, K, Na, Mg, Mn, Zn) (Conti, 2000; Stocker et al., 2005), among them, the main mineral element is potassium while copper presents lowest amount (Nada et al., 2003). Vitamins such as thiamin (B1), riboflavin (B2), pyridoxine (B6), and ascorbic acid (C) have also been reported but their amount is very small in honey (Ball, 2007; Nada et al., 2003). When honey is treated with mild heat or prolonged storage, a compositional change can occur due to caramelization of the carbohydrates, the Maillard reaction, and decomposition of fructose in the acid medium of honey (Villamiel et al., 2001)

Phytochemicals are chemical substances naturally occurring in plants and many of them are now recognized to have health-promoting activity (Apostolidis et al., 2006; Liu, 2003; Liu, 2004; Sun et al., 2002; Vattem et al., 2005). Phenolic substances are the largest group of phytochemicals (King & Young, 1999). The plants containing phytochemicals might be used as a supply of the bees; thereby bioactive compounds can be transferred to honey. Studies have shown that honey contains great variation in contents of different phytochemicals according to floral sources and climatic conditions, which contribute to different characteristic colors, flavors, aromas, and bioactivities (Abu-Tarboush et al., 1993; Molan, 1996). As herbal medicines are derived from different plants, which can produce different therapeutic properties (Villegas et al., 1997), some honey derived from these specific plants may provide added value for health promotion. Honey produced by bees fed herbal extracts has shown greater antioxidant activity than normal honey (Rosenblat et al., 1997).

The Study of the Antioxidant Activity of Phenolic Components of Natural Honey in Nigeria

ABSTRACT.

In this study, ten honey and five propolis samples from different geographical origins were tested. Both honey and propolis samples showed high content of total phenolic compounds (330-610 mg gallic acid equivalent (GAE)/100 g honey; 365-1022 mg GAE/g ethanol extract of propolis (EEP). The total flavonoids ranged from (15.1-42.6 mg catechin equivalent (CE)/100 g for honey; to 123-74 mg CE/g for EEP. These honeybee products of Ethiopia had high total radical scavenging properties with respect to 2,2-diphenyl-1-picrylhydrazyl (DPPH); 18.1-59.8% and 48.6-87.8% for honey and EEP respectively. Furthermore, the hydroxymethylfurfural (HMF) of the honey samples was found to be low with a mean value of 4.8 mg/kg suggesting that the samples were of good quality. The antioxidant properties of the products showed a good correlation (r2 = 0.50-0.82) with their polyphenolic contents.

ASSESSMENT OF NUTRIENT AND ANTI-NUTRIENT COMPOSITION OF SOME INDIGENEOUS GREEN LEAFY VEGETABLES IN NIGERIA

Native vegetables are also sometimes referred to as wild vegetables or plants whose leaves, roots, or fruits are edible and used as vegetables by rural and urban populations as a result of tradition, custom, and habit. Indigenous vegetables are typically grown in areas with a temperate climate (Towns and Shackleton, 2018). The young growth points and the tender leaves of the plant are the parts of the plant that are used in the preparation of vegetable dishes for the vast majority of species. Petioles and, in some instances, younger, more tender stems are also included; however, more mature, woodier stems are thrown away (Redzic, 2006; Rensburg et al., 2004). These vegetables are consumed in large quantities, particularly during times of natural disasters and famines when the cultivation of other vegetables is not possible. Vegetables that are either domesticated or grown wild in regions with disturbed soils or agricultural activity are considered to be indigenous vegetables (Assan, 2014). The wild varieties are those that grow in their natural habitat, which is the wilderness. On the other hand, the semi-wild varieties, also known as semi-cultivated varieties, are those that are protected because they grow near homes or in home gardens (Venter, Rensburg, Vorster, Heever, and Zijl, 2007).
Indigenous leafy vegetables are typically grown at a subsistence level and are more prevalent in rural areas. This is because urban populations have greater access to supermarkets. Indigenous leafy vegetables are still generally regarded as weeds by researchers and extension personnel. These individuals also criticize farmers for failing to keep this weed population under control, which results in this essential food being labeled as not being worthy of the space it occupies in the fields (Mayekiso and Mditshwa, 2017). Because they are easily able to adapt to harsh or difficult environments, indigenous vegetables may have the potential to make a positive contribution to the global food production system (Maseko et al., 2017). The consumption of these indigenous vegetables has decreased as a direct result of the widespread availability of exotic vegetables. There has been a significant decrease in the availability of native green leafy vegetables, which has been caused in part by an excessive cultivation of field crops, a change in habitat, as well as chemical eradication of wild vegetable populations (Mathaba, 2017). Indigenous Leafy Vegetables play an important role in the food security strategies of many rural households, and their utilization and production fall under the purview of the more senior women in those households (Vorster, Stevens, and Steyn, 2008).