Olive Leaf and FIV
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Olive leaf extract (OLE) is about as close to the perfect herbal supplement for an FIV+ cat as it is
possible to get. Its downside is that of many herbal supplements: it has a strong taste that would
probably not be tolerated by most cats. Although no research appears to have been done to date
of olive leaf as an FIV therapy, research as an HIV therapy has been so promising that a number
of researchers have pointed to the possibility of creating new HIV drugs based on synthetic
derivatives. Since the 1990's, olive leaf has been touted as an inhibitor of the enzyme "reverse
transcriptase," which retroviruses like HIV and FIV use to translate their RNA genome into DNA
for insertion into the DNA of the infected cell. This view has uncertain origins and seems to be
rooted in a study dating from 1998 which is, unfortunately, unavailable for inspection . A
2003 study demonstrated that the active ingredient in olive leaf, oleuropein, is a potent inhibitor
of both free viral and cell-to-cell transmission of HIV; that it restores patterns of cellular
signaling to a pre-infection state; and that it upregulates proteins that inhibit "apoptosis" (cellular
self-destruction) caused by viral exposure . A number of more recent (2007) published studies
identify oleuropein, the chief active constituent of olive leaf, and its metabolite hydroxytyrosol,
as HIV inhibitors at both the fusion and integration stages. It accomplishes the former by binding
the viral envelope protein responsible for fusion  and the latter by inhibition of the viral
enzyme integrase at three separate points of activity . Whether these recent findings are in
addition to reverse transcriptase inhibition or whether they correct a previously erroneous
identification of OLE's mode of action is unclear. Misunderstandings sometimes arise as a result of the use of assays for detection of reverse transcription simply to confirm viral replication or the decline thereof, not to establish the point of inhibition.
A report presented at the 2004 International Conference on AIDS confirms that OLE does not
interact with antiretroviral drugs commonly used to treat HIV. "Combination antiviral assays
demonstrate that OLE exhibits synergistic interactions with both AZT and 3TC. The synergism
between OLE and 3TC is about 10-fold greater than that between OLE and AZT. Conclusion
This is the first characterization of the anti-HIV activity of OLE. Our results demonstrate
synergism between OLE and HAART. This information should help in rational design of HIV
treatment regimens that incorporate OLE" . A writer on the alternative treatment Keep Hope
Alive website claims that two people using OLE as monotherapy reported a viral load that
dropped, then rose again after several months, suggesting that perhaps the virus mutates and
overcomes inhibition. This is known to happen with several other natural compounds, such as
l-chicoric acid, a substance found in green coffee beans. However, other anecdotal accounts
mention a fall without a subsequent rise. Of course, there is no guarantee that OLE also inhibits FIV, but many substances that inhibit HIV enzymes are known to inhibit the same enzymes in FIV. This is true not only of nucleosides that inhibit HIV reverse transcription, but also of newer HIV integrase inhibitors. FIV integrase has a 37% homology (identity) in amino acid sequence to its HIV counterpart . Limited evidence provided by a private owner (see Reports) seems to confirm the ability of OLE to significantly inhibit FIV, most probably at the integration stage.
Olive leaf has many other potentially useful properties. It is a potent antioxidant that placed
second only to resveratrol, the antioxidant in the skin of red grapes, in a recent trial .
Antioxidants are key to a variety of beneficial immune processes. OLE is also a natural
antibiotic, with documented action against many bacteria (e.g., e coli) and fungi (e.g., candida
albicans) . Since FIV can open a pathway to infection with bacteria and fungi, this activity has
some significance. OLE has also been used to control blood sugar in diabetic animals  and
blood pressure in animals with high blood pressure .
Any vet should be able to vouch for the safety of olive leaf. It comes in several brand names for
animal use (e.g., Olivet, Olipet) which should be dependable. It is important, though, to use
products with the highest possible oleuropein content. No product listing less than 15% on the
labeling should be used. Unfortunately, regardless of the capsule dosage, the capsules often tend
to be large and dog-sized, so that the contents must either be repacked in smaller capsules or
emptied out for whatever other kinds of administration is envisioned.
 Ng TB, et al (1997) Anti-HIV natural products with special emphasis on HIV reverse transcriptase inhibitors, Life Sci 61 (10): 933-49.
 Lee-Huang S, Zhang L, Huang PL, Chang YT, Huang PL. Anti-HIV activity of olive leaf extract (OLE) and modulation of host cell gene expression by HIV-1 infection and OLE treatment. Biochem Biophys Res Commun. 2003 Aug 8;307(4):1029-37.
 Bao J, Zhang DW, Zhang JZ, Huang PL, Huang PL, Lee-Huang S. Computational study of bindings of olive leaf extract (OLE) to HIV-1 fusion protein gp41. FEBS Lett. Jun
 Lee-Huang S, Huang PL, Zhang D, Lee JW, Bao J, Sun Y, Chang YT, Zhang J, Huang PL. Discovery of small-molecule HIV-1 fusion and integrase inhibitors oleuropein and hydroxytyrosol: part II. integrase inhibition. Biochem Biophys Res Commun. 2007 Mar 23;354(4):879-84.
 Lee-Huang S, Huang P, Huang P. Anti-HIV activity of olive leaf extract and synergism with HAART. Int Conf AIDS. 2004 Jul 11-16; 15: abstract no. WePeA5651.
 Llano M, Vanegas M, Fregoso O, Saenz D, Chung S, Peretz M, and Poeschla EM. LEDGF/p75 Determines Cellular Trafficking of Diverse Lentiviral but Not Murine Oncoretroviral Integrase Proteins and Is a Component of Functional Lentiviral Preintegration Complexes. J. Virol. September 2004 vol. 78 no. 17 9524-9537.
 O'Brien NM, Carpenter R, O'Callaghan YC, O'Grady MN, Kerry JP. Modulatory effects of resveratrol, citroflavan-3-ol, and plant-derived extracts on oxidative stress in U937 cells. J Med
Food. 2006 Summer;9(2):187-95.
 Markin D, Duek L, Berdicevsky I. In vitro antimicrobial activity of olive leaves. Mycoses. 2003 Apr;46(3-4):132-6.
 Khayyal MT, el-Ghazaly MA, Abdallah DM, Nassar NN, Okpanyi SN, Kreuter MH. Blood pressure lowering effect of an olive leaf extract (Olea europaea) in L-NAME induced hypertension in rats. Arzneimittelforschung. 2002;52(11):797-802.