Anti-inflammatory effects of several plant extracts on porcine alveolar macrophages in vitro1

Abstract

Certain plant extracts are bioactive substances of some foods or traditional herbs, known to possess antioxidant, antibacterial, and perhaps immunoregulatory effects. This study investigated the in vitro anti-inflammatory effects of 7 plant extracts (anethol, capsicum oleoresin, carvacrol, cinnamaldehyde, eugenol, garlicon, and turmeric oleoresin) on porcine alveolar macrophages collected from weaned pigs (n = 6 donor pigs) by bronchoalveolar lavage. The experimental design for this assay was a 2 [with or without 1 μg lipopolysaccharide (LPS)/mL] × 5 (5 different amounts of each plant extract) factorial arrangements in a randomized complete block design. The application of plant extracts were 0, 25, 50, 100, and 200 μg/mL, except for cinnamaldehyde and turmeric oleoresin, which were 0, 2.5, 5, 10, and 20 μg/mL. The 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay was used to determine the number of live cells, Griess assay was applied to detect nitric oxide (NO) production, and ELISA was used to measure tumor necrosis factor-α (TNF-α), IL-1β, transforming growth factor-β (TGF-β), and IL-10 in the cell culture supernatants of macrophages. The LPS increased (P < 0.001) the secretion of TNF-α, IL-1β, and TGF-β. Without LPS, anethol and capsicum oleoresin increased (linear, P < 0.001) cell viability of macrophages, whereas other plant extracts reduced (linear, P < 0.001) it. Anethol, capsicum oleoresin, and carvacrol enhanced (linear, P < 0.001) the cell proliferation of LPS-treated macrophages. Without LPS, anethol, capsicum oleoresin, cinnamaldehyde, or turmeric oleoresin stimulated TNF-α secretion, whereas all plant extracts except eugenol enhanced IL-1β concentration in the supernatants of macrophages. However, all plant extracts suppressed (linear, P < 0.001) TNF-α, and all plant extracts except turmeric oleoresin decreased (linear, P < 0.05) IL-1β secretion from LPS-treated macrophages. Anethol and capsicum oleoresin decreased (linear, P < 0.001) TGF-β from macrophages in the absence of LPS, but the other plant extracts increased it. Anethol, capsicum oleoresin, and carvacrol also suppressed (linear, P < 0.001) TGF-β from macrophages with LPS stimulation; the other plant extracts enhanced or did not affect it. The anti-inflammatory cytokine, IL-10, was not detected in any supernatants. Only very low amounts of NO were detected in the supernatants of macrophages. In conclusion, the TNF-α results indicate all plant extracts tested here may have anti-inflammatory effects to varying degrees.

Antiinflammatory effects of essential oil from the leaves of Cinnamomum cassia and cinnamaldehyde on lipopolysaccharide-stimulated J774A.1 cells

“…[21] Cinnamaldehyde has been reported to inhibit LPS-induced pro-inflammatory cytokine production in murine macrophage RAW264.7 cells[6] and porcine alveolar macrophage. [22] Our results confirmed the previous studies and extended the information that these oils also had an inhibitory effect on chemokines MCP-1 and MIP-1α.…”

Effects of dietary Capsicum oleoresin on productivity and immune responses in lactating dairy cows

“…These anti-inflammatory effects of capsaicin were shown by Park et al (2004), who reported that capsaicin suppressed tumor necrosis factor (TNF) production in murine macrophage. In food animals, Capsicum oleoresin linearly decreased TNF, IL-1B, and transforming growth factor production of LPS-induced porcine macrophages in vitro (Liu et al, 2012), suggesting an anti-inflammatory effect of capsaicin on macrophages in pigs. Oh et al (2013) infused Capsicum oleoresin (2 g/d) into the abomasum of lactating dairy cows and measured inflammatory cytokines production of LPSinduced peripheral blood mononuclear cells ex vivo and subpopulations of T cells in blood.…”

“…Recent findings suggested, however, that the improvement in animal performance may be due to a host response (physiological and immunological) rather than direct antimicrobial or sensory effects. For example, Capsicum oleoresin or its mixture with other plant extracts have reduced oxidative stress (Karadas et al, 2014), prevented disease symptoms Liu et al, 2012), and improved gut health during normal or disease conditions (Liu et al, 2014a,b) in both poultry and swine. In addition, studies using rats showed that capsaicinoids, active compounds in Capsicum, had modulatory effects on immune cells such as neutrophils and T cells (Franco-Penteado et al, 2006;Takano et al, 2007), and decreased oxidative stress markers and induced negative energy balance (Yoshioka et al, 2000;Abdel-Salam et al, 2012).…”

“…Capsaicinoids have been shown to have immunomodulatory effects in vitro and in vivo in rats (Sancho et al, 2002;Park et al, 2004;Liu et al, 2012). Capsaicin and Capsicum oleoresin reduced IL-2 and IFN-γ production in murine Peyer's patches, lymphoid tissues where systemic immune responses are induced in the intestine (Takano et al, 2007).…”

Carum copticumL.: A Herbal Medicine with Various Pharmacological Effects

“…The effect of carvacrol on cell culture supernatants of macrophages in porcine induced alveolar inflammatory showed inhibitory effect of carvacrol on TNF- α , IL-1 β , and TGF- β [35]. Carvacrol also inhibited secretion of TNF- α and IL-1 β in porcine alveolar macrophage [36].…”