Antioxidative Properties and Inhibition of Key Enzymes Relevant to Type-2 Diabetes and Hypertension by Essential Oils from Black Pepper

Abstract

The antioxidant properties and effect of essential oil of black pepper (Piper guineense) seeds on α-amylase, α-glucosidase (key enzymes linked to type-2 diabetes), and angiotensin-I converting enzyme (ACE) (key enzyme linked to hypertension) were assessed. The essential oil was obtained by hydrodistillation and dried with anhydrous Na2SO4, and the phenolic content, radical [1,1-diphenyl-2 picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and nitric oxide (NO)] scavenging abilities as well as the ferric reducing antioxidant property (FRAP) and Fe2+-chelating ability of the essential oil were investigated. Furthermore, the effect on α-amylase, α-glucosidase, and ACE enzyme activities was also investigated. The characterization of the constituents was done using GC. The essential oil scavenged DPPH∗, NO∗, and ABTS∗ and chelated Fe2+. α-Pinene, β-pinene, cis-ocimene, myrcene, allo-ocimene, and 1,8-cineole were among the constituents identified by GC. The essential oil inhibited α-amylase, α-glucosidase, and ACE enzyme activities in concentration-dependent manners, though exhibiting a stronger inhibition of α-glucosidase than α-amylase activities. Conclusively, the phenolic content, antioxidant activity, and inhibition of α-amylase, α-glucosidase, and angiotensin-1 converting enzyme activities by the essential oil extract of black pepper could be part of the mechanism by which the essential oil could manage and/or prevent type-2 diabetes and hypertension.

Black pepper (Piper nigrum) essential oil demonstrates tissue remodeling and metabolism modulating potential in human cells

“…Other animal model studies have shown that the major active component d‐limonene has preventive and ameliorating effects on insulin resistance and dyslipidemia (Jing et al, ; Santiago, Jayachitra, Shenbagam, & Nalini, ). These studies suggest that BPEO has the potential to modulate metabolism and thus be used to prevent and treat metabolic diseases (Oboh et al, ).…”

“…Consistent with this finding, our results show BPEO influences the regulation of oncogenes in skin cells. Oboh et al (2013) reported that essential oils distilled from a closely related species (Piper guineense) inhibited key enzymes associated with Type 2 diabetes and hypertension. Other animal model studies have shown that the major active component d-limonene has preventive and ameliorating effects on insulin resistance and dyslipidemia (Jing et al, 2013;Santiago, Jayachitra, Shenbagam, & Nalini, 2014).…”

“…The use of black pepper (Piper nigrum) essential oil (BPEO) has been well established; BPEO has been shown to possess antibacterial, antifungal, antioxidant, and anti-inflammatory properties in different settings (Jeena, Liju, Umadevi, & Kuttan, 2014;Oboh, Ademosun, Odubanjo, & Akinbola, 2013;Zhang et al, 2016). BPEO has also been shown to inhibit key enzymes involved in human diseases, such as angiotensin-1 converting enzyme, alpha-glucosidase, and alphaamylase.…”

Psychoneuropharmacological activities and chemical composition of essential oil of fresh fruits of Piper guineense (Piperaceae) in mice

“…Biological studies attributed to the plant include antioxidant and anti-diabetic (Oboh et al, 2013;Etim et al, 2013), hypolipidemic and hypokalaemic (Nwaichi and Igbinobaro, 2012), insecticidal (Adewoyin et al, 2006), anti-microbial (Oyedeji et al, 2005), sedative activity (Tankam and Ito, 2013) and anticonvulsant activity of aqueous extract of its seed (Abila et al, 1993). The acute toxicity study of the oil conducted in our laboratory indicates the LD 50 value of the oil to be 693 mg/kg, i.p.…”

“…P. guineense found within the same species and geographical area has been reported to vary in their chemical composition, for example, Ekundayo et al (1988) showed myristicin, safrole, sarisan and elemicin as main compounds; Oyedeji et al (2005) reported β-pinene, α-pinene and germacrene-B as major components; Olonisakin et al (2006) indicated β-pinene, D-Limonene, caryophyllene and car-3-ene as most abundant constituents, while Oboh et al (2013) reported β-pinene, α-pinene, 1,8-cineole and γ-terpinene as the major components of the plant fruit essential oil from this Nigerian spp. The variations in chemical constituents of this plant species could contribute to its divergent biological activities and this therefore necessitate evaluating its chemical composition along with pharmacological activities.…”