Frankincense extract protects against testicular damage through augmentation of antioxidant defense mechanisms and modulation of apoptotic genes expression

Abstract

Frankincense (Boswellia sacra Fluck.,) is traditionally used in the treatment of altered male fertile potential in several countries. This study evaluated the cytoprotective action of B. sacra oleo gum resin extract against cyclophosphamide (CP) induced testicular toxicity in rats (in-vivo) and lipopolysaccharide (LPS) induced cytotoxicity in human Leydig cells (in-vitro). The methanolic extract of B. sacra was standardized for the presence of different boswellic acids using high-performance liquid chromatography (HPLC) and volatile constituents in the extract were detected by gas chromatography-mass spectrometry (GC-MS). Two doses of B. sacra extract were used in the in-vivo study. The HPLC analysis showed that extract contains about 36% w/w of total boswellic acids and GC-MS analysis revealed the presence of another 71 different constituents. Administration of B. sacra extract to rats increased serum testosterone levels, antioxidant enzyme activities, and sperm count with improved sperm quality in a dose-dependent manner, when compared to CP treated animals. Boswellia sacra extract also protected the human Leydig cells against LPS-induced damage and increased the expression of the Bcl-2 gene along with a decrease in caspase-3 gene expression. The results of this study show that B. sacra extract has a protective effect on the male reproductive system.

Figure 1

Effect on body weight, testis weight, and relative weight of testis to body weight. All values are mean ± SEM, n = 6. There was no significant change in the weights between the groups. CP = cyclophosphamide (200 mg/kg, i.p), BS Boswellia sacra extract.

Figure 2

Effect on serum hormone levels. All values are mean ± SEM, n = 6. ***P < 0.001 compared to control. ⁺P < 0.05, ⁺⁺⁺P < 0.001 compared to CP treated group CP = cyclophosphamide (200 mg/kg, i.p), B S = Boswellia sacra extract.

Figure 3

Effect on different sperm parameters. All values are mean ± SEM, n = 6. *P < 0.05, **P < 0.01, ***P < 0.001 compared to control. ⁺P < 0.05, ⁺⁺P < 0.01, ⁺⁺⁺P < 0.001 compared to CP treated group CP = cyclophosphamide (200 mg/kg, i.p), B S Boswellia sacra extract.

Figure 4

Different sperm defects observed in head and tail. The defects in the head are shown by a purple arrow (), and the tail defects are shown by a black arrow (). Red-colored arrows () show cytoplasmic residues.

Figure 5

Effect on antioxidant enzymes. All values are mean ± SEM, n = 6. *P < 0.05, **P < 0.01, compared to control. ⁺⁺⁺P < 0.001 compared to CP treated group CP = Cyclophosphamide (200 mg/kg, i.p), B S Boswellia sacra extract.

Figure 6

Histological examination of testis.

Figure 7

Cell viability assay on human Leydig cells (in-vitro). All values are mean ± SEM, n = 6.

Figure 8

Cytoprotective effect on LPS induced cytotoxicity in human Leydig cells (in-vitro). All values are mean ± SEM, n = 6.

Figure 9

Effect on expression of Bcl-2 and caspase-3 in human Leydig cells (in-vitro). All values are mean ± SEM, n = 6. ***P < 0.001 compared to control, ⁺⁺⁺P < 0.001 compared to LPS treated cells. B S Boswellia sacra extract, ADR Adrenomedullin.